title: Longitudinal and cross sectional assessments of health utility in adults with HIV/AIDS: a systematic review and meta-analysis.
abstract: BACKGROUND
  Utility estimates are important health outcomes for economic evaluation of care and treatment interventions for patients with HIV/AIDS. We conducted a systematic review and meta-analysis of utility measurements to examine the performance of preference-based instruments, estimate health utility of patients with HIV/AIDS by disease stages, and investigate changes in their health utility over the course of antiretroviral treatment.
  
  
  METHODS
  We searched PubMed/Medline, Cochrane Database of Systematic Review, NHS Economic Evaluation Database and Web of Science for English-language peer-reviewed papers published during 2000-2013. We selected 49 studies that used 3 direct and 6 indirect preference based instruments to make a total of 218 utility measurements. Random effect models with robust estimation of standard errors and multivariate fractional polynomial regression were used to obtain the pooled estimates of utility and model their trends.
  
  
  RESULTS
  Reliability of direct-preference measures tended to be lower than other types of measures. Utility elicited by two of the indirect preference measures - SF-6D (0.171) and EQ-5D (0.114), and that of Time-Trade off (TTO) (0.151) was significantly different than utility elicited by Standard Gamble (SG). Compared to asymptomatic HIV patients, symptomatic and AIDS patients reported a decrement of 0.025 (p = 0.40) and 0.176 (p = 0.001) in utility scores, adjusting for method of assessment. In longitudinal studies, the pooled health utility of HIV/AIDS patients significantly decreased in the first 3 months of treatment, and rapidly increased afterwards. Magnitude of change varied depending on the method of assessment and length of antiretroviral treatment.
  
  
  CONCLUSIONS
  The study provides an accumulation of evidence on measurement properties of health utility estimates that can help inform the selection of instruments for future studies. The pooled estimates of health utilities and their trends are useful in economic evaluation and policy modelling of HIV/AIDS treatment strategies.
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. bach@jhu.edu.|Institute for Preventive Medicine and Public Health, Hanoi Medical University, Hanoi, Vietnam. bach@jhu.edu.
authors.forename: Bach Xuan
authors.initials: BX
authors.lastname: Tran
authors.affiliation: School of Medicine and Pharmacy, Vietnam National University, Hanoi, Vietnam. nhlong.smp@vnu.edu.vn.
authors.forename: Long Hoang
authors.initials: LH
authors.lastname: Nguyen
authors.affiliation: School of Public Health, University of Alberta, Edmonton, Alberta, Canada. arto.ohinmaa@ualberta.ca.
authors.forename: Arto
authors.initials: A
authors.lastname: Ohinmaa
authors.affiliation: Institute for Preventive Medicine and Public Health, Hanoi Medical University, Hanoi, Vietnam. maher.rachel9@gmail.com.
authors.forename: Rachel Marie
authors.initials: RM
authors.lastname: Maher
authors.affiliation: Institute for Preventive Medicine and Public Health, Hanoi Medical University, Hanoi, Vietnam. nongminhvuong.hmu@gmail.com.
authors.forename: Vuong Minh
authors.initials: VM
authors.lastname: Nong
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. clatkin@jhsph.edu.
authors.forename: Carl A
authors.initials: CA
authors.lastname: Latkin
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy*; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D003627:Data Interpretation, Statistical; D003695:Delivery of Health Care / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D011788:Quality of Life; D012044:Regression Analysis; D015203:Reproducibility of Results
chemical_list: D044966:Anti-Retroviral Agents