Meta-analysis of repeated measures study designs.

RATIONALE, AIMS AND OBJECTIVES Repeated measures studies are found in many areas of research, particularly in areas of healthcare. There is currently little information available to inform the method of meta-analysis of repeated measures studies so that the structural dependence of the data is appropriately accommodated and the findings are meaningful. METHOD Using a published meta-analysis on the impact of diet advice on weight reduction of obese or overweight individuals, we demonstrate possible approaches for repeated measures meta-analysis. These approaches differ in terms of the type of result obtained (e.g. effect at a particular time-point, trend over time, change between time-points) and the data needed for the analysis (e.g. means, regression slope estimates). Some approaches involve violating assumptions of independence in the data structure and so to investigate the impact of this violation a simulation study is carried out. RESULTS The different approaches described for the meta-analyses of repeated measures studies can all provide useful effect estimates depending on the question to be addressed by the meta-analysis. However, violation of the independence assumption in some approaches can lead to biased estimates. CONCLUSIONS In practice, the methods available to carry out meta-analyses of repeated measures studies will not only depend upon the question of interest, but also on the data available from the primary studies.

[1]  R. Jeffery,et al.  A randomized trial of counseling for fat restriction versus calorie restriction in the treatment of obesity. , 1995, International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity.

[2]  Jason L. Horowitz,et al.  The prevention of depressive symptoms in children and adolescents: A meta-analytic review. , 2006, Journal of consulting and clinical psychology.

[3]  A. Tan,et al.  Meta‐analysis of holmium laser enucleation versus transurethral resection of the prostate for symptomatic prostatic obstruction , 2007, The British journal of surgery.

[4]  Mark Petticrew,et al.  Systematic reviews from astronomy to zoology: myths and misconceptions , 2001, BMJ : British Medical Journal.

[5]  W. Scarfe,et al.  A meta-analysis of mandibular intercanine width in treatment and postretention. , 1998, The Angle orthodontist.

[6]  N. G. Best,et al.  WinBUGS User Manual: Version 1.4 , 2001 .

[7]  R. Tamura,et al.  The use of repeated measures analyses in developmental toxicology studies. , 1992, Neurotoxicology and teratology.

[8]  C D Naylor,et al.  Meta-analysis of controlled clinical trials. , 1989, The Journal of rheumatology.

[9]  M. Borenstein,et al.  Publication Bias in Meta-Analysis: Prevention, Assessment and Adjustments , 2006 .

[10]  Mark C Simmonds,et al.  Meta-analysis of individual patient data from randomized trials: a review of methods used in practice , 2005, Clinical trials.

[11]  S. Nolen-Hoeksema,et al.  Age, gender, race, socioeconomic status, and birth cohort differences on the children's depression inventory: a meta-analysis. , 2002, Journal of abnormal psychology.

[12]  N. Laird,et al.  Meta-analysis in clinical trials. , 1986, Controlled clinical trials.

[13]  C. P. Winlove,et al.  Fluids reverse the early lipopolysaccharide-induced albumin leakage in rodent mesenteric venules , 2004, Intensive Care Medicine.

[14]  M Blettner,et al.  Traditional reviews, meta-analyses and pooled analyses in epidemiology. , 1999, International journal of epidemiology.

[15]  M. Borenstein,et al.  Publication Bias in Meta-Analysis , 2006 .

[16]  P Glasziou,et al.  WITHDRAWN: Advice on low-fat diets for obesity. , 2008, The Cochrane database of systematic reviews.

[17]  S. Thompson,et al.  How should meta‐regression analyses be undertaken and interpreted? , 2002, Statistics in medicine.

[18]  L. Doyle,et al.  Early developmental intervention programs post hospital discharge to prevent motor and cognitive impairments in preterm infants. , 2008, The Cochrane database of systematic reviews.

[19]  David R. Jones,et al.  How vague is vague? A simulation study of the impact of the use of vague prior distributions in MCMC using WinBUGS , 2005, Statistics in medicine.

[20]  J. Harvey-Berino.  The efficacy of dietary fat vs. total energy restriction for weight loss. , 1998, Obesity research.

[21]  Nancy P Barnett,et al.  Brief motivational intervention for adolescent smokers in medical settings. , 2005, Addictive behaviors.

