Purpose
Laser trabeculoplasty (LT) is an alternative to topical medications for the treatment of open-angle glaucoma (OAG). However, patient characteristics and healthcare costs associated with receiving LT have not been well studied. The purpose of this analysis was: (1) identify predictors of LT treatment vs. continuation of glaucoma medications (Rx); and (2) estimate the resource utilization and costs associated with the use of LT vs. Rx.
Methods
This study used medical and pharmacy data between 2007-2012 from an insurance claims dataset that included over 150 million individuals. Patient inclusion required at least two OAG ICD-9-CM codes one week apart and an LT claim (LT cohort index date) or second medication class claim (Rx cohort index date) after prior treatment with prostaglandin analog monotherapy. Patients were followed for 12 months pre and 24 months post index date. Attributes used to predict use of LT therapy included age, sex, employment status, Rx adherence, number of comorbidities, and geographic region. Costs included glaucoma specific Rx and CPT codes. Medical encounters and Rx claims were evaluated pre and post treatment. Comparisons between the groups were analyzed using Chi-square and Student’s t-tests (descriptive); logistic regression (predictive); and generalized linear models (cost).
Results
The study included 4,743 LT and 16,484 Rx patients. Baseline demographics age, sex and employment status were similar among cohorts. Significant differences were observed with respect to co-morbidities, glaucoma Rx adherence, and geographic region. Younger age (odds ratio (OR): 1.21; p<0.001), low Rx adherence (OR: 1.18; p=0.001), high co-morbid disease burden (OR: 1.12; p=0.006), and geographic region (OR: 1.50; p<0.001) significantly predicted use of LT. Of patients treated with LT, 60% did not have an Rx claim within 45 days after treatment; however by two years this proportion reduced to 22%. LT was associated with significantly higher medical ($2,684 vs. $1,980; p<0.001), lower pharmacy ($807 vs. $1,467; p<0.001), and higher overall costs ($3,441 vs. $3,408 p=0.002).
Conclusions
Poor Rx adherence, age, and number of comorbidities were predictors of receiving LT among OAG patients. Despite the potential for LT to address poor adherence, most patients had a claim for an Rx within two years after LT. Overall healthcare costs were greater among persons receiving LT compared to Rx therapy.