Obstructive Sleep Apnea Screening and Overactive Bladder Symptoms: a Retrospective Cohort Study

Objectives: To evaluate the utility of implementing universal screening for obstructive sleep apnea (OSA) and its potential impact on overactive bladder (OAB) symptoms among patients presenting with overactive bladder syndrome.

Methods: Patients presenting with new symptoms of OAB were universally screened for OSA using the STOP-BANG questionnaire. OAB symptom severity and subjective bother were quantified (ICIQ-OAB, UDI-6, and IIQ-7). For patients that screened high-risk for sleep apnea, a referral was reflexively placed for sleep medicine. Female pelvic medicine and reconstructive surgeons — blinded to the apnea screening scores—were monitored for their baseline sleep medicine referral patterns for each of the patients. Patient demographics were analyzed using Chi-squared, Fisher’s exact, or t-tests where appropriate. OAB symptom scores were evaluated by sleep apnea risk stratification using t-tests. Risk factors for overactive bladder symptoms were analyzed using simple and multiple linear regression models. Concordance between provider-initiated referrals and high-risk apnea screen-reflexed referrals was measured using Cohen’s Kappa. The subset of patients who were referred for polysomnography were later re-surveyed for completion of sleep study, initiation of CPAP, and changes to OAB and sleep apnea symptoms.

Results: Ninety patients presenting with symptoms of overactive bladder were screened from August 2019 to April 2020. Baseline characteristics were overall similar between patient populations stratified by low- / intermediate- versus high- risk OSA risk stratification except for race and type 2 diabetes mellitus as noted in Table 1. Of the 90 patients screened, 22% were at high-risk for OSA and were reflexively referred for polysomnography. Patients who screened at high-risk for OSA had OAB symptom and bother scores that were 25 to 83% higher than those who screened low or intermediate risk. These findings were also clinically significant when normalized for the Minimal Clinically Important Difference scores of each test instrument (Figure 1). When controlling for age, race, diabetes mellitus, and recurrent UTI, screening high risk for OSA was still associated with higher OAB symptoms scores (ICIQ_bother 8 (2.2,13.8) p = 0.01, UDI 6 11.3 (0.7,22) p = 0.04, and 22.2 (9.2,35.1) p = 0.001).The blinded referral patterns of the female pelvic medicine and reconstructive surgeons showed a fair concordance with OSA screening-triggered referrals (Cohen’s Kappa 0.21, p=0.04).

Conclusions: Universal screening among patients presenting with overactive bladder symptoms revealed 22% were at high risk for OSA. Those who screened high risk for OSA had a significant association with higher severity and subjective bother of overactive bladder symptoms. Better identification of patients at high risk of OSA can aid in referral for evaluation and management of OSA to treat a co-morbid condition that worsens OAB symptoms. Further studies are needed to elucidate this association and determine the impact of treating OSA in OAB patients.