Cambridge, MA 

Lexington, MA 

Hadley, MA 

Bethesda, MD 

Chicago, IL 

Abt Associates Inc. 

Suite 800 North 

4550 Montgomery Avenue 

Bethesda, MD 20814-3343 

The Study of 

Thimerosal and 

Autism 

Documentation and 

Codebook for the 

Child Body Weights 

File: 

September 3, 2010 

Prepared for 

Frank DeStefano 

National Immunization 

Program 

Centers for Disease Control 

and Prevention 

Atlanta, GA 30329 

Prepared by 

Cristofer Price 

Yeqin He 
This documentation was prepared by Cristofer Price and Yeqin He of Abt Associates Inc. 

for the Immunization Safety Office (ISO) of the Centers for Disease Control and 

Prevention (CDC) Atlanta, GA 30333. Questions about the documentation, substantive 

questions, or technical issues regarding the data file should be directed to the CDC ISO, 

MS D26, 1600 Clifton Road, Atlanta, Georgia 30333 (404-639-8256). 

Suggested Citation for Study of Thimerosal and Autism Public Use Data Set: 

Price, C.S., He, Y. (2010) The Study of Thimerosal and Autism: Data Set 

Documentation. Bethesda MD: Abt Associates, Inc; Prepared for the National 

Immunization Program Centers for Disease Control and Prevention Atlanta, GA 

Abt Associates Inc. 1 
Documentation and Codebook
 

for the
 

Child Body Weights File
 

1. Introduction to the Child Vaccination Histories File............................................... 2
 

2. File Formats and Variable Descriptions................................................................... 3
 

3. Example Records in the Child Body Weights File.................................................... 4
 

1. Introduction to the Child Vaccination Histories File 

The Child Body Weights File contains the data that were used for the analyses reported in 

the Technical Report, Volume II, Chapter 18. 

Section 2 of the current document shows the file formats and variable descriptions of the 

Child Body Weights File. Section 3 shows some example records from the Child Body 

Weights File with an explanation of how to interpret the variables. 

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2. File Formats and Variable Descriptions 

The Childhood Vaccination Histories File is provided in two formats: 1) ASCII text format, and 2) SAS file. There are multiple 

records per ID on this data set. There are 1,095 unique ChildIDs in the data set. 

Exhibit 2.1.
 

Variables Included in the Child Body Weights File
 

Sourcea
 

Med. Comp.
 Variable Type Label Notesb 

Chrt. Aut. 

ChildID Num Child ID for merging data sets See Vol II, Chapter 18. 

SortDays1 Num Age in days (used to sort file) X See Vol II, Chapter 18. 

Res_Vacdays1 Num Resolved: Age in days at vac receipt X X See Vol II, Chapter 18. 

MercAmt Num Mercury amount (in vac receipt) X See Vol II, Chapter 18. 

RecptWt1 Num Weight at vaccine receipt (grams) X See Vol II, Chapter 18. 

inVacHist Num =1 if record in Child Vac History File X See Vol II, Chapter 18. 

Ch_WgtGrams Num Chart: child age in days when weight recorded X See Vol II, Chapter 18. 

Ch_WgtDays1 Num Chart: child age in days when weight recorded X See Vol II, Chapter 18. 

inWts Num =1 record in chart weights file X See Vol II, Chapter 18. 

=1 if wgt observed, =0 if wt imputed, X See Vol II, Chapter 18. 

Wgt_Observed Num =. if no thim containing vac recvd 

=1 if wgt imputed, =0 if wt observed, X See Vol II, Chapter 18. 

Wgt_Imputed Num =. if no thim containing vac recvd 

a Data Source: Medical chart abstraction, or computer automated data set (VSD data). b Vol II and section numbers correspond to Technical Report Volumes I (Price et al, 2009), which is included with this data set. 

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3. Example Records in the Child Body Weights File 

Exhibit 3.1 shows some example records from the Child Body Weights File with an explanation 

of how to interpret the data. The first example record shows that the child’s body weight was 

recorded in his medical chart (ch_wgtGrams = 3884 grams) the day he was born (Sortdays1 = 1), 

and no thimerosal-containing vaccines or immune globulin preparations were received that day 

(Res_VacDays1=., and MercAmt=.). When the child was 4 days old (Sortdays1 = 4), he received 

a vaccine containing 12.5 micrograms of mercury (MercAmt=12.5), but his weight was not 

recorded in his medical chart on that day (ch_wgtGrams = ., and Wgt_Observed=0). Therefore 

his weight on that day was imputed (Wgt_Imputed=1), as described in Volume II, Chapter 18, via 

linear interpolation using his weights at ages 1 day and 15 days. Body weights were also 

imputed for vaccines received at age 58 days. When the child was 130 days old, he received 

thimerosal-containing vaccines and he was weighed and his weight was recorded in his medical 

chart on the same day. 

Exhibit 3.1. Example Records in the Child Body Weights File 

in Ch_ ch_ 

Child Sort Res_ Merc Vac Wgt Wgt in Wgt_ Wgt_ 

ID Days1 Vacdays1 Amt RecptWt1 Hist Grams Days1 Wts Observed Imputed 

1 1 . . . . 3884 1 1 . . 

1 4 4 12.5 3926.43 1 . . . 0 1 

1 15 . . . . 4082 15 1 . . 

1 58 58 25 4834.69 1 . . . 0 1 

1 58 58 25 4834.69 1 . . . 0 1 

1 58 58 0 4834.69 1 . . . . . 

1 130 130 25 6095 1 6095 130 1 1 0 

1 130 130 25 6095 1 6095 130 1 1 0 

1 130 130 0 6095 1 6095 130 1 . . 

1 181 . . . . 6350 181 1 . . 

1 193 193 25 6861 1 6861 193 1 1 0 

1 193 193 25 6861 1 6861 193 1 1 0 

1 193 193 12.5 6861 1 6861 193 1 1 0 

1 278 . . . . 7966 278 1 . . 

1 280 280 0 7910 1 7910 280 1 . . 

1 375 375 25 9384 1 9384 375 1 1 0 

1 375 375 0 9384 1 9384 375 1 . . 

1 487 487 25 10461 1 10461 487 1 1 0 

1 487 487 0 10461 1 10461 487 1 . . 

1 487 487 0 10461 1 10461 487 1 . . 

1 487 487 0 10461 1 10461 487 1 . . 

1 495 . . . . 10433 495 1 . . 

1 578 . . . . 11141 578 1 . . 

1 767 . . . . 12701 767 1 . . 

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