Cataract surgery and effectiveness 2. An index approach for the measurement of output and efficiency of cataract surgery at different surgery departments

Purpose: To describe a model for comparing the performance of cataract surg ery among ophthalmology departments in terms of economic efficiency. Methods: An index approach for the measurement of outcome of cataract surge ry is modeled. The index approach uses information about activities and dif ficulties in daily life as well as visual acuity and age. The change in act ivities and difficulties after surgery is expressed by changes in distances , and an overall index score is calculated as ratios of values to distances . Values to distances are estimated as solutions to linear programming prob lems. Index scores are calculated for two groups of patients, those with an ocular co-morbidity and those without. Economic efficiency is also estimat ed by use of an index approach. In the estimation of efficiency we use the calculated index scores of outcome of surgery as a measure of output of the ophthalmology department. Four different departments providing cataract su rgery are compared. Results: The studied departments showed differences to a great extent when traditional measures of cataract surgery outcomes were used. These differen ces changed when the outcomes were compared by use of index scores. When ec onomic efficiency was calculated the difference between the departments was further reduced and only one department was considered inefficient accordi ng to the model. Conclusion: An index approach was used to study outcomes of cataract surger y and economic efficiency in four departments. This approach takes into acc ount the complexity of cost in relation to feasible outcome. The ranking be tween the departments described by traditional methods turned out different ly using the model.