Natural history of lower urinary tract symptoms in treatment-seeking women with pelvic organ prolapse; the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN).

BACKGROUND: The association of pelvic organ prolapse with overactive bladder and other lower urinary tract symptoms, and the natural history of those symptoms are not well characterized. Previous cross-sectional studies demonstrated conflicting relationships between prolapse and lower urinary tract symptoms. OBJECTIVE: This study primarily aimed to determine the baseline association between lower urinary tract symptoms and prolapse and to assess longitudinal differences in symptoms over 12 months in women with and without prolapse. Secondary aims were to explore associations between lower urinary tract symptoms and prolapse treatment. We hypothesized that: (1) prolapse is associated with the presence of lower urinary tract symptoms, (2) lower urinary tract symptoms are stable over time in patients with and without prolapse, and (3) prolapse treatment is associated with lower urinary tract symptom improvement. STUDY DESIGN: Women enrolled in the Symptoms of Lower Urinary Tract Dysfunction Research Network Observational Cohort Study with adequate 12-month follow-up data were included. Prolapse and lower urinary tract symptom treatment during follow-up was guided by standard of care. Outcome measures included the Lower Urinary Tract Symptoms Tool total severity score (in addition to overactive bladder, obstructive, and stress urinary incontinence subscales) and Urogenital Distress Inventory-6 Short Form. Prolapse (yes or no) was defined primarily when Pelvic Organ Prolapse Quantification System points Ba, C or Bp were >0 (beyond the hymen). Mixed-effects models with random effects for patient slopes and intercepts were fitted for each lower urinary tract symptom outcome and prolapse predictor, adjusted for other covariates. The study had >90% power to detect differences as small as 0.4 standard deviation for less prevalent group comparisons (eg, prolapse vs not). RESULTS: A total of 371 women were analyzed, including 313 (84%) with no prolapse and 58 (16%) with prolapse. Women with prolapse were older (64.6±8.8 vs 55.3±14.1 years; P<.001) and more likely to have prolapse surgery (28% vs 1%; P<.001) and pessary treatment (26% vs 4%; P<.001) during the study. Average baseline Lower Urinary Tract Symptoms Tool total severity scores were lower (fewer symptoms) for participants with prolapse compared with those without (38.9±14.0 vs 43.2±14.0; P=.036), but there were no differences in average scores between prolapse groups for other scales. For all urinary outcomes, average scores were significantly lower (improved) at 3 and 12 months compared with baseline (all P<.05). In mixed-effects models, there were no statistically significant interactions between pelvic organ prolapse measurement and visit and time-dependent prolapse treatment groups (P>.05 for all regression interaction coefficients). The Lower Urinary Tract Symptoms Tool obstructive severity score had a statistically significant positive association with Pelvic Organ Prolapse Quantification System Ba, Bp, and point of maximum vaginal descent. The Lower Urinary Tract Symptoms Tool total severity scale had a statistically significant negative association with Pelvic Organ Prolapse Quantification System Ba and point of maximum vaginal descent. No other associations between prolapse and lower urinary tract symptoms were significant (P>.05 for all regression coefficients). Symptom differences between prolapse groups were small: all regression coefficients (interpretable as additive percentage change in each score) were between -5 and 5 (standard deviation of outcomes ranged from 14.0-32.4). CONCLUSION: Among treatment-seeking women with urinary symptoms, obstructive symptoms were positively associated with prolapse, and overall lower urinary tract symptom severity was negatively associated with prolapse. Lower Urinary Tract Symptoms Tool scores improved over 12 months regardless of prolapse status, including in those with treated prolapse, untreated prolapse, and without prolapse.