DETERMINANTS OF NONCOMPLIANCE AND ATTRITION IN THE ELDERLY

Background. This report identifies demographic and health-related base line factors associated with non-compliance and attrition in elderly s ubjects participating in a preventive intervention study over a 4-year follow-up period. Methods. The Cox proportional hazards model and pol ychotomous logistic regression were used to evaluate time to clinic as sessment noncompliance and type of non-participation. Results. Of 1785 subjects, 35.6% were non-compliant during follow-up which meant they were eligible to participate at the time they were contacted but would not or could not return for an assessment. Refusals due to a lack of continuing interest or being too busy, and those citing health problem s constituted the major subgroups of non-compliers. Death, unable to c ontact, and ineligible due to disenrolment or moving away accounted fo r nearly 20%. Four-year compliance was achieved by 44.4% of the partic ipants. Time to non-compliance was significantly shorter with older ag e, lower annual income, poorer personal health ranking, and, to a marg inal extent, depression. Lower annual income was associated with all r easons for non-participation including disenrolment or moving. Other f actors correlated with specific types of nonparticipation. Conclusions . These results can be useful in designing more effective cohort maint enance strategies. Greater resources may be allocated to subgroups who are less likely to continue.