Number 61 n October 12, 2012

Wireless Substitution: State-level Estimates From the

National Health Interview Survey, 2010–2011

by Stephen J. Blumberg, Ph.D., Julian V. Luke, National Center for Health Statistics;

Nadarajasundaram Ganesh, Ph.D., Michael E. Davern, Ph.D., NORC at the University of Chicago;

and Michel H. Boudreaux, M.S., State Health Access Data Assistance Center, University of Minnesota

Abstract

Objectives—This report updates subnational estimates of the percentage of

adults and children living in households without a landline telephone but with at

least one wireless telephone (i.e., wireless-only households). State-level estimates

for 2011 are presented, as well as estimates for selected U.S. counties and groups

of counties, for other household telephone service use categories (e.g., those that

had only landlines and those that had landlines yet received all or almost all calls

on wireless telephones), and for two earlier 12-month periods (January–

December 2010 and July 2010–June 2011).

Methods—Small-area statistical modeling techniques were used to estimate

the prevalence of adults and children living in households with various household

telephone service types for 93 disjoint geographic areas that make up the

United States. This modeling was based on 2007–2011 data from the National

Health Interview Survey, 2006–2010 data from the American Community Survey,

and auxiliary information on the number of listed telephone lines per capita in

2007–2011.

Results—The prevalence of wireless-only adults and children varied

substantially across states. State-level estimates for 2011 ranged from 15.3%

(Rhode Island) to 44.6% (Idaho) of adults and from 15.2% (Rhode Island) to

58.6% (Mississippi) of children.

Keywords: cell phones • telephone surveys • small domain estimation

Introduction

The prevalence and use of wireless

telephones (also known as cellular

telephones, cell phones, or mobile

phones) has changed substantially over

the past decade. Today, an everincreasing number of adults have chosen

to use wireless telephones rather than

landline telephones to make and receive

calls. As of the second half of 2011, one

in three U.S. households (34.0%) had

only wireless telephones (1). The

prevalence of such ‘‘wireless-only’’

households markedly exceeds the

prevalence of households with only

landline telephones (10.2%), as it has

since 2009, and this difference is

expected to grow.

The National Health Interview

Survey (NHIS) is the most widely cited

source for data on the ownership and

use of wireless telephones. Every 6

months, the Centers for Disease Control

and Prevention’s (CDC) National Center

for Health Statistics (NCHS) releases a

report with the most up-to-date

estimates available from the federal

government concerning the size and

characteristics of the wireless-only

population (1). That report, published as

part of the NHIS Early Release Program

(http://www.cdc.gov/nchs/nhis/

releases.htm), presents national and

regional estimates.

Direct state-level estimates of this

prevalence had not been available from

NHIS data because the sample size of

NHIS was insufficient for direct, reliable

annual estimates for most states;

however, in April 2011, NCHS released

the results of statistically modeled

estimates of the prevalence of wirelessonly adults and children at the state

level, using data from NHIS and the

Census Bureau’s American Community

Survey (ACS), along with auxiliary

information on the number of listed

telephone lines per capita (2). Those

estimates for 12-month periods from

January 2007 through June 2010 were

the first multiyear state-level estimates

of the size of this population available

from the federal government.

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Center for Health Statistics 
Page 2 National Health Statistics Reports n Number 61 n October 12, 2012

In this report, estimates through

December 2011 are updated. Estimates

are presented for adults and children

living in wireless-only households,

wireless-mostly households (defined as

households that have landlines yet

receive all or almost all calls on

wireless telephones), dual-use

households (receive significant amounts

of calls on both landlines and wireless

telephones), landline-mostly households

(have wireless telephones yet receive all

or almost all calls on landlines), and

landline-only households.

Methods

The methods employed to produce

the estimates for this report were

identical to the methods used for the

estimates published in 2011 (2).

Small-area statistical modeling

techniques were used to combine NHIS

data collected from within specific

geographies (states and some counties)

with auxiliary data that are

representative of those geographies to

produce model-based estimates.

Specifically, a combination of direct

survey estimates from the 2007–2011

NHIS, direct survey estimates from the

2006–2010 ACS, and auxiliary

information on the number of listed

telephone lines per capita in 2007–2011

were used. The small-area model was

used to derive estimates of the

proportion of people who lived in

households that were wireless-only,

wireless-mostly, dual-use, landlinemostly, and landline-only for 10

6-month periods: January–June and

July–December in each year from 2007

through 2011.

Estimates were separately derived

for adults (aged 18 and over) and

children (under age 18) for 93

nonoverlapping areas that comprise the

United States. Twenty-six of these areas

were states and one was the District of

Columbia; other areas consisted of

selected counties, groups of counties, or

the balance of the state population

excluding the selected counties. No

areas crossed state lines, and every

location in the United States was part of

one (and only one) of the 93 areas.

Areas considered for inclusion in this

report were urban areas that receive

federal Section 317 immunization grants

and other substate areas that are strata

for CDC’s National Immunization

Survey (3). Areas were selected for this

report on the basis of available survey

sample sizes and the stability of the

modeled estimates.

For each telephone category, the

6-month estimates for all 93 small areas

were modeled jointly. That is, all

6-month periods were modeled together

in a single model rather than separately

as 10 models (one for each 6-month

period). Separate small-area models

were fitted for each of the telephone

service use categories (e.g., wirelessonly, dual-use) and by age group (adults

or children). The model-based estimates

for each telephone service use category,

small area, and 6-month period were

derived using a standard small-area

modeling and estimation approach

known as ‘‘empirical best linear

unbiased prediction’’ (4–6). The

model-based estimates were a weighted

combination of three distinct sets of

estimates: (a) the direct estimate from

NHIS for the small area during the

6-month period of interest, (b) a

synthetic estimate derived from a

regression model involving ACS and

auxiliary data for the small area during

the 6-month period of interest, and (c)

adjusted direct estimates from NHIS for

the small area during all 6-month

periods other than the 6-month period of

interest. By using estimates from all 10

6-month periods, the model-based

estimate allows for ‘‘borrowing

strength’’ across time. When these three

distinct sets of estimates were combined,

the weights associated with each set

reflected the relative precision of each

estimate.

Although model-based estimates

were produced for every small area and

6-month period, consecutive 6-month

period estimates were combined to

produce 12-month estimates. The

small-area estimates for 12-month

periods were obtained by simply

averaging the two consecutive 6-month

estimates. This helped to reduce the

variability of the estimates. Then, the

12-month small-area estimates for each

phone category were adjusted so that

they agreed with the national direct

estimates from NHIS for the

corresponding phone category and year.

The 12-month estimates were further

adjusted so that they agreed with the

2008, 2009, or 2010 ACS estimate for

the population without telephone service

(landline or wireless) for each small

area. For states with multiple small

areas, 12-month state-level estimates

were obtained by appropriately

weighting the 12-month small-area

estimates by population size.

Model-based estimates were

produced for 2007–2011. Because the

models now included full-year data from

2010 and 2011, the estimates for

January 2007–June 2010 differed from

the estimates previously reported (5),

which were based on models that did

not include data from 2011 or the

second half of 2010. These differences

were generally small (e.g., for the

prevalence of wireless-only adults, mean

= –0.1, interquartile range = 0.7).

Therefore, the updated estimates for

2007–2009 are not presented in this

report. Instead, this report only includes

estimates for January–December 2010,

July 2010–June 2011, and January–

December 2011.

Estimates for Adults and

Children Living in

Wireless-only

Households

Results from the small-area

modeling strategy showed great

variation in the prevalence of adults

living in wireless-only households

across states. Estimates for 2011 ranged

from a high of 44.6% in Idaho to a low

of 15.3% in Rhode Island (Table 1).

Other states in which the prevalence of

wireless-only adults was relatively high

(exceeding 40%) were Arkansas

(44.4%), Mississippi (42.3%), and

North Dakota (41.6%). Most other states

in the northeast region joined Rhode

Island with prevalence rates below 25%,

including New Jersey (16.5%),

Connecticut (18.7%), New York

(19.7%), Massachusetts (21.3%),

Pennsylvania (23.4%), and

New Hampshire (23.6%).
National Health Statistics Reports n Number 61 n October 12, 2012	 Page 3

Similarly, results showed great

variation in the prevalence of wireless-only

children across states, ranging from a high

of 58.6% in Mississippi to a low of 15.2%

in Rhode Island (Table 1). Other states with

a high prevalence of wireless-only children

included Arkansas (55.5%), Idaho (54.8%),

New Mexico (51.9%), and Texas (49.2%).

Other states with a low prevalence of

wireless-only children included Connecticut

(16.5%), New Jersey (20.1%), New York

(20.3%), and Massachusetts (22.6%).

Estimates for Adults

Living in Households

With Wireless

Telephones

Table 2 presents modeled estimates

for 2011 for the prevalence of adults

living in households with various

telephone service types, including but

not limited to wireless-only status.

Estimates are presented for adults living

in wireless-mostly households, landlinemostly households, dual-use households,

and landline-only households. These

results can be used to obtain the

prevalence of adults living in

households with any wireless telephones

(regardless of whether the wireless

telephones are the only telephones).

Estimates ranged from a high of 92.9%

in Delaware to a low of 80.4% in

West Virginia. Nineteen states exceeded

90%, with Illinois (92.4%), Nebraska

(91.8%), Minnesota (91.8%), and Idaho

(91.7%) joining Delaware with the

highest rates. Along with West Virginia,

states with the lowest rates included

Vermont (83.7%), New Mexico (84.0%),

New York (85.6%), and Indiana

(86.2%).

Table 2 can also be used to look at the

prevalence of adults living in households

that receive all or almost all calls on

wireless telephones, regardless of whether

the households have landline telephones.

Both wireless-only and wireless-mostly

adults are in this group. Estimates of the

prevalence of adults living in households

where wireless telephones are the primary

means of receiving calls ranged from

61.1% in Arkansas to 35.0% in

Connecticut. One-half of the states (25

total) had rates of primary wireless use

exceeding 50%, including Texas (59.1%),

Idaho (58.6%), Colorado (57.2%), and

Oklahoma (56.7%) joining Arkansas at the

top end. Other states below 40% included

Rhode Island (36.1%), New York (37.6%),

West Virginia (37.9%), New Hampshire

(38.7%), and Vermont (39.4%).

Table 3 presents modeled estimates

for 2011 for the prevalence of children

living in households with various

telephone service types. This table can

be used to calculate estimates for

children similar to those for adults

described above.

Implications

The increasing prevalence of

wireless-only households has

implications for random-digit-dial

(RDD) telephone surveys. Until recently,

such surveys did not include wireless

telephone numbers in their samples.

Now, despite operational challenges (7),

most major RDD telephone surveys do

include wireless telephone numbers

(8,9). If they did not, the exclusion of

households with only wireless

telephones (along with the 2.0% of

households that have no telephone

service) could bias results (10).

Statistical challenges exist when

combining samples of wireless-only

households with samples of landline

households from RDD surveys. To

ensure that each sample is appropriately

represented in the final data set and

appropriately weighted in the final

analyses, reliable and current estimates

of the prevalence of wireless-only

households are needed (7). Moreover, if

the persons interviewed on their wireless

telephones are not screened to exclude

persons who also have landlines, reliable

and current estimates of the prevalence

of landline and wireless telephone

service use may be required to address

the probability that an individual could

be in both samples (7).

This report presents survey

researchers with the most up-to-date

estimates available from the federal

government concerning the prevalence of

landline and wireless telephone service

use in each state. Telecommunications

companies may also find these estimates

useful for understanding changing

conditions in state and local markets.

