How to Design, Analyse and Report Cluster Randomised Trials in Medicine and Health Related Research

How to Design, Analyse and Report Cluster Randomised Trials in Medicine and Health Related Research

Volumn , Issue , 2014, Pages 1-247

  Campbell, Michael J ^a   Walters, Stephen J ^a  

^a UNIVERSITY OF SHEFFIELD   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 84903618992     PISSN: None     EISSN: None     Source Type: Book    
DOI: 10.1002/9781118763452     Document Type: Book

References (184)

1. http://www.youtube.com/watch?v=I4gfGl_JBEA
2. http://www.newton.ac.uk/programmes/DAE/seminars/
3. http://crtethics.wikispaces.com
4. http://www.equator-network.org/
5. Adams, G., Gulliford, M.C., Ukoumunne, O.C. et al. (2004) Patterns of intra-cluster correlation from primary care research to inform study design and analysis. Journal of Clinical Epidemiology, 57, 785-794.
6. Altman, D.G. (1991) Practical Statistics for Medical Research, Chapman & Hall, London.
7. Altman, D.G., Machin, D., Bryant, T.N. and Gardner, M.J. (2000) Statistics with Confidence: Confidence Intervals and Statistical Guidelines, 2nd edn, BMJ Books, London.
8. Arain, M., Campbell, M.J., Cooper, C.L. and Lancaster, G.A. (2010) What is a pilot or feasibility study? A review of current practice and editorial policy. BMC Medical Research Methodology, 10, 67. doi: 10.1186/1471-2288-10-67.
9. Armitage, P., Berry, G. and Matthews, J.N.S. (2002) Statistical Methods in Medical Research, 4th edn, Blackwell Science, Oxford.
10. Bellary, S., O'Hare, J.P., Raymond, N.T. et al. (2008) Enhanced diabetes care to patients of south Asian ethnic origin (the United Kingdom Asian Diabetes Study): a cluster randomised controlled trial. Lancet, 371, 1769-1776.
11. Blackberry, I.D., Furler, J.S., Best, J.D. et al. (2013) Effectiveness of general practice based, practice nurse led telephone coaching on glycaemic control of type 2 diabetes: the Patient Engagement And Coaching for Health (PEACH) pragmatic cluster randomised controlled trial. British Medical Journal, 347, f5272.
12. Bland, J.M. and Kerry, S.M. (1997) Statistics notes: trials randomised in clusters. British Medical Journal, 315, 600.
13. Borm, G.F., Melis, R.J.F., Teerenstra, S. and Peer, P.G. (2005) Pseudo cluster randomization: a treatment allocation method to minimize contamination and selection bias. Statistics in Medicine, 24 (23), 3535-3547. : 10.1002/sim.2200.
14. Breslow, N.E. and Clayton, D.G. (1993) Approximate inference in generalized linear mixed models. Journal of the American Statistical Association, 88 (421), 9-25.
15. Brown, C., Lilford, R.J. (2006) The stepped wedge trial design: a systematic review. BMC Medical Research Methodology 2006, 6, 54. doi: 10.1186/1471-2288-6-54.
16. Burton, P., Gurrin, L. and Sly, P. (1998) Tutorial in biostatistics: extending the simple linear regression model to account for correlated responses: an introduction to generalised estimating equations and multi-level mixed modelling. Statistics in Medicine, 17, 1261-1291.
17. Campbell, M. (1999) Design and analysis of research studies in wound healing, in ChronicWound Healing: Clinical Measurement and Basic Science (eds R. Mani, V. Falanga, C. Shearman and D. Sandeman), WB Saunders, London, pp. 170-178.
18. Campbell, M.J. (2000) Cluster randomized trials in general (family) practice research. Statistical Methods in Medical Research, 9, 81-94.
19. Campbell, M.J. (2004) Extending CONSORT to include cluster trials. British Medical Journal, 328, 654-655.
20. Campbell, M.J. (2006) Statistics at Square Two, 2nd edn, Wiley-Blackwell, Oxford.
21. Campbell, M.J. (2009) Resting heart rate as predictor, what about absolute risks? British Medical Journal, 338, b1197.
22. Campbell, M., Donner, A. and Klar, N. (2007) Developments in cluster randomized trials and Statistics in Medicine. Statistics in Medicine, 26 (1), 2-19. : 10.1002/sim.
23. Campbell, M.K., Elbourne, D.R. and Altman, D.G. (2004) CONSORT statement: extension to cluster randomised trials. British Medical Journal, 328 (7441), 702-708. : 10.1136/bmj.328.7441.702.
