Test-retest reliability for pulse wave velocity and cardio-ankle vascular index among Afro-Caribbean young adults

Abstract

BackgroundThis study evaluated the test-retest reliability of carotid-femoral pulse wave velocity (PWV) and cardio-ankle vascular index (CAVI) among young adults in Jamaica.MethodsWe recruited participants from the Jamaica 1986 Birth Cohort Study. PWV was measured using the Arteriograph device™ (TensioMed, Budapest) and CAVI with the VaSera™ device (Fukuda Denshi, Tokyo). Both measurements were done twice on the same day with a 1-hour interval between measurements. Test-retest reliability was estimated using the intra-class correlation coefficient (ICC) and Bland-Altman plots. Kappa statistic was used to assess agreement between repeated tests in classifying participants as high PWV or CAVI, defined as being in the upper tertile of measurements.ResultsAnalyses included 89 participants (43 males; 46 females; mean age 28.4 ± 0.50 years). Mean PWV for first and second readings were 6.56 cm/s and 6.64 cm/s, respectively (mean difference −0.08 [95%CI −0.18, 0.03, p = 0.142]). Mean values for first and second CAVI were 6.53 and 6.20, respectively, (mean difference 0.34 [95%CI 0.18, 0.50, p < 0.001]). ICC for PWV was 0.88 (95%CI 0.83, 0.92) and for CAVI 0.57 (95%CI 0.41, 0.69). Bland-Altman plots indicated that measurements taken from both devices were highly reproducible, with most points (85/89 for PWV; 86/89 for CAVI) falling within 2 SD of the mean difference. Kappa statistic was 0.76 for PWV and 0.56 for CAVI.ConclusionPWV (Arteriograph™) and CAVI (VaSera™) have good test-retest reliability among Jamaican youth adults; however repeated CAVI values were marginally lower than the first measurement and the ICC and kappa estimates were lower.