Sling surgery is the gold standard treatment for stress urinary incontinence in women. While sling surgery has been extensively studied in younger and middle-aged women, outcomes in older, frail women are largely unknown. Frailty, which is recognized as a state of vulnerability that increases the risk of adverse outcomes when faced with a stressor, has been shown to be associated with an increased risk of adverse events after urologic and pelvic surgeries. However, little is known about the effects of frailty following sling surgery in terms of complications (inclusive of urinary tract infections), repeat procedures both for persistent urinary incontinence and for bladder outlet obstruction, and 1-year mortality. To this end, we designed a population-based study using a 100% sample of Medicare beneficiaries undergoing sling surgery to examine the association between frailty and these important surgical outcomes following sling surgery.

We used a 100% sample of Medicare claims (Inpatient, Outpatient, and Carrier Files) for all women who underwent sling surgery (CPT 52788) from 2014 to 2016 in the United States.  Women were grouped using a Claims-based Frailty Index (CFI) into four categories of frailty: not frail (CFI<0.15), pre-frail (0.15=<CFI<0.25), mildly frail (0.25=<CFI<0.35), and moderately-severely frail (CFI>=0.35). Both short- and long-term outcomes were assessed. Short-term outcomes included 30-day complications, both overall and for urinary tract infection (UTI) separately; long-term outcomes included the need for repeat procedures (for both urinary incontinence and for outlet obstruction) and mortality within 1 year of surgery.  Univariate analysis was performed using Pearson ꭓ2 for categorical variables; for continuous variables, ANOVA was used. Relative risk was calculated using Generalized Estimating Equations (GEEs) to explore the association between frailty and the outcome variables of interest adjusting for age, race, Charlson Comorbidity Index, and procedure year.  Both univariate and multivariate models were created.

A total of 56,610 women >=65 years underwent sling surgery during the study period. The majority of women were not frail (46.2%) or pre-frail (48.7%) while only 4.8% and 0.4% were mildly and moderately-severely frail, respectively. As CFI increased, there was a significant increase in rates of UTI and 30-day complications, along with repeat procedures at 1 year (Figure). After adjusting for age and comorbidities, moderate-severe frailty was associated with an increased RR of UTI (RR 2.25; CI 1.87-2.71), any 30-day complications (RR 2.27, CI 2.00-2.59), and 1-year mortality (RR 6.16, CI 3.71-10.23). Additionally, only women with mild-severe frailty demonstrated an increased RR of both repeat anti-incontinence procedures (RR 1.58, CI 1.28-1.96) and sling revisions (RR 1.38, CI 1.06-1.79) at 1 year.

As CFI increased, women had an increased relative risk of UTI, any 30-day complication, need for repeat procedures, and mortality at 1 year.

While there were far fewer sling surgeries performed in mildly and moderately-severely frail women, there was both an increased risk of 30-day complications and UTIs along with need for repeat procedures and mortality at 1 year in this vulnerable population. To date, this is the first study that has utilized a Claims-based Frailty Index in 100% of Medicare recipients to stratify women undergoing sling surgery into categories of frailty to assess rates of complications and need for additional procedures. These data highlight that frailty should be considered when making decisions regarding sling surgery in frail older adults.