Healthcare charges in patients who transition from ocular hypertension to primary open-angle glaucoma based on ophthalmic coding data

Abstract

The purpose of this research was to assess the impact of transition from ocular hypertension (OHT) to primary open-angle glaucoma (POAG) on healthcare charges. A case-control group was identified using PharMetrics claims database (1998-2005). Cases (n=1055) had a transition from OHT to POAG based on International Classification of Disease, Ninth Edition coding (ICD-9=365.11). Controls (n=2110) retained an ICD-9 code for OHT (ICD-9=365.04) and were matched to cases (2:1) on gender, age, diagnosis year, and follow-up time post-diagnosis. The index date marked the transition for cases and a date of similar duration after OHT diagnosis for controls. Conditional logistic regression and multiple linear regression models determined the impact of transitioning on healthcare charges. Cases had significantly higher increases in ophthalmology-related charges ($797 vs. -$385, P<0.0001) but similar total healthcare charges ($1689 vs. $1386, P=0.8277) from the year pre- to year post-index date when compared with controls. After adjusting for key covariates, cases were 1.56 times (95% CI: 1.33-1.82) more likely to have increased total charges and 5.26 times (95% CI: 4.27-6.47) more likely to have increased ophthalmology-related charges compared with controls. In multiple linear regression analyses, cases experienced $48 (55%) higher increases in ophthalmology-related charges from the year pre- to year post-index date compared with controls ($85 vs. $37, respectively; P<0.0001). Patients with a transition from OHT to POAG based on ICD-9 coding had higher ophthalmology-related charges the year after transition compared with patients who retained a code for OHT. Prevention of this transition could result in healthcare resource savings.