title: EuroQol (EQ-5D) measure of quality of life predicts mortality, emergency department utilization, and hospital discharge rates in HIV-infected adults under care.
abstract: BACKGROUND
  Health-related quality of life (HR-QOL) is a relevant and quantifiable outcome of care. We implemented HR-QOL assessment at all primary care visits at UCSD Owen Clinic using EQ-5D. The study aim was to estimate the prognostic value of EQ-5D for survival, hospitalization, and emergency department (ED) utilization after controlling for CD4 and HIV plasma viral load (pVL).
  
  
  METHODS
  We conducted a retrospective analysis of HIV clinic based cohort (1996-2000). The EQ-5D includes single item measures of: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each item is coded using 3-levels (1 = no problems; 2 = some problems; 3 = severe problems). The instrument includes a global rating of current health using a visual analog scale (VAS) ranging from 0 (worst imaginable) to 100 (best imaginable). An additional single item measure of health change (better, much the same, worse) was included. A predicted VAS (pVAS) was estimated by regressing the 5 EQ-5D health states on VAS using reference cell coding of health states and random effects linear models. Survival models were fit using Cox modelling. Hospitalization and ED rate models were estimated using population-averaged Poisson models.
  
  
  RESULTS
  965 patients met eligibility criteria. 12% were female; 42% were non-white. Median time-at-risk was 1.2 years. Median CD4 was 233. Median log10(pVL) was 4.6. 47 deaths occurred. In two Cox models controlling for CD4 and pVL, the adjusted hazard ratios (aHR) for VAS and pVAS as time-varying covariates were 0.73 (95% CI: 0.63-0.83) and 0.66 (95% CI: 0.56-0.77) respectively, for every 10 point increase in (p)VAS rating. In Poisson regression models predicting ED visit rates and hospital discharge rates controlling for current CD4 and pVL, each of the EQ-5D health dimensions, VAS, and health change items were significantly (p < 0.05) associated with the outcomes. For ED visit rates, the adjusted incidence rate ratios (aIRR) were 0.86 (0.83-0.89) and 0.79 (0.75-0.82) for VAS and pVAS, respectively. For hospital discharge rates, the aIRR's were 0.85 (0.82-0.88) and 0.79 (0.75-0.82) for VAS and pVAS, respectively.
  
  
  CONCLUSIONS
  EQ-5D is a brief and prognostically useful predictor of mortality, hospitalization, and ED utilization among adults under care for HIV infection, even after adjusting for CD4 and HIV plasma viral load.
authors.affiliation: Department of Medicine, University of California San Diego, San Diego, CA, USA. cmathews@ucsd.edu
authors.forename: William C
authors.initials: WC
authors.lastname: Mathews
authors.forename: Susanne
authors.initials: S
authors.lastname: May
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D010147:Pain Measurement; D010351:Patient Discharge / Q000706:statistics & numerical data; D016012:Poisson Distribution; D011320:Primary Health Care / Q000706:statistics & numerical data*; D011379:Prognosis; D016016:Proportional Hazards Models; D011788:Quality of Life; D012189:Retrospective Studies; D018570:Risk Assessment; D018434:Sickness Impact Profile; D016019:Survival Analysis; D019562:Viral Load