title: Geographical variations in the benefit of applying a prioritization system for cataract surgery in different regions of Spain.
abstract: BACKGROUND
  In Spain, there are substantial variations in the utilization of health resources among regions. Because the need for surgery differs in patients with appropriate surgical indication, introducing a prioritization system might be beneficial. Our objective was to assess geographical variations in the impact of applying a prioritization system in patients on the waiting list for cataract surgery in different regions of Spain by using a discrete-event simulation model.
  
  
  METHODS
  A discrete-event simulation model to evaluate demand and waiting time for cataract surgery was constructed. The model was reproduced and validated in five regions of Spain and was fed administrative data (population census, surgery rates, waiting list information) and data from research studies (incidence of cataract). The benefit of introducing a prioritization system was contrasted with the usual first-in, first-out (FIFO) discipline. The prioritization system included clinical, functional and social criteria. Priority scores ranged between 0 and 100, with greater values indicating higher priority. The measure of results was the waiting time weighted by the priority score of each patient who had passed through the waiting list. Benefit was calculated as the difference in time weighted by priority score between operating according to waiting time or to priority.
  
  
  RESULTS
  The mean waiting time for patients undergoing surgery according to the FIFO discipline varied from 1.97 months (95% CI 1.85; 2.09) in the Basque Country to 10.02 months (95% CI 9.91; 10.12) in the Canary Islands. When the prioritization system was applied, the mean waiting time was reduced to a minimum of 0.73 months weighted by priority score (95% CI 0.68; 0.78) in the Basque Country and a maximum of 5.63 months (95% CI 5.57; 5.69) in the Canary Islands. The waiting time weighted by priority score saved by the prioritization system varied from 1.12 months (95% CI 1.07; 1.16) in Andalusia to 2.73 months (95% CI 2.67; 2.80) in Aragon.
  
  
  CONCLUSIONS
  The prioritization system reduced the impact of the variations found among the regions studied, thus improving equity. Prioritization allocates the available resources within each region more efficiently and reduces the waiting time of patients with greater need. Prioritization was more beneficial than allocating surgery by waiting time alone.
authors.affiliation: Evaluation and Clinical Epidemiology Department, Institut Municipal d'Assistència Sanitària (IMAS), Passeig Marítim, 25-29, 08003, Barcelona, Spain. rroman@imas.imim.es
authors.forename: Rubén
authors.initials: R
authors.lastname: Román
authors.forename: Mercè
authors.initials: M
authors.lastname: Comas
authors.forename: Javier
authors.initials: J
authors.lastname: Mar
authors.forename: Enrique
authors.initials: E
authors.lastname: Bernal
authors.forename: Alberto
authors.initials: A
authors.lastname: Jiménez-Puente
authors.forename: Santiago
authors.initials: S
authors.lastname: Gutiérrez-Moreno
authors.forename: Xavier
authors.initials: X
authors.lastname: Castells
mesh_terms: D002387:Cataract Extraction / Q000592:standards*; D002391:Catchment Area, Health / Q000706:statistics & numerical data*; D003198:Computer Simulation; D017598:Efficiency, Organizational; D006292:Health Priorities / Q000592:standards*; D006301:Health Services Needs and Demand / Q000706:statistics & numerical data; D006801:Humans; D017146:Models, Organizational; D009313:National Health Programs / Q000458:organization & administration; D009885:Ophthalmology / Q000592:standards; D018579:Patient Selection; D011785:Quality Assurance, Health Care; D013030:Spain; D014850:Waiting Lists