Erin K. Dursa
Post Deployment Health, Office of Public Health, Department of Veterans Affairs
Aaron Schneiderman
Post Deployment Health, Office of Public Health, Department of Veterans Affairs
Nonresponse Bias Measurement and Adjustment in the Follow-up Study of a National Cohort of Gulf War and Gulf War Era Veterans (Wave 3)
Erin K. Dursa
Post Deployment Health, Office of Public Health, Department of Veterans Affairs
Aaron Schneiderman
Post Deployment Health, Office of Public Health, Department of Veterans Affairs
Heather Hammer
Abt SRBI
Stanislav Kolenikov
Abt SRBI
The 2013 Follow-up Study of a National Cohort of Gulf War and Gulf War Era Veterans is a multimode web, mail, and CATI survey of 15,000 deployed Gulf War veterans and 15,000 non-deployed Gulf War Era veterans first surveyed in 1995-1997 and in 2005. The 2013 Wave 3 follow-up survey used response propensity logistic regression modeling to examine mechanisms of attrition. Nonresponse weight adjustment successfully removed about 80% of the nonresponse bias in the test variable - marital status in 1991. It also significantly reduced the nonresponse bias initially observed in three of the five key Wave 3 survey variables examined: Chronic Multisymptom Illness, smoking, and alcohol use. However, significant correlations between the examined outcomes and response propensities indicate nonresponse bias for the other two key variables: PTSD symptoms and general health. Respondents tend to have lower PTSD symptom screening scores (i.e., screen negative for PTSD) and higher self-reported general health compared with nonrespondents. This paper describes the methodology used in the nonresponse analysis, discusses performance of the nonresponse correction and its meaning for the results.