title: Time spent on health-related activities by senior Australians with chronic diseases: what is the role of multimorbidity and comorbidity?
abstract: OBJECTIVE
  To examine the effect of various morbidity clusters of chronic diseases on health-related time use and to explore factors associated with heavy time burden (more than 30 hours/month) of health-related activities.
  
  
  METHODS
  Using a national survey, data were collected from 2,540 senior Australians. Natural clusters were identified using cluster analysis and clinical clusters using clinical expert opinion. We undertook a set of linear regressions to model people's time use, and logistic regressions to model heavy time burden.
  
  
  RESULTS
  Time use increases with the number of chronic diseases. Six of the 12 diseases are significantly associated with higher time use, with the highest effect for diabetes followed by depression; 18% reported a heavy time burden, with diabetes again being the most significant disease. Clusters and dominant comorbid groupings do not contribute to predicting time use or time burden.
  
  
  CONCLUSIONS
  Total number of diseases and specific diseases are useful determinants of time use and heavy time burden. Dominant groupings and disease clusters do not predict time use.
  
  
  CONCLUSIONS
  In considering time demands on patients and the need for care co-ordination, care providers need to be aware of how many and what specific diseases the patient faces.
authors.affiliation: Australian Primary Health Care Research Institute, Australian National University, Australian Capital Territory.
authors.forename: M Mofizul
authors.initials: MM
authors.lastname: Islam
authors.affiliation: Australian Primary Health Care Research Institute, Australian National University, Australian Capital Territory.
authors.forename: Ian S
authors.initials: IS
authors.lastname: McRae
authors.affiliation: Australian Primary Health Care Research Institute, Australian National University, Australian Capital Territory.
authors.forename: Laurann
authors.initials: L
authors.lastname: Yen
authors.affiliation: Australian Primary Health Care Research Institute, Australian National University, Australian Capital Territory.
authors.forename: Tanisha
authors.initials: T
authors.lastname: Jowsey
authors.affiliation: Health Services and Policy Research, University of Exeter Medical School, England, UK.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Valderas
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D001315:Australia / Q000453:epidemiology; D002908:Chronic Disease / Q000453:epidemiology*; D016000:Cluster Analysis; D015897:Comorbidity; D017281:Cost of Illness; D005260:Female; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care / Q000523:psychology / Q000706:statistics & numerical data*; D012044:Regression Analysis; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D013995:Time
keywords: behaviour; chronic illness; comorbidity; disease cluster; health practice; multimorbidity; self-management; time