Effects of Higher Quality of Care on Initiation of Long-term Dialysis in Patients With CKD and Diabetes

BackgroundThe burden of diabetes-related chronic kidney disease (CKD) on individuals and society is increasing, shifting attention toward improving the quality of care for patients with CKD and diabetes. We assessed the quality of CKD care and its association with long-term dialysis, acute kidney injury (AKI), and death.Study DesignRetrospective cohort study (2004-2011).Setting & ParticipantsAdults in Taiwan with incident CKD enrolled in the Longitudinal Cohort of Diabetes Patients.Predictors3 CKD-care quality indicators based on medical and pharmacy claims data were studied: prescription of renin-angiotensin system inhibitors, testing for proteinuria, and nutritional guidance. Each was examined individually, and all were summed into an overall quality score.OutcomesThe primary outcome was initiation of long-term dialysis therapy. Secondary outcomes were hospitalization due to AKI and death from any cause.MeasurementsUsing instrumental variables related to the quality indicators to minimize both unmeasured and measured confounding, we fit a 2-stage residual inclusion model to estimate HRs and 95% CIs for each outcome.ResultsAmong the 63,260 patients enrolled, 43.9% were prescribed renin-angiotensin system inhibitors, 60.6% were tested for proteinuria, and 13.4% received nutritional guidance. During a median follow-up of 37.9 months, 1,471 patients started long-term dialysis therapy, 2,739 patients were hospitalized due to AKI, and 4,407 patients died. Higher overall quality scores were associated with lower hazards for long-term dialysis in instrumental variable analyses (HR of 0.62 [95% CI, 0.40-0.98] per 1-point greater score) and hospitalization due to AKI (HR of 0.69 [95% CI, 0.50-0.96] per 1-point greater score). The hazard for all-cause death was nonsignificantly lower (HR of 0.80 [95% CI, 0.62-1.03] per 1-point greater score).LimitationsPotential misclassification and uncontrolled confounding by indication.ConclusionsOur findings suggest potential opportunities to improve long-term outcomes among patients with diabetes and CKD by improving the quality of their CKD care.