Urinary incontinence after radical prostatectomy: can men at risk be identified preoperatively?

BACKGROUND: Incontinence after radical prostatectomy for early stage prostate cancer can significantly affect quality of life. Identification of risk factors preoperatively would enable clinicians to counsel men and their partners about the risk of incontinence following surgery. We conducted a population-based study to identify subjective and objective preoperative factors, other than PSA and Gleason score, that may predict urinary incontinence following radical prostatectomy.
METHODS: Men booked for radical prostatectomy at 2 sites in Alberta were enrolled prospectively. Assessment was completed 2 weeks prior to surgery and included the International Prostate Symptom Score (IPSS) with a single quality-of-life (QOL) question, 24-hour pad test, and bladder diary. These parameters were repeated at 3 and 12 months postoperatively. A model predicting incontinence was developed using stepwise multivariable logistic regression analysis. Incontinence was defined as more than 8 g of urine loss on 24-hour pad test.
RESULTS: A total of 245 patients from 2 centers were enrolled; 228 (93%) completed data collection up to 12 months postsurgery. At the baseline preoperative assessment, 4% (10/228) of subjects had > or = 8 g of urine loss on 24-hour pad test, although these and all other subjects described complete continence. At 3 months postop, 43% had > or = 8 g on 24-hour pad testing (our definition of incontinence) (median 31 g, range 8.3-1654 g, SD 219.12); at 12 months, 15% had more than 8 g of urine loss on pad test (median 21.0 g, range 8.1-3380 g, SD 578.0). For all subjects, mean IPSS and the single QOL scores at baseline (7.4 and 1.5) did not change significantly at 3 months (7.2 and 2.5), but both were lower than or equal to baseline at 12 months (5.4 and 1.5). The IPSS was predictive of incontinence at 3 months, but not at 12 months. Bladder diary did not correlate with IPSS. Risk factors affecting continence at 12 months were preoperative urine loss > or = 8 g, previous transurethral resection of prostate (TURP), and age greater than 65 years.
CONCLUSION: Our results support previous research on risk factors for incontinence after radical prostatectomy and add to the current data by having presurgery (baseline) measures. Interestingly, a small percentage of men (4%) who reported complete continence were incontinent preoperatively, based on our definition of > or = 8 g weight gain on 24-hour pad test. Identified preoperative risk factors affecting continence were increasing age, baseline incontinence, and previous TURP. Mean IPSS was lower at 12 months than at baseline, suggesting that even mildly symptomatic men will improve after surgery. Men reported that regular contact with the continence research nurse provided a much-appreciated source of informed support as they recovered.