Factors associated with flexible cystoscope longevity: an analysis of supplier and health service datasets

To investigate the associations between how reusable flexible cystoscopes (FCs) are managed during their functioning lifetime and their longevity.

This was an exploratory retrospective analysis of administrative data collected by a medical supplies company (KARL STORZ Endoscopy (UK) Ltd) on FC usage linked at a National Health Service (NHS) hospital trust level to data from NHS England's Hospital Episodes Statistics dataset on the number of FCs performed each year in the NHS in England. Number of uses before failure (defined as user-determined need for FC return to the supplier) were analysed descriptively and using a negative binomial regression model.

Data were available for 1918 FCs across 70 hospitals. The median (interquartile range) number of uses and min of use before failure were 58 (20-147.75) and 706.5 (208.25-1718), respectively. Eighty-five percent of returned FCs were exchanged (i.e. replaced with a new FC), at a median of 66 uses. The two most common reasons for failure - damage to the working channel and control handle housing - were observed in 76.3% and 63.8% of returned FCs, respectively. A greater number of uses before failure was significantly associated with recency, same-site same-complex decontamination, on-site endoscopic specialist availability, decontamination in a general endoscopy unit, and drying cabinet or bowl storage rather than vacuum packaging. Top-quintile-volume units were associated with a significantly higher number of uses before failure, however, there was otherwise no clear independent volume-longevity association.

This exploratory analysis generates mechanistically plausible hypotheses regarding factors that could promote FC longevity. These findings are of relevance as we seek to understand how to optimise the cost, resilience and environmental sustainability of healthcare. A prospectively designed study could investigate whether there is a causal link between the key factors identified and longevity of FC usage.