Earlier studies have reported wide regional variability in glaucoma procedure rates, suggesting nonclinical factors influencing procedure rates. This study was designed to investigate the possible influence of fees on procedure rates.Methods
Databases were accessed to obtain yearly provincial population, procedure and ophthalmologist numbers, and physician fees for trabeculoplasties, trabeculectomies, and glaucoma drainage device (GDD) implantations from 1992 to 2007. Regression models using generalized estimating equation methods were used to evaluate the influence of fees on procedure rates after adjusting for temporal trends and the number of ophthalmologists per 1000 persons with glaucoma.Results
Trends in glaucoma procedure rates and fees varied widely among provinces: decrease of 98% to an increase of 380% for trabeculoplasties, decrease of 72% to an increase of 42% for trabeculectomies, and decrease of 32% to an increase of 1292% for GDD. In 2007, provincial remuneration varied from $125 to $553 for trabeculoplasties, $370 to $748 for trabeculectomies, and $426 to $956 for GDD. The regression models found for every 1000 persons with glaucoma, a $100 increase in fee was associated with 0.68 more trabeculoplasties (P=0.94), 1.2 fewer trabeculectomies (P=0.17), and 0.18 more GDD implantations (P=0.18); and for every additional ophthalmologist per 1000 persons with glaucoma, 53.8 more trabeculoplasties (P=0.24), 0.34 more trabeculectomies (P=0.86), and 0.79 more GDD implantations (P=0.0004). A regression model examining procedure substitution effect did not find any association between relative remuneration and procedure rate.Conclusion
Our analysis did not show an influence of physician remuneration fee on procedure rates in Canada during the study period.