biostudies-literatureHanlon PVersus ArthritisMedical Research CouncilWellcome Truste1003931https://www.ebi.ac.uk/biostudies/studies/S-EPMC8901063biostudies-literatureUnknown19(3)<h4>Background</h4>Cohorts such as UK Biobank are increasingly used to study multimorbidity; however, there are concerns that lack of representativeness may lead to biased results. This study aims to compare associations between multimorbidity and adverse health outcomes in UK Biobank and a nationally representative sample.<h4>Methods and findings</h4>These are observational analyses of cohorts identified from linked routine healthcare data from UK Biobank participants (n = 211,597 from England, Scotland, and Wales with linked primary care data, age 40 to 70, mean age 56.5 years, 54.6% women, baseline assessment 2006 to 2010) and from the Secure Anonymised Information Linkage (SAIL) databank (n = 852,055 from Wales, age 40 to 70, mean age 54.2, 50.0% women, baseline January 2011). MultimorPLoS medicineAssociations between multimorbidity and adverse health outcomes in UK Biobank and the SAIL Databank: A comparison of longitudinal cohort studies.PMC890106321970MR/S021949/1201492/Z/16/ZLewsey JJani BDMair FSNicholl BMcAllister DAHanlon PfalseAssociations between multimorbidity and adverse health outcomes in UK Biobank and the SAIL Databank: A comparison of longitudinal cohort studies.<h4>Background</h4>Cohorts such as UK Biobank are increasingly used to study multimorbidity; however, there are concerns that lack of representativeness may lead to biased results. This study aims to compare associations between multimorbidity and adverse health outcomes in UK Biobank and a nationally representative sample.<h4>Methods and findings</h4>These are observational analyses of cohorts identified from linked routine healthcare data from UK Biobank participants (n = 211,597 from England, Scotland, and Wales with linked primary care data, age 40 to 70, mean age 56.5 years, 54.6% women, baseline assessment 2006 to 2010) and from the Secure Anonymised Information Linkage (SAIL) databank (n = 852,055 from Wales, age 40 to 70, mean age 54.2, 50.0% women, baseline January 2011). Multimor2022-01-01T00:00:00Z2022 Mar2025-04-22T22:00:06.713Z2025-04-06T03:57:49.295ZS-EPMC89010633525509210.1371/journal.pmed.1003931