Direct cost and predictive factors for treatment in patients with ocular hypertension or early, moderate and advanced primary open-angle glaucoma: the CoGIS study in Germany.

BACKGROUND: The main objectives of this analysis were to assess the treatment costs and to identify major cost drivers and factors predicting direct costs in German patients with ocular hypertension (OHT) or primary open-angle glaucoma (POAG).
METHODS: This non-interventional cross-sectional study was conducted in two university hospitals and 13 ophthalmology practices in Germany regions (Bavaria, Rhineland-Palatinate, North Rhine-Westphalia, Hamburg and Mecklenburg-Western Pomerania) between May 2009 and January 2010 to assess resource utilisation in patients with OHT (ICD-10: 40.0) or POAG (ICD-10: 40.1) at early, moderate or advanced stages, according to the European Glaucoma Society classification Guidelines. Treatment patterns and direct costs were evaluated retrospectively for 5 years. Resource utilisation data (medication, hospitalisation, outpatient surgery, visits to ophthalmologists) were abstracted from the charts, and unit costs were applied to estimate direct costs per year (in Euros, 2009), calculated from the perspective of the statutory health insurance in Germany (Gesetzliche Krankenversicherung). Factors predicting costs were assessed in multivariate regression analysis.
RESULTS: One hundred and fifty-four patients (17.5% OHT, 27.9% early, 22.7% moderate, and 31.8% advanced POAG), on average 67 years old (SD 11) were included in the study. Average total annual direct costs per patient for OHT were <euro>226 (SD 117), for early POAG <euro>423 (SD 647), moderate <euro>493 (SD 385) and advanced POAG <euro>809 (SD 877). Glaucoma-related medications and hospitalisation represented the two major components of direct costs, increasing with the progression of glaucoma. In addition to treatment switches (p = 0.0001), factors predictive of an increase in total direct costs included the number of hospital interventions (p < 0.0001), disease-state changes since the start of treatment (p = 0.05), and current disease state (p = 0.05).
CONCLUSIONS: Direct costs of treatment are higher in glaucoma compared to OHT and further increase in more severe glaucoma states. Additional treatment changes are major contributing factors to the increased treatment costs of glaucoma. If intraocular pressure can be controlled over the long term, progression to moderate and advanced states avoided, and patients remain on initial treatments, treatment costs could decline due to reduced and less expensive healthcare resource utilisation.