24. Campbell, M., Fitzpatrick, R., Haines, A. et al. (2000) Framework for design and evaluation of complex interventions to improve health. British Medical Journal, 321, 694-696.
25. Campbell, M.J., Julious, S.A. and Altman, D.G. (1995) Estimating sample sizes for binary, ordered categorical, and continuous outcomes in two group comparisons. British Medical Journal, 311, 1145-1148.
26. Campbell, M.J., Machin, D. and Walters, S.J. (2007) Medical Statistics: A Text Book for the Health Sciences, 4th edn, Wiley-Blackwell, Chichester.
27. Campbell, M., Mason, S. and Nicholl, J. (2010) Relative risks, odds ratios and cluster randomised trials. SIS2010, Padua, Italy, http://homes.stat.unipd.it/mgri/SIS2010/Program/1-SSI_RSS/868-1460-1-RV.pdf (accessed 28 October 2013).
28. Campbell, N., Murray, E., Derbyshire, J. et al. (2007) Designing and evaluating complex interventions to improve health care. British Medical Journal, 7591, 455-459.
29. Campbell, M.K., Piaggio, G. and Elbourne, D.R. (2012) Consort 2010 statement: extension to cluster,. British Medical Journal, 5661, 1-21. doi: 10.1136/bmj.e5661.
30. Campbell, R., Starkey, F., Holliday, J. et al. (2008) An informal school-based peer-led intervention for smoking prevention in adolescence (ASSIST): a cluster randomised trial. Lancet, 371, 1595-1602.
31. Campbell, M.J. and Swinscow, T.D.V. (2009) Statistics at Square One, 11th edn, BMJ Books Blackwell Publishing, Oxford, 140pp.
32. Chambers, J.M. and Hastie, T.J. (1992) Statistical Models in S, Chapman & Hall, London.
33. Chaudhry, S.H., Brehaut, J.C., Grimshaw, J.M. et al. (2013) Challenges in research ethics review of cluster randomized trials: international survey of investigators. Clinical Trials, 10, 257-268.
34. Chen, D.-G. and Peace, K.E. (2011) Clinical Trial Data Analysis Using R, Chapman & Hall/CRC-Biostatistics Series, Boca-Raton, FL.
35. Craig, P., Dieppe, P. and Macintyre, S. (2008) Developing and evaluating complex interventions: the new Medical Reearch Council guidance. British Medical Journal, 337. doi: 10.11.1136/bmj.a1655, www.mrc.ac.uk/complexinterventionsguidance (accessed 20 November 2013).
36. Cornfield, J. (1978) Randomization by group: a formal analysis. American Journal of Epidemiology, 108, 100-102.
37. Crawley, M.J. (2012) The R Book, 2nd edn, Wiley-Blackwell, Chichester.
38. Davies, M., Heller, S., Skinner, T. et al. (2008) Effectiveness of the diabetes education and self-management for ongoing and newly diagnosed (DESMOND) programme for people with newly diagnosed type 2 diabetes: cluster randomised controlled trial. British Medical Journal, 336, 491-495. doi: 10.1136/bmj.39474.922025.BE.
39. Der, G. and Everitt, B.S. (2009) A Handbook of Statistical Analyses Using SAS, 3rd edn, Chapman & Hall/CRC Press, Boca Raton, FL.
40. Diehr, P., Martin, D., Koepsel, T. and Cheadle, A. (1995) Breaking the matches in a paired t-test for community interventions when the number of pairs is small. Statistics in Medicine, 14, 1491-1504.
41. Diggle, P.J., Heagerty, P., Liang, K.-Y. and Zeger, S.L. (2002) Analysis of Longitudinal Data, 2nd edn, Oxford University Press, Oxford.
42. Donner, A., Birkett, N. and Buck, C. (1981) Randomization by cluster. Sample size requirements and analysis. American Journal of Epidemiology, 114, 906-914.
43. Donner, A. and Klar, N. (2000) Design and Analysis of Cluster Randomised Trials in Health Research, Arnold, London.
44. Donner, A., Taljaard, M. and Klar, N. (2007) The merits of breaking the matches in community intervention studies: a cautionary tale. Statistics in Medicine, 9, 2036-2051.
45. Durkalski, V., Palesch, Y., Lipsitz, S. and Rust, P. (2003) Analysis of cluster matched-pair data. Statistics in Medicine, 22, 2417-2428.
46. Eisenhart, C. (1947) The assumptions underlying the analysis of variance. Biometrics, 3, 1-21.
47. Eldridge, S., Ashby, D., Feder, G., Rudnicka, A.R., Ukoumunne, O.C. (2004) Lessons for cluster randomised trials in the twenty-first century: a systematic review of trials in primary care. Clinical Trials, 1, 80-90.
