title: Methodological issues facing studies of atherosclerotic change.
abstract: BACKGROUND
  The association between coronary heart disease and lesions of the coronary arteries has led to investigations of different interventions on atherosclerotic change. Currently, B-mode ultrasound of the peripheral arterial vessels, rather than arteriography of the coronary arteries, provides the most accurate evaluation of atherosclerotic disease extent in the patient.
  
  
  RESULTS
  When measuring the effect of risk factor modification on atherosclerotic change, it is important to select appropriate methods and end points for quantifying disease and evaluating subsequent change. Measurements must be valid, precise, and reliable and require appropriate a priori definitions of end points and their change. Consistent methodology within studies is crucial. Multiple measurements and data reduction methods can increase the efficiency of comparisons and merit careful consideration. Missing data arising from nonvisualization of sites complicate analyses. Identifying both covariates of atherosclerotic change and possible confounding interventions require monitoring biochemical, physiological, and/or clinical variables and making inferences from these.
  
  
  CONCLUSIONS
  To strengthen the rationale for use of B-mode ultrasonography in assessing the natural history of atherosclerosis, four methodological issues must be addressed: evaluation of primary end points using composite and/or individual measurements of atherosclerotic assessment from the carotid arteries, evaluation of new methodology that may allow assessment of the anatomy of specific lesions and/or their potential for rupture, development of methods making complementary use of both angiographic measurements of lumen diameter and ultrasound assessment of the arterial wall, and concrete demonstration of a direct link between increasing intimal-medial thickness and subsequent clinical events. The use of a continuous variable (intimal-medial thickness) in ultrasound studies offers cost/benefit advantages; this methodology continues to evolve.
authors.affiliation: Clinical Trials Branch, National Heart, Lung, and Blood Institute, Bethesda, MD 20892.
authors.forename: J L
authors.initials: JL
authors.lastname: Probstfield
authors.forename: R P
authors.initials: RP
authors.lastname: Byington
authors.forename: D A
authors.initials: DA
authors.lastname: Egan
authors.forename: M A
authors.initials: MA
authors.lastname: Espeland
authors.forename: S E
authors.initials: SE
authors.lastname: Margitic
authors.forename: W A
authors.initials: WA
authors.lastname: Riley
authors.forename: C D
authors.initials: CD
authors.lastname: Furberg
mesh_terms: D001161:Arteriosclerosis / Q000000981:diagnostic imaging*; D002986:Clinical Trials as Topic / Q000379:methods; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D005069:Evaluation Studies as Topic; D006801:Humans; D014463:Ultrasonography / Q000379:methods*