Outpatient versus inpatient observation after percutaneous native kidney biopsy: a cost minimization study

Background/aims: Percutaneous kidney biopsy (PKB) is the primary diagnostic tool for kidney disease. Outpatient 'day surgery' (ODS) following PKB in low-risk patients has previously been described as a safe alternative to inpatient observation (IO). This study aims to determine if ODS is less costly compared to IO while accounting for all institutional costs (IC) associated with post-PKB complications, including death.

Methods: A cost minimization study was performed using decision analysis methodology which models relative costs in relation to outcome probabilities yielding an optimum decision. The potential outcomes included major complications (bleeding requiring blood transfusion or advanced intervention), minor complications (bleeding or pain requiring additional observation), and death. Probabilities were obtained from the published literature and a base case was selected. IC were obtained for all complications from institutional activity-based cost estimates. The base case assumed a complication rate of 10% with major bleeding occurring in 2.5% of patients (for both arms) and death in 0.1 and 0.15% of IO and ODS patients, respectively.

Results: ODS costs USD 1,394 per biopsy compared to USD 1,800 for IO inclusive of all complications. IC for ODS remain less when overall complications <20%, major complications <5.5%, and IC per death <USD 1.125 million. ODS remained favored through sensitivity analysis.

Conclusion: Outpatient management after PKB for low-risk patients costs less from the institutional perspective compared to IO, inclusive of complications and death. ODS should be considered for low-risk patients undergoing native kidney biopsy.