Agreement between patient global impression scale of improvement, pelvic floor distress inventory and 15D in measuring the outcome of pelvic organ prolapse surgery.

AIMS To evaluate the correlation between three commonly used patient-reported outcome measures, two generic and one condition-specific instrument, in assessing the change in health-related quality of life following pelvic organ prolapse surgery. METHODS The generic health-related quality of life measure 15-dimensional instrument (15D), Patient Global Impression of Improvement (PGI-I), and prolapse-specific Pelvic Floor Distress Inventory (PDFI-20) were used to assess the effectiveness of pelvic organ prolapse surgery in the national FINPOP study of 3535 surgeries (83% of all pelvic organ prolapse operations) performed in Finland in 2015. Spearman correlations between PGI-I, change in 15D and its dimensions and change in PFDI-20 and its subscales over a 2-year follow-up were investigated. The proportion of concordant ratings was also studied by investigating the proportion of women rated similarly (worse/no change/better/much better) by two instruments according to validated cutoffs. RESULTS Among 2248 women for whom the 2-year change in all instruments could be measured, changes in PFDI-20 and 15D and its dimensions were weak (ρ < 0.2 for all except excretion; ρ = 0.39 and sexual activity; ρ = 0.27). PFDI-20 change (ρ = 0.39) and its subscales (ρ = 0.19-0.40, all P < .001) were more strongly correlated with PGI-I. The proportion of fully concordant ratings were higher for PFDI-20 and PGI-I (50.6%) than for PFDI-20 and 15D (33.0%). CONCLUSION The weak correlations between 15D, PGI-I, and PDFI-20 observed in this study show that the quantified health gains are strongly dependent on the chosen patient-reported outcome measures. This demonstrates the importance of using condition-specific sensitive outcome measures in assessing the impact of surgical treatment in pelvic organ prolapse.