[22]  F. Sacks,et al.  A randomized controlled trial of a moderate-fat, low-energy diet compared with a low fat, low-energy diet for weight loss in overweight adults , 2001, International Journal of Obesity.

[23]  S. Nolen-Hoeksema,et al.  Age, gender, race, socioeconomic status, and birth cohort difference on the children's depression inventory: A meta-analysis. , 2002 .

[24]  L. Stewart,et al.  To IPD or not to IPD? , 2002, Evaluation & the health professions.

[25]  David R. Jones,et al.  Empirical assessment of effect of publication bias on meta-analyses , 2000, BMJ : British Medical Journal.

[26]  M. Parmar,et al.  Meta-analysis of the literature or of individual patient data: is there a difference? , 1993, The Lancet.

[27]  Lurdes Y T Inoue,et al.  Combining longitudinal studies of PSA. , 2004, Biostatistics.

[28]  William Caplan,et al.  Weight-loss outcomes: a systematic review and meta-analysis of weight-loss clinical trials with a minimum 1-year follow-up. , 2007, Journal of the American Dietetic Association.

[29]  A. Avenell,et al.  Weight loss with high and low carbohydrate 1200 kcal diets in free living women , 1997, European Journal of Clinical Nutrition.

[30]  R. Wing,et al.  Effects of a Behavioral Weight Loss Program Stressing Calorie Restriction Versus Calorie Plus Fat Restriction in Obese Individuals With NIDDM or a Family History of Diabetes , 1995, Diabetes Care.

[31]  Harvey Goldstein,et al.  Multilevel modelling of medical data , 2002, Statistics in medicine.

[32]  M. Ussher,et al.  Cannabinoid type 1 receptor antagonists (rimonabant) for smoking cessation. , 2007, The Cochrane database of systematic reviews.

[33]  D. Altman,et al.  Measuring inconsistency in meta-analyses , 2003, BMJ : British Medical Journal.

[34]  Douglas G Altman,et al.  Statistics Notes: Units of analysis , 1997, BMJ.

[35]  M. A. Best.  Bayesian Approaches to Clinical Trials and Health‐Care Evaluation , 2005 .

[36]  P. McGovern,et al.  Nutrient and Food Intake in Obese Women on a Low-Fat or Low-Calorie Diet , 1996, American journal of health promotion : AJHP.

[37]  J. Baron,et al.  A randomized controlled trial of low carbohydrate and low fat/high fiber diets for weight loss. , 1986, American journal of public health.

[38]  B. Mccarthy,et al.  Forest floor fuel dynamics in mixed-oak forests of south-eastern Ohio , 2006 .

[39]  J. Fleiss,et al.  Meta-analysis in epidemiology, with special reference to studies of the association between exposure to environmental tobacco smoke and lung cancer: a critique. , 1991, Journal of clinical epidemiology.

[40]  M. Barker,et al.  Milk intake and bone mineral acquisition in adolescent girls: randomised, controlled intervention trial , 1997, BMJ.

[41]  Alex J. Sutton,et al.  Methods for Meta-Analysis in Medical Research , 2000 .

[42]  D. Albarracín,et al.  Nature, decay, and spiraling of the effects of fear-inducing arguments and HIV counseling and testing: a meta-analysis of the short- and long-term outcomes of HIV-prevention interventions. , 2007, Health psychology : official journal of the Division of Health Psychology, American Psychological Association.

[43]  L. Hedges,et al.  Statistical Methods for Meta-Analysis , 1987 .

[44]  John Wong,et al.  Meta-analysis: The Effect of Dietary Counseling for Weight Loss , 2007, Annals of Internal Medicine.

[45]  Richard D Riley,et al.  Evidence synthesis combining individual patient data and aggregate data: a systematic review identified current practice and possible methods. , 2007, Journal of clinical epidemiology.

[46]  P. Müller,et al.  Bayesian Meta‐analysis for Longitudinal Data Models Using Multivariate Mixture Priors , 2003, Biometrics.

[47]  A Whitehead,et al.  Borrowing strength from external trials in a meta-analysis. , 1996, Statistics in medicine.

[48]  J. Hoeksma,et al.  On growth curves and mixture models , 2006 .

[49]  P. McGovern,et al.  Comparison of a low-fat, ad libitum complex-carbohydrate diet with a low-energy diet in moderately obese women. , 1994, The American journal of clinical nutrition.