Meta-analysis: methods, strengths, and weaknesses.
ABSTRACT Meta-analysis is a systematic, quantitative approach to the combination of data from several clinical trials that address the same question. This analytic approach can help resolve questions that remain unclear from the results of individual trials. Meta-analysis is of particular interest in oncology because of the small differences in efficacy between therapeutic alternatives. The large number of patients included in meta-analyses permit small to moderate benefits of a treatment to be reliably detected and larger treatment benefits to be quantified more accurately. Despite these apparent benefits, the use of meta-analysis has met with a great deal of resistance and has generated much controversy in clinical journals. After a brief description of the basic methods of conducting meta-analyses, this article will explore both their advantages and disadvantages.
- SourceAvailable from: Susan E Cashin[Show abstract] [Hide abstract]
ABSTRACT: Childhood overweight has increased in the United States. Success of weight-loss programs has been limited (Barlow, S.E., & Dietz, W.H. (1998). Obesity evaluation and treatment: Expert committee recomendations. Pediatrics, 102, e29.). The purpose of this investigation was to systematically examine the effectiveness of weight-loss interventions for children. For this meta-analysis, seven weight-loss intervention studies were coded and quality index scores calculated. The interventions had a significant positive effect on weight-loss average d = 0.95, with a 95% confidence interval of 0.79 to 1.11. Limited interventional studies with effective long-term maintenance of weight loss in children are available in the literature. However, there are effective methods for weight loss in children.Journal of Pediatric Nursing 02/2006; 21(1):45-56. · 0.92 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: The interpretation of clinical significance continues to be an obstacle for researchers in behavioral medicine. To review selected behavioral medicine research to critically examine the perception among investigators that behavioral effects on health are small based on common metrics of clinical significance. Using quantitative findings from recent behavioral medicine research in medical and psychiatric journals, we explored results in terms of several statistical metrics to assess potential clinical significance: r coefficients, risk ratios, risk difference measures, and attributable risk. Translated into r coefficients, even established health predictors such as smoking, obesity, and fitness had only modest effects (rs =.03-.22), and the range of effect sizes were comparable with those based on psychological predictors including depression and stress-reactivity (rs =.06-.22). In contrast, effects for both classes of predictors were suggestive of clinical significance based on public health statistics. Our choice of statistics for defining "small" and "large" effect sizes affects the perceived importance of behavioral health findings. In the assessment of health outcomes with low incidence rates, effects expressed as correlations using even the most robust predictors will often appear small. In these instances, we challenge researchers to move beyond conventional data analysis approaches and to expand their clinical interpretation efforts by employing additional statistical methods favored in medicine and public health.Annals of Behavioral Medicine 05/2004; 27(2):138-45. · 4.20 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Various methods for statistical analysis of data are available to clinicians and researchers. Meta-analysis is a tool by which small, related studies are identified and, through systematic review, are combined into a common data pool for a single, larger population analysis. As with all statistical methods, there are indications and contraindications for the use of meta-analysis. Additionally, meta-analysis is dependent upon the quality of data applied, the bias of the test itself, and the interpretation of the results. This article will discuss these aspects of meta-analysis, including the history of its development and usage in the scientific community, basic terminology, and a relevant literature review.Special Care in Dentistry 01/2008; 28(4):125-30.