Is the existing evidence about costs for outcomes associated with chlamydia sufficiently robust for economic evaluation of the National Chlamydia Screening Programme in England?

Abstract

BackgroundEconomic evaluations of chlamydia screening programmes do not consistently show that widespread chlamydia screening is cost-effective, which shows uncertainty in some of the assumptions incorporated into the models used. We explored differences in cost estimates used in published cost-effectiveness analyses. MethodsStudies were identified from a systematic review of cost-effectiveness analyses of chlamydia screening commissioned by the European Centre for Disease Prevention and Control (2014). We included studies from developed countries that took a national health service or statutory health insurance system perspective for comparison with the English setting (n=14; England, Scotland, the Netherlands, Sweden, Ireland, Denmark, Canada, and Australia). Management costs for seven major sequelae of chlamydia infection (pelvic inflammatory disease, ectopic pregnancy, tubal factor infertility, chronic pelvic pain, epididymitis, neonatal conjunctivitis, and neonatal pneumonia) were extracted from each paper. We adjusted costs to 2013–14 pounds sterling using the Hospital & Community Health Services index and historical Bank of England foreign currency exchange rates. We assessed the effect of considering different sequelae, management costs, or both on the estimated cost-effectiveness of chlamydia screening by applying unit costs of sequelae included in each paper to one set of literature-derived progression probabilities to estimate an overall cost of sequelae per chlamydia infection. FindingsOnly half of the studies included all seven major chlamydia sequelae. Papers commonly referred to one previously published source that mostly included older estimates (>10 years old). Sequelae management costs per case ranged from £171 to £3635 (pelvic inflammatory disease), £953 to £3615 (ectopic pregnancy), £546 to £6752 (tubal factor infertility), £159 to £3341 (chronic pelvic pain), £22 to £1008 (epididymitis), £11 to £1459 (neonatal conjunctivitis), and £433 to £3992 (neonatal pneumonia). Total cost of sequelae per case of chlamydia using a standard set of progression probabilities ranged from £37 to £412. InterpretationThe large disparities in estimated unit costs of chlamydia sequelae considered in existing cost-effectiveness analyses can be attributed to different assumptions about disease management pathways and costs from different country perspectives. Therefore, updated cost-estimates for chlamydia sequelae specific to the English setting are needed to inform future economic evaluations of chlamydia control programmes in England. FundingNone.