Risk factors for prolonged length of hospital stay following elective hip replacement surgery: a retrospective longitudinal observational study

Objectives Our aim was to identify which patients are likely to stay in hospital longer following total hip replacement surgery. Design Longitudinal, observational study used routinely collected data. Setting Data were collected from an NHS Trust in South-West England between 2016 and 2019. Participants 2352 hip replacement patients had complete data and were included in analysis. Primary and secondary outcome measures Three measures of length of stay were used: a count measure of number of days spent in hospital, a binary measure of <= 7 days/>7 days in hospital and a binary measure of remaining in hospital when medically fit for discharge. Results The mean length of stay was 5.4 days following surgery, with 18% in hospital for more than 7 days, and 11% staying in hospital when medically fit for discharge. Longer hospital stay was associated with older age (OR=1.06, 95% CI 1.05 to 1.08), being female (OR=1.42, 95% CI 1.12 to 1.81) and more comorbidities (OR=3.52, 95% CI 1.45 to 8.55) and shorter length of stay with not having had a recent hospital admission (OR=0.44, 95% CI 0.32 to 0.60). Results were similar for remaining in hospital when medically fit for discharge, with the addition of an association with highest socioeconomic deprivation (OR=2.08, 95% CI 1.37 to 3.16). Conclusions Older, female patients with more comorbidities and from more socioeconomically deprived areas are likely to remain in hospital for longer following surgery. This study produced regression models demonstrating consistent results across three measures of prolonged hospital stay following hip replacement surgery. These findings could be used to inform surgery planning and when supporting patient discharge following surgery.