title: Reproducibility of carotid vessel wall thickness measurements. The Rotterdam Study.
abstract: We studied the reproducibility of measurement of ultrasonographically assessed common carotid intima-media thickness and assessed whether measurement error of intima-media thickness occurred randomly or was associated with potential determinants of atherosclerosis. Eighty participants of the Rotterdam Study underwent a second ultrasound scan of both carotid arteries within 3 months of the first scan. The replicate measurements involved the posterior intima-media thickness of the distal common carotid artery. Mean differences (SD) in intima-media thickness of the right common carotid artery between paired measurements of sonographers, readers and visits were -0.004 mm (0.10), 0.066 mm (0.07), and -0.013 mm (0.13), respectively. Similar results were obtained for the left common carotid artery. Measurement error of intima-media thickness, i.e. the absolute difference in measurements between two subsequent visits, increased significantly with increasing common carotid intima-media thickness. This association disappeared after logarithmical transformation of the intima-media thickness data. Age, sex, smoking, body mass index, serum lipids, fibrinogen, and systolic and diastolic blood pressure were not significantly associated with the measurement error of intima-media thickness. Our findings indicate that measurements of common carotid intima-media thickness are highly reproducible. Measurement error of intima-media thickness is small and appears to be proportional with the level of intima-media thickness and is not significantly associated with most risk factors for atherosclerotic vessel wall disease.
authors.affiliation: Department of Epidemiology & Biostatistics, Erasmus University Medical School, Rotterdam, The Netherlands.
authors.forename: M L
authors.initials: ML
authors.lastname: Bots
authors.forename: P G
authors.initials: PG
authors.lastname: Mulder
authors.forename: A
authors.initials: A
authors.lastname: Hofman
authors.forename: G A
authors.initials: GA
authors.lastname: van Es
authors.forename: D E
authors.initials: DE
authors.lastname: Grobbee
mesh_terms: D000368:Aged; D001161:Arteriosclerosis / Q000000981:diagnostic imaging / Q000209:etiology; D001794:Blood Pressure; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000473:pathology; D002784:Cholesterol / Q000097:blood; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011446:Prospective Studies; D011897:Random Allocation; D015203:Reproducibility of Results; D012307:Risk Factors; D014463:Ultrasonography
chemical_list: D002784:Cholesterol