title: Obesity, lifestyle risk-factors, and health service outcomes among healthy middle-aged adults in Canada.
abstract: BACKGROUND
  The extent to which uncomplicated obesity among an otherwise healthy middle-aged population is associated with higher longitudinal health-care expenditures remains unclear.
  
  
  METHODS
  To examine the incremental long-term health service expenditures and outcomes associated with uncomplicated obesity, 9398 participants of the 1994-1996 National Population Health Survey were linked to administrative data and followed longitudinally forward for 11.5 years to track health service utilization costs and death. Patients with pre-existing heart disease, those who were 65 years of age and older, and those with self-reported body mass indexes of <18.5 kg/m² at inception were excluded. Propensity-matching was used to compare obesity (+/- other baseline risk-factors and lifestyle behaviours) with normal-weight healthy controls. Cost-analyses were conducted from the perspective of Ontario's publicly-funded health care system.
  
  
  RESULTS
  Obesity as an isolated risk-factor was not associated with significantly higher health-care costs as compared with normal weight matched controls (Canadian $8,294.67 vs. Canadian $7,323.59, P = 0.27). However, obesity in combination with other lifestyle factors was associated with significantly higher cumulative expenditures as compared with normal-weight healthy matched controls (CAD$14,186.81 for those with obesity + 3 additional risk-factors vs. CAD$7,029.87 for those with normal BMI and no other risk-factors, P < 0.001). The likelihood that obese individuals developed future diabetes and hypertension also rose markedly when other lifestyle factors, such as smoking, physical inactivity and/or psychosocial distress were present at baseline.
  
  
  CONCLUSIONS
  The incremental health-care costs associated with obesity was modest in isolation, but increased significantly when combined with other lifestyle risk-factors. Such findings have relevance to the selection, prioritization, and cost-effective targeting of therapeutic lifestyle interventions.
authors.affiliation: Institute for Clinical Evaluative Sciences, 2075 Bayview Avenue, Toronto, ON, Canada. david.alter@ices.on.ca
authors.forename: David A
authors.initials: DA
authors.lastname: Alter
authors.forename: Harindra C
authors.initials: HC
authors.lastname: Wijeysundera
authors.forename: Barry
authors.initials: B
authors.lastname: Franklin
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
authors.forename: Alice
authors.initials: A
authors.lastname: Chong
authors.forename: Paul I
authors.initials: PI
authors.lastname: Oh
authors.forename: Jack V
authors.initials: JV
authors.lastname: Tu
authors.forename: Therese A
authors.initials: TA
authors.lastname: Stukel
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002170:Canada / Q000453:epidemiology; D002908:Chronic Disease / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data / Q000639:trends; D005102:Health Expenditures; D007722:Health Knowledge, Attitudes, Practice; D006293:Health Promotion / Q000379:methods*; D006296:Health Services / Q000191:economics / Q000706:statistics & numerical data*; D006801:Humans; D008019:Life Style; D008134:Long-Term Care / Q000191:economics; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000517:prevention & control* / Q000523:psychology; D017063:Outcome Assessment, Health Care / Q000191:economics; D012307:Risk Factors; D057185:Sedentary Behavior; D012907:Smoking / Q000453:epidemiology; D012959:Socioeconomic Factors; D013315:Stress, Psychological