Authors: Yaping Jin, William Jeon, Michael Brent, Rick Glazier, Yvonne Buys, Graham Trope
Author Disclosure Block: Y. Jin: None. W. Jeon: None. M. Brent: Grant/research support; Name of Commercial Company(s); Novartis and Bayer. Membership on an advisory panel, standing committee or board of directors; Name of Commercial Company(s); Novartis, Bayer, and Allergan. R. Glazier: None. Y. Buys: None. G. Trope: None.

Abstract Body: 

Purpose: In 2004, Ontario delisted routine eye exams for residents aged 20-64. We investigated if delisting reduced the incidence of eye disease diagnoses in the Ontario Health Insurance Plan (OHIP) among affected Ontarians post-2004 in relation to pre-2004.

Study Design: A time-series analysis.

Methods: We analyzed yearly Ontario health administrative billing data from 2000 to 2014. Included in analyses were Ontarians without diabetes and/or without a visit to OHIP-insured ophthalmologist/optometrist one year prior to the study year. This was because Ontarians aged 20-64 in these categories were affected by de-listing. Eye disease diagnoses submitted by all OHIP-insured healthcare providers were identified utilizing ICD-9 diagnostic codes. All eye diseases were grouped together in the analyses. Cases of newly billed eye disease diagnoses per 100 person-years were compared post- versus pre-delisting among subgroups of Ontarians affected (aged 20-64) and unaffected (aged 0-19 or 65+) by delisting. Newly occurred diabetes was excluded and then included as a part of eye disease diagnoses as a diabetes diagnosis may or may not relate to an eye disease diagnosis.

Results: When diabetes was excluded as a part of eye disease diagnoses, a significantly reduced incident cases (per 100 person-years) of OHIP-insured eye disease diagnoses was observed immediately following the delisting among affected age groups: from 25.8 in 2003 to 6.2 in 2005 in the 20-39 age group and from 46.0 in 2003 to 10.9 in 2005 in the 40-64 age group. The reduced incidence remained at a similar low level from 2005 to 2014. The average reduction was -20.5% for the 20-39 age group (p<0.0001) and -37.0% for the 40-64 age group (p<0.0001). For those ages unaffected by delisting, the incidence of OHIP-insured eye disease diagnoses was stable throughout the study years: around 25-30 cases per 100 person-years for the 0-19 age group (p=0.30) and about 50 cases per 100 person-years for the 65+ age group (p=0.18). A similar trend was documented when diabetes was included as a part of eye disease diagnoses.

Conclusions: A significantly reduced incidence of OHIP-insured eye disease diagnoses was observed soon after delisting came into effect. This large and persistent reduction in diagnoses of eye disease  raises concerns about undetected eye disease and consequences for visual health that should be further investigated.