title: Cost-effectiveness of screening for anal cancer using regular digital ano-rectal examinations in men who have sex with men living with HIV.
abstract: BACKGROUND
  Anal cancer in men who have sex with men (MSM) living with HIV is an important issue but there are no consistent guidelines for how to screen for this cancer. In settings where screening with anal cytology is unavailable, regular anal examinations have been proposed in some guidelines but their cost-effectiveness is unknown.
  
  
  METHODS
  Our objective was to estimate the cost-effectiveness of regular anal examinations to screen for anal cancer in HIV-positive MSM living in Australia using a probabilistic Markov model. Data sources were based on the medical literature and a clinical trial of HIV-positive MSM receiving an annual anal examination in Australia. The main outcome measures for calculating effectiveness were undiscounted and discounted (at 3%) lifetime costs, life years gained, quality-adjusted life years (QALY) gained and incremental cost-effectiveness ratio (ICER).
  
  
  RESULTS
  Base-case analysis estimated the average cost of screening for and management of anal cancer ranged from $195 for no screening to $1,915 for lifetime annual screening of men aged ≥ 50. Screening of men aged ≥ 50 generated ICERs of $29,760 per QALY gained (for screening every four years), $32,222 (every three years) and $45,484 (every two years). Uncertainty for ICERs was mostly influenced by the cost (financially and decrease in quality of life) from a false-positive result, progression rate of anal cancer, specificity of the anal examination, the probability of detection outside a screening program and the discount rate.
  
  
  CONCLUSIONS
  Screening for anal cancer by incorporating regular anal examinations into routine HIV care for MSM aged ≥ 50 is most likely to be cost-effective by conventional standards. Given that anal pap smears are not widely available yet in many clinical settings, regular anal exams for MSM living with HIV to detect anal cancer earlier should be implemented.
authors.affiliation: Sexual Health Unit, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia.|Melbourne Sexual Health Centre, Alfred Health, Carlton, Australia; j.ong@unimelb.edu.au.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Ong
authors.affiliation: Melbourne Sexual Health Centre, Alfred Health, Carlton, Australia.|Department of Sexual Health, Central Clinical School, Monash University, Clayton, Australia.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Fairley
authors.affiliation: Chris O'Brien Lifehouse, Camperdown, Australia.
authors.forename: Susan
authors.initials: S
authors.lastname: Carroll
authors.affiliation: Melbourne Sexual Health Centre, Alfred Health, Carlton, Australia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Walker
authors.affiliation: Melbourne Sexual Health Centre, Alfred Health, Carlton, Australia.|Department of Sexual Health, Central Clinical School, Monash University, Clayton, Australia.
authors.forename: Marcus
authors.initials: M
authors.lastname: Chen
authors.affiliation: Melbourne Sexual Health Centre, Alfred Health, Carlton, Australia.|Department of Sexual Health, Central Clinical School, Monash University, Clayton, Australia.
authors.forename: Tim
authors.initials: T
authors.lastname: Read
authors.affiliation: Department of Medicine, Kirby Institute, University of New South Wales, Darlinghurst, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Grulich
authors.affiliation: Melbourne Sexual Health Centre, Alfred Health, Carlton, Australia.|Department of Sexual Health, Central Clinical School, Monash University, Clayton, Australia.
authors.forename: Catriona
authors.initials: C
authors.lastname: Bradshaw
authors.affiliation: Department of Medicine, Kirby Institute, University of New South Wales, Darlinghurst, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Kaldor
authors.affiliation: Sexual Health Unit, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia.
authors.forename: Philip
authors.initials: P
authors.lastname: Clarke
mesh_terms: D000328:Adult; D000368:Aged; D001005:Anus Neoplasms / Q000175:diagnosis*; D003362:Cost-Benefit Analysis; D051517:Digital Rectal Examination; D015658:HIV Infections / Q000150:complications*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008875:Middle Aged; D019057:Quality-Adjusted Life Years
keywords: HIV; anal cancer; cost-effectiveness; men who have sex with men; screening