Using Historical Records to Reconstruct Early Life SES Exposures in Decedents: Preliminary Findings from a Pilot Study Kathryn Rose and J. Stephen Perhac University of North Carolina at Chapel Hill

Background Early life socioeconomic conditions associated with increased risk of chronic diseases in adulthood In most ongoing epidemiologic studies early life SES not ascertained at study inception –Collect from study participants while study is ongoing –Obtain from historical records

Linkage of death certificates with individual census records (Hill, 2000; Preston,1996) –Elderly, white men: 70% linkage –Elderly black men: 56% linkage Study of link between childhood SES and Alzheimer’s disease (Moceri, 2001) –Attempted linkage with birth certificates and declassified census records 86% of participants linked to birth certificates and/or census record No significant variation by gender, age or education Can Early Life SES Be Obtained From Historical Records?

Rationale for Current Pilot Study Feasibility of using public records to obtain early life SES information: –Accessibility –Cost ($$$ and time) –Availability of parental SES data Completeness Comparability to data from other sources What are the sociodemographic determinants of successful linkage?

Participants Atherosclerosis Risk in Communities (ARIC) Study –Baseline examination –Participants born between 1922 and participants from NC field center who subsequently died –Born between (N=334) –Born in NC (N=319) or

Search Strategy Death Certificates SS-5s Database for searching records containing parental SES NC Born Request NC Birth Certificates Born Search 1930 Census

Attempting Linkage to Records with Parental SES Information Sources: –Death Certificates Available for > 99% of decedents –Social Security application (SS-5) data Obtained for 99% of decedents Information abstracted: –Mother and father’s names –Participant data: Name(s), date and place of birth, race, gender

Searching for NC Birth Certificates Death Certificates SS-5s Database for searching records containing parental SES N=451 NC Born N=319 Request NC Birth Certificates

NC Birth Certificate Search 269 of 321 (84%) requested records found –Yield of usable records lower (N= %) –Yield: Higher for whites than blacks (81% vs. 72%) Higher for men than women (81% vs. 76%) Did not not vary by education –95% contained parental occupational data

Searching for 1930 Census Records Death Certificates SS-5s Database for searching records containing parental SES Born N=334 Search 1930 Census

Linkage with 1930 Census Records Accessed using a proprietary website with computerized index Criteria Used to determine match: –Place of birth match vs. census address –Match on both parents’ names –Match on race –If participant born at the time of census Did age and name match?

Linkage with 1930 Census Records 238 of 334 records (71%) found on initial searches –Yield: Higher for whites (74%) than blacks (57%) Higher for men (73%) than women (68%) Lower for those with less than HS education (69%) than for those with 12+ years of education (72%) Highest between 1927 and 1931 (80% +)

Sociodemographic Information Available from 1930 Census Records Virtually complete and legible Socioeconomic information Home ownership Household size Literacy of mother and father Occupational data on parents –Job title –Industry –Whether an owner or an employee –Current employment status

NC Born N=319 Born N= Birth Certificates Obtained (84%) 238 Census Records Located (74%) Search on 382 decedent records 9% not located 91% birth certificate and / or census record Summary: Data Linkage

NC Born N=319 Born N= decedents searched on both sources 79% both birth certificate and census record 19% census record only 1% birth certificate only 1% no birth certificate or census record

Strengths and Limitations: Birth Certificate Data Strengths Data collected directly from parents at time participant was born Records archived by state Limitations Limited SES data Variation in content across time and place Access rules vary by state During this time period records not always filed at birth Costly

Strengths and Limitations: Census Data Strengths Data collected in a standardized manner across U.S. by trained census takers Large amount of parental SES-related data Inexpensive Every person is indexed Limitations Records are hand- written Data abstraction is tedious Limited ability to track those not born in close proximity to census Only declassified after 72 years

Next Steps Continued search of census records Comparison of the parental occupational data from different sources –Census vs. birth certificate –1920 vs census –Historical records vs. those reported by participants

Conclusions It is feasible to use birth certificates and early census records as a source of early life SES information –Accessible –Parental SES information is complete –Labor-intensive and potentially expensive Potential use in such data is missing due to loss to follow-up

Acknowledgements UNC at Chapel Hill Program on Demographics and Economics of Aging Research Dr. Gerardo Heiss The ARIC Study B. Renee Ferguson Brigitt Heier