Patient emergency health-care use before hospital admission for COVID-19 and long-term outcomes in Scotland: a national cohort study

• Published in: The Lancet. Digital health 2023-07, Vol.5 (7), p.e446-e457
• Main Authors: Docherty, Annemarie B, Farrell, James, Thorpe, Mathew, Egan, Conor, Dunn, Sarah, Norman, Lisa, Shaw, Catherine A, Law, Andrew, Leeming, Gary, Norris, Lucy, Brooks, Andrew, Prodan, Bianca, MacLeod, Ruairidh, Baxter, Robert, Morris, Carole, Rennie, Diane, Oosthuyzen, Wilna, Semple, Malcolm G, Baillie, J Kenneth, Pius, Riinu, Seth, Sohan, Harrison, Ewen M, Lone, Nazir I
• Format: Article
• Language: English
• Subjects: Adult; Cohort Studies; COVID-19 - epidemiology; COVID-19 - therapy; COVID-19 Vaccines; Hospitals; Humans; Retrospective Studies
• ISSN: 2589-7500; 2589-7500
• DOI: 10.1016/S2589-7500(23)00051-1

It is unclear what effect the pattern of health-care use before admission to hospital with COVID-19 (index admission) has on the long-term outcomes for patients. We sought to describe mortality and emergency readmission to hospital after discharge following the index admission (index discharge), and to assess associations between these outcomes and patterns of health-care use before such admissions. We did a national, retrospective, complete cohort study by extracting data from several national databases and linking the databases for all adult patients admitted to hospital in Scotland with COVID-19. We used latent class trajectory modelling to identify distinct clusters of patients on the basis of their emergency admissions to hospital in the 2 years before the index admission. The primary outcomes were mortality and emergency readmission up to 1 year after index admission. We used multivariable regression models to explore associations between these outcomes and patient demographics, vaccination status, level of care received in hospital, and previous emergency hospital use. Between March 1, 2020, and Oct 25, 2021, 33 580 patients were admitted to hospital with COVID-19 in Scotland. Overall, the Kaplan-Meier estimate of mortality within 1 year of index admission was 29·6% (95% CI 29·1–30·2). The cumulative incidence of emergency hospital readmission within 30 days of index discharge was 14·4% (95% CI 14·0–14·8), with the number increasing to 35·6% (34·9–36·3) patients at 1 year. Among the 33 580 patients, we identified four distinct patterns of previous emergency hospital use: no admissions (n=18 772 [55·9%]); minimal admissions (n=12 057 [35·9%]); recently high admissions (n=1931 [5·8%]), and persistently high admissions (n=820 [2·4%]). Patients with recently or persistently high admissions were older, more multimorbid, and more likely to have hospital-acquired COVID-19 than patients with no or minimal admissions. People in the minimal, recently high, and persistently high admissions groups had an increased risk of mortality and hospital readmission compared with those in the no admissions group. Compared with the no admissions group, mortality was highest in the recently high admissions group (post-hospital mortality HR 2·70 [95% CI 2·35–2·81]; p