Revisiting the "Weekend Effect" on Adult and Pediatric Liver and Kidney Offer Acceptance.

BACKGROUND Weekends can impose resource and manpower constraints on hospitals. Studies using data from prior allocation schemas showed increased adult organ discards on weekends. We examined the impact of day of the week on adult and pediatric organ acceptance using contemporary data. MATERIAL AND METHODS Retrospective analysis of UNOS-PTR match-run data of all offers for potential kidney and liver transplant from 1/1/2016 to 7/1/2021 were examined to study the rate at which initial offers were declined depending on day of the week. Risk factors for decline were also evaluated. RESULTS Of the total initial adult/pediatric liver and kidney offers, the fewest offers occurred on Mondays and Sundays. The decline rate for adult/pediatric kidneys was highest on Saturdays and lowest on Tuesdays. The decline rate for adult livers was highest on Saturday and lowest on Wednesday. In contrast, the decline rate for pediatric livers was highest on Tuesdays and lowest on Wednesdays. Independent risk factors from multivariate analysis of the adult/pediatric kidney and liver decline rate were analyzed. The weekend offer remains an independent risk factor for adult kidney and liver offer declines, but for pediatric offers, these were not significant independent risk factors. CONCLUSIONS Although allocation systems have changed, and the availability of kidneys and livers have increased in the USA over the past 5 years, the weekend effect remains significant for adult liver and kidney offers for declines. Interestingly, the weekend effect was not seen for pediatric liver and kidney offers.