To identify factors associated with attrition in a longitudinal study of cardiovascular prevention.
Demographic, clinical and psychosocial variables potentially associated with attrition were investigated in 1,841 subjects enrolled in the southwestern Pennsylvania Heart Strategies Concentrating on Risk Evaluation study. Attrition was defined as study withdrawal, loss to follow-up, or missing ≥50% of study visits.
Over four years of follow up, 291 subjects (15.8%) met criteria for attrition. In multivariable regression models, factors that were independently associated with attrition were: Black race (Odds Ratio(OR):2.21, 95%Confidence Interval(CI):1.55, 3.16; P<0.001), younger age (OR per 5-year increment:0.88, 95%CI:0.79, 0.99; P<0.05), male sex (OR: 1.79, 95%CI: 1.27, 2.54; P<0.05), no health insurance (OR:2.04, 95%CI:1.20, 3.47; P<0.05), obesity (OR:1.80, 95%CI:1.07, 3.02; P<0.05), CES-D depression score≥16 (OR:2.02, 95%CI:1.29, 3.19; P<0.05), higher ongoing life events questionnaire score (OR=1.09, 95%CI= 1.04–1.13; P<0.001). Having a spouse/partner participating in the study was associated with lower odds of attrition (OR=0.60 95%CI=0.37–0.97; P<0.05). A synergistic interaction was identified between black race and depression.
Attrition over four years was influenced by sociodemographic, clinical and psychological factors that can be readily identified at study entry. Recruitment and retention strategies targeting these factors may improve participant follow-up in longitudinal cardiovascular prevention studies.