Intra- and inter-rater reliability of urethral mobility measurement by ultrasound in women: a cross-section study

To verify the intra- and inter-rater reliability of urethral mobility measurement evaluated by ultrasound (US).

This is a reliability study realized according to Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) recommendations. Twenty-one nulliparous women (25.5 ± 3.3 SD years) were volunteers. Two examiners (E1 and E2) performed the measurement of urethral mobility at rest and Valsalva on the same day. Three measurements were recorded for each moment and the mean of them were used for analysis. To perform the analysis, bladder mobility was calculated using the following equation: \( UM=\sqrt{{\left( Vy- Ry\right)}^2+{\left( Vx- Rx\right)}^2} \), where “x” is the vertical distance, “y” is the horizontal distance from the dorsocaudal margin of the pubic symphysis, “V” is the Valsalva maneuver, and “R” means rest. The intraclass correlation coefficient (ICC) was calculated considering: ICC ≥ 0.75, excellent; 0.40 ≤ ICC <0.75, satisfactory; ICC < 0.40, poor, with a significance level of 5% and 95% confidence interval.

The intra-rater reliabilities of E1 and E2 were considered excellent between the two evaluations, with ICC 0.98 (p < 0.0001) for the E1 and 0.84 (p < 0.0001) for E2. The inter-rater reliability was considered excellent (ICC = 0.83).

Both intra- and inter-rater reliabilities of urethral mobility measurement were considered to have excellent agreement.