Relative efficiency of unequal versus equal cluster sizes in cluster randomized and multicentre trials

Statistics in Medicine

Volumn 26, Issue 13, 2007, Pages 2589-2603

  van Breukelen, Gerard J P ^a   Candel, Math J J M ^a   Berger, Martijn P F ^a  

^a MAASTRICHT UNIVERSITY   (Netherlands)

Author keywords

Cluster randomized trials; Mixed regression; Multicentre trials; Optimal design; Power; Relative efficiency; Sample size

Indexed keywords

ACCURACY; ARTICLE; CALCULATION; CLINICAL RESEARCH; CLUSTER ANALYSIS; CONTROLLED STUDY; CORRELATION COEFFICIENT; INTERMETHOD COMPARISON; METHODOLOGY; RANDOMIZATION; RELATIVE BIOLOGIC EFFECTIVENESS; SAMPLE SIZE; STATISTICAL DISTRIBUTION; VARIANCE;

CLUSTER ANALYSIS; HUMANS; MODELS, STATISTICAL; MULTICENTER STUDIES; NETHERLANDS; RANDOMIZED CONTROLLED TRIALS; RESEARCH DESIGN;

EID: 34249700581     PISSN: 02776715     EISSN: 10970258     Source Type: Journal    
DOI: 10.1002/sim.2740     Document Type: Article

References (22)

1. Senn S. Some controversies in planning and analyzing multi-centre trials. Statistics in Medicine 1998; 17: 1753-1765.
2. Raudenbush SW. Statistical analysis and optimal design for cluster randomized trials. Psychological Methods 1997; 2:173-185.
3. Donner A, Klar N. Cluster randomization trials in epidemiology: theory and application. Journal of Statistical Planning and Inference 1994; 42:37-56.
4. Raudenbush SW, Liu X. Statistical power and optimal design for multisite trials. Psychological Methods 2000; 5:199-213. DOI 10.1037 // 1082-989X.5.2.199
5. Moerbeek M, Van Breukelen GJP, Berger MPF. A comparison between traditional methods and multilevel regression for the analysis of multicentre intervention studies. Journal of Clinical Epidemiology 2003; 56: 341-350. DOI 10.1016/S0895-4356(03)00007-6
6. Moerbeek M, Van Breukelen GJP, Berger MPF. Design issues for experiments in multilevel populations. Journal of Educational and Behavioral Statistics 2000; 25:271-284.
7. Moerbeek M, Van Breukelen GJP, Berger MPF. Optimal experimental designs for multilevel models with covariates. Communications in Statistics A 2001; 30:2683-2697. DOI 10.1081/STA-100108453
8. Moerbeek M, Van Breukelen GJP, Berger MPF. Optimal experimental design for multilevel logistic models. The Statistician 2001; 50:17-30.
9. Liu X. Statistical power and optimum sample allocation ratio for treatment and control having unequal costs per unit of randomization. Journal of Educational and Behavioral Statistics 2003; 28:231-248.
10. Headrick TC, Zumbo BD. On optimizing multi-level designs: power under budget constraints. Australian New Zealand Journal of Statistics 2005; 47:219-229.
11. Ankenman BE, Aviles AI, Pinheiro JC. Optimal designs for mixed-effects models with two random nested factors. Statistica Sinica 2003; 13:385-401.
12. Manatunga AK, Hudgens MG, Chen S. Sample size estimation in cluster randomized studies with varying cluster size. Biometrical Journal 2001; 43:75-86.
13. Fedorov V, Jones B. The design of multicentre trials. Statistical Methods in Medical Research 2005; 14:205-248. DOI 10.1191/ 0962280205sm399oa
14. Cochran WG. Sampling Techniques (3rd edn). Wiley: New York, 1977.
15. Kerry SM, Bland JM. Unequal cluster sizes for trials in English and Welsh general practices: implications for sample size calculations. Statistics in Medicine 2001; 20:377-390.
16. Searle S, Casella G, McCulloch C. Variance Components. Wiley: New York, 1992.
17. Atkinson AC, Donev AN. Optimum Experimental Design. Clarendon: Oxford, 1996.
18. Silvey S. Optimal Design: An Introduction to the Theory of Parameter Estimation. Chapman & Hall: London, 1980.
19. Mood AM, Graybill FA, Boes DC. Introduction to the Theory of Statistics (3rd edn). McGraw-Hill: Tokyo, 1974.
20. Searle S, Pukelsheim F. Effect of intraclass correlation on weighted averages. The American Statistician 1986; 40:103-105.
21. Smeeth L, Siu-Woon E. Intraclass correlation coefficients for cluster randomized trials in primary care: data from the MRC trial of the assessment and management of older people in the community. Controlled Clinical Trials 2002; 23:409-421.
22. Torgerson DJ. Contamination in trials: is cluster randomisation the answer? British Medical Journal 2001; 322:355-357. DOI 10.1136/bmj.322.7282.355