title: Different Multimorbidity Measures Result in Varying Estimated Levels of Physical Quality of Life in Individuals with Multimorbidity: A Cross-Sectional Study in the General Population.
abstract: BACKGROUND
  Multimorbidity adversely affects health-related quality of life. Methodological factors may impact the magnitude of this relationship.
  
  
  OBJECTIVE
  To evaluate how physical health-related quality of life varies in individuals with multimorbidity depending on the length of the list of candidate conditions considered.
  
  
  METHODS
  Secondary analysis from PRECISE, a cohort study of the general adult population of Quebec, Canada. Multimorbidity was measured using the 21-chronic condition list from the Disease Burden Morbidity Assessment, and physical health-related quality of life was measured using the physical component summary (PCS) of SF-12v2. The PCS was calculated, (a) using 2 or more conditions from the 21-condition list (MM2+, 21) and then from a reduced 6-condition list (MM2+, 6) and (b) using three or more conditions from each list (MM3+, 21, and MM3+, 6).
  
  
  RESULTS
  The analysis included 1,710 individuals (mean age 51.3, 40.5% men). Multimorbidity prevalence ranged from 63.8% (MM2+, 21 conditions) to 3.8% (MM3+, 6 conditions). The mean [95% CI] PCS dropped from 45.7 [CI: 45.0-46.3] (MM2+, 21) to 40.2 [CI: 38.7-41.8] (MM2+, 6) and from 44.2 [CI: 43.4-44.9] (MM3+, 21) to 34.8 [CI: 31.9-37.6] (MM3+, 6).
  
  
  CONCLUSIONS
  The length of the list of candidate conditions considered has a great impact on the estimations of physical health-related quality of life.
authors.affiliation: Département de Médecine de Famille et de Médecine d'Urgence, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, Québec, Canada J1H 5H3; Centre Intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-Saint-Jean, 305 Saint-Vallier, Chicoutimi, Canada; Département de Médecine Générale, Université d'Angers, L'Université Nantes Angers Le Mans, 1 rue Haute de Reculée, 49045 Angers Cedex 01, France; Laboratoire d'Ergonomie et d'Épidémiologie en Santé au Travail, Université d'Angers, L'Université Nantes Angers Le Mans, 1 rue Haute de Reculée, 49045 Angers Cedex 01, France.
authors.forename: Aline
authors.identifier: 0000-0003-0952-2844
authors.initials: A
authors.lastname: Ramond-Roquin
authors.affiliation: Faculty of Medicine, McGill University, Montreal, Canada.
authors.forename: Jeannie
authors.initials: J
authors.lastname: Haggerty
authors.affiliation: Centre Intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-Saint-Jean, 305 Saint-Vallier, Chicoutimi, Canada.
authors.forename: Mireille
authors.identifier: 0000-0002-5851-4958
authors.initials: M
authors.lastname: Lambert
authors.affiliation: Centre Intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-Saint-Jean, 305 Saint-Vallier, Chicoutimi, Canada.
authors.forename: Jose
authors.identifier: 0000-0001-6888-8219
authors.initials: J
authors.lastname: Almirall
authors.affiliation: Département de Médecine de Famille et de Médecine d'Urgence, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, Québec, Canada J1H 5H3; Centre Intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-Saint-Jean, 305 Saint-Vallier, Chicoutimi, Canada.
authors.forename: Martin
authors.identifier: 0000-0002-9874-3771
authors.initials: M
authors.lastname: Fortin
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D011788:Quality of Life; D011792:Quebec / Q000453:epidemiology