Glaucoma: 5% of Patients Account for One Quarter of Costs

Joe Barber Jr, PhD

November 07, 2012

Patients with glaucoma consume the greatest share of resources in the first 6 months after their diagnosis, according to the findings of a longitudinal cohort study.

Remarkably, 5% of patients account for just less than one quarter of glaucoma-related expenditures, Joshua D. Stein, MD, from the University of Michigan in Ann Arbor, and colleagues report in an article published in the September issue of the American Journal of Ophthalmology.

Although glaucoma-related healthcare accounts for more than $1 billion in healthcare costs in the United States annually, the authors note that few studies have examined the pattern of resource use for patients with open-angle glaucoma. "Although there have been many studies examining the cost of caring for people with glaucoma, most have been based on persons with prevalent [open-angle glaucoma], and few have examined changes in cost of care over time," the authors write. "The few longitudinal studies lacked sufficient power to examine long-term trends in resource use, and none confined their study cohort to incident cases, thus limiting their ability to assess the impact of disease progression on the cost of care."

In the study, the authors identified 19,927 patients in the InVision Data Mart data set who were newly diagnosed with incident open-angle glaucoma between 2001 and 2009. The researchers then assessed glaucoma-related charges in blocks of 6 months. Across the entire study population, 37% of all glaucoma-related charges incurred in the first 6 months after diagnosis, after which the proportion of charges remained steady over time.

The authors included patients who were enrolled in commercial, Medicaid, or Medicare Advantage plans for at least 3 years and who had at least 1 diagnosis of open-angle glaucoma. The authors performed univariate and multivariate logistic regression analysis to determine whether sociodemographic factors, ocular conditions, or surgeries affected the likelihood of being in the top 5% for annual glaucoma-related charges in the first 2 years after diagnosis.

In total, glaucoma-related care cost $42,333,499 during the first 2 years after diagnosis for the study cohort. Visits to eye care providers and glaucoma medications accounted for 32% and 31% of the expenditures in the first 2 years, respectively.

The costliest 5% of patients accounted for $10,202,871 (24.1%) of the total expenditures. In multivariate analyses, residence in the Midwest (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.53 - 0.78; P < .0001) or Southeast (OR, 0.78; 95% CI, 0.66 - 0.93; P = .0064), and younger age (OR, 0.91; 95% CI, 0.88 - 0.94; P < .0001) were associated with lower odds of being in the top 5% for annual glaucoma-related charges, whereas diabetic retinopathy (OR, 1.97; 95% CI, 1.65 - 2.34; P < .0001), age-related macular degeneration (OR, 1.38; 95% CI, 1.15 - 1.64; P = .0004), cataract (OR, 1.59; 95% CI, 1.31 - 1.94; P < .0001), and pseudophakia/aphakia (OR, 1.87; 95% CI, 1.59 - 2.20; P < .0001) were associated with greater odds of being in the top 5%.

The limitations of the study included the use of claims data and the loss of patients to follow-up over time.

"In this analysis of a large administrative data set, we found that in people with incident glaucoma, the greatest resource use occurs at the time of diagnosis, and after that, resource use continues at a steady pace over time (up to 5 years in our sample)," the authors conclude. "These findings have importance for future evaluations of the cost-effectiveness of screening and treatment of glaucoma."

Jacob Wilensky, MD, from the University of Illinois Chicago College of Medicine, questioned whether the study provided new information. "Previous studies that have looked at cost in defined populations have shown the front-loaded cost found here," Dr. Wilensky told Medscape Medical News by email. "Since glaucoma is a chronic disease and treatment lasts for years, perhaps a more germane question is whether drug therapy until it fails costs more or less than early laser or surgical therapy in current practice (assuming the long-term clinical results are comparable)."

Dr. Stein and one coauthor receive support from Pfizer. One coauthor serves as a consultant for Allergan, Pfizer, and Genentech and receives support from Alcon Research Institute and Pfizer. One coauthor receives support from Pfizer and Genetic. One coauthor is a consultant for Allergan, Genentech, and Pfizer and receives support from Genzyme. Dr. Wilensky has disclosed no relevant financial relationships.

Am J Ophthalmol. 2012;154:452-459. Abstract