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Industry-supported meta-analyses compared with meta-analyses with non-profit or no support: differences in methodological quality and conclusions.

Jørgensen AW, Maric KL, Tendal B, Faurschou A, Gøtzsche PC - BMC Med Res Methodol (2008)

Bottom Line: This analysis did not change the results much.Transparency is essential for readers to make their own judgment about medical interventions guided by the results of meta-analyses.We found that industry-supported meta-analyses are less transparent than meta-analyses with non-profit support or no support.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Nordic Cochrane Centre, Department 3343, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark. awj@cochrane.dk

ABSTRACT

Background: Studies have shown that industry-sponsored meta-analyses of drugs lack scientific rigour and have biased conclusions. However, these studies have been restricted to certain medical specialities. We compared all industry-supported meta-analyses of drug-drug comparisons with those without industry support.

Methods: We searched PubMed for all meta-analyses that compared different drugs or classes of drugs published in 2004. Two authors assessed the meta-analyses and independently extracted data. We used a validated scale for judging the methodological quality and a binary scale for judging conclusions. We divided the meta-analyses according to the type of support in 3 categories: industry-supported, non-profit support or no support, and undeclared support.

Results: We included 39 meta-analyses. Ten had industry support, 18 non-profit or no support, and 11 undeclared support. On a 0-7 scale, the median quality score was 6 for meta-analyses with non-profit or no support and 2.5 for the industry-supported meta-analyses (P < 0.01). Compared with industry-supported meta-analyses, more meta-analyses with non-profit or no support avoided bias in the selection of studies (P = 0.01), more often stated the search methods used to find studies (P = 0.02), searched comprehensively (P < 0.01), reported criteria for assessing the validity of the studies (P = 0.02), used appropriate criteria (P = 0.04), described methods of allocation concealment (P = 0.05), described methods of blinding (P = 0.05), and described excluded patients (P = 0.08) and studies (P = 0.15). Forty percent of the industry-supported meta-analyses recommended the experimental drug without reservations, compared with 22% of the meta-analyses with non-profit or no support (P = 0.57).In a sensitivity analysis, we contacted the authors of the meta-analyses with undeclared support. Eight who replied that they had not received industry funding were added to those with non-profit or no support, and 3 who did not reply were added to those with industry support. This analysis did not change the results much.

Conclusion: Transparency is essential for readers to make their own judgment about medical interventions guided by the results of meta-analyses. We found that industry-supported meta-analyses are less transparent than meta-analyses with non-profit support or no support.

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Related in: MedlinePlus

Search for meta-analyses and reasons for exclusion.
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Figure 1: Search for meta-analyses and reasons for exclusion.

Mentions: The search in PubMed identified 1188 records of meta-analyses. Most were ineligible because they did not compare drugs (Figure 1). We included 39 meta-analyses, 10 of which were Cochrane reviews. Ten had industry support, 18 non-profit or no support, and 11 undeclared support (Table 1 and additional file 1: References of included meta-analyses).


Industry-supported meta-analyses compared with meta-analyses with non-profit or no support: differences in methodological quality and conclusions.

Jørgensen AW, Maric KL, Tendal B, Faurschou A, Gøtzsche PC - BMC Med Res Methodol (2008)

Search for meta-analyses and reasons for exclusion.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2553412&req=5

Figure 1: Search for meta-analyses and reasons for exclusion.
Mentions: The search in PubMed identified 1188 records of meta-analyses. Most were ineligible because they did not compare drugs (Figure 1). We included 39 meta-analyses, 10 of which were Cochrane reviews. Ten had industry support, 18 non-profit or no support, and 11 undeclared support (Table 1 and additional file 1: References of included meta-analyses).

Bottom Line: This analysis did not change the results much.Transparency is essential for readers to make their own judgment about medical interventions guided by the results of meta-analyses.We found that industry-supported meta-analyses are less transparent than meta-analyses with non-profit support or no support.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Nordic Cochrane Centre, Department 3343, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark. awj@cochrane.dk

ABSTRACT

Background: Studies have shown that industry-sponsored meta-analyses of drugs lack scientific rigour and have biased conclusions. However, these studies have been restricted to certain medical specialities. We compared all industry-supported meta-analyses of drug-drug comparisons with those without industry support.

Methods: We searched PubMed for all meta-analyses that compared different drugs or classes of drugs published in 2004. Two authors assessed the meta-analyses and independently extracted data. We used a validated scale for judging the methodological quality and a binary scale for judging conclusions. We divided the meta-analyses according to the type of support in 3 categories: industry-supported, non-profit support or no support, and undeclared support.

Results: We included 39 meta-analyses. Ten had industry support, 18 non-profit or no support, and 11 undeclared support. On a 0-7 scale, the median quality score was 6 for meta-analyses with non-profit or no support and 2.5 for the industry-supported meta-analyses (P < 0.01). Compared with industry-supported meta-analyses, more meta-analyses with non-profit or no support avoided bias in the selection of studies (P = 0.01), more often stated the search methods used to find studies (P = 0.02), searched comprehensively (P < 0.01), reported criteria for assessing the validity of the studies (P = 0.02), used appropriate criteria (P = 0.04), described methods of allocation concealment (P = 0.05), described methods of blinding (P = 0.05), and described excluded patients (P = 0.08) and studies (P = 0.15). Forty percent of the industry-supported meta-analyses recommended the experimental drug without reservations, compared with 22% of the meta-analyses with non-profit or no support (P = 0.57).In a sensitivity analysis, we contacted the authors of the meta-analyses with undeclared support. Eight who replied that they had not received industry funding were added to those with non-profit or no support, and 3 who did not reply were added to those with industry support. This analysis did not change the results much.

Conclusion: Transparency is essential for readers to make their own judgment about medical interventions guided by the results of meta-analyses. We found that industry-supported meta-analyses are less transparent than meta-analyses with non-profit support or no support.

Show MeSH
Related in: MedlinePlus