References

1.Blumberg SJ, Luke JV. Wireless

substitution: Early release of

estimates from the National Health

Interview Survey, July–December

2011. National Center for Health

Statistics. June 2012. Available from:

http://www.cdc.gov/nchs/nhis.htm.

2.

Blumberg SJ, Luke JV, Ganesh N, et

al. Wireless substitution: State-level

estimates from the National Health

Interview Survey, January 2007–June

2010. National health statistics

reports; no 39. Hyattsville, MD:

National Center for Health Statistics.

2011. Available from: http://www.

cdc.gov/nchs/data/nhsr/nhsr039.pdf.

3.

CDC. National Immunization Survey:

A user’s guide for the 2010 publicuse data file. 2011. Available from:

ftp://ftp.cdc.gov/pub/Health_

Statistics/NCHS/Dataset_

Documentation/NIS/NISPUF10_

DUG.PDF.

4.

Jiang J, Lahiri P. Mixed model

prediction and small area estimation

(with discussion). Test 15(1):1–96.

2006.

5.Rao JNK. Small area estimation.

Hoboken, NJ: John Wiley & Sons,

Inc. 2003.

6.Rao JNK, Yu M. Small-area

estimation by combining time-series

and cross-sectional data. Can J Stat

22(4):511–28. 1994.

7.AAPOR Cell Phone Task Force. New

considerations for survey researchers

when planning and conducting RDD

telephone surveys in the U.S. with

respondents reached via cell phone

numbers. American Association for

Public Opinion Research. 2010.

Available from: http://aapor.org/

cell_phone_task_force.htm.

8.

CDC. Methodologic changes in the

Behavioral Risk Factor Surveillance

System in 2011 and potential effects

on prevalence estimates. MMWR

61(22):410–3. 2012.

9.CDC. Announcement: Addition of

households with only cellular

telephone service to the National

Immunization Survey, 2011. MMWR

61(34):685. 2012.

10. Blumberg SJ, Luke JV. Reevaluating

the need for concern regarding

noncoverage bias in landline surveys.

Am J Public Health 99(10):1806–10.

2009.
Page 4 National Health Statistics Reports n Number 61 n October 12, 2012

Table 1. Modeled estimates (with standard errors) of the percentage of persons living in wireless-only households, by selected

geographic areas, age, and period: United States, 2010–2011

Adults aged 18 and over Children under age 18

January– July 2010– January– January– July 2010– January–

Geographic area December 2010 June 2011 December 2011 December 2010 June 2011 December 2011

Percent (standard error)

Alabama ....................... 29.3 (1.6) 32.2 (1.7) 34.4 (1.8) 38.0 (3.0) 41.5 (3.1) 44.3 (3.2)

Jefferson County ................. 30.4 (2.6) 36.6 (2.7) 41.9 (2.9) 39.6 (4.7) 48.0 (4.6) 56.1 (4.8)

Rest of Alabama ................. 29.1 (1.8) 31.4 (1.9) 33.2 (2.0) 37.7 (3.4) 40.4 (3.4) 42.5 (3.6)

Alaska ......................... 22.2 (2.9) 26.9 (3.0) 30.4 (3.2) 20.8 (4.8) 25.4 (4.9) 27.4 (4.9)

Arizona ........................ 33.2 (1.5) 36.3 (1.6) 38.2 (1.8) 39.2 (2.4) 43.7 (2.4) 44.6 (2.7)

Maricopa County ................. 37.4 (2.0) 40.7 (2.1) 42.3 (2.3) 42.2 (3.1) 47.4 (3.2) 47.4 (3.4)

Rest of Arizona .................. 27.0 (2.2) 29.7 (2.4) 32.1 (2.7) 34.3 (3.5) 37.8 (3.7) 40.2 (4.2)

Arkansas ....................... 39.7 (2.1) 42.3 (2.1) 44.4 (2.2) 49.9 (3.7) 53.2 (3.4) 55.5 (3.5)

California . . . . . . . . . . . . . . . . . . . . . . . 21.7 (0.6) 25.2 (0.6) 27.9 (0.7) 23.0 (1.0) 28.0 (1.0) 32.3 (1.2)

Alameda County ................. 22.2 (2.2) 25.4 (2.3) 28.0 (2.6) 20.6 (3.3) 25.9 (3.6) 30.5 (4.0)

Fresno County .................. 22.9 (2.2) 26.5 (2.3) 30.5 (2.6) 26.4 (3.4) 27.7 (3.2) 30.6 (3.5)

Los Angeles County ............... 21.1 (1.1) 25.2 (1.2) 28.3 (1.3) 20.7 (1.7) 26.7 (1.9) 32.4 (2.1)

Northern counties1 ....... ....... 20.1 (2.3) 22.9 (2.5) 25.4 (2.8) 24.2 (3.7) 28.6 (4.1) 32.7 (4.7)

San Bernardino County ............. 19.9 (1.8) 23.2 (2.0) 26.8 (2.3) 24.1 (2.9) 28.0 (3.1) 32.6 (3.6)

San Diego County ................ 18.6 (1.5) 20.4 (1.7) 22.5 (1.9) 18.3 (2.5) 20.6 (2.7) 22.0 (3.0)

Santa Clara County ............... 24.3 (2.0) 28.7 (2.2) 31.9 (2.5) 27.4 (3.2) 32.6 (3.5) 35.1 (3.9)

Rest of California. . . . . . . . . . . . . . . . . 22.6 (1.0) 26.0 (1.1) 28.4 (1.2) 24.3 (1.6) 29.6 (1.7) 33.9 (1.9)

Colorado . . . . . . . . . . . . . . . . . . . . . . . 33.2 (1.7) 36.5 (1.7) 38.7 (1.9) 34.4 (2.6) 39.5 (2.7) 41.9 (2.8)

City of Denver counties2 ..... ..... 28.9 (2.0) 31.5 (2.1) 33.0 (2.3) 31.5 (3.4) 35.9 (3.6) 38.1 (3.8)

Rest of Colorado . . . . . . . . . . . . . . . . . 36.0 (2.4) 39.8 (2.5) 42.4 (2.7) 36.4 (3.7) 42.1 (3.8) 44.5 (4.0)

Connecticut...................... 15.3 (1.5) 17.3 (1.6) 18.7 (1.8) 13.9 (2.2) 15.9 (2.3) 16.5 (2.4)

Delaware . . . . . . . . . . . . . . . . . . . . . . . 21.3 (2.7) 24.3 (2.8) 26.9 (3.0) 22.7 (4.6) 26.1 (4.9) 28.4 (5.3)

District of Columbia. . . . . . . . . . . . . . . . . 37.0 (3.5) 41.2 (3.6) 44.2 (3.7) 44.6 (7.1) 48.9 (6.6) 50.9 (6.3)

Florida. . . . . . . . . . . . . . . . . . . . . . . . . 30.0 (1.0) 32.6 (1.1) 34.4 (1.2) 37.1 (1.7) 41.0 (1.8) 43.0 (1.9)

Miami-Dade County ............... 31.8 (2.8) 34.0 (3.0) 35.9 (3.2) 37.4 (4.4) 42.5 (4.9) 45.5 (5.5)

Duval County ................... 33.2 (1.8) 37.8 (1.9) 41.3 (2.1) 44.7 (3.4) 50.3 (3.5) 52.4 (3.7)

Orange County .................. 36.2 (2.8) 38.1 (3.0) 39.7 (3.2) 44.1 (4.6) 46.7 (4.8) 48.0 (5.3)

Rest of Florida .................. 28.8 (1.2) 31.2 (1.3) 32.7 (1.4) 35.1 (2.1) 38.5 (2.2) 40.5 (2.4)

Georgia . . . . . . . . . . . . . . . . . . . . . . . . 29.1 (1.3) 31.9 (1.4) 34.3 (1.6) 34.8 (2.2) 36.2 (2.3) 38.6 (2.5)

Fulton/DeKalb counties............. 36.5 (2.6) 40.1 (2.7) 41.9 (2.9) 35.8 (4.1) 42.3 (4.4) 46.6 (4.9)

Rest of Georgia. . . . . . . . . . . . . . . . . . 27.6 (1.5) 30.2 (1.6) 32.7 (1.8) 34.6 (2.5) 35.1 (2.6) 37.2 (2.8)

Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . 23.1 (1.9) 24.8 (1.9) 26.0 (2.0) 29.0 (3.4) 34.2 (3.6) 35.6 (3.9)

Idaho ......................... 38.8 (2.6) 42.4 (2.6) 44.6 (2.7) 44.7 (4.0) 50.1 (3.9) 54.8 (3.9)

Illinois . . . . . . . . . . . . . . . . . . . . . . . . . 27.7 (1.2) 30.7 (1.3) 33.0 (1.4) 31.0 (2.0) 34.9 (2.1) 37.5 (2.3)

Cook County ................... 32.0 (1.6) 35.1 (1.7) 38.3 (2.0) 34.2 (2.9) 39.0 (3.0) 42.7 (3.3)

Madison/St. Clair counties ........... 33.8 (3.2) 34.2 (3.4) 34.6 (3.6) 46.3 (5.6) 47.0 (5.9) 45.3 (6.3)

Rest of Illinois. . . . . . . . . . . . . . . . . . . 26.0 (1.5) 29.1 (1.6) 31.3 (1.8) 29.2 (2.5) 32.9 (2.6) 35.6 (2.8)

Indiana ........................ 28.3 (1.5) 31.1 (1.5) 32.8 (1.7) 35.0 (2.5) 40.0 (2.6) 42.9 (2.9)

Lake County.................... 22.6 (3.2) 26.5 (3.4) 29.0 (3.5) 38.3 (6.1) 42.3 (6.2) 43.6 (6.2)

Marion County .................. 35.4 (3.0) 39.0 (3.3) 42.0 (3.7) 40.7 (5.1) 46.8 (5.6) 52.3 (6.3)

Rest of Indiana . . . . . . . . . . . . . . . . . . 27.6 (1.7) 30.1 (1.8) 31.5 (2.0) 33.6 (3.0) 38.6 (3.1) 41.1 (3.4)

Iowa . . . . . . . . . . . . . . . . . . . . . . . . . . § § § § § §

Kansas ........................ 33.3 (1.8) 36.2 (1.9) 38.0 (2.0) 40.4 (3.1) 43.6 (3.1) 44.8 (3.1)

Johnson/Wyandotte counties ......... 24.4 (2.5) 26.9 (2.6) 28.7 (2.8) 27.2 (4.3) 28.9 (4.2) 31.1 (4.4)

Rest of Kansas .................. 36.1 (2.2) 39.2 (2.3) 41.1 (2.4) 45.0 (3.8) 48.7 (3.9) 49.6 (3.9)

Kentucky ....................... 31.1 (2.1) 32.7 (2.1) 33.7 (2.3) 36.8 (3.2) 41.1 (3.4) 41.3 (3.5)

Louisiana ....................... 30.2 (1.9) 32.3 (1.9) 33.5 (2.1) 38.5 (3.1) 41.8 (3.0) 43.4 (3.2)

Maine . . . . . . . . . . . . . . . . . . . . . . . . . 25.7 (2.1) 29.1 (2.2) 31.6 (2.4) 27.5 (4.0) 32.1 (4.0) 35.3 (4.2)

Maryland . . . . . . . . . . . . . . . . . . . . . . . 21.4 (1.3) 24.2 (1.4) 26.5 (1.5) 20.5 (2.1) 23.8 (2.2) 27.2 (2.4)

Baltimore City . . . . . . . . . . . . . . . . . . . 28.9 (3.0) 32.5 (3.2) 34.8 (3.4) 32.8 (4.8) 37.4 (4.9) 39.4 (5.1)