48. Eldridge, S., Ashby, D. and Kerry, S. (2006) Sample size for cluster randomised trials: effect of coefficient of variation of cluster size and analysis method. International Journal of Epidemiology, 35, 1292-1300.
49. Eldridge, S., Kerry, S., Torgerson, D.J. (2009). Bias in identifying and recruiting participants in cluster randomised trials: what can be done? BMJ, 339, b4006.
50. Eldridge, S. and Kerry, S. (2012) A Practical Guide to Cluster Randomised Trials in Health Services Research, John Wiley & Sons, Ltd, Chichester.
51. Eldridge, S., Spencer, A., Cryer, C. et al. (2005) Why modelling a complex intervention is an important precursor to trial design: lessons from studying an intervention to reduce falls-related injuries in older people. Journal of Health Services Research and Policy, 10 (3), 133-142. : 10.1258/1355819054338942.
52. Evans, S., Royston, P. and Day, S. (2004) Minim: Allocation by Minimization in Clinical Trials, http://www-users.york.ac.uk/~mb55/guide/minim.htm (accessed 28 October 2013).
53. Evans, I., Thornton, H., Chalmers, I. and Glasziou, P. (2011) Testing Treatments: Better Research for Better Healthcare, Pinter and Martin, www.testingtreatments.org (accessed 28 October 2013).
54. Everitt, B.S. and Hothorn, T. (2006) A Handbook of Statistical Analyses Using R, Chapman & Hall/CRC Press, Boca Raton, FL.
55. Fairclough, D.L. (2002) Design and Analysis of Quality of Life Studies in Clinical Trials, Chapman & Hall, New York.
56. Fayers, P.M. and Machin, D. (2007) Quality of Life: The Assessment, Analysis and Interpretation of Patient-Reported Outcomes, 2nd edn, John Wiley & Sons, Ltd, Chichester.
57. Feldman, H. and McKinlay, S. (1992) Cohort versus cross-sectional design in large field trials: precision, sample size, and a unifying model. Statistics in Medicine, 1607-1614.
58. Feng, Z., Diehr, P., Yasui, Y. et al. (1999) Explaining community-level variance in group randomized trials. Statistics in Medicine, 18 (5), 539-556.
59. Feng, Z., McLaran, D. and Grizzle, J. (1996) A comparison of statistical methods for clustered data analysis with Gaussian error. Statistics in Medicine, 15, 1793-1806.
60. Flynn, T., Whitley, E. and Peters, T. (2002) Recruitment strategies in a cluster randomized trial - cost implications. Statistics in Medicine, 21, 397-405.
61. Freedman, L. (1982) Tables of the number of patients in clinical tials using the logrank test. Statistics in Medicine, 1, 121-129.
62. Freedman, L., Green, S. and Byar, D. (1990) Assessing the gain in efficiency due to matching in a community intervention study. Statistics in Medicine, 9, 943-953.
63. Freeman, J.V., Walters, S.J. and Campbell, M.J. (2008) How to Display Data, BMJ Books, Blackwell, Oxford.
64. Gail, M., Byar, D.P., Pechacek, T. and Corle, D. (1992) Aspects of statistical design for the community intervention trial for smoking cessation (COMMIT). Controlled Clinical Trials, 13, 6-21.
65. Gilbody, S., Bower, P., Torgerson, D. and Richards, D. (2008) Cluster randomized trials produced similar results to individually randomized trials in a meta-analysis of enhanced care for depression. Journal of Clinical Epidemiology, 61 (2), 160-168. : 10.1016/j.jclinepi.2007.04.015.
66. Giraudeau, B. and Ravaud, P. (2009) Preventing bias in cluster randomised trials. PLoS Medicine, 6 (5), e1000065. : 10.1371/journal.pmed.1000065.
67. Giraudeau, B., Ravaud, P. and Donner, A. (2008) Sample size calculation for cluster randomized cross-over trials. Statistics in Medicine, 27 (27), 5578-5585. : 10.1002/sim.
68. Goldstein, H. (2002) Multilevel Statistical Models, John Wiley & Sons, Ltd, Chichester.
69. Grant, A.M., Altman, D.G., Babiker, A.B. et al. (2005) Issues in data monitoring and interim analysis of trials. Health Technology Assessment, 9 (7), 1-238, III-IV.
70. Greven, S. and Kneib, T. (2010) On the behaviour of marginal and conditional AIC in linearmixed models. Biometrika, 97 (4), 773-789.
