Publication Probability of a Study circumstantial Evidence for in Medical Study on Odds Ratio Value Publication Bias Areas

A summarized odds ratio, calculated from odds ratios ef published studies in a meta-analysis, may be overestlmated because of publication bias. A method has been developed estimating indirectly the summarized odds ratio of all studies in a given research areeq including not only those published but also unpublished in the present study, a publication probability according to odds ratio yalue was obtained from the probability density function of all the studies and a histogram of those published A publication probabiltty, according to odds ratio value, enables us to infer the quantitative relationship between publication probability and odds ratio. A notable nonpnblication of studies whose odds ratios were close to unity was shown from examples of studies on the relationship between passive smoking and lung cancer, whereas nonpublication of studies whose summarized odds ratio was located far from unity was not detected frorn examples of studies on the relationship between cryptorchidism and testicular cancer. in both study areas, however, the dithrences between the summarized odds ratios, either with or without the hypothetical unpubllshed studies, were not 1arge. The small difference, however, should not be ignored, when the study area is recognized as a social preblem,