Interobserver agreement of peritoneal dialysis exit site scoring: Results from the Standardizing Care to Improve Outcomes in Pediatric End Stage Kidney Disease (SCOPE) collaborative.

Background: Exit site infections are a risk factor for the development of peritonitis in patients on long-term peritoneal dialysis. Visual assessments of an exit site utilising currently available tools (Twardowski and Mid-European Pediatric Peritoneal Dialysis Study Group (MEPPS)) are necessary to objectively characterise the appearance of an exit site. The aim of this study was to assess the interobserver agreement of exit site evaluations utilising both exit site scoring tools.

Methods: Exit site evaluations were independently performed by two evaluators during outpatient visits at 13 sites within the Standardizing Care to Improve Outcomes in Pediatric End Stage Kidney Disease collaborative. The frequency and percentage of evaluations where both reviewers agreed were calculated. A sub-analysis was performed looking at evaluations where disagreement occurred.

Results: A total of 371 paired exit site evaluations were collected over 6 months. For the majority of evaluations (range: 78%-97% Twardowski, 78%-97% MEPPS), both reviewers agreed that no abnormality was present across all domains. When the analysis was restricted to evaluations where at least one reviewer noted an abnormality, interobserver agreement fell across all domains (range: 31%-61% Twardowski, 56%-66% MEPPS). Disagreements more commonly occurred regarding the presence versus absence of an abnormality, rather than a difference in the severity of an abnormality.

Conclusions: Whereas interobserver agreement is high when the appearance of a peritoneal dialysis catheter exit site is characterised as 'normal', interobserver disagreement is common when the appearance of the exit site is 'abnormal'. Further work is warranted to improve interobserver agreement of exit site assessments and to identify domains conferring an increased risk of infection.