Prince George’s County............. 20.1 (2.2) 23.7 (2.5) 26.8 (2.7) 24.9 (4.0) 29.9 (4.4) 33.8 (4.8)

Rest of Maryland . . . . . . . . . . . . . . . . . 20.6 (1.6) 23.0 (1.7) 25.2 (1.9) 18.0 (2.6) 20.8 (2.6) 24.3 (2.9)

Massachusetts.................... 17.3 (1.2) 19.3 (1.3) 21.3 (1.4) 15.6 (2.0) 18.2 (2.1) 22.6 (2.5)

Suffolk County .................. 28.7 (3.0) 31.8 (3.2) 33.8 (3.4) 30.5 (6.2) 35.6 (6.9) 40.2 (7.5)

Rest of Massachusetts ............. 16.0 (1.3) 17.9 (1.4) 19.9 (1.5) 14.5 (2.0) 16.9 (2.2) 21.3 (2.6)

Michigan ....................... 30.8 (1.4) 33.4 (1.5) 35.8 (1.6) 36.6 (2.4) 39.5 (2.5) 43.1 (2.7)

Wayne County .................. 37.4 (2.4) 38.5 (2.5) 39.6 (2.7) 48.1 (4.4) 51.2 (4.4) 52.2 (4.8)

Rest of Michigan . . . . . . . . . . . . . . . . . 30.3 (1.5) 33.0 (1.5) 35.6 (1.7) 35.6 (2.6) 38.4 (2.7) 42.3 (2.9)

Minnesota ...................... 27.2 (1.3) 30.1 (1.4) 32.3 (1.5) 24.0 (2.2) 27.5 (2.3) 31.6 (2.6)

Twin Cities counties3 ....... ....... 27.9 (1.8) 31.4 (1.9) 33.9 (2.1) 23.3 (3.0) 28.0 (3.2) 31.9 (3.5)

Rest of Minnesota ................ 26.4 (1.9) 28.5 (2.0) 30.4 (2.2) 24.7 (3.3) 26.9 (3.3) 31.3 (3.8)

See footnotes at end of table.
National Health Statistics Reports n Number 61 n October 12, 2012 Page 5

Table 1. Modeled estimates (with standard errors) of the percentage of persons living in wireless-only households, by selected

geographic areas, age, and period: United States, 2010–2011—Con.

Adults aged 18 and over Children under age 18

January– July 2010– January– January– July 2010– January–

Geographic area December 2010 June 2011 December 2011 December 2010 June 2011 December 2011

Percent (standard error)

Mississippi ...................... 37.3 (1.9) 39.8 (2.0) 42.3 (2.1) 49.3 (3.4) 55.7 (3.5) 58.6 (3.5)

Missouri ........................ 25.8 (1.5) 29.5 (1.6) 32.5 (1.7) 30.9 (2.7) 35.9 (2.8) 40.6 (3.0)

St. Louis County/City .............. 27.5 (2.4) 29.4 (2.5) 30.6 (2.6) 22.1 (3.7) 24.0 (3.7) 25.6 (4.0)

Rest of Missouri ................. 25.3 (1.8) 29.5 (1.9) 33.1 (2.1) 33.3 (3.3) 39.1 (3.4) 44.7 (3.7)

Montana ....................... § § § § § §

Nebraska ....................... 32.9 (2.3) 36.0 (2.3) 38.5 (2.6) 31.8 (3.6) 34.5 (3.5) 38.5 (3.9)

Nevada ........................ 27.9 (1.7) 31.5 (1.8) 34.7 (1.9) 30.9 (3.1) 36.5 (3.2) 40.6 (3.4)

Clark County ................... 29.0 (2.1) 32.4 (2.2) 35.2 (2.3) 31.7 (3.8) 37.0 (3.8) 39.9 (4.0)

Rest of Nevada .................. 24.9 (2.9) 29.2 (3.0) 33.5 (3.3) 28.4 (5.4) 35.3 (5.8) 42.5 (6.4)

New Hampshire ................... 17.3 (1.9) 20.6 (2.0) 23.6 (2.2) 16.6 (3.2) 22.2 (3.5) 26.5 (4.0)

New Jersey. . . . . . . . . . . . . . . . . . . . . . 14.0 (1.1) 15.3 (1.1) 16.5 (1.2) 13.4 (1.8) 16.6 (1.9) 20.1 (2.3)

Essex County ................... 28.7 (3.1) 31.3 (3.2) 33.5 (3.4) 23.5 (4.7) 24.6 (4.6) 25.9 (4.9)

Rest of New Jersey ............... 13.6 (1.1) 14.8 (1.1) 16.0 (1.3) 13.0 (1.8) 16.3 (2.0) 19.8 (2.4)

New Mexico ..................... 29.9 (1.6) 33.2 (1.6) 36.0 (1.7) 44.7 (2.9) 48.9 (2.9) 51.9 (3.1)

Southern counties4 ....... ....... 34.0 (2.8) 37.2 (2.7) 38.3 (2.7) 60.2 (5.4) 62.8 (4.6) 61.6 (4.4)

Rest of New Mexico ............... 28.4 (1.9) 31.7 (2.0) 35.2 (2.1) 38.6 (3.4) 43.5 (3.7) 48.1 (4.0)

New York ....................... 16.7 (0.9) 18.1 (0.9) 19.7 (1.1) 17.2 (1.4) 18.3 (1.5) 20.3 (1.6)

City of New York counties5 ..... ..... 19.8 (1.3) 21.3 (1.3) 22.9 (1.5) 20.8 (2.2) 21.3 (2.1) 23.7 (2.3)

Rest of New York. . . . . . . . . . . . . . . . . 14.3 (1.2) 15.7 (1.3) 17.2 (1.5) 14.7 (1.9) 16.2 (2.0) 18.0 (2.3)

North Carolina .................... 27.1 (1.4) 30.0 (1.4) 32.8 (1.6) 36.5 (2.4) 41.3 (2.5) 45.8 (2.6)

North Dakota..................... 38.1 (3.2) 40.3 (3.1) 41.6 (3.1) 41.8 (5.4) 42.8 (4.8) 44.1 (4.8)

Ohio .......................... 28.0 (1.1) 30.7 (1.2) 33.4 (1.3) 33.5 (2.2) 38.5 (2.3) 41.3 (2.4)

Cuyahoga County ................ 26.6 (2.3) 29.2 (2.5) 31.2 (2.7) 29.8 (3.9) 31.0 (4.1) 30.2 (4.4)

Franklin County.................. 36.1 (2.9) 39.5 (3.1) 41.1 (3.3) 39.4 (4.1) 48.1 (4.3) 50.8 (4.5)

Rest of Ohio. . . . . . . . . . . . . . . . . . . . 27.1 (1.4) 29.8 (1.4) 32.8 (1.6) 33.2 (2.6) 38.2 (2.7) 41.5 (2.9)

Oklahoma....................... 29.9 (1.9) 32.4 (1.9) 34.6 (2.0) 35.6 (3.5) 38.0 (3.4) 39.9 (3.4)

Oregon ........................ 33.0 (2.1) 35.6 (2.1) 38.2 (2.2) 36.6 (3.6) 39.0 (3.6) 40.7 (3.6)

Pennsylvania..................... 18.4 (1.0) 21.1 (1.1) 23.4 (1.2) 22.1 (1.8) 26.2 (1.9) 28.9 (2.2)

Allegheny County ................ 31.3 (3.2) 34.8 (3.3) 38.0 (3.5) 31.1 (5.5) 36.2 (5.7) 40.6 (5.9)

Philadelphia County ............... 21.8 (2.4) 24.8 (2.5) 27.4 (2.7) 28.7 (4.2) 33.3 (4.3) 35.7 (4.5)

Rest of Pennsylvania .............. 16.3 (1.1) 18.8 (1.2) 20.9 (1.4) 20.1 (2.0) 24.0 (2.3) 26.6 (2.5)

Rhode Island..................... 13.3 (1.7) 14.3 (1.8) 15.3 (1.9) 15.3 (3.2) 16.0 (3.2) 15.2 (3.3)

South Carolina. . . . . . . . . . . . . . . . . . . . 30.2 (1.7) 33.8 (1.8) 36.1 (1.9) 37.7 (3.0) 41.8 (3.0) 43.6 (3.1)

South Dakota .................... § § § § § §

Tennessee ...................... 31.0 (1.5) 33.4 (1.6) 35.7 (1.7) 38.9 (2.5) 41.1 (2.6) 44.4 (2.9)

Davidson County ................. 41.6 (3.5) 43.8 (3.6) 45.5 (3.8) 46.4 (5.9) 50.5 (6.1) 51.6 (6.3)

Shelby County .................. 35.6 (3.0) 38.0 (3.2) 40.5 (3.5) 40.7 (5.1) 43.9 (5.3) 47.2 (5.7)

Rest of Tennessee ................ 28.7 (1.8) 31.1 (1.9) 33.5 (2.1) 37.6 (3.1) 39.3 (3.2) 42.9 (3.6)

Texas ......................... 35.4 (1.0) 37.6 (1.0) 39.9 (1.1) 40.4 (1.5) 44.3 (1.5) 49.2 (1.6)

Bexar County ................... 33.3 (2.2) 37.7 (2.3) 40.7 (2.6) 42.6 (3.5) 47.6 (3.6) 50.7 (3.8)

Dallas County ................... 47.4 (2.2) 50.6 (2.3) 53.3 (2.5) 48.2 (3.3) 53.4 (3.5) 59.0 (3.8)

El Paso County .................. § § § § § §

Harris County ................... 37.1 (1.8) 38.9 (1.8) 39.1 (2.0) 42.5 (2.7) 44.2 (2.7) 44.3 (2.9)

Rest of Texas ................... 33.8 (1.3) 35.7 (1.3) 38.0 (1.4) 38.8 (2.0) 42.5 (2.0) 48.0 (2.1)

Utah .......................... 29.6 (2.4) 33.7 (2.5) 37.0 (2.8) 31.8 (3.5) 37.8 (3.6) 41.3 (3.8)

Vermont ........................ 20.6 (2.6) 24.6 (2.8) 28.7 (3.2) 16.9 (4.2) 22.6 (4.6) 29.1 (5.3)

Virginia ........................ 22.6 (1.4) 24.6 (1.5) 26.6 (1.7) 20.0 (2.0) 22.9 (2.2) 27.0 (2.5)

Washington...................... 30.2 (1.4) 32.3 (1.5) 33.8 (1.6) 30.8 (2.2) 32.7 (2.2) 35.1 (2.4)

Eastern counties6 ........ ........ 26.1 (2.0) 28.7 (2.1) 31.4 (2.4) 29.1 (3.4) 33.0 (3.6) 38.4 (3.9)

King County .................... 36.5 (2.4) 40.3 (2.6) 42.9 (2.8) 28.9 (3.6) 34.3 (3.9) 37.7 (4.4)

Rest of Washington ............... 28.2 (2.3) 28.9 (2.4) 29.2 (2.5) 32.7 (3.6) 31.8 (3.5) 32.1 (3.7)

West Virginia. . . . . . . . . . . . . . . . . . . . . 21.6 (2.3) 23.8 (2.3) 25.7 (2.5) 27.8 (4.0) 30.8 (4.0) 31.5 (3.9)

Wisconsin....................... 29.0 (1.6) 31.7 (1.7) 33.8 (1.8) 29.6 (2.7) 32.0 (2.8) 34.9 (3.1)

Milwaukee County ................ § § § § § §

Rest of Wisconsin ................ 27.3 (1.8) 30.0 (1.9) 32.0 (2.1) 26.3 (3.1) 28.9 (3.3) 32.4 (3.6)

Wyoming ....................... § § § § § §

§ Model-based estimates for Iowa, Montana, South Dakota, Texas-El Paso County, Wisconsin-Milwaukee County, and Wyoming are not reported. For at least one telephone service use category,

direct estimates from the National Health Interview Survey were more than double or less than one-half the synthetic estimate. These differences between two components of the model-based

estimates suggest that the direct estimates for these areas may be biased. Biased estimates violate a key model-based estimation assumption. 1

Includes Butte, Colusa, Del Norte, Glenn, Humboldt, Lake, Lassen, Mendocino, Modoc, Plumas, Shasta, Sierra, Siskiyou, Tehama, and Trinity.
Page 6 National Health Statistics Reports n Number 61 n October 12, 2012

2

Includes Adams, Arapahoe, Denver, and Douglas. Previously published estimates for City of Denver counties (2) did not include Adams, Arapahoe, or Douglas. 3

Includes Anoka, Carver, Dakota, Hennepin, Ramsey, Scott, and Washington. 4

Includes Catron, Chaves, Curry, De Baca, Dona Ana, Eddy, Grant, Hidalgo, Lea, Lincoln, Luna, Otero, Roosevelt, Sierra, and Socorro. 5

Includes Bronx, Kings, New York, Queens, and Richmond. 6

Includes Adams, Asotin, Benton, Chelan, Columbia, Douglas, Ferry, Franklin, Garfield, Grant, Kittitas, Klickitat, Lincoln, Okanogan, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman, and

Yakima. Previously published estimates for Eastern Washington counties (2) did not include Spokane or Yakima.

