Assessing Nonresponse Bias at Follow-up in a Large Prospective Cohort of Relatively Young and Mobile Military Service Members
Abstract
Background: Nonresponse bias in a longitudinal study could affect the magnitude and direction of measures of association. We identified sociodemographic, behavioral, military, and health related predictors of response to the first follow-up questionnaire in a large military cohort and assessed the extent to which nonresponse biased measures of association. Methods: Data are from the baseline and first follow-up survey of the Millennium Cohort Study. Seventy-six thousand, seven hundred and seventy-five eligible individuals completed the baseline survey and were presumed alive at the time of follow-up; of these, 54,960 (71.6%) completed the first follow-up survey. Logistic regression models were used to calculate inverse probability weights using propensity scores. Results: Characteristics associated with a greater probability of response included female gender, older age, higher education level, officer rank, active-duty status, and a self-reported history of military exposures. Ever smokers, those with a history of chronic alcohol consumption or a major depressive disorder, and those separated from the military at follow-up had a lower probability of response. Nonresponse to the follow-up questionnaire did not result in appreciable bias; bias was greatest in subgroups with small numbers. Conclusions: These findings suggest that prospective analyses from this cohort are not substantially biased by non-response at the first follow-up assessment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 21, 2010
- Accession Number
- ADA530996
Entities
People
- Alyson J. Littman
- Besa Smith
- Edward J. Boyko
- Gary Dean Gackstetter
- Isabel Gomez Jacobson
- Jaime Horton
- Paul J. Amoroso
- Timothy Steven Wells
- Tomoko Hooper
- Tyler Clain Smith
Organizations
- Naval Health Research Center