71. Griffiths, C., Foster, G., Barnes, N. et al. (2004) Specialist nurse intervention to reduce unscheduled asthma care in a deprived multiethnic area: the east London randomised controlled trial for high risk asthma (ELECTRA). British Medical Journal, 328 (7432), 144. : 10.1136/bmj.37950.784444.EE.
72. Grosskurth, H., Mosha, F., Todd, J. et al. (1995) Impact of improved treatment of sexually transmitted diseases on HIV infection in rural Tanzania: randomised controlled trial. Lancet, 346, 530-536.
73. Group, G. H. S (1987) The Gambia hepatitis intervention study. Cancer Research, 47, 5782-5787.
74. Gulliford, M.C., Adams, G., Ukoumunne, O.C. et al. (2005) Intraclass correlation coefficient and outcome prevalence are associated in clustered binary data. Journal of Clinical Epidemiology, 58 (3), 246-251. : 10.1016/j.jclinepi.2004.08.012.
75. Guo, X., Pan,W., Connett, J.E., Hannan, P.J. and French, S.A. (2005). Small-sample performance of the robust score test and its modifications in generalized estimating equations. Statistics in Medicine, 24, 3479-3495.
76. Hahn, S., Puffer, S., Torgerson, D.J. and Watson, J. (2005) Methodological bias in cluster randomised trials. BMC Medical Research Methodology, 5, 10. doi: 10.1186/1471-2288-5-10.
77. Hall, A.J., Inskip, H.M., Loik, F., et al. (1987) The Gambia hepatitis intervention study. The Gambia Hepatitis Study Group. Cancer Research, 47, 5782-7.
78. Harper, R., Brazier, J.E., Waterhouse, J.C. et al. (1997) Comparison of outcome measures for patients with chronic obstructive pulmonary disease (COPD) in an outpatient setting. Thorax, 52, 879-887.
79. Hayes, R. and Moulton, L. (2009) Cluster Randomised Trials, Chapman&Hall/CRC Press, Boca Raton, FL.
80. Hedges, J.R., Feldman, H.A., Bitner, V.B. et al. (2000) Impact of community intervention to reduce patient delay time on use of reperfusion therapy for acute myocardial infarction: rapid early action for coronary treatment (REACT) Trial. Academic Emergency Medicine, 7, 862-872.
81. Heo, M. and Leon, A.C. (2005) Comparison of statistical methods for analysis of clustered binary observations. Statistics in Medicine, 24 (6), 911-923. : 10.1002/sim.1958.
82. Hogg, R.V. and Tanis, E.A. (1988) Probability and Statistical Inference. 3rd edn. New York, McMillan.
83. Hopewell, S., Clarke, M., Moher, D. et al. (2008) CONSORT for reporting randomised trials in journal and conference abstracts. Lancet, 371, 281-283.
84. Hunsberger, S., Murray, D., Davis, C.E. and Fabsitz, R.R. (2001) Imputation strategies for missing data in a school-based multi-centre study: the Pathways study. Statistics in Medicine, 20 (2), 305-316.
85. Hussey, M.A. and Hughes, J.P. (2007) Design and analysis of stepped wedge cluster randomized trials. Contemporary Clinical Trials, 28, 182-191.
86. ICH E6 (R1) (1996) Guidelines for Good Clinical Practice (CPMP/ICH/135/95), EMEA, Canary Wharf, http://www.ich.org/products/guidelines/efficacy/efficacy-single/article/good-clinical-practice.html.
87. ICH E9 Expert Working Group (1999) ICH Harmonised Tripartite Guideline: statistical principles for clinical trials. Statistics in Medicine, 18, 1905-1942.
88. Ioannidis, J.P., Evans, S.J., Gotzsche, P.C. et al. (2004) Better reporting of harms in randomized trials: an extension of the CONSORT statement. Annals of Internal Medicine, 141 (10), 781-788.
89. Ivers, N.M., Taljaard, M., Dixon, S. et al. (2011) Impact of CONSORT extension for cluster randomised trials on quality of reporting and study methodology: review of random sample of 300 trials, 2000-8. British Medical Journal, 343, d5886. doi: 10.1136/bmj.d5886.
90. Julious, S.A. (2005) Sample size of 12 rule of thumb for a pilot study. Pharmaceutical Statistics, 4, 287-291.
91. Julious, S. and Campbell, M. (1997) Sample sizes for ordered categorical data. Statistics in Medicine, 15, 1065-1066.
92. King, M., Davidson, O., Taylor, F. et al. (2002) Effectiveness of teaching general practitioners skills in brief cognitive behaviour therapy to treat patients with depression: randomised controlled trial. British Medical Journal, 324, 947-952.
