Predictors of implantable pulse generator placement after sacral neuromodulation: who does better?

Numerous studies have documented a relationship between provider variables, including surgeon volume and specialty, and outcomes for surgical procedures. In this study we analyzed claims data from a Medicare database to analyze outcomes of sacral neuromodulation (SNM) with respect to both provider and patient factors.

A 5% random sample of Medicare beneficiaries from 1997 to 2007 was the data source. Data retrieved included demographic information, ICD-9 diagnosis codes, and CPT procedure codes. Multivariate analysis was performed to identify predictors of progression to implantable pulse generator (IPG) implantation.

After stage I testing, urologists were more likely than gynecologists to proceed to IPG placement (Center for Medicare and Medicaid Services: 49% vs. 43%, p < 0.0001). After percutaneous testing, gynecologists were more likely than urologists to proceed to battery placement (63% vs.44%, p = 0.005). Among the patient variables analyzed, women were more likely than men to progress to battery placement. Patients treated by high-volume providers had higher rates of IPG placement after formal stage I trials (71% vs. 33%, p < 0.0001).

The rate of IPG implantation after SNM was greater among high-volume providers. Women had better outcomes than men. Further research may better define the relationship between outcomes of sacral neuromodulation and specific etiology of voiding dysfunction.