Generational differences in practice patterns of ophthalmologists in Ontario: Implications for workforce planning

Abstract Body:

Purpose: To investigate the effect of generational and gender differences on practice patterns of Ontario ophthalmologists over the past two decades.

Study Design: Age-Period-Cohort (APC) analysis

Methods: The Ontario Health Insurance Plan (OHIP) physician billings database for fiscal years 1992 to 2013 was used to calculate number of ophthalmologists, yearly median billings, number of patients and number of patient visits. Age, gender, fiscal year, and year of birth were also extracted. Cohorts were defined based on birth year into 10-year categories (i.e. 1915-1924) and fiscal year was used as an indicator of period. Age groups were defined by 5-year increments (i.e. <35 to 75-79). Yearly median OHIP billing dollars were converted to 2013 dollars. Hierarchical age-period-cohort (APC) models were used to disentangle the unique effects of age, period, and cohort on changes in total payments and the number of visits per ophthalmologist over time.

Results: 388 (11.3% female) ophthalmologists were practicing in Ontario in 1992 and 457 (19.9% female) in 2013. Results from the unadjusted APC model indicated significant age affects (p<0.0001) with the overall age-trajectory of payments peaking in middle age and a decline in older ages. There was also a general trend of increasing yearly OHIP billing dollars in both men and women (p< 0.001). In addition to the age and period effects, cohort effects were significant for both men and women (p< 0.001) with a general trend of higher total payments in each succeeding recent cohort. To note, there were significant interactions between gender and birth cohort (p=0.048) and gender and age (p=0.015) suggesting that the gender gap in payments widens in recent cohorts (e.g. 1975-1984 to 1945-1954). However, after adjusting for the volume of visits and patients in practice, gender differences were largely reduced although remained significant (p < 0.001).

Conclusions: The practice patterns of ophthalmologists differ significantly among various generations. Recent cohorts of ophthalmologists have a greater yearly OHIP dollars billed compared to the older cohorts at the same age group. The widening gender gap of OHIP billing dollars in more recent cohorts was partially explained by differences in the number of visits per patients among female and male ophthalmologists in each cohort. As recent cohorts with an increasing number of females enter the workforce, generational differences in practice patterns of ophthalmologists will likely shift the effective healthcare supply and demand, and thus have important implications for ophthalmology workforce planning.