93. Kinmonth, A.-L., Fulton, Y. and Campbell, M.J. (1992) The management of feverish children at home. British Medical Journal, 305, 1134-1136.
94. Kinmonth, A.L., Woodcock, A., Griffin, S. et al. (1998) Randomised controlled trial of patient centred care of diabetes in general practice: impact on current wellbeing and future disease risk. British Medical Journal, 317, 1202-1208.
95. Klar, N. and Darlington, G. (2004) Methods for modelling change in cluster randomization trials. Statistics in Medicine, 23, 2341-2357.
96. Klar, N. and Donner, A. (1997) The merits of matching in community intervention trials. Statistics in Medicine, 16, 1763-1764.
97. Lake, S., Kammann, E., Klar, N. and Betensky, R. (2002) Sample size re-estimation in cluster randomization trials. Statistics in Medicine, 21 (10), 1337-1350. : 10.1002/sim.1121.
98. Lancaster, G.A., Campbell, M.J., Eldridge, S. et al. (2010) Trials in primary care: statistical issues in the design, conduct and evaluation of complex interventions. Statistical Methods in Medical Research, 19 (4), 349-377. : 10.1177/0962280209359883 (Epub 2010 May 4).
99. Lancaster, G.A., Dodd, S. and Williamson, P.R. (2004) Design and analysis of pilot studies: recommendations for good practice. Journal of Evaluation in Clinical Practice, 10 (2), 307-312. : 10.1111/j.2002.384.doc.x.
100. Landau, S. and Everitt, B.S. (2004) A Handbook of Statistical Analyses Using SPSS, 3rd edn, Chapman & Hall/CRC Press, Boca Raton, FL.
101. Lee, Y. and Nelder, J.A. (2004) Conditional and marginal models: another view. Statistical Science, 19 (2), 219-238.
102. Lee, K. and Thompson, S. (2005) The use of random effect models to allow for clustering in individually randomized trials. Clinical Trials, 2, 163-173.
103. Lewsey, J. (2004) Comparing completely and stratified randomization designs in cluster randomized trials when the stratifying factor is cluster size: a simulation study. Statistics in Medicine, 23, 897-905.
104. Liang, K.-Y. and Zeger, S. (1986) Longitudinal data analysis using generalized linear models. Biometrika, 73, 13-22.
105. Little, R.J.A. and Rubin, D.B. (2002) Statistical Analysis with Missing Data, 2nd edn.Wiley-Blackwell, New Jersey.
106. Long J.S. and Ervin L.H. (2000) Using Heteroscedasticity Consistent Standard Errors in the Linear Regression Model. The American Statistician, 54, 217-224.
107. Ma, J., Akhtar-Danesh, N., Dolovich, L. and Thabane, L. the CHAT Investigators (2011) Imputation strategies for missing binary outcomes in cluster randomized trials. BMC Medical Research Methodology, 11, 18. doi: 10.1186/1471-2288-11-18.
108. Ma, J., Raina, P., Beyene, J. and Thabane, L. (2013) Comparison of population-averaged and cluster-specific models for the analysis of cluster randomised trials with missing binary outcomes: a simulation study. BMC Medical Research Methodology, 13, 9. doi: 10.1186/1471-2288-13-9.
109. Machin, D. and Campbell, M.J. (2005) Design of Studies for Medical Research, John Wiley & Sons, Ltd, Chichester.
110. Machin, D., Campbell, M., Tan, S. and Tan, S. (2008) Statistical Tables for the Design of Clinical Studies, (3rd edn). Chichester, Wiley-Blackwell.
111. Machin, D. and Fayers, P.M. (2010) Randomized Clinical Trials: Design, Practice and Reporting, John Wiley & Sons, Ltd, Chichester.
112. Mancl, L. and DeRouen, T. (2001) A covariance estimator for GEE with improved small sample properties. Biometrics, 57, 126-134.
113. Manly, B.F.J. (1994) Multivariate Statistical Methods: A Primer, 2nd edn, Chapman & Hall, London.
114. Martin, D., Diehr, P., Perrin, E. and Koepsell, T. (1993) The effect of matching on the power of randomized community intervention studies. Statistics in Medicine, 12, 329-338.
115. Mason, S., Knowles, E., Colwell, B. et al. (2007) Effectiveness of paramedic practitioners in attending 999 calls from elderly people in the community: cluster randomised controlled trial. British Medical Journal (Clinical Research Edition), 335 (7626), 919. : 10.1136/bmj.39343.649097.55.
116. Matcham, J., Julious, S., Pyke, S.L. et al. (2011) Proposed best practice for statisticians in the reporting and publication of pharmaceutical industry-sponsored clinical trials. Pharmaceutical Statistics, 10, 70-73. doi: 10.1002/pst.417.
