Assessing Health Care Burden in Glaucoma Patients with and Without Physical or Mental Comorbidities

Glaucoma is a collection of eye diseases that damage the eye's optic nerve resulting in vision loss and blindness. Treatment for glaucoma is primarily pharmacologic; however, studies have shown patients have difficulty adhering to topical regimens. The reasons for potentially poor adherence are numerous, including influence from a myriad of either physical or mental comorbid conditions faced by many glaucoma patients. Neither adherence nor associated outcomes have been estimated in these 2 groups of glaucoma patients.

To (a) characterize glaucoma patients with and without select physical or mental comorbidities and (b) estimate differences between the 2 groups for 3 types of outcomes: health care resource use (HCRU; office-based/outpatient-based provider visits, emergency room visits, inpatient stays, home health provider days, prescription fills); health care expenditures; and health-related quality of life (HRQoL) as measured by the physical and mental component scores of the Short Form-12.

We used first-year data from each glaucoma patient's 2-year panel survey in the Medical Expenditure Panel Survey (MEPS) database, 2003-2014. Two groups were created using ICD-9-CM codes collected by MEPS to compare glaucoma patients with and without at least 1 selected physical or mental comorbid condition. Between-group comparisons in the outcomes of interest (HCRU, expenditure, HRQoL) were estimated using multivariable regression analyses while adjusting for socio-demographic and clinical characteristics at baseline.

We identified 2,928 unique glaucoma patients during the 11 years of collected data, including 1,539 (53%) who had at least 1 physical or mental comorbid condition of interest. Comparing those with at least 1 select physical or mental comorbidity to those without (n = 1,389), unadjusted HCRU and expenditures were greater in patients with a physical or mental comorbidity (all P < 0.05). After adjustment, significant associations with increased HCRU remained for office-based provider visits and home health provider days (each P < 0.01). Average total expenditures were $12,324 in those with comorbidities and $8,590 for those without. HRQoL (unadjusted and adjusted) was lower in those with a physical or mental comorbid condition (all P < 0.05).

Some differences in HCRU and expenditures were accounted for by differences in baseline characteristics between those with and those without 1 or more physical or mental comorbid conditions, but differences remained after adjustment. Results suggest that glaucoma patients with physical and mental comorbidities may experience greater HCRU and associated expenditures, and lower HRQoL, when compared with glaucoma patients without these comorbidities With this knowledge, future work may include estimating the effect of the number of these comorbid conditions on each of the 3 types of outcomes.

This study received funding support from Allergan. During the time this work was conducted, Serbin was a postdoctoral fellow who was supported by a training grant from Allergan to the University of Washington. Campbell is an employee of Allergan. Serbin, Devine, and Basu each have nothing to disclose. This study was presented as a poster at the International Society for Pharmacoeconomics and Outcomes Research Meeting; May 20-24, 2017; Boston, MA.