Percutaneous tibial nerve stimulation not cost-effective as primary overactive bladder therapy, according to study

June 1, 2011

Percutaneous tibial nerve stimulation is not a cost-effective means of treating overactive bladder as a primary intervention, but cost is not the only factor to consider when confronting OAB, and cost alone may not be a sufficient reason to avoid the therapy.

Key Points

Phoenix-Percutaneous tibial nerve stimulation (PTNS) is not a cost-effective means of treating overactive bladder as a primary intervention, but cost is not the only factor to consider when confronting OAB, and cost alone may not be a sufficient reason to avoid the therapy, say researchers from Yale University School of Medicine, New Haven, CT.

"The patients who might prefer PTNS are those on multiple medications who do not want another medication added to their regimen," first author Heidi Wen Chen, MD, told Urology Times. "Also, a number of these patients may be suffering side effects such as dry mouth or constipation associated with their medications, and they don't need an additional agent that might exacerbate those effects."

She and her colleagues addressed the question of relative costs of OAB therapies because there appeared to be a gap in the literature regarding the cost-effectiveness of PTNS, explained Dr. Chen, a fellow and instructor in obstetrics, gynecology, and reproductive sciences at Yale.

According to their study, PTNS added significant costs to the management of OAB with modest quality of life improvements. Their figures show that for every 100 patients treated, PTNS led to a gain of 4.8 quality-adjusted life years (QALY) at a cost of $303,480 when compared to extended-release tolterodine tartrate (Detrol LA). The incremental cost-effectiveness ratio, or marginal cost per QALY gained, was $63,563. PTNS was cost-effective 21.6% of the time. The team observed that for PTNS to be cost-effective, the utility value for persistent urinary incontinence would have to decrease to 0.66 from 0.73 (with 0 usually assigned to death, and 1 to perfect health) or the persistence of continuing PTNS beyond 12 months would have to increase to 73% from 55%.

Therapy still worth considering

"PTNS is definitely worth looking into. Just because it appears to be not cost-effective as a primary intervention does not mean that it would not be if it was analyzed as a secondary intervention. It should be realized that cost analyses such as ours are built on a lot of assumptions, and if PTNS can be made cheaper to administer in a specific practice, it could well become cost effective," said Dr. Chen.

"The model we used billed at $203 per session, but I have heard of treatment costs ranging from $120 to $220 per session."

The therapeutic models the Yale team used consisted of a 1-year time frame in which PTNS was administered once weekly for 3 months, then followed by maintenance therapy at unspecified intervals out to 1 year. Other weighted assumptions included the utility of improved continence (0.82 QALY) and the effects of continued incontinence (0.72 QALY). Side effects were assumed to have a 5% reduction in QALY. Less than $50,000 per QALY gained was considered to be cost-effective, which is a well-accepted threshold.

One of the study's authors observed that the $50,000 threshold was chosen prior to the analysis and that if society's willingness to pay for improved health increased, the analysis would be more favorable toward PTNS.

Univariate analyses of costs, efficacy, side effects, and utility indices over a range of reported and plausible values were used to provide a basis for the team's conclusions. Dr. Chen noted that in addition to doctors, other health care professionals such as physician assistants and nurses could administer PTNS if they receive the training. This could affect overall costs.