Clinical and Economic Burden of Glaucoma by Disease Severity: A United States Claims-Based Analysis

Abstract

Purpose: To provide updated estimates of the clinical and economic burden in patients with ocular hypertension (OHT) or open-angle glaucoma (OAG) by disease severity in the United States and to estimate incremental costs associated with disease progression.

Design: Retrospective cohort study.

Participants: Patients with 1 or more International Classification of Diseases, 10th Revision, Clinical Modification, diagnoses for OAG or OHT who are 40 years of age or older.

Methods: Patients were identified from IQVIA's PharMetrics Plus database during the index period (October 1, 2015, to August 31, 2017). Patients had continuous health plan enrollment for 12 months or more before and after the index date (first OAG or OHT diagnosis during index period) and were stratified by baseline disease severity based on diagnosis code. Annual eye-related outpatient healthcare use and costs were estimated on a per-user basis. A generalized linear model was used to estimate adjusted mean costs by severity and to evaluate the impact of observed disease worsening on costs. A multivariate logistic regression analysis evaluated the relationship between severity and odds of falls or fractures.

Main outcome measures: Total eye-related outpatient costs and odds of falls or fractures.

Results: One hundred seventy-seven thousand three hundred fifty-two OHT and OAG patients were identified (67.8% with OAG). Open-angle glaucoma patients showed higher eye-related outpatient costs than OHT patients (median, $516 [interquartile range (IQR), $323-$898] vs. $344 [IQR, $197-$617], respectively). Patients with severe OAG showed higher eye-related outpatient costs than moderate and mild OAG patients (median, $639 [IQR, $381-$1264] vs. $546 [IQR, $345-$950] vs. $476 [IQR, $304-$765], respectively; P < 0.0001), as well as higher glaucoma-related pharmacy costs (median, $493 [IQR, $122-$1457] vs. $244 [IQR, $84-$1113] vs. $139 [IQR, $66-$818], respectively; P < 0.0001). In adjusted analyses, disease worsening was associated with at least 2-fold higher annual eye-related outpatient costs (P < 0.0001). Severe OAG patients had significantly higher odds of fall or fracture compared with OHT patients (odds ratio, 1.34; 95% confidence interval, 1.13-1.59).

Conclusions: Updated estimates showed highest eye-related costs for those with severe disease and disease progression among patients with OAG and OHT. Severe OAG was associated with increased risk of falls or fractures compared with patients with OHT. Therapies that delay disease progression may provide clinical and economic benefits.

Keywords: Claims; Falls; Fractures; GLM; Healthcare costs; Logistic regression; Ocular hypertension; Open-angle glaucoma; Retrospective study; Severity.