Supplementary Material for: The Impact of Health Care Appointment Non-Adherence on Graft Outcomes in Kidney Transplantation
Background: Non-adherence to medication is a well-studied and known cause of late allograft loss, but it is difficult to measure and prospectively monitor. The aim of this study was to assess if appointment non-adherence was correlated with medication non-adherence and a predictor of graft outcomes. Methods: This was a longitudinal cohort study that used the National United States Renal Data System and veterans affairs health records data with time-to-event analyses conducted to assess the impact on graft and patient survival. Results: The number of transplants that were included in the analysis was 4,646 (3,656 with complete records); 14.6% of patients had an appointment no show rate of ≥12% (non-adherence). Appointment and medication non-adherence were highly correlated and both were significant independent predictors of outcomes. Those with appointment non-adherence had 1.5 times the risk of acute rejection (22.0 vs. 14.7%, p < 0.0001) and a 65% higher risk of graft loss (adjusted hazards ratio (aHR) 1.65, 95% CI 1.38-1.97, p < 0.0001). There was a significant interaction between appointment and medication non-adherence; those with appointment and medication non-adherence were at very high risk of graft loss (aHR 4.18, 95% CI 3.39-5.15, p < 0.0001), compared to those with only appointment non-adherence (aHR 1.39, 95% CI 0.97-2.01, p = 0.0766) or only medication non-adherence (aHR 2.44, 95% CI 2.11-2.81, p < 0.0001). Conclusion: These results demonstrate that non-adherence to health care appointments is a significant and independent risk factor for graft loss.