Healthcare charges in patients with glaucoma who undergo laser trabeculoplasty

Abstract

The objective of this study was to assess the impact of laser trabeculoplasty (LTP) on healthcare charges in patients with primary open-angle glaucoma (POAG). Using a managed care database (PharMetrics; Watertown, MA, USA), we formed a case-control group nested within a POAG cohort (n=72,412) formed using International Classification of Disease, Ninth Edition (ICD-9) coding data. Cases (n=1145) had LTP (Current Procedural Terminology code: 65855) with ≥1 year of continuous enrollment both prior to, and following LTP index date in PharMetrics from 1998-2005. Using the date of LTP as the index date, controls (n=2290) without LTP were matched to cases on gender, age, and index year in a 2:1 ratio. Cases and controls had ≥6 months of continuous enrollment in PharMetrics prior to receiving a diagnosis of POAG (ICD-9 code: 365.11). One-year total and ophthalmology healthcare charges were calculated in the year pre- and post-index date (excluding charges for LTP at the index date). Conditional logistic regression models and multiple linear regression models determined the impact of LTP on healthcare charges, while controlling for glaucoma duration and other key covariates. While the mean age of cases (60.1±13.1 years) and controls (60.3±13.6 years) was similar (P=0.5589), cases had more comorbid systemic conditions (P<0.05) and underwent more cataract surgery in the year after index date (4.4% vs. 2.1%; P=0.002). In the year after index date, ophthalmology-related charges increased by $1364 for cases vs. $30 for controls (P=0.0003). Total healthcare charges increased by $5084 for cases and $1594 for controls in the year after index date (P=0.0085). Cases and controls experienced similar increases in ophthalmology-related pharmacy charges from the year pre- to the year post-index date ($26 vs. $43, P=0.385). In both logistic regression and linear regression models, which adjusted for several covariates, performing LTP was associated with increased total healthcare and ophthalmology-related charges. Among patients with POAG in this study, performing LTP was associated with increased total and ophthalmology-related healthcare charges, while ophthalmology pharmacy charges did not decline.