Hypothesis / aims of study
In the US, 49.6% of women report having a form of urinary incontinence (UI), including stress incontinence (SUI), overactive bladder (OAB) and mixed UI (MUI) [1]. Surgical treatments for SUI include a sling, sacral neuromodulation (SNS) for OAB, and sling or SNS for MUI [2]. It is known that the decision to seek care is influenced by severity of symptoms and knowledge of available treatments. However, the relationship between race/ethnicity, socioeconomic status and receiving treatment is poorly understood. The primary aim of this study is to describe the associations between surgical treatments for SUI, OAB, and MUI. The secondary aim of this study is to evaluate if racial and/or socioeconomic factors influence receiving the indicated surgical treatment for SUI or OAB or MUI. Our hypothesis is that racial and socioeconomic factors predict whether a patient will receive surgical treatment, including race, insurance status, and income level.
Study design, materials and methods
We acquired data from the 2019 National Ambulatory Surgery Sample (NASS), a publicly available deidentified dataset that tracks inpatient encounters across 130 hospitals as part of the Healthcare Cost and Utilization Project. We identified population estimates of 37,694 adult females with OAB (with or without UUI), 87,673 with SUI, and 22,292 with MUI, grouped using their respective ICD10 codes. We excluded patients <18 years, male patients, and those with a diagnosis of neurogenic bladder. We identified surgery (sling or SNS) using their respective CPT codes.
Chi-square analysis was used to make comparisons between surgical treatments for each diagnosis, with significance assessed at <0.05. Associations between demographic variables and whether a patient received the indicated treatment for their diagnosis of OAB, SUI, or MUI were examined through logistic regression analysis. Multivariate logistic regression models were used to adjust for age, hospital location, race/ethnicity, median income quartile of patient zip code, insurance status, and age. Results are reported as adjusted odds ratios (aOR) with 95% confidence intervals and a p value <0.05 indicating significance. Data extractions and analysis were conducted using SPSS.
Results
Approximately 2.5% have been estimated to have been treated for SUI, OAB or MUI in 2019 from the NASS sample. Of those with OAB, 25 % received sacral neuromodulation. Of those with SUI, 75.2 % received a sling, and of those with MUI, 60.8% received sling. In an adjusted model, it was estimated that Black, Hispanic and Asian/Pacific Islander (AAPI) patients were less likely than White patients to receive surgical treatment for OAB (aOR= 0.691;95%CI[0.624, 0.765]; aOR=0.632;95%CI [0.565, 0.708 ]; aOR= 0.389;95%CI[0.292, 0.519 ] respectively). It was estimated that Medicare and Medicaid patients were more likely than private insurance to receive SNS treatment for OAB (aOR=1.641;95% Cl[1.528, 1.762]; aOR= 1.347;95% CI [1.218, 1.490] respectively). It was estimated that the highest income quartile patients were less likely than private insurance to receive surgical treatment for OAB (aOR= 0.617;95% CI [0.556, 0.672]).
In an adjusted model, it was estimated that Black and AAPI patients were less likely than White to receive surgical treatment for SUI (aOR=0.706;95% Cl[0.644, 0.773]; aOR= 0.756;95%CI [0.664, 0.860] respectively). Medicare and self-pay patients were less likely than private insurance to receive treatment for SUI (aOR=0.877;95% Cl[0.829, 0.927]; aOR= 0.827;95%CI [0.709,0.965] respectively). The highest income quartile patients were less likely than the lowest income quartile to receive surgical treatment for SUI (aOR=0.915;95% Cl[0.860, 0.927]).
In an adjusted model, it was estimated that Black patients were less likely and Hispanic patients more likely than White to receive surgical treatment for MUI (aOR=0.686;95% Cl[0.590, 0.797]; aOR= 1.119;95%CI [1.010, 1.240] respectively). Medicare and Medicaid patients were less likely than private insurance (aOR=0.879;95% Cl[0.801, 0.964]; aOR= 0.845; 95% CI[ 0.749, 0.955] respectively), and the highest income quartile was less likely than the lowest income quartile to receive surgical treatment for MUI (aOR= 0.857;95% Cl[0.769, 0.956]).
Interpretation of results
Analysis of a national surgery database demonstrates that sling was the most utilized surgical treatment for both SUI and MUI. While SNS was the most utilized surgical treatment for OAB, the majority of OAB patients did not undergo surgical treatment. There were trends in the associations between certain race/ethnicity, insurance status, or income groups and whether they received the indicated treatment for their diagnosis. One of the most salient examples being: even when considering age, insurance status, and income, Black women were significantly less likely to receive surgical treatment for MUI, OAB and SUI.