Clinical adjudication of hemodialysis catheter-related bloodstream infections: findings from the REDUCCTION Trial

Key Points The inter-rater reliability of reporting hemodialysis catheter-related infectious events between site investigators and trial adjudicators in Australia and New Zealand was substantial. The high concordance level in reporting catheter infections improves confidence in using site-level bacteremia rates as a clinical metric for quality benchmarking and future pragmatic clinical trials. A rigorous adjudication protocol may not be needed if clearly defined criteria to ascertain catheter-associated bacteremia are used. Background Hemodialysis catheter-related bloodstream infection (HD-CRBSI) are a significant source of morbidity and mortality among dialysis patients, but benchmarking remains difficult because of varying definitions of HD-CRBSI. This study explored the effect of clinical adjudication process on HD-CRBSI reporting. Methods The REDUcing the burden of Catheter ComplicaTIOns: a National approach trial implemented an evidence-based intervention bundle using a stepped-wedge design to reduce HD-CRBSI rates in 37 Australian kidney services. Six New Zealand services participated in an observational capacity. Adult patients with a new hemodialysis catheter between December 2016 and March 2020 were included. HD-CRBSI events reported were compared with the adjudicated outcomes using the end point definition and adjudication processes of the REDUcing the burden of Catheter ComplicaTIOns: a National approach trial. The concordance level was estimated using Gwet agreement coefficient (AC1) adjusted for service-level effects and implementation tranches (Australia only), with the primary outcome being the concordance of confirmed HD-CRBSI. Results A total of 744 hemodialysis catheter-related infectious events were reported among 7258 patients, 12,630 catheters, and 1.3 million catheter-exposure days. The majority were confirmed HD-CRBSI, with 77.9% agreement and substantial concordance (AC1=0.77; 95% confidence interval [CI], 0.73 to 0.81). Exit site infections have the highest concordance (AC1=0.85; 95% CI, 0.78 to 0.91); the greatest discordance was in events classified as other (AC1=0.33; 95% CI, 0.16 to 0.49). The concordance of all hemodialysis catheter infectious events remained substantial (AC1=0.80; 95% CI, 0.76 to 0.83) even after adjusting for the intervention tranches in Australia and overall service-level clustering. Conclusions There was a substantial level of concordance in overall and service-level reporting of confirmed HD-CRBSI. A standardized end point definition of HD-CRBSI resulted in comparable hemodialysis catheter infection rates in Australian and New Zealand kidney services. Consistent end point definition could enable reliable benchmarking outside clinical trials without the need for independent clinical adjudication.