NOTE: Estimates were calculated by NORC at the University of Chicago.

SOURCES: CDC/NCHS, National Health Interview Survey, 2007–2011; U.S. Census Bureau, American Community Survey, 2006–2010; and infoUSA.com, Inc. consumer database, 2007–2011.
National Health Statistics Reports n Number 61 n October 12, 2012 Page 7

Table 2. Modeled estimates (with standard errors) of the percent distribution of household telephone status for adults aged 18 and over,

by selected geographic areas: United States, 2011

No

Wireless- Wireless- Landline- Landline­ telephone

Geographic area only mostly Dual-use mostly only service1 Total

Percent (standard error)

Alabama ....................... 34.4 (1.8) 14.4 (1.4) 25.3 (1.8) 15.6 (1.4) 8.3 (1.2) 1.9 100.0

Jefferson County ................. 41.9 (2.9) 14.0 (2.0) 23.4 (2.7) 12.3 (1.9) 6.9 (1.7) 1.5 100.0

Rest of Alabama ................. 33.2 (2.0) 14.5 (1.5) 25.6 (2.1) 16.2 (1.6) 8.6 (1.3) 1.9 100.0

Alaska ......................... 30.4 (3.2) 23.4 (2.9) 17.1 (2.9) 16.5 (2.5) 11.6 (2.5) 1.0 100.0

Arizona ........................ 38.2 (1.8) 16.5 (1.3) 20.1 (1.6) 12.1 (1.2) 10.9 (1.3) 2.2 100.0

Maricopa County ................. 42.3 (2.3) 18.1 (1.8) 20.7 (2.0) 8.5 (1.3) 8.3 (1.4) 2.2 100.0

Rest of Arizona .................. 32.1 (2.7) 14.3 (2.0) 19.3 (2.5) 17.3 (2.2) 14.7 (2.3) 2.3 100.0

Arkansas ....................... 44.4 (2.2) 16.7 (1.7) 16.9 (1.8) 10.7 (1.4) 8.9 (1.4) 2.4 100.0

California . . . . . . . . . . . . . . . . . . . . . . . 27.9 (0.7) 20.1 (0.7) 29.6 (0.8) 13.1 (0.6) 7.8 (0.4) 1.5 100.0

Alameda County ................. 28.0 (2.6) 16.6 (2.1) 38.7 (3.1) 9.5 (1.7) 6.1 (1.6) 1.1 100.0

Fresno County .................. 30.5 (2.6) 9.1 (1.6) 28.0 (2.8) 15.2 (2.0) 15.3 (2.2) 1.9 100.0

Los Angeles County ............... 28.3 (1.3) 19.2 (1.2) 31.0 (1.5) 11.8 (1.0) 8.2 (0.9) 1.6 100.0

Northern counties2 ....... ....... 25.4 (2.8) 16.6 (2.4) 22.1 (3.0) 20.7 (2.6) 13.3 (2.5) 1.8 100.0

San Bernardino County ............. 26.8 (2.3) 19.2 (2.1) 34.3 (2.8) 11.4 (1.7) 6.7 (1.5) 1.5 100.0

San Diego County ................ 22.5 (1.9) 23.4 (1.9) 33.3 (2.3) 10.7 (1.4) 8.6 (1.4) 1.4 100.0

Santa Clara County ............... 31.9 (2.5) 20.3 (2.2) 26.6 (2.6) 10.1 (1.6) 10.0 (1.8) 1.0 100.0

Rest of California. . . . . . . . . . . . . . . . . 28.4 (1.2) 21.3 (1.1) 27.7 (1.2) 14.5 (0.9) 6.6 (0.7) 1.5 100.0

Colorado . . . . . . . . . . . . . . . . . . . . . . . 38.7 (1.9) 18.5 (1.5) 21.6 (1.7) 12.0 (1.3) 7.5 (1.1) 1.6 100.0

City of Denver counties3 ............ 33.0 (2.3) 21.5 (2.0) 24.7 (2.3) 12.3 (1.6) 6.8 (1.4) 1.6 100.0

Rest of Colorado . . . . . . . . . . . . . . . . . 42.4 (2.7) 16.6 (2.0) 19.7 (2.4) 11.8 (1.8) 8.0 (1.6) 1.6 100.0

Connecticut...................... 18.7 (1.8) 16.3 (1.7) 34.8 (2.3) 18.6 (1.8) 10.5 (1.5) 1.1 100.0

Delaware . . . . . . . . . . . . . . . . . . . . . . . 26.9 (3.0) 19.0 (2.6) 26.5 (3.3) 20.5 (2.7) 6.1 (1.8) 1.0 100.0

District of Columbia. . . . . . . . . . . . . . . . . 44.2 (3.7) 15.7 (2.8) 20.8 (3.2) 13.6 (2.5) *3.3 (1.5) 2.4 100.0

Florida. . . . . . . . . . . . . . . . . . . . . . . . . 34.4 (1.2) 17.3 (0.9) 25.7 (1.1) 11.8 (0.8) 8.8 (0.7) 2.1 100.0

Miami-Dade County ............... 35.9 (3.2) 13.8 (2.3) 26.5 (3.4) 13.0 (2.3) 8.7 (2.2) 2.0 100.0

Duval County ................... 41.3 (2.1) 17.7 (1.7) 22.2 (2.0) 7.0 (1.1) 8.7 (1.3) 3.2 100.0

Orange County .................. 39.7 (3.2) 20.4 (2.6) 22.3 (3.1) 10.6 (2.0) *5.1 (1.7) 1.9 100.0

Rest of Florida . . . . . . . . . . . . . . . . . . 32.7 (1.4) 17.2 (1.2) 26.5 (1.4) 12.7 (1.0) 9.1 (0.9) 1.9 100.0

Georgia . . . . . . . . . . . . . . . . . . . . . . . . 34.3 (1.6) 21.6 (1.4) 23.7 (1.6) 11.4 (1.1) 6.7 (0.9) 2.3 100.0

Fulton/DeKalb counties ............. 41.9 (2.9) 20.4 (2.4) 23.3 (2.8) 7.8 (1.6) *4.7 (1.4) 1.9 100.0

Rest of Georgia. . . . . . . . . . . . . . . . . . 32.7 (1.8) 21.8 (1.6) 23.8 (1.8) 12.2 (1.3) 7.2 (1.1) 2.3 100.0

Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . 26.0 (2.0) 15.6 (1.7) 36.5 (2.4) 10.1 (1.4) 9.9 (1.5) 1.9 100.0

Idaho ......................... 44.6 (2.7) 14.0 (1.8) 19.1 (2.3) 14.0 (1.9) 6.4 (1.4) 1.9 100.0

Illinois . . . . . . . . . . . . . . . . . . . . . . . . . 33.0 (1.4) 18.1 (1.2) 28.1 (1.5) 13.2 (1.1) 6.0 (0.8) 1.6 100.0

Cook County ................... 38.3 (2.0) 17.4 (1.6) 27.1 (2.0) 9.4 (1.2) 6.0 (1.1) 1.8 100.0

Madison/St. Clair counties ........... 34.6 (3.6) 15.3 (2.6) 29.5 (3.8) 13.2 (2.5) *5.4 (2.0) 2.0 100.0

Rest of Illinois. . . . . . . . . . . . . . . . . . . 31.3 (1.8) 18.5 (1.5) 28.3 (1.9) 14.3 (1.4) 6.0 (1.0) 1.5 100.0

Indiana ........................ 32.8 (1.7) 16.0 (1.4) 22.2 (1.7) 15.2 (1.3) 11.7 (1.3) 2.1 100.0

Lake County.................... 29.0 (3.5) 18.2 (2.9) 21.7 (3.5) 18.7 (3.0) 10.4 (2.7) 2.0 100.0

Marion County .................. 42.0 (3.7) 13.2 (2.4) 20.7 (3.4) 15.6 (2.6) *7.2 (2.2) 1.2 100.0

Rest of Indiana . . . . . . . . . . . . . . . . . . 31.5 (2.0) 16.3 (1.6) 22.5 (2.0) 14.8 (1.6) 12.6 (1.6) 2.3 100.0

Iowa . . . . . . . . . . . . . . . . . . . . . . . . . . § § § § § § §

Kansas ........................ 38.0 (2.0) 15.4 (1.4) 23.6 (1.8) 12.0 (1.3) 9.4 (1.3) 1.6 100.0

Johnson/Wyandotte counties ......... 28.7 (2.8) 17.2 (2.3) 37.7 (3.2) 8.7 (1.7) 6.3 (1.7) 1.4 100.0

Rest of Kansas .................. 41.1 (2.4) 14.8 (1.8) 19.1 (2.1) 13.0 (1.7) 10.4 (1.7) 1.7 100.0

Kentucky ....................... 33.7 (2.3) 16.9 (1.8) 18.5 (2.1) 17.7 (1.9) 11.0 (1.7) 2.2 100.0

Louisiana ....................... 33.5 (2.1) 16.1 (1.6) 28.5 (2.1) 11.3 (1.4) 8.1 (1.3) 2.5 100.0

Maine . . . . . . . . . . . . . . . . . . . . . . . . . 31.6 (2.4) 12.1 (1.7) 18.1 (2.1) 25.8 (2.3) 10.9 (1.8) 1.4 100.0

Maryland . . . . . . . . . . . . . . . . . . . . . . . 26.5 (1.5) 19.9 (1.4) 26.9 (1.7) 17.4 (1.4) 7.6 (1.0) 1.7 100.0

Baltimore City . . . . . . . . . . . . . . . . . . . 34.8 (3.4) 13.5 (2.3) 24.7 (3.4) 12.7 (2.3) 10.4 (2.5) 4.0 100.0

Prince George’s County............. 26.8 (2.7) 23.8 (2.7) 25.7 (3.1) 13.4 (2.1) 9.6 (2.1) 0.7 100.0

Rest of Maryland . . . . . . . . . . . . . . . . . 25.2 (1.9) 20.1 (1.8) 27.5 (2.2) 18.9 (1.8) 6.8 (1.2) 1.6 100.0