117. McCandlish, R., Bowler, U., van Asten, H. et al. (1998) A randomised controlled trial of care of the perineum during second stage of normal labour. British Journal of Obstetrics and Gynaecology, 105 (12), 1262-1272.
118. Mdege, N.D., Man, M.-S., Taylor Nee Brown, C.A. and Torgerson, D.J. (2011) Systematic review of stepped wedge cluster randomized trials shows that design is particularly used to evaluate interventions during routine implementation. Journal of Clinical Epidemiology, 64 (9), 936-948.
119. Medical Research Council (1948) Streptomycin treatment of pulmonary tuberculosis: a Medical Research Council investigation. British Medical Journal, ii, 7692.
120. Medical Research Council (2008) Developing and Evaluating Complex Interventions: New Guidance, Medical Research Council, www.mrc.ac.uk/complexinterventionsguidance (accessed 28 October 2013).
121. Mermin, J., Ekwaru, J.P., Were, W. et al. (2011) Utility of routine viral load, CD4 cell count, and clinical monitoring among adults with HIV receiving antiretroviral therapy in Uganda: randomised trial. British Medical Journal, 343, d6792.
122. Moerbeek, M. (2006) Power and money in cluster randomized trials: when is it worth measuring a covariate. Statistics in Medicine, 25 (25), 2607-2617. : 10.1002/sim.2297.
123. Moher, D., Schulz, K.F. and Altman, D.G. for the CONSORT Group (2001) The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomised trials. Lancet, 357, 1191-1194, http://www.consort-statement.org/ (accessed 28 October 2013).
124. Morrell, C.J., Slade, P., Warner, R. et al. (2009) Clinical effectiveness of health visitor training in psychologically informed approaches for depression in postnatal women: pragmatic cluster randomised trial in primary care. British Medical Journal, 338, 1-12.
125. Moulton, L.H. (2004) Covariate-based constrained randomization of group randomised trials. Clinical Trials, 1, 297-305.
126. Murray, D. (1998) Design and Analysis of Group Randomized Trials, Oxford University Press, New York.
127. Neuhaus, J. and Jewell, N. (1993) A geometric approach to assess bias due to omitted covariates in generalized liner models. Biometrika, 80, 807-815.
128. Niederer, I., Kriemler, S., Zahner, L. et al. (2009) Influence of a lifestyle intervention in preschool children on physiological and psychological parameters (Ballabeina): study design of a cluster randomized controlled trial. BMC Public Health, 9, 94. doi: 10.1186/1471-2458-9-94.
129. Nixon, R. and Thompson, S.G. (2003) Baseline adjustments for binary data in repeated cross-sectional cluster randomized trials. Statistics in Medicine, 22, 2673-2692.
130. Norman, G., Sloan, J. and Wrywich, K. (2003) Interpretation of changes in health-related quality of life. The remarkable universality of half a standard deviation. Medical Care, 41, 582-592.
131. Nourhashemi, F., Andrieu, S., Gillette-Guyonnet, S. et al. (2010) Effectiveness of a specific care plan in patients with Alzheimer's disease: cluster randomised trial (PLASA study). British Medical Journal, 340, c2466.
132. O'Cathain, A.,Walters, S.J., Nicholl, J.P. et al. (2002) Use of evidence based leaflets to promote informed choice in maternity care: randomised controlled trial in everyday practice. British Medical Journal (Clinical Research Edition), 324 (7338), 643.
133. Omar, R.Z. and Thompson, S.G. (2000) Analysis of a cluster randomized trial with binary outcome data using a multi-level model. Statistics in Medicine, 19, 2675-2688.
134. Pan, W. and Wall, M.M. (2002) Small-sample adjustments in using the sandwich variance estimator in generalized estimating equations. Statistics in Medicine, 21, 1429-1441.
135. Perneger, T. (1998) What's wrong with Bonferroni adjustments? British Medical Journal, 316, 1236.
136. Petrie, A. and Sabin, C., (2005) Medical Statistics at a Glance, (2nd edn). Blackwell, Oxford.
137. Peters, T.J., Richards, S.H., Bankhead, C.R. and Al, E. (2003) Comparison of methods for analysing cluster randomized trials: an example involving a factorial design. International Journal of Epidemiology, 32, 840-846.
