Optimal follow-up intervals for different stages of chronic kidney disease: a prospective observational study.

BACKGROUND: Chronic kidney disease (CKD) is a public health challenge; however, evidence-based, optimal follow-up intervals for patients with CKD have not been identified. This study aimed to identify appropriate follow-up intervals for different stages of CKD.

METHODS: We studied 2682 patients with CKD. The number of patients experiencing a 50% increase in creatinine and those reaching end-stage renal failure were examined on the basis of their CKD stage. The renal function testing interval was defined as the estimated time for 0.1% of the patients with CKD to have a composite renal outcome, after adjusting for clinical risk factors. Transitions from CKD stage-based subgroups were analyzed using parametric cumulative incidence models. Other sensitivity analyses involved estimation of the time to renal event occurrence for 1% of patients.

RESULTS: Of the 913 patients (34%) who had a composite renal event, 29 had stage 3A (10.5%), 151 had stage 3B (16.3%), 429 had stage 4 (41.0%), and 304 had stage 5 CKD (70.9%). The estimated renal function testing intervals for patients with CKD were 6.0 months for stage 3A, 3.4 months for stage 3B, 2.0 months for stage 4, and 1.2 months for stage 5.

CONCLUSIONS: The optimal follow-up intervals were longer for patients with lower CKD stages. These estimates are longer than those recommended by the current guidelines and serve as a reference for nephrologists in selecting an appropriate follow-up interval for each patient.

TRIAL REGISTRATION: UMIN clinical trial registry number: UMIN000020038.