Comparative Cost-effectiveness of the Baerveldt Implant, Trabeculectomy With Mitomycin, and Medical Treatment.

IMPORTANCE: The Tube vs Trabeculectomy Trial (TVT) found that the 350-mm2 Baerveldt implant (tube) and trabeculectomy with mitomycin may be similarly effective in lowering intraocular pressure in primary open-angle glaucoma. However, to date, there are no published long-term clinical data on the cost-effectiveness of trabeculectomy with mitomycin vs tube insertion.

OBJECTIVE: To assess the cost-effectiveness of these procedures compared with maximal medical treatment.

DESIGN, SETTING, AND PARTICIPANTS: We used the Markov cohort model with a 5-year time horizon to study a hypothetical cohort of 100 000 patients who required glaucoma surgery.

MAIN OUTCOMES AND MEASURES: Quality-adjusted life-years (QALYs) gained, costs from the societal perspective, and the incremental cost-effectiveness ratio of medical treatment, trabeculectomy, and tube insertion. Costs were identified from Medicare Current Procedural Terminology and Ambulatory Payment Classification reimbursement codes and Red Book medication costs. The QALYs were based on visual field and visual acuity outcomes. The hypothetical societal limit to resources was included using a willingness-to-pay threshold of $50 000 per QALY. Costs and utilities were discounted at 3% per year. Uncertainty was assessed using deterministic sensitivity analyses.

RESULTS: The mean costs for medical treatment, trabeculectomy, and tube insertion were $6172, $7872 and $10 075, respectively; these amounts resulted in a cost difference of $1700 (95% CI, $1644-$1770) for medical treatment vs trabeculectomy, $3904 (95% CI, $3858-$3953) for medical treatment vs tube insertion, and $2203 (95% CI, $2121-$2261) for trabeculectomy vs tube insertion. The mean 5-year probability of blindness was 4% for both surgical procedures and 15% for medical treatment. The utility gained after medical treatment, trabeculectomy, and tube insertion was 3.10, 3.30, and 3.38 QALYs, respectively. The incremental cost-effectiveness ratio was $8289 per QALY for trabeculectomy vs medical treatment, $13 896 per QALY for tube insertion vs medical treatment, and $29 055 per QALY for tube insertion vs trabeculectomy. The cost-effectiveness of each surgical procedure was most sensitive to early and late surgical failure rates and was minimally affected by adverse events, rates of visual field progression, or medication costs.

CONCLUSIONS AND RELEVANCE: Assuming a willingness to pay of $50 000 per QALY, trabeculectomy and tube insertion are cost-effective compared with medical treatment alone. Trabeculectomy, however, is cost-effective at a substantially lower cost per QALY compared with tube insertion. More research is necessary to reliably account for patient preferences between the 2 operations.