138. Pinheiro, J.C. and Bates, D.M. (2000) Mixed Effect Models in S and SPLUS, Springer, New York.
139. Pocock, S. (1983) Clinical Trials: A Practical Approach, John Wiley & Sons, Ltd, Chichester.
140. Preisser, J.S., Young, M.L., Zaccaro, D.J. and Wolfson, M. (2003) An integrated population-averaged approach to the design, analysis and sample size determination of cluster-unit trials. Statistics in Medicine, 22 (8), 1235-1254. : 10.1002/sim.1379.
141. Prentice, R., Rossouw, J., Furberg, C. et al. (1998) Design of the WHI clinical trial and observational study. Controlled Clinical Trials, 19, 61-109.
142. Puder, J.J., Marques-Vidal, P., Schindler, C. et al. (2011) Effect of multidimensional lifestyle intervention on fitness and adiposity in predominantly migrant preschool children (Ballbeina): cluster randomized controlled trial. British Medical Journal, 343, d6195. doi: 10.1136/bmj.d6195.
143. Puffer, S., Torgerson, D. and Watson, J. (2003) Evidence for risk of bias in cluster randomised trials: review of recent trials published in three general medical journals. British Medical Journal, 237, 785-789.
144. Rabe-Hesketh, S. and Everitt, B.S. (2007) A Handbook of Statistical Analyses Using Stata, 4th edn, Chapman & Hall/CRC Press, Boca Raton, FL.
145. Richards, S.H., Bankhead, C., Peters, T.J., Austoker, J., Hobbs, F.D.R., Brown, J. et al. (2001) Cluster randomised controlled trial comparing the effectiveness and cost-effectiveness of two primary care interventions aimed at improving attendance for breast screening,. Journal of Medical Screening, 8, 91-98.
146. Robinson, K.A. and Goodman, S.N. (2011) A systematic examination of the citation of prior research in reports of randomized, controlled trials. Annals Internal Medicine, 154, 50-55.
147. Rollnick, S., Miller, W.R. and Butler, C.C. (2007) Motivational Interviewing in Health Care: Helping Patients Change Behavior, The Guildford Press, London.
148. Rotondi, M. and Donner, A. (2012) Sample size estimation in cluster randomized trials: an evidence-based perspective. Computation Statistics and Data Analysis, 56, 1174-1187. doi: 10.1016/j.csda.2010.12.010.
149. Satterthwaite, F.E. (1946) An approximate distribution of estimates of variance components. Biometrics Bulletin, 2, 110-114. doi: 10.2307/3002019.
150. Scott, N.W., McPherson, G.C., Ramsay, C.R. and Campbell, M.K. (2002) The method of minimization for allocation to clinical trials. Controlled Clinical Trials, 23, 662-674.
151. Schulz, K.F., Altman, D.G. and Moher, D. for the CONSORT Group (2010) CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials. British Medical Journal, 340, c332.
152. Senn, S.J. (2002) Cross-Over Trials in Medical Research, 2nd edn, JohnWiley & Sons, Ltd, Chichester.
153. Simpson, J.M., Klar, N. and Donner, A. (1995) Accounting for cluster randomization: a review of primary prevention trials, 1990 through 1993. American Journal of Public Health, 85, 1378-1383.
154. Skarbinski, J., Ouma, P.O., Causer, L.M. et al. (2009) Effect of malaria rapid diagnostic tests on the management of uncomplicated malaria with artemether-lumefantrine in Kenya: a cluster randomized trial. American Journal of Tropical Medicine and Hygiene, 80 (6), 919-926.
155. Soncini, J.A., Maserejian, N.N., Trachtenberg, F. et al. (2007) The longevity of amalgam versus compomer/composite restorations in posterior primary and permanent teeth: findings from the New England Children's Amalgam Trial. Journal of the American Dental Association, 138, 763-772.
156. StataCorp. (2009) Stata Statistical Software: Release 11. College Station, TX: StataCorp LP.
157. Stiell, I.G., Clement, C.M., Grimshaw, J. et al. (2009) Implementation of the Canadian C-Spine Rule: prospective 12 centre cluster randomised trial. British Medical Journal, 339, b4146.
158. Taljaard, M., Donner, A. and Klar, N. (2008) Imputation strategies for missing continuous outcomes in cluster randomized trials. Biometrical Journal, 50 (3), 329-345.
159. Taves, D.R. (1974) Minimization: a new method of assigning patients to treatment and control groups. Clinical Pharmacology and Therapeutics, 15, 443-453.
160. Teerenstra, S., Eldridge, S., Graff, M. et al. (2012) A simple sample size formula for analysis of covariance in cluster randomized trials. Statistics in Medicine, 31 (20), 2169-2178. : 10.1002/sim.5352.
