Impact of discontinuing government-funded routine eye exams on new glaucoma diagnoses in Ontario

Ontario Ministry of Health and Long-Term Care. Changes to OHIP Coverage for Eye Care Services. Available at www.familyoptometryptbo.ca/librairie/documents/ChangestoOHIPCoverageforEyeCareServices_000.pdf. Accessed Feb. 9, 2021. Focus on Geography Series, 2011 Census. Province of Ontario. Available at www12.statcan.gc.ca/census-recensement/2011/as-sa/fogs-spg/Facts-pr-eng.cfm?Lang=eng&GC=35. Accessed Feb. 9, 2021. Ontario Association of Optometrists. Suggested Schedule of Professional Fees. Effective Jun. 1, 2012. Ngo, 2018, Significant disparities in eyeglass insurance coverage in Canada, Can J Ophthalmol, 53, 260, 10.1016/j.jcjo.2017.10.007 Nichani, 2021, The frequency and source of prescription eyewear insurance coverage in Ontario: a repeated population-based cross-sectional study using survey data, CMAJ Open, 9, E224, 10.9778/cmajo.20200104 Manulife Financial. Insurance for Professionals: Valuable Protection Designed for Members of Participating Associations. Totonto, 2021. Available at www1.manulife.com/can/affinity/affinity.nsf/LookupFiles/DownloadableFilepp.ehc.bro/$File/pp_ehc_bro.pdf. Accessed Feb. 9, 2021. 2021, 2021 Hong, 2014, Does government assistance improve utilization of eye care services by low-income individuals?, Can J Ophthalmol, 49, 320, 10.1016/j.jcjo.2014.03.006 Jin, 2012, De-insurance in Ontario has reduced use of eye care services by the socially disadvantaged, Can J Ophthalmol, 47, 203, 10.1016/j.jcjo.2012.03.017 Jeon, 2020, Delisted routine eye examinations for nonrefractive eye conditions: a comparative analysis, CMAJ Open, 8, e479, 10.9778/cmajo.20190125 Quigley, 2003, How are glaucoma patients identified?, J Glaucoma, 12, 451, 10.1097/00061198-200312000-00001 Buys, 2012, Referral source, symptoms, and severity at diagnosis of ocular hypertension or open-angle glaucoma in various practices, Can J Ophthalmol, 47, 217, 10.1016/j.jcjo.2012.03.031 Harrison, 1988, Referral patterns to an ophthalmic outpatient clinic by general practitioners and ophthalmic opticians and the role of these professionals in screening for ocular disease, BMJ, 297, 1162, 10.1136/bmj.297.6657.1162 Williams, 1996, A summary of studies on the quality of health care administrative databases in Canada, 339 Goel V, Williams JI, Anderson GM, Blackstien-Hirsch P, Fooks C, Naylor CD.Patterns of Health Care in Ontario, 2nd ed. Available at www.ices.on.ca/Publications/Atlases-and-Reports/1996/Patterns-of-health-care-2nd-ed. Accessed Feb. 9, 2021. Madore O.The Canada Health Act: Overview and Options. Available at:www.publications.gc.ca/Collection-R/LoPBdP/CIR/944-e.htm. Accessed Jan. 21, 2021. Ontario Ministry of Health and Long-Term Care. What OHIP Covers. Available at www.ontario.ca/page/what-ohip-covers#section-5. Accessed Feb. 9, 2021. Wagner, 2002, Segmented regression analysis of interrupted time series studies in medication use research, J Clin Pharm Ther, 27, 299, 10.1046/j.1365-2710.2002.00430.x Penfold, 2013, Use of interrupted time series analysis in evaluating health care quality improvements, Acad Pediatr, 13, S38, 10.1016/j.acap.2013.08.002 Bernal, 2017, Interrupted time series regression for the evaluation of public health interventions: a tutorial, Int J Epidemiol, 46, 348 Statistics Canada. Postal Codes Conversion File (PCCF). Reference Guide: October 2010 Postal Codes. Ottawa, 2011. Available at www.statcan.gc.ca/pub/92-153-g/92-153-g2011001-eng.pdf. Accessed Mar. 12, 2021. Statistics Canada. Rural and Small Town Canada. Ottawa, 2021. Available at www150.statcan.gc.ca/n1/pub/21-006-x/21-006-x2001003-eng.pdf. Accessed Feb. 9, 2021. Quigley, 2006, The number of people with glaucoma worldwide in 2010 and 2020, Br J Ophthalmol, 90, 262, 10.1136/bjo.2005.081224 Tham, 2014, Global prevalence of glaucoma and projections of glaucoma burden through 2040: a systematic review and meta-analysis, Ophthalmology, 121, 2081, 10.1016/j.ophtha.2014.05.013 Dan, 2015, The impact of multimedia education on uptake of comprehensive eye examinations in rural China: a randomized, controlled trial, Ophthalmic Epidemiol, 22, 283, 10.3109/09286586.2015.1056812 Lian, 2013, Screening for diabetic retinopathy with or without a copayment in a randomized controlled trial: influence of the inverse care law, Ophthalmology, 120, 1247, 10.1016/j.ophtha.2012.11.024 Laidlaw, 1994, The sight test fee: effect on ophthalmology referrals and rate of glaucoma detection, BMJ, 309, 634, 10.1136/bmj.309.6955.634 Kiran, 2013, Unintended consequences of delisting routine eye exams on retinopathy screening for people with diabetes in Ontario, Canada, CMAJ, 185, e167, 10.1503/cmaj.120862 Ross, 2006, Use of health care services by lower-income and higher-income uninsured adults, JAMA, 295, 2027, 10.1001/jama.295.17.2027 Wilchesky, 2004, Validation of diagnostic codes within medical services claims, J Clin Epidemiol, 57, 131, 10.1016/S0895-4356(03)00246-4 Buys, 2012, Comparison of newly diagnosed ocular hypertension and open-angle glaucoma: ocular variables, risk factors, and disease severity, J Ophthalmol, 2012, 10.1155/2012/757106 Buys, 2013, Socioeconomic status as a risk factor for late presentation of glaucoma in Canada, Can J Ophthalmol, 48, 83, 10.1016/j.jcjo.2012.10.003