Intra- and Inter-Rater Reliability, Measurement Error and Criteria and Convergent Validities of the Dualpex Plus for the Vaginal Manometry of Pelvic Floor Muscles in Women With Urinary Incontinence.

Abstract

Objective: To test the Intra- and inter-rater reliability, measurement error and criteria and convergent validities of the Dualpex Plus (DP) for vaginal manometry in women with urinary incontinence (UI).

Design: This is a clinimetric properties study.

Setting: University Hospital in Brazil.

Population: One hundred and two women with UI.

Methods: Vaginal manometry was performed with DP and Peritron (Pr), in a random order. Intra-rater reliability was tested within a 1-week interval; inter-rater reliability was tested on the same day by two different evaluators. Perception of contraction and comfort with each device were assessed and compared with Chi-square or paired t tests. Reliability was evaluated by intraclass correlation coefficient (ICC) with a 95% confidence interval (CI). Criteria (with Pr) and convergent (with Oxford score) validities were evaluated by Pearson's correlation. The standard error of measurement (SEM) and the minimum detectable change were also calculated.

Main outcome measures: Intra- and inter-rater reliability, measurement error and criteria and convergent validities of the Dualpex Plus.

Results: DP showed substantial inter-rater and excellent intra-rater reliability (ICC = 0.85; 95% CI 0.76-0.91 and 0.90; 95% CI 0.86-0.93, respectively); strong and positive criteria validity (r = 0.83; p < 0.001) and convergent validity (r = 0.45; p < 0.001). Pressure values for pelvic floor muscle contraction were different between DP and Pr [17.61 ± 12.22 vs. 34.91 ± 21.22 cmH₂O; p < 0.001]. SEM was doubtful (19%) and the minimum detectable change was 0.152 cmH₂O. DP was more comfortable than Pr and perception of contraction was higher for Pr.

Conclusion: Dualpex Plus showed adequate clinimetric properties. Measurement error was considered doubtful. DP was more comfortable than Pr and perception of contraction was higher for Pr.