BackgroundElective older adult inpatient admissions are increasingly common. Older adults are at an elevated risk of adverse events in hospital, potentially increasing with lengthier hospital stay. Hospital-led organisational strategies may optimise hospital stay for elective older adult inpatients.ObjectivesTo evaluate the effectiveness and cost-effectiveness of hospital-led multicomponent interventions to reduce hospital stay for older adults undergoing elective hospital admissions.Data sourcesSeven bibliographic databases (MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Health Management Information Consortium, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature and Allied and Complementary Medicine Database) were searched from inception to date of search (August 2017), alongside carrying out of web searches, citation searching, inspecting relevant reviews, consulting stakeholders and contacting authors. This search was duplicated, with an additional cost-filter, to identify cost-effectiveness evidence.Review methodsComparative studies were sought that evaluated the effectiveness or cost-effectiveness of relevant interventions in elective inpatients with a mean or median age of ≥ 60 years. Study selection, data extraction and quality assessment were completed independently by two reviewers. The main outcome was length of stay, but all outcomes were considered. Studies were sorted by procedure, intervention and outcome categories. Where possible, standardised mean differences or odds ratios were calculated. Meta-analysis was performed when multiple randomised controlled trials had the same intervention, treatment procedure, comparator and outcome. Findings were explored using narrative synthesis.FindingsA total of 218 articles were included, with 80 articles from 73 effectiveness studies (n = 26,365 patients) prioritised for synthesis, including 34 randomised controlled trials conducted outside the UK and 39 studies from the UK, of which 12 were randomised controlled trials. Fifteen studies included cost-effectiveness data. The evidence was dominated by enhanced recovery protocols and prehabilitation, implemented to improve recovery from either colorectal surgery or lower limb arthroplasty. Six other surgical categories and four other intervention types were identified. Meta-analysis found that enhanced recovery protocols were associated with 1.5 days’ reduction in hospital stay among patients undergoing colorectal surgery (Cohen’sd = –0.51, 95% confidence interval –0.78 to –0.24;p < 0.001) and with 5 days’ reduction among those undergoing upper abdominal surgery (Cohen’sd = –1.04, 95% confidence interval –1.55 to –0.53;p < 0.001). Evidence from the UK was not pooled (owing to mixed study designs), but it echoed findings from the international literature. Length of stay usually was reduced with intervention or was no different. Other clinical outcomes also improved or were no worse with intervention. Patient-reported outcomes were not frequently reported. Cost and cost-effectiveness evidence came from 15 highly heterogeneous studies and was less conclusive.LimitationsStudies were usually of moderate or weak quality. Some intervention or treatment types were under-reported or absent. The reporting of variance data often precluded secondary analysis.ConclusionsEnhanced recovery and prehabilitation interventions were associated with reduced hospital stay without detriment to other clinical outcomes, particularly for patients undergoing colorectal surgery, lower limb arthroplasty or upper abdominal surgery. The impacts on patient-reported outcomes, health-care costs or additional service use are not well known.Future workFurther studies evaluating of the effectiveness of new enhanced recovery pathways are not required in colorectal surgery or lower limb arthroplasty. However, the applicability of these pathways to other procedures is uncertain. Future studies should evaluate the implementation of interventions to reduce service variation, in-hospital patient-reported outcomes, impacts on health and social care service use, and longer-term patient-reported outcomes.Study registrationThis study is registered as PROSPERO CRD42017080637.FundingThe National Institute for Health Research Health Services and Delivery Research programme.