Bias with Respect to Socioeconomic Status: A Closer Look at Zip Code Matching in a Pneumococcal Vaccine Effectiveness Study

Download as .RIS

Citation

Link-Gelles, Ruth; Westreich, Daniel J.; Aiello, Allison E.; Shang, Nong; Weber, David J.; Holtzman, Corinne R.; Scherzinger, Karen; Reingold, Arthur L.; Schaffner, William; & Harrison, Lee H., et al. (2016). Bias with Respect to Socioeconomic Status: A Closer Look at Zip Code Matching in a Pneumococcal Vaccine Effectiveness Study. SSM - Population Health, 2, 587-594. PMCID: PMC5033249

Abstract

In 2010, 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the US for prevention of invasive pneumococcal disease in children. Individual-level socioeconomic status (SES) is a potential confounder of the estimated effectiveness of PCV13 and is often controlled for in observational studies using zip code as a proxy. We assessed the utility of zip code matching for control of SES in a post-licensure evaluation of the effectiveness of PCV13 (calculated as [1-matched odds ratio]*100). We used a directed acyclic graph to identify subsets of confounders and collected SES variables from birth certificates, geo-coding, a parent interview, and follow-up with medical providers. Cases tended to be more affluent than eligible controls (for example, 48.3% of cases had private insurance vs. 44.6% of eligible controls), but less affluent than enrolled controls (52.9% of whom had private insurance). Control of confounding subsets, however, did not result in a meaningful change in estimated vaccine effectiveness (original estimate: 85.1%, 95% CI 74.8-91.9%; adjusted estimate: 82.5%, 95% CI 65.6-91.1%). In the context of a post-licensure vaccine effectiveness study, zip code appears to be an adequate, though not perfect, proxy for individual SES.

URL

http://dx.doi.org/10.1016/j.ssmph.2016.08.005

Reference Type

Journal Article

Year Published

2016

Journal Title

SSM - Population Health

Author(s)

Link-Gelles, Ruth
Westreich, Daniel J.
Aiello, Allison E.
Shang, Nong
Weber, David J.
Holtzman, Corinne R.
Scherzinger, Karen
Reingold, Arthur L.
Schaffner, William
Harrison, Lee H.
Rosen, Jennifer B.
Petit, Susan
Farley, Monica M.
Thomas, Ann R.
Eason, Jeffery T.
Wigen, Christine
Barnes, Meghan M.
Thomas, Ola
Zansky, Shelley M.
Beall, Bernard
Whitney, Cynthia G.
Moore, Matthew R.

PMCID

PMC5033249

ORCiD

Aiello - 0000-0001-7029-2537