Massachusetts.................... 21.3 (1.4) 18.9 (1.4) 31.7 (1.8) 17.0 (1.4) 10.1 (1.2) 1.1 100.0

Suffolk County .................. 33.8 (3.4) 15.9 (2.7) 23.8 (3.5) 13.0 (2.6) 11.8 (2.8) 1.7 100.0

Rest of Massachusetts ............. 19.9 (1.5) 19.2 (1.5) 32.6 (2.0) 17.4 (1.5) 9.9 (1.3) 1.0 100.0

Michigan ....................... 35.8 (1.6) 15.6 (1.3) 23.8 (1.6) 15.7 (1.3) 7.1 (1.0) 2.0 100.0

Wayne County .................. 39.6 (2.7) 17.1 (2.2) 21.3 (2.6) 13.3 (1.9) 5.8 (1.5) 2.9 100.0

Rest of Michigan . . . . . . . . . . . . . . . . . 35.6 (1.7) 15.5 (1.3) 24.0 (1.7) 15.9 (1.4) 7.2 (1.0) 1.9 100.0

Minnesota ...................... 32.3 (1.5) 19.0 (1.3) 27.5 (1.6) 13.0 (1.1) 6.8 (0.9) 1.4 100.0

Twin Cities counties4 .............. 33.9 (2.1) 19.8 (1.8) 27.6 (2.1) 12.1 (1.5) 5.2 (1.1) 1.5 100.0

Rest of Minnesota ................ 30.4 (2.2) 18.1 (1.8) 27.4 (2.3) 14.0 (1.7) 8.8 (1.5) 1.3 100.0

See footnotes at end of table.
Page 8 National Health Statistics Reports n Number 61 n October 12, 2012

Table 2. Modeled estimates (with standard errors) of the percent distribution of household telephone status for adults aged 18 and over,

by selected geographic areas: United States, 2011—Con.

No

Wireless- Wireless- Landline- Landline­ telephone

Geographic area only mostly Dual-use mostly only service1 Total

Percent (standard error)

Mississippi ...................... 42.3 (2.1) 13.2 (1.5) 19.0 (1.8) 15.4 (1.6) 8.0 (1.3) 2.2 100.0

Missouri ........................ 32.5 (1.7) 17.4 (1.4) 25.2 (1.7) 15.1 (1.3) 7.8 (1.1) 2.0 100.0

St. Louis County/City .............. 30.6 (2.6) 16.3 (2.1) 28.7 (2.9) 14.5 (2.0) 8.6 (1.8) 1.3 100.0

Rest of Missouri ................. 33.1 (2.1) 17.7 (1.7) 24.2 (2.1) 15.2 (1.6) 7.6 (1.3) 2.2 100.0

Montana ....................... § § § § § § §

Nebraska ....................... 38.5 (2.6) 15.5 (1.9) 24.7 (2.5) 13.1 (1.8) 6.7 (1.5) 1.5 100.0

Nevada ........................ 34.7 (1.9) 20.4 (1.6) 23.7 (1.8) 9.4 (1.2) 10.0 (1.3) 1.8 100.0

Clark County ................... 35.2 (2.3) 19.7 (1.9) 24.4 (2.2) 7.7 (1.3) 11.2 (1.7) 1.9 100.0

Rest of Nevada .................. 33.5 (3.3) 22.2 (2.8) 21.9 (3.1) 13.8 (2.4) 7.1 (2.0) 1.5 100.0

New Hampshire ................... 23.6 (2.2) 15.1 (1.9) 31.2 (2.6) 21.4 (2.1) 7.4 (1.5) 1.3 100.0

New Jersey. . . . . . . . . . . . . . . . . . . . . . 16.5 (1.2) 24.7 (1.5) 31.8 (1.7) 16.0 (1.3) 9.4 (1.1) 1.5 100.0

Essex County ................... 33.5 (3.4) 11.7 (2.4) 36.2 (4.0) *2.3 (1.1) 13.7 (3.0) 2.7 100.0

Rest of New Jersey ............... 16.0 (1.3) 25.1 (1.5) 31.7 (1.7) 16.5 (1.3) 9.3 (1.1) 1.5 100.0

New Mexico ..................... 36.0 (1.7) 14.8 (1.3) 22.9 (1.6) 10.2 (1.1) 12.2 (1.3) 3.8 100.0

Southern counties5 ....... ....... 38.3 (2.7) 11.3 (1.7) 24.1 (2.5) 9.8 (1.6) 14.3 (2.1) 2.0 100.0

Rest of New Mexico ............... 35.2 (2.1) 16.1 (1.7) 22.5 (2.0) 10.3 (1.4) 11.5 (1.6) 4.5 100.0

New York ....................... 19.7 (1.1) 17.9 (1.0) 33.0 (1.4) 15.0 (1.0) 12.3 (1.0) 2.1 100.0

City of New York counties6 ..... ..... 22.9 (1.5) 19.3 (1.4) 31.8 (1.8) 10.4 (1.1) 12.7 (1.3) 2.9 100.0

Rest of New York. . . . . . . . . . . . . . . . . 17.2 (1.5) 16.9 (1.5) 33.9 (2.0) 18.4 (1.6) 11.9 (1.4) 1.6 100.0

North Carolina .................... 32.8 (1.6) 13.2 (1.2) 26.5 (1.6) 18.0 (1.4) 7.8 (1.0) 1.7 100.0

North Dakota..................... 41.6 (3.1) 9.4 (1.8) 26.6 (3.0) 9.2 (1.8) 12.1 (2.3) 1.0 100.0

Ohio .......................... 33.4 (1.3) 18.1 (1.1) 22.3 (1.3) 17.5 (1.1) 6.3 (0.8) 2.2 100.0

Cuyahoga County ................ 31.2 (2.7) 20.3 (2.4) 21.0 (2.7) 19.0 (2.3) 7.0 (1.7) 1.5 100.0

Franklin County.................. 41.1 (3.3) 17.6 (2.5) 25.4 (3.3) 10.8 (2.1) *2.9 (1.3) 2.2 100.0

Rest of Ohio. . . . . . . . . . . . . . . . . . . . 32.8 (1.6) 17.9 (1.3) 22.1 (1.5) 18.2 (1.4) 6.7 (0.9) 2.3 100.0

Oklahoma....................... 34.6 (2.0) 22.1 (1.8) 22.5 (1.9) 11.5 (1.4) 7.7 (1.2) 1.7 100.0

Oregon ........................ 38.2 (2.2) 14.5 (1.6) 15.5 (1.8) 18.9 (1.8) 11.2 (1.6) 1.7 100.0

Pennsylvania..................... 23.4 (1.2) 17.1 (1.1) 30.7 (1.5) 17.4 (1.1) 9.9 (0.9) 1.5 100.0

Allegheny County ................ 38.0 (3.5) 15.2 (2.6) 21.5 (3.3) 17.6 (2.7) *6.6 (2.1) 1.1 100.0

Philadelphia County ............... 27.4 (2.7) 20.1 (2.4) 26.8 (2.9) 12.2 (2.0) 10.1 (2.0) 3.4 100.0

Rest of Pennsylvania .............. 20.9 (1.4) 16.8 (1.3) 32.5 (1.8) 18.2 (1.4) 10.3 (1.1) 1.3 100.0

Rhode Island..................... 15.3 (1.9) 20.8 (2.1) 33.3 (2.6) 17.8 (2.0) 10.6 (1.8) 2.2 100.0

South Carolina. . . . . . . . . . . . . . . . . . . . 36.1 (1.9) 15.8 (1.4) 21.2 (1.7) 15.2 (1.4) 9.5 (1.2) 2.3 100.0

South Dakota .................... § § § § § § §

Tennessee ...................... 35.7 (1.7) 17.7 (1.4) 26.4 (1.8) 11.6 (1.2) 6.5 (1.0) 2.1 100.0

Davidson County ................. 45.5 (3.8) 17.5 (2.8) 19.6 (3.4) 10.5 (2.3) *5.7 (2.0) 1.2 100.0

Shelby County .................. 40.5 (3.5) 16.4 (2.6) 26.0 (3.5) 6.6 (1.7) 8.4 (2.3) 2.2 100.0

Rest of Tennessee ................ 33.5 (2.1) 17.9 (1.7) 27.4 (2.2) 12.7 (1.5) 6.3 (1.2) 2.2 100.0

Texas ......................... 39.9 (1.1) 19.2 (0.9) 22.7 (1.0) 9.8 (0.7) 6.6 (0.6) 1.8 100.0

Bexar County ................... 40.7 (2.6) 19.3 (2.1) 22.7 (2.4) 8.1 (1.5) 7.2 (1.5) 1.9 100.0

Dallas County ................... 53.3 (2.5) 17.0 (1.9) 14.0 (1.9) 7.3 (1.3) 6.9 (1.4) 1.6 100.0

El Paso County .................. § § § § § § §

Harris County ................... 39.1 (2.0) 22.4 (1.7) 20.2 (1.8) 12.2 (1.4) 4.0 (0.9) 2.1 100.0

Rest of Texas ................... 38.0 (1.4) 19.4 (1.2) 24.7 (1.3) 10.3 (0.9) 5.8 (0.7) 1.8 100.0

Utah .......................... 37.0 (2.8) 14.8 (2.0) 27.2 (2.8) 10.8 (1.8) 8.6 (1.8) 1.7 100.0

Vermont ........................ 28.7 (3.2) 10.7 (2.1) 20.4 (3.1) 23.9 (3.0) 14.9 (2.9) 1.4 100.0

Virginia ........................ 26.6 (1.7) 22.7 (1.6) 25.5 (1.8) 15.5 (1.4) 7.7 (1.1) 2.0 100.0

Washington...................... 33.8 (1.6) 20.9 (1.4) 21.1 (1.5) 15.0 (1.3) 7.5 (1.0) 1.7 100.0

Eastern counties7 ........ ........ 31.4 (2.4) 20.9 (2.1) 24.2 (2.4) 15.4 (1.9) 6.3 (1.4) 1.8 100.0

King County .................... 42.9 (2.8) 15.8 (2.1) 23.8 (2.7) 11.0 (1.8) 4.9 (1.4) 1.5 100.0

Rest of Washington ............... 29.2 (2.5) 24.1 (2.4) 18.1 (2.4) 17.3 (2.1) 9.6 (1.9) 1.7 100.0

West Virginia. . . . . . . . . . . . . . . . . . . . . 25.7 (2.5) 12.2 (1.9) 14.9 (2.2) 27.6 (2.6) 17.1 (2.4) 2.5 100.0

Wisconsin....................... 33.8 (1.8) 12.5 (1.3) 22.5 (1.8) 18.6 (1.6) 11.2 (1.4) 1.4 100.0

Milwaukee County ................ § § § § § § §

Rest of Wisconsin ................ 32.0 (2.1) 13.2 (1.6) 22.4 (2.1) 20.2 (1.9) 10.8 (1.6) 1.4 100.0

Wyoming ....................... § § § § § § §

* Estimate has a relative standard error greater than 30% and less than or equal to 50%. Such estimates are considered unreliable.

