By Gail F. Schwartz, MD
This study compared the cost-effectiveness of treating patients with newly-diagnosed mild open-angle glaucoma (OAG) with prostaglandin analogs (PGAs), laser trabeculoplasty (LTP) or observation only. The authors report in the April issue of the Archives of Ophthalmology that PGAs and LTP are both cost-effective options for the management of this condition. Assuming optimal medication adherence, they found that PGAs confer greater value compared with LTP. However, when assuming more realistic levels of medication adherence at current prices for PGAs, LTP may be a more cost-effective alternative.
The authors raise a very interesting point regarding the cost of nonadherence. While PGA treatment provided some cost savings over LTP, approximately 40 percent of the American public under ocular hypotensive therapy with a PGA cannot take the drops consistently on a daily basis. However, because glaucoma progression may take a long time to measure via imaging or visual fields, measuring the relationships between nonadherence (which is typically partial and not complete, with enormous variability), progression and cost is nearly impossible.
The authors used a Markov model with a 25-year horizon to compare the treatments. They found that the incremental cost-effectiveness of LTP over no treatment is $16,824 per quality-adjusted life year. By comparison, they calculated the incremental cost-effectiveness of PGAs over no treatment as $14,179 per quality-adjusted life year, with greater health-related quality of life relative to LTP treatment. However, they determined that if PGAs are 25 percent less effective than the documented effectiveness reported in clinical trials, due to poor patient adherence, LTP can provide greater value.
They say that identifying strategies to improve medication adherence will not only improve patient outcomes but also improve the cost-effectiveness of treating glaucoma with PGAs or other medications. They add that if researchers can develop novel means of administering glaucoma medications (e.g., intraocular injections) that reduce the need for adherence, this, too, can improve the cost-effectiveness of caring for patients with OAG, assuming that these medications are not too expensive.
Several recent studies look at communication strategies that can be used with patients to assess adherence, such as asking open-ended questions. Ophthalmologists and staff should employ these techniques to try to gauge which treatment is best.