Prediction of patient attrition from experimental behavioral interventions

Attrition of patients in treatment and control was compared for loss from the study and loss from care. Previously diagnosed hypertensive patients who were under treatment but out of control (diastolic blood pressure greater than 90 and systolic blood pressure greater than 140 mm Hg) were assigned to conventional care or to an experimental nursing intervention group. The intervention involved eight visits covering a 6-month period. Attrition from the study for the experimental group was defined as completion of four or fewer experimental sessions; for the control group it was defined as making no visits to a treatment center during a 6-month posttest observation period. Attrition from care by the facilities where the study was conducted was defined as no visits to these sources of care during a 1 1/2-year follow-up period. More controls than experimentals were lost from the study. No differences could be found between patients lost from the study and those lost from both the study and care. A logistic regression was used to predict attrition. The four significant predictor variables were: perceived difficulty in following a diet, knowledge of disease, perceived severity of symptoms, and the experimental condition. The study showed: social psychological variables, important predictors of attrition, should be used to identify patients at risk of leaving care for their chronic diseases.