§ Model-based estimates for Iowa, Montana, South Dakota, Texas-El Paso County, Wisconsin-Milwaukee County, and Wyoming are not reported. For at least one telephone service use category,

direct estimates from the National Health Interview Survey were more than double or less than one-half the synthetic estimate. These differences between two components of the model-based

estimates suggest that the direct estimates for these areas may be biased. Biased estimates violate a key model-based estimation assumption.
National Health Statistics Reports n Number 61 n October 12, 2012 Page 9

1

The proportion of adults living in households with no telephone service was not modeled. Other proportions were adjusted so that this estimate agreed with the 2010 American Community Survey

estimate for this proportion. 2

Includes Butte, Colusa, Del Norte, Glenn, Humboldt, Lake, Lassen, Mendocino, Modoc, Plumas, Shasta, Sierra, Siskiyou, Tehama, and Trinity. 3

Includes Adams, Arapahoe, Denver, and Douglas. Previously published estimates for City of Denver counties (2) did not include Adams, Arapahoe, or Douglas. 4

Includes Anoka, Carver, Dakota, Hennepin, Ramsey, Scott, and Washington. 5

Includes Catron, Chaves, Curry, De Baca, Dona Ana, Eddy, Grant, Hidalgo, Lea, Lincoln, Luna, Otero, Roosevelt, Sierra, and Socorro. 6

Includes Bronx, Kings, New York, Queens, and Richmond. 7

Includes Adams, Asotin, Benton, Chelan, Columbia, Douglas, Ferry, Franklin, Garfield, Grant, Kittitas, Klickitat, Lincoln, Okanogan, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman, and

Yakima. Previously published estimates for Eastern Washington counties (2) did not include Spokane or Yakima.

NOTE: Estimates were calculated by NORC at the University of Chicago.

SOURCES: CDC/NCHS, National Health Interview Survey, 2007–2011; U.S. Census Bureau, American Community Survey, 2006–2010; and infoUSA.com, Inc. consumer database, 2007–2011.
Page 10 National Health Statistics Reports n Number 61 n October 12, 2012

Table 3. Modeled estimates (with standard errors) of the percent distribution of household telephone status for children under age 18, by

selected geographic areas: United States, 2011

No

Wireless- Wireless- Landline- Landline­ telephone

Geographic area only mostly Dual-use mostly only service1 Total

Percent (standard error)

Alabama ....................... 44.3 (3.2) 22.1 (2.6) 22.1 (2.8) 6.0 (1.6) *3.8 (1.4) 1.6 100.0

Jefferson County ................. 56.1 (4.8) 14.6 (3.1) 21.4 (4.1) † † 1.0 100.0

Rest of Alabama ................. 42.5 (3.6) 23.3 (3.0) 22.2 (3.2) 6.5 (1.8) *3.8 (1.6) 1.7 100.0

Alaska ......................... 27.4 (4.9) 27.4 (4.5) 13.0 (3.8) 19.2 (4.3) *12.8 (4.1) 0.3 100.0

Arizona ........................ 44.6 (2.7) 20.8 (2.1) 19.8 (2.2) 6.1 (1.3) 6.5 (1.5) 2.2 100.0

Maricopa County ................. 47.4 (3.4) 21.5 (2.7) 18.0 (2.7) *3.0 (1.2) 8.0 (2.0) 2.1 100.0

Rest of Arizona .................. 40.2 (4.2) 19.5 (3.2) 22.8 (3.8) 11.1 (2.7) *4.1 (1.9) 2.3 100.0

Arkansas ....................... 55.5 (3.5) 19.3 (2.7) 16.3 (2.7) *3.6 (1.3) † 3.0 100.0

California . . . . . . . . . . . . . . . . . . . . . . . 32.3 (1.2) 21.3 (1.0) 29.6 (1.1) 9.3 (0.7) 6.0 (0.6) 1.5 100.0

Alameda County ................. 30.5 (4.0) 19.5 (3.3) 40.3 (4.5) *6.4 (2.1) † 0.8 100.0

Fresno County .................. 30.6 (3.5) 10.1 (2.2) 23.5 (3.4) 12.8 (2.6) 20.5 (3.4) 2.4 100.0

Los Angeles County ............... 32.4 (2.1) 20.5 (1.8) 30.7 (2.1) 8.1 (1.3) 6.9 (1.2) 1.5 100.0

Northern counties2 ....... ....... 32.7 (4.7) 20.6 (3.7) 24.0 (4.5) 11.1 (3.1) *10.2 (3.5) 1.5 100.0

San Bernardino County ............. 32.6 (3.6) 22.0 (3.1) 28.0 (3.6) 10.9 (2.4) *4.5 (1.8) 1.9 100.0

San Diego County ................ 22.0 (.03) 23.7 (3.0) 35.8 (3.7) 9.2 (2.1) 8.3 (2.2) 1.0 100.0

Santa Clara County ............... 35.1 (3.9) 19.2 (3.1) 33.2 (4.1) *5.3 (1.8) *6.0 (2.2) 1.3 100.0

Rest of California. . . . . . . . . . . . . . . . . 33.9 (1.9) 22.5 (1.7) 27.7 (1.9) 10.0 (1.3) 4.4 (0.9) 1.5 100.0

Colorado . . . . . . . . . . . . . . . . . . . . . . . 41.9 (2.8) 20.7 (2.2) 25.5 (2.6) 6.9 (1.5) *3.7 (1.1) 1.2 100.0

City of Denver counties3 ............ 38.1 (3.8) 22.7 (3.1) 27.1 (3.6) *5.4 (1.8) *5.4 (2.0) 1.2 100.0

Rest of Colorado . . . . . . . . . . . . . . . . . 44.5 (4.0) 19.3 (3.0) 24.5 (3.5) 8.0 (2.2) † 1.2 100.0

Connecticut...................... 16.5 (2.4) 21.4 (2.6) 35.2 (3.2) 15.7 (2.4) 10.4 (2.1) 0.8 100.0

Delaware . . . . . . . . . . . . . . . . . . . . . . . 28.4 (5.3) 23.9 (4.5) 30.5 (5.5) *7.7 (3.1) *8.1 (3.6) 1.5 100.0

District of Columbia. . . . . . . . . . . . . . . . . 50.9 (6.3) 18.9 (4.7) 25.7 (5.3) † † 1.7 100.0

Florida. . . . . . . . . . . . . . . . . . . . . . . . . 43.0 (1.9) 19.9 (1.5) 26.1 (1.7) 3.1 (0.7) 5.5 (1.0) 2.3 100.0

Miami-Dade County ............... 45.5 (5.5) 21.2 (4.0) 21.0 (4.7) † *7.6 (3.3) 1.9 100.0

Duval County ................... 52.4 (3.7) 19.2 (2.8) 21.8 (3.3) † † 3.5 100.0

Orange County .................. 48.0 (5.3) 23.5 (4.0) 24.6 (4.7) † † 1.5 100.0

Rest of Florida . . . . . . . . . . . . . . . . . . 40.5 (2.4) 19.6 (1.9) 27.4 (2.2) 3.7 (0.9) 6.5 (1.3) 2.2 100.0

Georgia . . . . . . . . . . . . . . . . . . . . . . . . 38.6 (2.5) 25.8 (2.2) 25.4 (2.3) 5.0 (1.2) *2.7 (0.9) 2.5 100.0

Fulton/DeKalb counties ............. 46.6 (4.9) 20.8 (3.7) 27.8 (4.6) † † 1.6 100.0

Rest of Georgia. . . . . . . . . . . . . . . . . . 37.2 (2.8) 26.7 (2.6) 24.9 (2.6) 5.8 (1.4) *2.7 (1.0) 2.6 100.0

Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . 35.6 (3.9) 21.6 (3.2) 33.0 (4.0) *4.2 (1.6) † 2.5 100.0

Idaho ......................... 54.8 (3.9) 18.1 (2.9) 13.1 (2.7) 7.7 (2.1) *4.7 (1.8) 1.6 100.0

Illinois . . . . . . . . . . . . . . . . . . . . . . . . . 37.5 (2.3) 20.6 (1.9) 29.2 (2.2) 8.3 (1.4) *2.7 (0.8) 1.7 100.0

Cook County ................... 42.7 (3.3) 20.1 (2.6) 27.5 (3.1) *4.9 (1.5) *3.4 (1.3) 1.4 100.0

Madison/St. Clair counties ........... 45.3 (6.3) 17.0 (4.1) 26.8 (5.7) *8.4 (3.4) † 2.0 100.0

Rest of Illinois. . . . . . . . . . . . . . . . . . . 35.6 (2.8) 20.9 (2.4) 29.8 (2.8) 9.3 (1.8) *2.6 (1.0) 1.7 100.0

Indiana ........................ 42.9 (2.9) 19.6 (2.2) 21.2 (2.5) 8.4 (1.6) 5.1 (1.5) 2.9 100.0

Lake County.................... 43.6 (6.2) 21.3 (4.4) 17.4 (4.7) *12.5 (4.1) † 2.2 100.0

Marion County .................. 52.3 (6.3) 18.0 (4.2) 19.1 (5.0) *7.9 (3.2) † 1.2 100.0

Rest of Indiana . . . . . . . . . . . . . . . . . . 41.1 (3.4) 19.7 (2.7) 21.9 (3.0) 8.0 (1.9) *6.0 (1.8) 3.3 100.0

Iowa . . . . . . . . . . . . . . . . . . . . . . . . . . § § § § § § §

Kansas ........................ 44.8 (3.1) 18.1 (2.3) 24.1 (2.6) 5.6 (1.5) *5.4 (1.6) 2.0 100.0

Johnson/Wyandotte counties ......... 31.1 (4.4) 18.3 (3.4) 43.2 (4.9) *3.8 (1.8) † 1.9 100.0

Rest of Kansas .................. 49.6 (3.9) 18.1 (2.8) 17.4 (3.0) *6.2 (1.9) *6.7 (2.1) 2.0 100.0

Kentucky ....................... 41.3 (3.5) 20.9 (2.8) 17.8 (2.8) 12.0 (2.3) *5.8 (1.9) 2.2 100.0

Louisiana ....................... 43.4 (3.2) 21.7 (2.6) 23.9 (2.8) 6.6 (1.6) † 2.8 100.0

Maine . . . . . . . . . . . . . . . . . . . . . . . . . 35.3 (4.2) 15.3 (2.9) 26.2 (3.9) 16.8 (3.2) *4.8 (2.0) 1.6 100.0

Maryland . . . . . . . . . . . . . . . . . . . . . . . 27.2 (2.4) 22.0 (2.2) 30.3 (2.7) 13.3 (1.9) 5.2 (1.3) 2.0 100.0

Baltimore City . . . . . . . . . . . . . . . . . . . 39.4 (5.1) 15.5 (3.5) 21.7 (4.4) *10.4 (3.2) *7.8 (3.2) 5.1 100.0

Prince George’s County............. 33.8 (4.8) 24.2 (4.1) 31.1 (5.1) *5.7 (2.4) † 1.2 100.0

Rest of Maryland . . . . . . . . . . . . . . . . . 24.3 (2.9) 22.4 (2.8) 31.3 (3.3) 15.2 (2.5) *5.0 (1.7) 1.8 100.0

Massachusetts.................... 22.6 (2.5) 21.1 (2.4) 39.0 (3.1) 11.2 (2.0) 5.1 (1.5) 1.1 100.0

Suffolk County .................. 40.2 (7.5) 23.6 (6.2) 29.0 (7.4) † † 1.5 100.0

Rest of Massachusetts ............. 21.3 (2.6) 20.9 (2.5) 39.7 (3.3) 11.7 (2.1) 5.3 (1.6) 1.0 100.0

Michigan ....................... 43.1 (2.7) 19.5 (2.1) 22.8 (2.4) 8.3 (1.6) 4.4 (1.2) 1.9 100.0

Wayne County .................. 52.2 (4.8) 19.6 (3.6) 19.5 (4.0) *4.0 (1.9) † 3.4 100.0

Rest of Michigan . . . . . . . . . . . . . . . . . 42.3 (2.9) 19.5 (2.3) 23.1 (2.5) 8.7 (1.7) 4.7 (1.3) 1.7 100.0

Minnesota ...................... 31.6 (2.6) 24.2 (2.3) 31.8 (2.7) 8.0 (1.5) *3.1 (1.1) 1.3 100.0

Twin Cities counties4 .............. 31.9 (3.5) 21.9 (3.0) 34.6 (3.8) 8.2 (2.1) † 1.1 100.0

Rest of Minnesota ................ 31.3 (3.8) 26.9 (3.5) 28.4 (3.9) 7.7 (2.2) *4.1 (1.8) 1.6 100.0

Mississippi . . . . . . . . . . . . . . . . . . . . . . 58.6 (3.5) 15.4 (2.5) 14.3 (2.6) 8.7 (2.1) † 2.4 100.0

See footnotes at end of table.
National Health Statistics Reports n Number 61 n October 12, 2012 Page 11

Table 3. Modeled estimates (with standard errors) of the percent distribution of household telephone status for children under age 18, by

selected geographic areas: United States, 2011—Con.

