STATE-LEVEL ESTIMATES FROM THE NHIS 

RESTRICTED DATA: ANALYSIS TO SUPPORT 

STATES IMPLEMENTATION AND EVALUATION OF 

THE ACA 

Joanna Turner, Senior Research Fellow 

University of Minnesota, SHADAC 

December 2, 2015 

FCSM, Washington, DC 
Background 

The Affordable Care Act (ACA) has made 

significant changes in health insurance coverage 

and health care systems across the U.S. 

States responsible for implementing many of the 

key elements 

State program administrators and policymakers 

need reliable state-level data 

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Data Needs to Evaluate the ACA 

Rich data on health care access, utilization, 

affordability, and health insurance coverage 

State-representative samples 

Timely 

Study changes over time 

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National Health Interview Survey 

(NHIS) 

Key data source for monitoring health and 

health care use of the US population since 1957 

Conducted annually by the National Center for 

Health Statistics (NCHS) 

In 2011, added new questions for monitoring the 

A〕A’◎ %@★°′′◇

Sample augmentation 

• Uninsured estimates now available for all states 

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Challenges of Using the NHIS for 

State-Level Analysis 

State-level identifiers are not available on public

use files; access restricted to a NCHS or Census 

Research Data Center 

Available sample weights do not account for 

state population totals and characteristics 

• Explored creating state-level weights, but did not 

have enough information 

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Project Goals 

Expand the role of NHIS in helping states to 

evaluate and monitor health reform 

Produce state-level estimates and make these 

★◆′*%′′°**y °□°%*°′*¥ □%° -HA[A〕’◎ [°◇° 〕¥§◇¥●

Submitted a proposal to conduct work at the 

U§%□¥●◎%◇y ☆$ M%§§¥◎☆◇°’◎ 〕¥§◎◆◎ +¥◎¥°●′′£ [°◇° 

Center (MnRDC) 

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Data Linking 

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IHIS 

data* 

Restricted 

NHIS data 

 

Merged by NCHS 

Integrated Health Interview Series – Harmonized NHIS data 

produced by the Minnesota Population Center and SHADAC 

(www.ihis.us/ihis) 
RDC PROCESS 

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Creation: 1-3 months 

Approval/Revisions: 

6-12 weeks 

Proposal 
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Proposal 

SSS After SSS forms 

have been 

submitted: 4-6 

weeks
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Supplement

any forms 

for the RDC 

Create 

analyses 

programs 

using public 

data 

Proposal 

Paperwork 

& File Prep 

SSS
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Proposal 

Paperwork 

& File Prep Data 

Merging 

SSS 1. Prepare public 

files (researcher): 

2-4 weeks 

2. Send public 

data file to NCHS 

3. Restricted files 

merged onto 

public files (by 

NCHS): 2-4 weeks 

4. Revisions: 2-4 

weeks 
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Getting 

acquainted: 1 

week 

Analyses: time 

varies by 

project 

Note: Max time 

allotted 3 

years from 

date project is 

approved 

Proposal 

Paperwork 

& File Prep 

Inside the 

RDC 

SSS

Data 

Merging 
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Proposal 

Paperwork 

& File Prep Data 

Merging 

Inside the 

RDC 

SSS

Releasing 

Output 

Strict 

requirements! 

1. Cells with < 5 

2. Formatting 

3. No 

intermediate 

output 

Preparation: 2-3 

weeks 

After requested: 

3-4 weeks 
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Separate 

review of 

materials 

(e.g., journal 

articles and 

tables for 

websites)

After 

requested: 

2-4 weeks 

Proposal 

Paperwork 

& File Prep Data 

Merging 

Inside the 

RDC Releasing 

Output 

SSS

Publication 

Review 
SHADAC DATA CENTER 

http://datacenter.shadac.org/ 

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Next Steps 

Add 2014 estimates 

Add measures by coverage type 

• Uninsured, private, and public 

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Resources 

-HA[A〕’◎ [°◇° 〕¥§◇¥●

• http://datacenter.shadac.org/

SHADAC brief on NHIS questionnaire changes 

• http://www.shadac.org/publications/nhisquestionnaire-changes-addressing-patientprotection-and-affordable-care-act

Integrated Health Interview Series (IHIS) 

• https://www.ihis.us/ihis/

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Contact Information 

Joanna Turner 

Senior Research Fellow 

turn0053@umn.edu

612.624.4802