Longer term post-hospital morbidity and mortality following admission with COVID-19: a systematic review and meta-analysis

Background: The acute mortality and morbidity associated with COVID-19 are well recognised, but the longer-term consequences for patients who survive hospitalisation are less clear. This systematic review aims to establish the longer-term (90 days or beyond) readmission and all-cause mortality outcomes of adult patients discharged after an index hospital admission with COVID-19. Methods: The systematic review was registered with PROSPERO (CRD42021253290) and reported according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Five databases were searched on 7 May 2024 for studies in English: Medline, Embase, Scopus, Web of Science and Global Health. Two reviewers independently screened studies and assessed eligibility. Risk of bias assessments were undertaken using ROBINS-E, funnel plots and Egger's test. The GRADE framework was used to evaluate the evidence quality. Data were pooled using a random-effects model with sensitivity and subgroup analyses. Results: Of 339 studies screened for morbidity, 39 were included (295 892 patients). Meta-analysis showed readmission frequency was 12% (95% CI 9-16%) at 90+ days (range 3-22 months). Of 5831 studies screened for mortality, 56 were included (176 920 patients). The post-hospital all-cause mortality was 5% (95% CI 4-6%) at 90+ days (range 3-36 months). Heterogeneity and risk of bias were generally high, with possible publication bias, resulting in GRADE evidence quality being very low. Conclusions: Patients who survive an index hospital admission with COVID-19 remain at longer-term risk of hospital readmission and/or death following discharge, which has implications for healthcare resource allocation and planning, and the search for interventions to reduce chronic complications.