Jefferson, T; et al Relation of study quality, concordance, take home message, funding, and impact in studies of influenza vaccines: systematic review BRITISH MEDICAL JOURNAL, 338: Art. No. b354 FEB 12 2009

[Eugene Garfield]

E-mail Address: jefferson.tom at gmail.com 

Author(s): Jefferson, T (Jefferson, T.); Di Pietrantonj, C (Di 
Pietrantonj, C.); Debalini, MG (Debalini, M. G.); Rivetti, A (Rivetti, 
A.); Demicheli, V (Demicheli, V.) 

Title: Relation of study quality, concordance, take home message, funding, 
and impact in studies of influenza vaccines: systematic review 

Source: BRITISH MEDICAL JOURNAL, 338: Art. No. b354 FEB 12 2009 

Language: English 

Document Type: Review 

KeyWords Plus: INFORMATION-SEEKING BEHAVIOR; CONFLICTS-OF-INTEREST; 
ELDERLY-PEOPLE; DRUG TRIALS; VACCINATION; ASSOCIATION; CARE; CONCLUSIONS; 
MORTALITY; BENEFITS 

Abstract: Objective To explore the relation between study concordance, 
take home message, funding, and dissemination of comparative studies 
assessing the effects of influenza vaccines.
Design Systematic review without meta-analysis.
Data extraction Search of the Cochrane Library, PubMed, Embase, and the 
web, without language restriction, for any studies comparing the effects 
of influenza vaccines against placebo or no intervention. Abstraction and 
assessment of quality of methods were carried out.
Data synthesis We identified 259 primary studies ( 274 datasets). Higher 
quality studies were significantly more likely to show concordance between 
data presented and conclusions (odds ratio 16.35, 95% confidence interval 
4.24 to 63.04) and less likely to favour effectiveness of vaccines (0.04, 
0.02 to 0.09). Government funded studies were less likely to have 
conclusions favouring the vaccines (0.45, 0.26 to 0.90). A higher mean 
journal impact factor was associated with complete or partial industry 
funding compared with government or private funding and no funding 
(differences between means 5.04). Study size was not associated with 
concordance, content of take home message, funding, and study quality. 
Higher citation index factor was associated with partial or complete 
industry funding. This was sensitive to the exclusion from the analysis of 
studies with undeclared funding.
Conclusion Publication in prestigious journals is associated with partial 
or total industry funding, and this association is not explained by study 
quality or size. 

Addresses: [Jefferson, T.; Di Pietrantonj, C.; Debalini, M. G.; Rivetti, 
A.; Demicheli, V.] ASL AL 20, Cochrane Vaccines Field, I-15100 
Alessandria, Italy 

Reprint Address: Jefferson, T, ASL AL 20, Cochrane Vaccines Field, I-15100 
Alessandria, Italy. 

E-mail Address: jefferson.tom at gmail.com 

Cited Reference Count: 33 

Times Cited: 0 

Publisher: B M J PUBLISHING GROUP 

Publisher Address: BRITISH MED ASSOC HOUSE, TAVISTOCK SQUARE, LONDON WC1H 
9JR, ENGLAND 

ISSN: 0959-8146 

DOI: 10.1136/bmj.b354 

29-char Source Abbrev.: BRIT MED J 

ISO Source Abbrev.: Br. Med. J. 

Source Item Page Count: 7 

Subject Category: Medicine, General & Internal 

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