BACKGROUND AND OBJECTIVE: The European Lacidipine Study of Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multi-national interventional trial to determine the effect of four-year treatment using the calcium antagonist lacidipine versus the beta-blocker atenolol on the progression of carotid atherosclerosis in 2259 asymptomatic hypertensive patients. B-mode ultrasound is used to measure the primary and secondary endpoints including the mean maximum intima-media thickness (IMT) of the carotid bifurcations and the common carotid arteries (CBM-max), the mean maximum IMT of 12 standard carotid sites (M-max) and the overall maximum IMT (T-max). This paper reports the cross-sectional reproducibility of ultrasound measurements at baseline. METHOD: To evaluate measurement reliability, each patient is scanned twice at baseline and again at four annual visits, with 80% of the replicate scans performed by the same sonographer and 20% by a different sonographer; 50% of the replicate scans are read by the same reader and the other 50% by different readers. RESULTS: The overall coefficient of reliability (R) was 0.859 for CBM-max, 0.872 for M-max and 0.794 for T-max. The reliability for CBM-max was stable during the 1 3/4-year baseline period (R = 0.848 to 0.953) and was uniform among the 23 field centres (R = 0.798 to 0.926). Intra- and inter-reader reliability were 0.915 and 0.872 respectively, and intra-sonographer reliability was 0.866. CONCLUSION: The results demonstrate that by implementing standardized protocols and strict quality control procedures, highly reliable ultrasonic measurements of carotid artery IMT can be achieved in large multi-national trials.
Baseline reproducibility of B-mode ultrasonic measurement of carotid artery intima-media thickness: the European Lacidipine Study on Atherosclerosis (ELSA)
PORTALUPPI, Francesco
2000
Abstract
BACKGROUND AND OBJECTIVE: The European Lacidipine Study of Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multi-national interventional trial to determine the effect of four-year treatment using the calcium antagonist lacidipine versus the beta-blocker atenolol on the progression of carotid atherosclerosis in 2259 asymptomatic hypertensive patients. B-mode ultrasound is used to measure the primary and secondary endpoints including the mean maximum intima-media thickness (IMT) of the carotid bifurcations and the common carotid arteries (CBM-max), the mean maximum IMT of 12 standard carotid sites (M-max) and the overall maximum IMT (T-max). This paper reports the cross-sectional reproducibility of ultrasound measurements at baseline. METHOD: To evaluate measurement reliability, each patient is scanned twice at baseline and again at four annual visits, with 80% of the replicate scans performed by the same sonographer and 20% by a different sonographer; 50% of the replicate scans are read by the same reader and the other 50% by different readers. RESULTS: The overall coefficient of reliability (R) was 0.859 for CBM-max, 0.872 for M-max and 0.794 for T-max. The reliability for CBM-max was stable during the 1 3/4-year baseline period (R = 0.848 to 0.953) and was uniform among the 23 field centres (R = 0.798 to 0.926). Intra- and inter-reader reliability were 0.915 and 0.872 respectively, and intra-sonographer reliability was 0.866. CONCLUSION: The results demonstrate that by implementing standardized protocols and strict quality control procedures, highly reliable ultrasonic measurements of carotid artery IMT can be achieved in large multi-national trials.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
