title: A cross-sectional, population-based study measuring comorbidity among people living with HIV in Ontario.
abstract: BACKGROUND
  As people diagnosed with HIV and receiving combination antiretroviral therapy are now living longer, they are likely to acquire chronic conditions related to normal ageing and the effects of HIV and its treatment. Comordidities for people with HIV have not previously been described from a representative population perspective.
  
  
  METHODS
  We used linked health administrative data from Ontario, Canada. We applied a validated algorithm to identify people with HIV among all residents aged 18 years or older between April 1, 1992 and March 31, 2009. We randomly selected 5 Ontario adults who were not identified with HIV for each person with HIV for comparison. Previously validated case definitions were used to identify persons with mental health disorders and any of the following physical chronic diseases: diabetes, congestive heart failure, acute myocardial infarction, stroke, hypertension, asthma, chronic obstructive lung disease, peripheral vascular disease and end-stage renal failure. We examined multimorbidity prevalence as the presence of at least two physical chronic conditions, or as combined physical-mental health multimorbidity. Direct age-sex standardized rates were calculated for both cohorts for comparison.
  
  
  RESULTS
  34.4% (95% confidence interval (CI) 33.6% to 35.2%) of people with HIV had at least one other physical condition. Prevalence was especially high for mental health conditions (38.6%), hypertension (14.9%) and asthma (12.7%). After accounting for age and sex differences, people with HIV had significantly higher prevalence of all chronic conditions except myocardial infarction and hypertension, as well as substantially higher multimorbidity (prevalence ratio 1.30, 95% CI 1.18 to 1.44) and combined physical-mental health multimorbidity (1.79, 95% CI 1.65 to 1.94). Prevalence of multimorbidity among people with HIV increased with age. The difference in prevalence of multimorbidity between the two cohorts was more pronounced among women.
  
  
  CONCLUSIONS
  People living with HIV in Ontario, especially women, had higher prevalence of comorbidity and multimorbidity than the general population. Quantifying this morbidity at the population level can help inform healthcare delivery requirements for this complex population.
authors: C,T, Lamont Primary Health Care Research Centre, Bruyère Research Institute, 43 Bruyère St,, Annex E,, Ottawa, ON K1N 5C8, Canada. ckendall@uottawa.ca.
authors: Claire E
authors: CE
authors: Kendall
authors: Jenna
authors: J
authors: Wong
authors: Monica
authors: M
authors: Taljaard
authors: Richard H
authors: RH
authors: Glazier
authors: William
authors: W
authors: Hogg
authors: Jaime
authors: J
authors: Younger
authors: Douglas G
authors: DG
authors: Manuel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D002908:Chronic Disease / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology; D005260:Female; D015658:HIV Infections; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012737:Sex Factors