|
Study (first author)
|
Criteria used to assess methodological quality of research
|
Results
|
Cho9
|
22 item validated scoring system
|
Study design in drug company sponsored clinical trials better than in research
where no stated sponsorship (P=0.04)
|
Clifford
|
5 item validated scoring system (Jadad) plus component (individual items on
Jadad scale and adequacy of concealment) approach
|
No difference by funding source for adequacy of allocation concealment
(P=0.377); no difference by funding source for overall/composite score on
Jadad scale (P=0.143)
|
Davidson
|
Sample size, blinding
|
For all trials higher rate of blinding for ones with industry sponsorship
(67.5% v 41.8%, P=0.01); for trials investigating medications no
difference in blinding (P=0.46); for sample size no difference between
clinical trials supported by drug companies and those with other sources of
funding or where funding not stated
|
Djulbegovic (1999)
|
5 item validated scoring system (Jadad)
|
No difference in quality scores between randomised controlled trials funded
solely by industry (mean 3.3 (SD 1.4); median: 3.5) and trials supported by
public sources (mean 2 (SD 0.96); median: 2) (P=0.308)
|
Djulbegovic
(2000)10
|
5 item validated scoring system (Jadad)
|
Randomised controlled trials funded solely or partly by industry had trend
towards higher quality scores (mean 2.94 (SD 1.3); median: 3) than trials
supported by government or other non-profit organisations (mean 2.4 (SD 0.8);
median: 2) (P=0.06)
|
Jadad
|
7 point validated scoring system (Guyatt and Oxman)
|
6/6 industry funded systematic reviews and meta-analyses had serious flaws
versus 34/44 non-industry funded reviews
|
Kjaergard
|
5 point validated scale including: concealment of allocation, generation of
allocation sequence, double blinding, dropouts/withdrawals, sample size
|
Clinical trials funded by either drug or device industry had higher quality
than trials with no external funding (P<0.001); quality of publicly funded
trials same as trials funded by drug or device industry (P=0.68)
|
Knox
|
9 item scale developed for this study, including clinical design,
generalisable data sources, statistical tests of significance performed on
appropriate outcomes, statement regarding perspective, description of costs of
the main included resources, description of time horizon, description of
source of total costs differences, discussion of limitations, comparisons with
other published studies
|
Drug company sponsored pharmacoeconomic analyses less likely to formally
report on study generalisability, but were more likely to provide information
on the key components of the methods section than were non-profit sponsored
analyses.
|
Liebeskind
|
100 point scale addressing 5 aspects of trial design and reporting:
randomisation, outcome, inclusion/exclusion criteria, description of
therapeutic regimen, statistical analysis
|
Clinical trials with corporate support had better quality than trials with
non-profit support (mean 73.1 (95% Cl 3.9) v 53.4 (9.8); P<0.0001)
|
Mandelkern
|
Presence or absence of placebo control
|
5/16 industry funded clinical trials had placebo controls compared with 3/16
non-industry funded trials
|
Massie11
|
Not stated
|
Higher proportion of industry funded clinical trials were adequately
controlled and designed than were trials with other sources of funding (71%
v 33%, P<0.01)
|
Neumann12
|
Adherence to recommended protocols for cost effectiveness studies (adequate
description of alternatives, study perspective clearly stated, discounted both
costs and QALYs if needed, incremental analyses performed correctly) plus
quality as judged by readers (scale of 1 to 7)
|
No difference between industry and non-industry funded studies on any measure:
adequate description of alternatives P=0.30; study perspective clearly stated
P=0.98; discounted both costs and QALYs P=0.65; incremental analyses performed
correctly P=0.73; quality as judged by readers P=0.49
|
Rochon
|
Modified version of Chalmers score including 14 items: control appearance
and/or regimen, randomisation, blinding, patients blinded, observers blinded
to treatment and results, previous estimate of numbers, testing compliance,
results of randomisation on pretreatment variables and inclusion in analysis,
major end points, post-beta estimate, confidence limits, statistical analyses,
withdrawals after randomisation, side effects discussion
|
No difference in quality score between industry only funded clinical trials
and those funded by government or foundations (mean 36.9% (SD 17.6%)
v 37.1% (17.8%), P=0.271)
|