161. Thabane, L., Ma, J., Chu, R. et al. (2010) A tutorial on pilot studies: the what, why and how. BMC Medical Research Methodology, 10, 1. doi: 10.1186/1471-2288-10-1.
162. Thomson, A., Hayes, R. and Cousens, S. (2009) Measures of between-cluster variability in cluster randomized trials with binary outcomes. Statistics in Medicine, 1739-1751. doi: 10.1002/sim.
163. Turner, R., Prevost, A. and Thompson, S. (2004) Allowing for imprecision of the intracluster correlation coefficient in the design of cluster randomized trials. Statistics in Medicine, 23 (8), 1195-214. : 10.1002/sim.1721.
164. Torgerson, D.J. (2001) Contamination in trials: is cluster randomisation the answer?. British Medical Journal, 322, 355-357.
165. Ukoumunne, O.C., Forbes, A.B., Carlin, J.B. and Gulliford, M.C. (2008) Comparison of the risk difference, risk ratio and odds ratio scales for quantifying the unadjusted intervention effect in cluster randomized trials. Statistics in Medicine, 27 (25), 5143-5155. : 10.1002/sim.
166. Ukoumunne, O.C. and Thompson, S.G. (2001) Analysis of cluster randomized trials with repeated cross-sectional binary measurements. Statistics in Medicine, 20 (3), 417-433.
167. Van Breukelen, G.J.P. and Candel, M.J.J.M. (2012) Comments on 'Efficiency loss because of varying cluster size in cluster randomized trials is smaller than literature suggests'. Statistics in Medicine, 31 (4), 397-400.
168. Walters, S.J. (2009) Consultants' forum: should post hoc sample size calculations be done? Pharmaceutical Statistics, 8 (2), 163-169.
169. Walters, S.J. (2009) Quality of Life Outcomes in Clinical Trials and Health Care Evaluation: A Practical Guide to Analysis and Interpretation, John Wiley & Sons, Ltd, Chichester.
170. Walters, S.J. (2010) Therapist effects in randomised controlled trials: what to do about them. Journal of Clinical Nursing, 19, 102-1112.
171. Walters, S. and Campbell, M. (2005) The use of bootstrap methods for estimating samples sizes and analysing health related quality of life outcomes. Statistics in Medicine, 24, 1075-1102.
172. Walters, S., Campbell, M. and Paisley, S. (2001) Methods for determining sample sizes for studies involving health-related quality of life measures: a tutorial. Health Services and Outcome Research, 2, 83-89.
173. Walters, S.J., Morrell, C.J. and Slade, P. (2011) Analysing data from a cluster randomised trial (cRCT) in primary care: a case study. Journal of Applied Statistics, 38 (10), 2253-2269.
174. Ware, J.E., Snow, K.K., Kosinski, M. and Gandek, B. (1993) SF-36 Health Survey Manual and Interpretation Guide, The Health Institute, New England Medical Centre, Boston, MA.
175. Weijer, C., Grimshaw, J.M., Eccles, M.P. et al. (2012) The Ottawa consensus statement on the ethical design and conduct of CRTs. PLoS Medicine, 9 (11), e1001346.
176. Welch, B.L. (1947) The generalization of 'Student's' problem when several different population variances are involved. Biometrika, 34, 28-35.
177. Whitehead, J. (1993) Sample size calculations for ordered categorical data. Statistics in Medicine, 12, 2257-2272.
178. Wikipedia (2013) http://en.wikipedia.org/wiki/Stata.
179. Williamson, P., Hutton, J.L., Bliss, J., Blunt, J., Campbell, M.J., Nicholson, R. (2000) Statistical review by research ethics committees. Journal of the Royal Statistical Society A, 163, 5-13.
180. Wood, D., Kinmonth, A.,Yarwood, J. et al. (1994) Randomised controlled trial evaluating cardiovascular screening and intervention in general practice: principal results of British family heart study. British Medical Journal, 308, 313. doi: 10.1136/bmj.308.6924.313.
181. Xie, T. and Waksman, J. (2003) Design and sample size estimation in clinical trials with clustered survival times as the primary endpoint. Statistics in Medicine, 22 (18), 2835-46. : 10.1002/sim.1536.
182. Zou, G.Y. (2004) A modified poisson regression approach to prospective studies with binary data. American Journal of Epidemiology, 159, 702-706.
183. Zou, G.Y. and Donner, A. (2011) Extension of the modified poisson regression model to prospective studies with correlated binary data. Statistical Methods in Medical Research. doi: 10.1177/0962280211427759.
184. Zou, G.Y., Donner, A. and Klar, N. (2005) Group sequential methods for cluster randomization trials with binary outcomes. Clinical Trials, 2, 479-487.