Association between transitional care in acute care hospitals and ambulatory care sensitive condition-related readmission.

Little is known about how ambulatory care sensitive condition (ACSC)-related readmissions can be reduced in acute care settings. This study examined the association between transitional care for hospitalised older patients with ACSC and ACSC-related readmissions. This retrospective observational cohort study included patients aged 65 years and older admitted with ACSC as the primary diagnosis from 1 April 2022 to 31 January 2023, using linked data from the Diagnosis Procedure Combination and the medical functions of the hospital beds database. The primary outcomes were cumulative readmissions within 1-7, 1-14, 1-21, 1-30 and 1-60 days, analysed using inverse probability treatment weighting regression models. Among 85 582 patients from 711 hospitals, 39 916 (46.6%) were female, with a median age of 82 years (interquartile range: 75-88); 57 127 (66.8%) patients received transitional care. The overall readmission rates were 2.9%, 6.0%, 8.7%, 11.4% and 17.5% among total hospitalisations within 7, 14, 21, 30 and 60 days, respectively. Overall, transitional care was associated with reduced odds of ACSC-related readmission, with odds ratios ranging from 0.72 (95% CI: 0.65-0.78) within 7 days to 0.91 (95% CI: 0.87-0.95) within 60 days. The association between transitional care and readmission varied by ACSC category. In chronic ACSC, the association was strongest for 7-day readmission, followed by a downward trend. In acute and vaccine-preventable ACSC, the association was strongest for 7-day readmission but levelled off after 21 days. Transitional care in acute care hospitals may be associated with a reduced risk of early readmissions due to ACSC when older patients are hospitalised.