Supplementary Material for: Improving Care after Acute Kidney Injury: A Prospective Time Series Study

Background: Acute kidney injury (AKI) complicates 15-20% of hospitalizations, and AKI survivors are at increased risk of chronic kidney disease and death. However, less than 20% of patients see a nephrologist within 3 months of discharge, even though a nephrologist visit within 90 days of discharge is associated with enhanced survival. To address this, we established an AKI Follow-Up Clinic and characterized the patterns of care delivered. Methods: We conducted a prospective time series study. All hospitalized patients who developed Kidney Disease Improving Global Outcomes (KDIGO) stage 2 or 3 AKI were eligible. The pre-intervention period consisted of electronic reminders to the nephrology consults and cardiovascular surgery services to refer to the AKI Follow-Up Clinic. In the post-intervention period, eligible patients were automatically scheduled into the AKI Follow-Up Clinic at discharge. The primary outcome was the percentage of KDIGO stages 2-3 AKI survivors assessed by a nephrologist within 30 days of discharge. Results: In the pre-intervention period, 8 of 46 patients (17%) were seen by a nephrologist within 30 days after discharge, and no additional patients were seen for 90 days. In the post-intervention period, 17 of 69 patients (25%) were seen by a nephrologist within 30 days after discharge (p = 0.36), with an additional 30 patients seen in 90 days (47 of 69, 68%, p < 0.001). The mean serum creatinine was 99 (SD 35) µmol/l prior to hospitalization and 133 (58) µmol/l at 3 months. Fifty-five of 79 patients (70%) received at least 1 medical intervention at their first AKI Follow-Up Clinic visit. Conclusions: An AKI Follow-Up Clinic with an automatic referral process increased the proportion of patients seen at 90 days, but not 30 days post discharge. Being seen in the AKI Follow-Up Clinic was associated with interventions in most patients. Future research is needed to evaluate the effect of the AKI Follow-Up Clinic on patient-centered outcomes, but physicians should be aware that AKI survivors may benefit from close outpatient follow-up and a multipronged approach to care similarly for other high-risk populations.