Minimizing attrition bias: a longitudinal study of depressive symptoms in an elderly cohort.

ABSTRACT:

Background

Attrition from mortality is common in longitudinal studies of the elderly. Ignoring the resulting non-response or missing data can bias study results.

Methods

1260 elderly participants underwent biennial follow-up assessments over 10 years. Many missed one or more assessments over this period. We compared three statistical models to evaluate the impact of missing data on an analysis of depressive symptoms over time. The first analytic model (generalized mixed model) treated non-response as data missing at random. The other two models used shared parameter methods; each had different specifications for dropout but both jointly modeled both outcome and dropout through a common random effect.

Results

The presence of depressive symptoms was associated with bein

SUBMITTER: Chang CC 

PROVIDER: S-EPMC2733930 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature