Time-to-event analysis of factors influencing delay in discharge from a subacute Complex Discharge Unit during the first year of the pandemic (2020) in an Irish tertiary centre hospital

ABSTRACT Background There is a paucity of data investigating delays in discharges from subacute complex care units exclusively dealing with complex cases. We aimed to analyse factors causing delays in discharges and explore their implications on the healthcare system in terms of length of stay (LOS), during the COVID-19 pandemic, using time-to-event analysis, to assist in future pandemic healthcare planning decisions. Methods Single-centre, retrospective, cross-sectional study. Demographics, clinical characteristics and length of stay (LOS) of all patients admitted to our subacute Complex Discharge Unit at our model 4 hospital during the pandemic were retrieved from electronic patient records. The outcome variable in our time-to-event analysis was a delay in discharge with a LOS >15 days. A cox proportional hazards regression model delineated factors contributing to delays. Results 390 patients were admitted between March 2020 - February 2021 to the subacute complex discharge unit. Among these, 326 (83.6%) patients were >65 years of age, and 233 (59.7%) patients were female. The median (IQR) age was 79 (70-86) years, with a median (IQR) LOS of 19.4 (10-41) days. A total of 237 (60.7%) events were uncensored, LOS > 15 days of which 138 (58.2%) were female, 124 (52.32%) had >4 comorbidities, and 153 (39.2%) were censored into LOS ≤15 days and death 19 (4.8%). Kaplan Meier’s plot allowed the comparison of factors causing a delay in discharge to single factors: age, gender, and multimorbidity. A multivariate cox regression analysis adjusted to each strata age, gender and multimorbidity predicted factors affecting LOS: Age strata 65 - 75 & 75 - 85 [HR 0.233; 95% CI (0.077-.708); p=.010] & [HR .301; 95% CI(.155-.588); p<.001] had common factor patient-centred needs prolonging LOS. The common factors complications arising from comorbidities in male [HR .145; 95 % CI (.081 -.261); p<.001] and female [HR .479; 95% CI (.311 -.737); p<.001], and patient-centred needs in male [HR .472; 95 % CI (.243 -.917); p.027] female [HR .361; 95% CI (.215 -.608); p<.001] exhibited statistically significant results. Conclusion Reducing LOS is imperative for better patient outcomes and hospital management. The most common factors delaying discharge were complexities that arose from primary diagnoses and patient-centred needs such as cognition, psychosocial needs and carer needs. Further research is needed into exploring multimorbidity as a risk factor for mortality in patients who experience prolonged LOS within a complex discharge unit.