title: A theoretical model for comparing UK costs of contact lens replacement modalities.
abstract: OBJECTIVE
  To develop a theoretical 'cost-per-wear' model of contact lens wear, as tool for UK practitioners to assist patients in determining the most cost-effective lens replacement and wearing frequency protocols.
  
  
  METHODS
  The annual cost of professional fees, contact lenses and solutions when wearing daily, two weekly and monthly replacement contact lenses was determined for spherical, toric and multifocal prescription types. This annual cost was divided by the number times lenses are worn per year, resulting in a cost-per-wear.
  
  
  RESULTS
  The cost-per-wear for two weekly and monthly replacement contact lenses is similar, both decreasing with increasing frequency of wear. The cost-per-wear of daily replacement lenses is lower than for reusable lenses when worn 1-2 days per week (DPW), but higher when worn 4-7 DPW. The 'cross-over point' for spherical lenses at which the cost-per-wear is virtually the same for the three replacement frequencies, approximately £2.06, occurs at 3 DPW. The cross-over point for toric lenses is at 4 DPW with daily compared to two weekly replacement lenses (£2.06) and between 2-3 DPW with daily compared to monthly replacement contact lenses (£2.39). The crossover point for multifocal lenses of all replacement frequencies is between 4 and 5 DPW (£1.79).
  
  
  CONCLUSIONS
  In general, daily replacement contact lenses are more cost-effective when worn on a part-time basis (1-3 DPW) and reusable lenses are more cost-effective when worn full-time (4-7 DPW). This cost-per-wear model will assist practitioners in making an informed decision when offering advice to patients relating to the most suitable replacement modality.
authors: EyeQ, Shop 3a, 2431 Gold Coast Highway, Mermaid Beach, Queensland 4218, Australia.
authors: Suzanne E
authors: SE
authors: Efron
authors: Nathan
authors: N
authors: Efron
authors: Philip B
authors: PB
authors: Morgan
authors: Sarah L
authors: SL
authors: Morgan
mesh_terms: D003263:Contact Lenses, Hydrophilic / Q000191:economics*; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006801:Humans; D017059:Models, Econometric; D006113:United Kingdom / Q000453:epidemiology; D014786:Vision Disorders / Q000191:economics* / Q000453:epidemiology / Q000534:rehabilitation*