Issues of Cost and Efficiency in the Design of Reliability Studies

• Published in: Biometrics Vol. 59; no. 4; pp. 1107 - 1112
• Main Authors: Shoukri, M. M., Asyali, M. H., Walter, S. D.
• Format: Journal Article
• Language: English
• Published: 350 Main Street , Malden , MA 02148 , U.S.A , and P.O. Box 1354, 9600 Garsington Road , Oxford OX4 2DQ , U.K Blackwell Publishing 01.12.2003; International Biometric Society
• Subjects: Analysis of Variance; Biometrics; Biometry - methods; Confidence interval; Correlations; Cost efficiency; Cost function; Cost functions; Costs and Cost Analysis; Estimate reliability; Fixed costs; Humans; Lagrange multiplier; Minimization of cost; Models, Statistical; Reliability index; Reproducibility of Results; Research Design - standards; Sample size; Saudi Arabia; Statistical variance; Saudi Arabia
• ISSN: 0006-341X; 1541-0420
• DOI: 10.1111/j.0006-341X.2003.00127.x

Reliability of continuous and dichotomous responses is usually assessed by means of the intraclass correlation coefficient (ICC). We derive the optimal allocation of the number of subjects k and the number of repeated measurements n that minimize the variance of the estimated ICC. Cost constraints are discussed for the case of normally distributed responses. Tables showing optimal choices of k and n are given, along with guidelines for the design of reliability studies in light of our results and those reported by others.