The purpose of this article is to describe how health practitioners can interpret the results from published meta-analytic reports of intervention effectiveness and efficacy studies, and then communicate those results, in a manner that helps patients make critical clinical and life decisions. The problem of using research evidence in clinical decision making is one of moving from generalized findings about intervention effectiveness to a prediction for a specific patient. To move toward a reasonable prediction, practitioners need information from a meta-analytic report that enables them to identify and understand the distribution of outcome results that are most applicable to a specific patient. Relevancy, effectiveness, and interpretation forms of information are discussed in this article. The focus is on the interpretation of the effect size statistics d and r for understanding the variation in responses that the patient might experience with an intervention.
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References
1.
Cohen, J.
(1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Erlbaum.
2.
Cooper, H. M.
, & Hedges, L. V. (Eds.). (1994). The handbook of research synthesis. New York: Russell Sage.
3.
Glasziou, P.
, Guyatt, G. H., Dans, A. L., Dans, L. F., Straus, S., & Sackett, D. L. (1998). Editorial: Applying the results of trials and systematic reviews to individual patients. ACP Journal Club, 129(3), A15–A16.
4.
Gould, S. J.
(1996). Full house: The spread of excellence from Plato to Darwin. New York: Three Rivers.
5.
Greenhouse, J. B.
, & Iyengar, S. (1994). Sensitivity analysis and diagnostics. In H. M. Cooper & L. V. Hedges(Eds.), The handbook of research synthesis (pp.383–398). New York: Russell Sage.
6.
Hall, J.A.
, Rosenthal, R., Tickle-Degnen, L., & Mosteller, F. (1994). Hypotheses and problems in research synthesis. In H. M. Cooper & L. V. Hedges (Eds.), The handbook of research synthesis (pp. 17–28). New York: Russell Sage.
7.
Kwakkel, G.
, Wagenaar, R., Koelman, T. W., Lankhorst, G. J., & Koetsier, J. C. (1997). Effects of intensity of rehabilitation after stroke: A research synthesis. Stroke, 28, 1550–1556.
8.
Mant, D.
(1999). Can randomised trials inform clinical decisions about individual patients?Lancet, 353, 743–746.
9.
McCartney, K.
, & Rosenthal, R. (2000). Effect size, practical importance, and social policy for children. Child Development, 71, 173–180.
10.
Moher, D.
, Cook, D. J., Eastwood, S., Olkin, I., Rennie, D., & Stroup, D. F. for the QUOROM Group. (1999). Improving the quality of reports of meta-analyses of randomised controlled trials: The QUOROM statement. Lancet, 354, 1896–1900.
11.
Ottenbacher, K. J.
, & Jannell, S. (1993). The results of clinical trials in stroke rehabilitation research. Archives of Neurology, 50, 37–44.
12.
Oxman, A. D.
, & Guyatt, G. H. (1992). A consumer’s guide to subgroup analyses. Annals of Internal Medicine, 116, 78–84.
13.
Pogue, J.
, & Yusuf, S. (1998). Overcoming the limitations of current meta-analysis of randomised controlled trials. Lancet, 351, 47–52.
14.
Rosenthal, R.
(1994). Parametric measures of effect size. In H. M. Cooper & L. V. Hedges (Eds.), The handbook of research synthesis (pp. 231–244). New York: Russell Sage.
15.
Rosenthal, R.
, & Rosnow, R. (1991). Essentials of behavioral research: Methods and data analysis (2nd ed.). New York: McGraw-Hill.
16.
Rosenthal, R.
, & Rubin, D. B. (1982). A simple general purpose display of magnitude of experimental effect. Journal of Educational Psychology, 74, 166–169.
17.
Rosser, W. W.
(1999). Application of evidence from randomised controlled trials to general practice. Lancet, 353, 661–664.
18.
Sackett, D. L.
, Richardson, W. S., Rosenberg, W., & Haynes, R. B. (1997). Evidence-based medicine: How to practice and teach EBM. New York: Churchill Livingstone.
19.
Shadish, W. R.
, & Haddock, C. K. (1994). Combining estimates of effect size. In H. M. Cooper & L. V. Hedges (Eds.), The handbook of research synthesis (pp. 261–281). New York: Russell Sage.
20.
Stock, W. A.
, Benito, J. G., & Lasa, N. B. (1996). Research synthesis: Coding and conjectures. Evaluation & the Health Professions, 19, 104–117.
21.
Stroup, D. F.
, Berlin, J. A., Morton, S. C., Olkin, I., Williamson, G. D., Rennie, D., Moher, D., Becker, B. J., Sipe, T. A., & Thacker, S. B. for the MOOSE Group. (2000). Meta-analysis of observational studies in epidemiology: A proposal for reporting. Journal of the American Medical Association, 283, 2008–2012.
22.
Tickle-Degnen, L.
(1998). Communicating with patients about treatment outcomes: The use of meta-analytic evidence in collaborative treatment planning. American Journal of Occupational Therapy, 52, 526–530.
23.
Wade, D. T.
, Collen, F. M., Robb, G. F., & Warlow, C. P. (1992). Physiotherapy intervention late after stroke and mobility. British Medical Journal, 304, 609–613.
24.
Werner, R. A.
, & Kessler, S. (1996). Effectiveness of an intensive outpatient rehabilitation program for postacute stroke patients. American Journal of Physical Medicine and Rehabilitation, 75, 114–120.
