Objective: The Activities Assessment Scale (AAS) is a 13-item postoperative functional activity scale validated in men who underwent hernia surgery. We evaluated the psychometric characteristics of the AAS in women who underwent vaginal surgery for pelvic organ prolapse (POP) and stress urinary incontinence (SUI).
Methods: Participants included 163 women with POP and SUI enrolled in a randomized trial comparing sacrospinous ligament fixation to uterosacral vault suspension with and without perioperative pelvic floor muscle training. Participants completed the AAS and SF-36 at baseline and 2 weeks and 6 months postoperatively. Internal reliability of the AAS was evaluated using Cronbach α. Construct validity and responsiveness were examined in cross-sectional and longitudinal data using Pearson correlation coefficient and analysis of variance. The AAS is scored from zero to 100 (higher scores=better function).
Results: Mean (SD) baseline AAS score was 87 (17.3) (range, 25-100). Functional activity declined from baseline to 2 weeks postoperatively (mean change, -4.5; 95% confidence interval, -7.6 to -1.42) but improved above baseline at 6 months (mean change, +10.9; 95% confidence interval, 7.8-14.0). Internal reliability of the AAS was excellent (Cronbach α=0.93). Construct validity was demonstrated by a correlation of 0.59 to 0.60 between the AAS and SF-36 physical functioning scale (P<0.0001) and lower correlations between the AAS and other SF-36 scales. Patients who improved in physical functioning based on the SF-36 between 2 weeks and 6 months postoperatively showed an effect size of 0.86 for change in the AAS over the same period.
Conclusions: The AAS is a valid, reliable, and responsive measure for evaluation of physical function in women after pelvic reconstructive surgery.
Trial registration: ClinicalTrials.gov NCT00597935.