Cost-effectiveness of bacteriuria screening before urogynecologic surgery.

BACKGROUND

Currently, there is controversy over who requires preoperative screening for bacteriuria in the urogynecologic population and whether treating asymptomatic bacteriuria reduces postoperative urinary tract infection rates.

OBJECTIVE

To evaluate the cost-effectiveness of selective, universal, and no preoperative bacteriuria screening protocols in women undergoing surgery for prolapse or stress urinary incontinence.

STUDY DESIGN

A simple decision tree model was created from a societal perspective to evaluate cost and effectiveness of 3 strategies to prevent postoperative urinary tract infection: (1) a universal protocol where all women undergoing urogynecologic surgery are screened for bacteriuria and receive preemptive treatment if bacteriuria is identified; (2) a selective protocol, where only women with a history of recurrent urinary tract infection are screened and treated for bacteriuria; and (3) a no-screening protocol, where no women are screened for bacteriuria. Our primary outcome was the incremental cost-effectiveness ratio, calculated in cost per quality-adjusted life-years. Secondary outcomes were the number of urine cultures, postoperative urinary tract infections, and pyelonephritis associated with each strategy. Costs were derived from the Centers for Medicare & Medicaid Services, Healthcare Cost and Utilization Project, and Medical Expenditure Panel Survey. Clinical estimates were derived from published literature and data from a historic surgical cohort. Quality-of-life-associated utilities for urinary tract infection (0.73), pyelonephritis (0.66), and antibiotic use (0.964) were derived from the published literature using the HALex scale, reported directly by affected patients. One-way sensitivity analyses were performed over the range of reported values.

RESULTS

In the base case scenario, selective screening is more costly (no screen: $101.69, selective: $101.98) and more effective (no screen: 0.096459 quality-adjusted-life-year, selective: 0.096464 quality-adjusted-life-year) than no screening, and is cost-effective, with an incremental cost-effectiveness ratio of $49,349 per quality-adjusted-life-year. Both selective screening and no screening dominate universal screening in being less costly (universal: $111.92) and more effective (universal: 0.096446 quality-adjusted-life-year), with a slightly higher rate of postoperative urinary tract infection (no screen: 17.1%, selective: 16.9%, universal: 16.6%). In 1-way sensitivity analyses, selective screening is no longer cost-effective compared with no screening when the cost of a urine culture exceeds $12, cost of a preoperative urinary tract infection exceeds $93, the cost of a postoperative urinary tract infection is below $339, the specificity of a urine culture is less than 96%, or preoperative bacteriuria rates in those without symptoms but a history of recurrent urinary tract infection is <23%. Universal screening only becomes cost-effective when the postoperative urinary tract infection rate increases to >50% in those without risk factors and untreated preoperative bacteriuria. When compared with no screening, selective screening costs an additional $104 per urinary tract infection avoided and $2607 per pyelonephritis avoided. Compared with selective screening, universal screening costs $4609 per urinary tract infection avoided and $115,223 per pyelonephritis avoided.

CONCLUSION

Implementation of a selective preoperative bacteriuria protocol is cost-effective in most scenarios and associated with only a <1% increase in the 30-day postoperative urinary tract infection rate. No screening is cost-effective when cost of a preoperative urinary tract infection is high and the rate of preoperative bacteriuria in those without risk factors is low.