Nonmodifiable characteristics associated with nonadherence to immunosuppressant therapy in renal transplant recipients

PURPOSE: Relationships between adherence to immunosuppressant therapy and adult renal transplant recipients' age, time posttransplant, race, and sex were evaluated to identify factors that predict nonadherence. METHODS: Pharmacy refill data were used to measure adherence. In a primary analysis, stepwise regression was used to assess the relationship between independent variables (age, sex, time posttransplant, and race) and adherence. In a secondary analysis to provide categorical summaries, stepwise regression was used to assess the relationship between independent variables (age quartiles, sex, time posttransplant quartiles, and race) and adherence. RESULTS: In the primary analysis, age and time posttransplant were significant predictors of adherence rate (p < 0.05), with adherence rate decreasing as age and time posttransplant increased. In the secondary analysis, age quartile 4 (>or=60 years) and time posttransplant quartile 1 (<or=4 years) were significant predictors of adherence (p < 0.01), with adherence rates lower among age quartile 4 and higher among posttransplant quartile 1. CONCLUSION: In patients who had received renal transplants, the rate of adherence to immunosuppressant therapy decreased as patient age and time since transplantation increased.