No

Wireless- Wireless- Landline- Landline­ telephone

Geographic area only mostly Dual-use mostly only service1 Total

Percent (standard error)

Missouri ........................ 40.6 (3.0) 19.7 (2.3) 22.8 (2.6) 9.5 (1.8) *4.7 (1.4) 2.7 100.0

St. Louis County/City .............. 25.6 (4.0) 22.6 (3.6) 35.9 (4.6) 9.8 (2.7) *4.4 (2.1) 1.8 100.0

Rest of Missouri ................. 44.7 (3.7) 18.9 (2.8) 19.3 (3.0) 9.4 (2.2) *4.7 (1.7) 2.9 100.0

Montana ....................... § § § § § § §

Nebraska ....................... 38.5 (3.9) 20.6 (3.0) 29.0 (3.7) *5.9 (1.9) *4.4 (1.8) 1.6 100.0

Nevada ........................ 40.6 (3.4) 25.1 (2.8) 19.1 (2.7) *2.9 (1.1) 10.6 (2.3) 1.6 100.0

Clark County ................... 39.9 (4.0) 23.5 (3.2) 19.2 (3.2) *2.7 (1.3) 12.9 (3.0) 1.8 100.0

Rest of Nevada .................. 42.5 (6.4) 29.7 (5.2) 18.8 (5.0) † † 1.1 100.0

New Hampshire ................... 26.5 (4.0) 18.7 (3.3) 39.1 (4.6) 13 (3.0) † 1.1 100.0

New Jersey. . . . . . . . . . . . . . . . . . . . . . 20.1 (2.3) 27.7 (2.6) 33.8 (2.8) 9.7 (1.8) 7.3 (1.6) 1.5 100.0

Essex County ................... 25.9 (4.9) *10.1 (3.2) 49.3 (6.1) † *10.7 (4.0) 3.8 100.0

Rest of New Jersey ............... 19.8 (2.4) 28.3 (2.7) 33.3 (2.9) 10.0 (1.8) 7.2 (1.7) 1.4 100.0

New Mexico ..................... 51.9 (3.1) 13.2 (2.0) 19.6 (2.6) *2.6 (1.0) 7.8 (1.9) 4.9 100.0

Southern counties5 ....... ....... 61.6 (4.4) 12.3 (2.7) 15.1 (3.2) † *7.0 (2.5) 1.3 100.0

Rest of New Mexico ............... 48.1 (4.0) 13.6 (2.6) 21.4 (3.4) *2.6 (1.3) 8.1 (2.4) 6.3 100.0

New York ....................... 20.3 (1.6) 19.6 (1.6) 38.4 (2.1) 12.2 (1.4) 7.4 (1.2) 2.1 100.0

City of New York counties6 ..... ..... 23.7 (2.3) 22.2 (2.2) 35.4 (2.7) 8.2 (1.5) 8.1 (1.6) 2.4 100.0

Rest of New York. . . . . . . . . . . . . . . . . 18.0 (2.3) 17.7 (2.2) 40.5 (3.0) 15.0 (2.2) 6.9 (1.6) 1.9 100.0

North Carolina .................... 45.8 (2.6) 15.2 (1.9) 25.1 (2.4) 8.4 (1.5) *3.5 (1.1) 2.0 100.0

North Dakota..................... 44.1 (4.8) 17.1 (3.3) 32.6 (4.6) † *5.3 (2.4) 0.3 100.0

Ohio .......................... 41.3 (2.4) 20.8 (2.0) 20.9 (2.1) 10.6 (1.5) *3.4 (1.0) 3.0 100.0

Cuyahoga County ................ 30.2 (4.4) 20.3 (3.6) 28.1 (4.5) 18.7 (3.7) † 1.5 100.0

Franklin County.................. 50.8 (4.5) 21.6 (3.4) 21.0 (3.8) *3.7 (1.7) † 1.9 100.0

Rest of Ohio. . . . . . . . . . . . . . . . . . . . 41.5 (2.9) 20.8 (2.4) 19.9 (2.5) 10.4 (1.9) *4.0 (1.3) 3.3 100.0

Oklahoma....................... 39.9 (3.4) 27.5 (3.0) 19.9 (2.8) 5.7 (1.6) *5.5 (1.7) 1.7 100.0

Oregon ........................ 40.7 (3.6) 17.5 (2.7) 18.4 (3.0) 13.8 (2.6) 8.0 (2.2) 1.6 100.0

Pennsylvania..................... 28.9 (2.2) 20.6 (1.9) 34.0 (2.4) 9.7 (1.5) 4.4 (1.1) 2.4 100.0

Allegheny County ................ 40.6 (5.9) 23.9 (4.6) 26.8 (5.4) *7.3 (3.0) † 1.4 100.0

Philadelphia County ............... 35.7 (4.5) 23.7 (3.7) 26.8 (4.3) *5.2 (2.1) † 4.5 100.0

Rest of Pennsylvania .............. 26.6 (2.5) 19.7 (2.3) 35.9 (2.9) 10.6 (1.8) 4.9 (1.4) 2.2 100.0

Rhode Island..................... 15.2 (3.3) 33.2 (4.1) 34.7 (4.6) *7.9 (2.5) *6.6 (2.6) 2.4 100.0

South Carolina. . . . . . . . . . . . . . . . . . . . 43.6 (3.1) 21.9 (2.5) 19.9 (2.6) 8.4 (1.7) *3.9 (1.3) 2.3 100.0

South Dakota .................... § § § § § § §

Tennessee ...................... 44.4 (2.9) 22.1 (2.3) 25.5 (2.7) 4.4 (1.3) † 2.2 100.0

Davidson County ................. 51.6 (6.3) 20.6 (4.4) 23.1 (5.3) † † 1.3 100.0

Shelby County .................. 47.2 (5.7) 20.1 (4.0) 26.0 (5.1) † † 1.9 100.0

Rest of Tennessee ................ 42.9 (3.6) 22.8 (2.9) 25.7 (3.3) *5.4 (1.6) † 2.4 100.0

Texas ......................... 49.2 (1.6) 21.2 (1.3) 18.8 (1.3) 5.2 (0.8) 3.7 (0.6) 1.8 100.0

Bexar County ................... 50.7 (3.8) 19.5 (2.9) 20.6 (3.2) *4.2 (1.5) † 2.5 100.0

Dallas County ................... 59.0 (3.8) 20.0 (2.9) 12.6 (2.6) *4.8 (1.7) † 1.8 100.0

El Paso County .................. § § § § § § §

Harris County ................... 44.3 (2.9) 25.5 (2.5) 17.7 (2.3) 6.3 (1.5) *4.1 (1.3) 2.2 100.0

Rest of Texas ................... 48.0 (2.1) 21.5 (1.8) 20.1 (1.8) 5.4 (1.0) 3.4 (0.8) 1.7 100.0

Utah .......................... 41.3 (3.8) 15.9 (2.8) 30.3 (3.7) *5.2 (1.7) *6.0 (2.0) 1.2 100.0

Vermont ........................ 29.1 (5.3) 13.3 (3.6) 22.7 (4.9) 26.6 (5.2) *7.3 (3.4) 1.0 100.0

Virginia ........................ 27.0 (2.5) 25.0 (2.4) 28.7 (2.6) 11.6 (1.8) 5.5 (1.4) 2.2 100.0

Washington...................... 35.1 (2.4) 26.7 (2.2) 22.9 (2.1) 7.2 (1.3) 6.7 (1.5) 1.5 100.0

Eastern counties7 ........ ........ 38.4 (3.9) 22.6 (3.2) 25.6 (3.7) 9.6 (2.4) † 1.3 100.0

King County .................... 37.7 (4.4) 22.5 (3.6) 33.4 (4.5) *4.0 (1.8) † 0.9 100.0

Rest of Washington ............... 32.1 (3.7) 31.0 (3.5) 16.0 (3.0) 7.7 (2.1) 11.4 (2.8) 1.9 100.0

West Virginia. . . . . . . . . . . . . . . . . . . . . 31.5 (3.9) 18.2 (3.1) 12.5 (2.9) 24.9 (3.7) 10.6 (2.9) 2.3 100.0

Wisconsin....................... 34.9 (3.1) 19.3 (2.5) 29.4 (3.1) 12.3 (2.2) *2.7 (0.9) 1.4 100.0

Milwaukee County ................ § § § § § § §

Rest of Wisconsin ................ 32.4 (3.6) 21.2 (3.0) 30.5 (3.7) 13.4 (2.6) § 1.5 100.0

Wyoming ....................... § § § § § § §

* Estimate has relative standard error greater than 30% and less than or equal to 50% and is considered unreliable.

† Estimate has relative standard error greater than 50% and is not shown.

§ Model-based estimates for Iowa, Montana, South Dakota, Texas-El Paso County, Wisconsin-Milwaukee County, and Wyoming are not reported. For at least one telephone service use category,

direct estimates from the National Health Interview Survey were more than double or less than one-half the synthetic estimate. These differences between two components of the model-based

estimates suggest that the direct estimates for these areas may be biased. Biased estimates violate a key model-based estimation assumption.
Page 12 National Health Statistics Reports n Number 61 n October 12, 2012

1

The proportion of children living in households with no telephone service was not modeled. Other proportions were adjusted so that this estimate agreed with the 2010 American Community

Survey estimate for this proportion. 2

Includes Butte, Colusa, Del Norte, Glenn, Humboldt, Lake, Lassen, Mendocino, Modoc, Plumas, Shasta, Sierra, Siskiyou, Tehama, and Trinity. 3

Includes Adams, Arapahoe, Denver, and Douglas. Previously published estimates for City of Denver counties (2) did not include Adams, Arapahoe, or Douglas. 4

Includes Anoka, Carver, Dakota, Hennepin, Ramsey, Scott, and Washington. 5

Includes Catron, Chaves, Curry, De Baca, Dona Ana, Eddy, Grant, Hidalgo, Lea, Lincoln, Luna, Otero, Roosevelt, Sierra, and Socorro. 6

Includes Bronx, Kings, New York, Queens, and Richmond. 7

Includes Adams, Asotin, Benton, Chelan, Columbia, Douglas, Ferry, Franklin, Garfield, Grant, Kittitas, Klickitat, Lincoln, Okanogan, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman, and

Yakima. Previously published estimates for Eastern Washington counties (2) did not include Spokane or Yakima.

NOTE: Estimates were calculated by NORC at the University of Chicago.

