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Bias in Reporting of Genetic Association Studies

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Studies of publication bias have noted that papers with significant positive results are easier to find than those with nonsignificant or negative results... As a result, overrepresentation of positive studies in systematic reviews might mean that such reviews are biased toward a positive result... Publication bias is just one in a group of related biases, all of which potentially lead to overrepresentation of significant or positive studies in systematic reviews... Other types of bias include time lag bias (positive studies are more likely to be published rapidly); multiple publication bias (positive studies are more likely to be published more than once); citation bias (positive studies are more likely to be cited by others); and language bias (positive studies are more likely to be published in English)... There is some evidence that the decision to publish in international versus domestic journals might be influenced by the results... For example, significant results are often published in international journals, whereas nonsignificant results appear in the local literature, resulting in a language bias—although, the reverse situation has also been described... They found 161 Chinese studies on 12 of these gene–disease associations, only 20 of which were indexed in PubMed... Chinese studies had significantly more prominent genetic effects than non-Chinese studies, and 48% were statistically significant per se, despite their smaller sample size... The larger genetic effects in Chinese studies are unlikely to reflect genuine heterogeneity and are more likely to do with publication bias operating within the Chinese literature, say the authors... It is possible that there was reluctance to submit and publish negative or inconclusive results when a large body of English-language literature has shown the presence of genetic effects... However, such “forced” confirmation negates the importance of independent confirmation of research results... First, language bias might be important to consider in meta-analyses of observational studies, where its effect might be larger than its effect on randomized evidence... Second, because human genome epidemiology is a global enterprise, a comprehensive global view is important to help decipher artifacts from true genetic effects.

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Different results in local literature studies
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pmed-0020419-g001: Different results in local literature studies

Mentions: In PLoS Medicine, John Ioannidis and colleagues have taken a closer look at bias in Chinese genetics studies. Research done in non-English-speaking countries has two outlets. A study might be published in English-language journals, which are usually indexed in major international bibliographic databases such as PubMed, or in domestic journals, many of which are not indexed in international databases. The Chinese literature is a prominent example of where domestic scientific journals are not catalogued in international databases. There is some evidence that the decision to publish in international versus domestic journals might be influenced by the results. For example, significant results are often published in international journals, whereas nonsignificant results appear in the local literature, resulting in a language bias—although, the reverse situation has also been described.


Bias in Reporting of Genetic Association Studies
Different results in local literature studies
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC1285068&req=5

pmed-0020419-g001: Different results in local literature studies
Mentions: In PLoS Medicine, John Ioannidis and colleagues have taken a closer look at bias in Chinese genetics studies. Research done in non-English-speaking countries has two outlets. A study might be published in English-language journals, which are usually indexed in major international bibliographic databases such as PubMed, or in domestic journals, many of which are not indexed in international databases. The Chinese literature is a prominent example of where domestic scientific journals are not catalogued in international databases. There is some evidence that the decision to publish in international versus domestic journals might be influenced by the results. For example, significant results are often published in international journals, whereas nonsignificant results appear in the local literature, resulting in a language bias—although, the reverse situation has also been described.

View Article: PubMed Central

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Studies of publication bias have noted that papers with significant positive results are easier to find than those with nonsignificant or negative results... As a result, overrepresentation of positive studies in systematic reviews might mean that such reviews are biased toward a positive result... Publication bias is just one in a group of related biases, all of which potentially lead to overrepresentation of significant or positive studies in systematic reviews... Other types of bias include time lag bias (positive studies are more likely to be published rapidly); multiple publication bias (positive studies are more likely to be published more than once); citation bias (positive studies are more likely to be cited by others); and language bias (positive studies are more likely to be published in English)... There is some evidence that the decision to publish in international versus domestic journals might be influenced by the results... For example, significant results are often published in international journals, whereas nonsignificant results appear in the local literature, resulting in a language bias—although, the reverse situation has also been described... They found 161 Chinese studies on 12 of these gene–disease associations, only 20 of which were indexed in PubMed... Chinese studies had significantly more prominent genetic effects than non-Chinese studies, and 48% were statistically significant per se, despite their smaller sample size... The larger genetic effects in Chinese studies are unlikely to reflect genuine heterogeneity and are more likely to do with publication bias operating within the Chinese literature, say the authors... It is possible that there was reluctance to submit and publish negative or inconclusive results when a large body of English-language literature has shown the presence of genetic effects... However, such “forced” confirmation negates the importance of independent confirmation of research results... First, language bias might be important to consider in meta-analyses of observational studies, where its effect might be larger than its effect on randomized evidence... Second, because human genome epidemiology is a global enterprise, a comprehensive global view is important to help decipher artifacts from true genetic effects.

No MeSH data available.