Incidence of Serum Creatinine Monitoring and Outpatient Visit Follow-Up among Acute Kidney Injury Survivors after Discharge: A Population-Based Cohort Study

Introduction: Acute kidney injury (AKI) affects 20% of hospitalized patients and worsens outcomes. To limit complications, post-discharge follow-up and kidney function testing are advised. The objective of this study was to evaluate the frequency of follow-up after discharge among AKI survivors. Methods: This was a population-based cohort study of adult Olmsted County residents hospitalized with an episode of stage II or III AKI between 2006 and 2014. Those dismissed from the hospital on dialysis, hospice, or who died within 30 days after discharge were excluded. The frequency and predictors of follow-up, defined as an outpatient serum creatinine (SCr) level or an in-person healthcare visit after discharge were described. Results: In the 627 included AKI survivors, the 30-day cumulative incidence of a follow-up outpatient SCr was 80% (95% confidence interval [CI]: 76% and 83%), a healthcare visit was 82% (95% CI: 79 and 85%), or both was 70% (95% CI: 66 and 73%). At 90 days and 1 year after discharge, the cumulative incidences of meeting both follow-up criteria rose to 82 and 91%, respectively. Independent predictors of receiving both an outpatient SCr assessment and healthcare visit within 30 days included lower estimated glomerular filtration rate at discharge, higher comorbidity burden, longer length of hospitalization, and greater maximum AKI severity. Age, sex, race/ethnicity, education level, and socioeconomic status did not predict follow-up. Conclusions: Among patients with moderate to severe AKI, 30% did not have follow-up with a SCr and healthcare visit in the 30-day post-discharge interval. Follow-up was associated with higher acuity of illness rather than demographic or socioeconomic factors.