SOURCES: CDC/NCHS, National Health Interview Survey, 2007–2011; U.S. Census Bureau, American Community Survey, 2006–2010; and infoUSA.com, Inc. consumer database, 2007–2011.
National Health Statistics Reports n Number 61 n October 12, 2012 Page 13

Technical Notes

Survey data sources

The estimates presented in this

report are based on National Health

Interview Survey (NHIS) data collected

from January 2007 through December

2011 and on American Community

Survey (ACS) data collected from 2006

through 2010. NHIS is a multipurpose

health survey conducted by the Centers

for Disease Control and Prevention’s

National Center for Health Statistics

(NCHS). ACS is a multipurpose survey

conducted by the U.S. Census Bureau to

produce estimates of demographic,

social, economic, and housing

characteristics.

NHIS is a multistage probability

household survey of a large sample of

households drawn from the civilian

noninstitutionalized household

population of the United States. This

face-to-face survey interview is

administered by trained field

representatives from the U.S. Census

Bureau, under contract to NCHS. NHIS

interviews are conducted continuously

throughout the year to collect

information that is used to assess

progress toward meeting national health

objectives. The content includes health

status, health risk factors, health-related

behaviors, health care access, and health

care utilization. NHIS also includes

questions about demographic and

socioeconomic characteristics, household

telephones, and whether anyone in the

household has a wireless telephone.

The sample for NHIS is stratified

by state, which allows use of NHIS data

in statistical models that produce

state-level estimates; however, for most

states, the limited number of sampling

strata and small sample sizes preclude

reliable direct state-level estimates.

Household telephone status information

was obtained for 75,150 persons in

2007, for 73,749 persons in 2008, for

88,053 persons in 2009, for 89,620

persons in 2010, and for 101,449

persons in 2011. Fewer than 0.5% of

persons with completed NHIS familylevel interviews had missing data for

household telephone status.

NHIS was used to derive the direct

estimates for each telephone service use

category by age group (adults aged 18

and over or children under age 18),

small area, and 6-month period. These

estimates were the dependent variables

in the statistical models. Also, NHIS

was the source for the national estimates

used for raking the model-based

estimates for each telephone service use

category by age group and year.

ACS is a multistage probability

survey that provides data on households

and group quarters. Here a subset of the

full ACS sample—the civilian

noninstitutionalized population—was

used to represent a population similar to

that sampled for NHIS. Data were

collected continuously through a

combination of mailed, telephone, and

face-to-face interviews. ACS is both

nationally and state representative and

has included approximately 2 million

housing units per year since 2006.

ACS data are released for calendar

years rather than for 6-month periods.

Moreover, 2011 ACS data were not

released until September 20, 2012.

Therefore, ACS data for 2006 were used

in models for both 6-month periods of

2007 (i.e., January–June 2007 and

July–December 2007). Similarly, ACS

data for 2007 were used in models for

both 6-month periods of 2008; data for

2008 were used in models for both

6-month periods of 2009; data for 2009

were used in models for both 6-month

periods of 2010; and data for 2010 were

used in models for both 6-month periods

of 2011. Moreover, the 2008, 2009, and

2010 ACS were the sources for the

proportion of adults or children living in

households with any telephone service

(landline or wireless). These ACS

estimates were used as benchmarking

totals when raking the model-based

estimates.

NHIS and ACS sampling weights

adjust for the probability of selection of

each household, and they are adjusted

for nonresponse. The results in this

report are based on weighted estimates.

R software (http://www.r-project.org)

was used to derive the model-based

estimates and standard errors. Design

effects were included in the models to

account for the complex survey designs.

Auxiliary data sources

The numbers of listed telephone

lines within each state for 2007–2011

were obtained from a consumer database

compiled by infoUSA.com, Inc. This

database is updated bimonthly with

information from 37 sources, including

postal delivery sequence files, National

Change of Address lists, utility company

records, and more than 4,000 white page

directories. These data were available

for each calendar year rather than each

6-month period. Therefore, annual data

on listed telephone lines were used in

models for both 6-month periods of that

calendar year. The count of listed

telephone lines was divided by the

number of civilian noninstitutionalized

persons, and because these proportions

were available at the state level only, the

same state-specific proportion was used

in the model for each small area in the

state.

Definitions

For each family contacted by NHIS,

one adult family member is asked

whether ‘‘you or anyone in your family

has a working cellular telephone.’’ An

NHIS family can be an individual or a

group of two or more related persons

living together in the same housing unit

(a ‘‘household’’). Thus, a family can

consist of only one person, and more

than one family can live in a household

(including, for example, a household

where there are multiple single-person

families, as when unrelated roommates

are living together).

To produce the statistics for this

report, families are identified as

‘‘wireless families’’ if anyone in the

family had a working cellular telephone

at the time of interview. This person (or

persons) could be a civilian adult, a

member of the military, or a child.

Households are identified as ‘‘wirelessonly’’ if they include at least one

wireless family and if there are no

working landline telephones inside the

household. To determine whether there

was a working landline telephone inside

the household, survey respondents were

asked if there was ‘‘at least one phone
Page 14 National Health Statistics Reports n Number 61 n October 12, 2012

inside your home that is currently

working and is not a cell phone.’’

Household telephone status (rather

than family telephone status) is used

because most telephone surveys draw

samples of households rather than

families. Adults and children are

identified as wireless-only if they live in

a wireless-only household. Individual

ownership or use of wireless telephones

is not determined. A similar approach is

used to identify adults and children

living in landline-only households and

in households with both landline and

wireless telephones.

NHIS includes an additional

question for persons living in families

with both landline and wireless

telephones. The respondent for the

family is asked to consider all of the

telephone calls his or her family

receives and to report whether ‘‘all or

almost all calls are received on cell

phones, some are received on cell

phones and some on regular phones, or

very few or none are received on cell

phones.’’ This question permits the

identification of persons living in

‘‘wireless-mostly’’ households (defined

as households with both landline and

cellular telephones in which all families

receive all or almost all calls on cell

phones) and ‘‘landline-mostly’’

households (defined as households with

both landline and cellular telephones in

which all families receive all or almost

all calls on landline telephones).

‘‘Dual-use’’ households are those with

both landline and cellular telephones

that are neither wireless-mostly or

landline-mostly. That is, they receive

some calls on cell phones and some on

landline telephones.

Small-area model

Detailed descriptions of the

small-area model and the derivation of

the model-based estimates and standard

errors are provided in an earlier report

(2). As noted above, the model-based

estimates were a weighted combination

of three distinct sets of estimates: (a) the

direct estimate from NHIS for the small

area during the 6-month period of

interest, (b) a synthetic estimate derived

from a regression model involving ACS

and auxiliary data for the small area

during the 6-month period of interest,

and (c) adjusted direct estimates from

NHIS for the small area during all

6-month periods other than the 6-month

period of interest.

The approach used to create the

model-based estimates can produce

substantially biased prevalence estimates

and unstable variance estimates when

the direct estimate from NHIS is based

on small sample sizes, when that sample

is drawn from only a few geographic

areas, and when those few geographic

areas are not very representative of the

state or county of interest. To identify

potentially problematic model-based

estimates, the person-level prevalence

ratio of the direct survey estimate to the

synthetic regression-based estimate was

examined for each of the telephone

service use categories and for each

small area. Ratios were computed across

all 6-month periods and for 2011 only.

If the ratios for any telephone service

use category were greater than two or

less than one-half, then all model-based

estimates for that reporting area were

suppressed from Tables 1–3 in this

report. This occurred for six small areas:

Iowa, Montana, South Dakota, Texas-El

Paso County, Wisconsin-Milwaukee

County, and Wyoming. For these areas,

the synthetic estimates derived from the

regression model are presented in the

Technical Notes Table.
National Health Statistics Reports n Number 61 n October 12, 2012 Page 15

Table. Synthetic regression-based estimates (with standard errors) of the percent distribution of household telephone status, by age, for

selected geographic areas where model-based estimates are not reported: United States, 2011

No

Wireless- Wireless- Landline- Landline­ telephone

Age and geographic area only mostly Dual-use mostly only service1 Total

Adults aged 18 and over Percent (standard error)

Iowa .......................... 31.9 (5.9) 15.8 (3.8) 24.4 (5.4) 14.9 (3.8) *11.0 (5.2) 1.9 100.0

Montana ....................... 32.6 (6.2) 18.0 (4.1) 21.7 (5.4) 15.8 (4.1) † 2.0 100.0

South Dakota .................... 33.0 (6.1) 16.8 (3.9) 24.4 (5.5) 15.3 (4.0) † 1.6 100.0

Texas-El Paso County ............... 41.2 (6.7) 16.0 (4.3) 25.6 (5.9) † † 2.4 100.0

Wisconsin-Milwaukee County........... 34.2 (6.2) 17.3 (4.1) 25.2 (5.6) *11.4 (3.5) *10.6 (5.2) 1.3 100.0

Wyoming ....................... 33.8 (6.3) 18.2 (4.1) 21.2 (5.4) 12.9 (3.8) *12.4 (5.6) 1.5 100.0

Children under age 18

Iowa .......................... 38.1 (8.1) 20.3 (5.4) 27.3 (7.2) † † 1.8 100.0

Montana ....................... 39.8 (8.6) 23.8 (5.9) *21.6 (6.8) † † 2.4 100.0

South Dakota .................... 39.7 (8.6) 21.5 (5.6) 25.2 (7.2) † † 1.2 100.0

Texas-El Paso County ............... 54.5 (8.6) *17.0 (5.4) *20.1 (6.6) † † 2.2 100.0

Wisconsin-Milwaukee County........... 40.5 (8.9) 21.2 (5.9) 27.2 (7.7) † † 1.0 100.0

Wyoming ....................... 40.8 (9.0) 22.2 (5.9) *21.1 (7.1) † † 1.8 100.0

* Estimate has relative standard error greater than 30% and less than or equal to 50% and is considered unreliable.

† Estimate has relative standard error greater than 50% and is not shown. 1

The proportion of persons living in households with no telephone service was not modeled. Other proportions were adjusted so that this estimate agreed with the 2010 American Community

Survey estimate for this proportion.

NOTES: Model-based estimates for these six areas are not reported in the text tables because the direct National Health Interview Survey estimates (a component of the model-based estimates)

may be biased. This table presents synthetic estimates (another component of the model-based estimates) for these areas. These synthetic estimates are the best available estimates for these

areas, but they should be used with caution as they are generally less reliable than the model-based estimates reported for other geographic areas. Estimates were calculated by NORC at the

University of Chicago.

SOURCES: U.S. Census Bureau, American Community Survey, 2006–2010 and infoUSA.com, Inc. consumer database, 2007–2011.
U.S. DEPARTMENT OF

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Acknowledgments

NCHS thanks NORC at the University of Chicago and SHADAC at the University of Minnesota for providing resources that supported this

research. The authors are solely responsible for the content of this report. Nadarajasundaram Ganesh developed the statistical models. The

authors thank Marketing Systems Group for providing the auxiliary data on listed telephone numbers and the staff of the NCHS Research Data

Center for their assistance.

Suggested citation

Blumberg SJ, Luke JV, Ganesh N, et al.

Wireless substitution: State-level estimates

from the National Health Interview Survey,

2010–2011. National health statistics reports;

no 61. Hyattsville, MD: National Center for

Health Statistics. 2012.

Copyright information

All material appearing in this report is in the

public domain and may be reproduced or

copied without permission; citation as to

source, however, is appreciated.

National Center for Health Statistics

Edward J. Sondik, Ph.D., Director
 

Jennifer H. Madans, Ph.D., Associate Director
 

for Science
 

Division of Health Interview Statistics

Jane F. Gentleman, Ph.D., Director

For free e-mail updates on NCHS publication releases, subscribe online at: http://www.cdc.gov/nchs/govdelivery.htm.
 

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