This week in the BMJ
Volume 326,
Number 7400,
Issue of 31 May 2003
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Research sponsored by drug companies is biased
Outpatient treatment for deep vein thrombosis of the leg is safe
Drug representatives may increase unnecessary GP prescribing
Reporting of clinical trials of drugs shows bias
"Opt-out" consent increases uptake of HIV screening
Evidence on stage based approach to smoking cessation is limited
Research sponsored by drug companies is biased
Outcomes in research that is sponsored by a pharmaceutical company tend to
favour the company's product. Lexchin and colleagues
(p 1167) reviewed 30 studies
that compared research sponsored by the drug industry and research that was
funded in other ways. The quality of the methods was at least as good in
research sponsored by industry as in research with other sources of funding,
but industry sponsored studies were four times as likely to produce favourable
outcomes. This might be due, the authors say, to an inappropriate comparator
or to publication bias.
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AGB/REX
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Outpatient treatment for deep vein thrombosis of the leg is safe
Deep vein thrombosis can be treated on an outpatient basis, without any
greater risk of complications. Initial treatment with low molecular weight
heparins means that activated partial thromboplastin time need not be
monitored. Major haemorrhage during initial treatment is less likely, and
overall mortality at the end of follow up is reduced, Tovey and Wyatt report
(p 1180). These drugs are cost
effective, safe, and preferred by patients. Pain or swelling of a lower limb
is a relatively common presenting complaint, and the differential diagnosis of
deep vein thrombosis is wide. No single investigation is ideal, and often
several tests can be performed, either sequentially or in combination.
Drug representatives may increase unnecessary GP prescribing
General practitioners who see drug companies' representatives at least once
a week are more likely to express views that lead to unnecessary prescribing.
In a questionnaire survey of the attitudes and behaviours of general
practitioners throughout England in relation to their prescribing rates,
Watkins and colleagues found that practitioners with the greatest contact with
drug representatives were most willing to prescribe new drugs and to comply
with patients' requests for drugs that are not clinically indicated
(p 1178). The doctors who saw
drug representatives most frequently tended to be singlehanded practitioners,
did not provide postgraduate training, and worked in deprived
areas.
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CSA PLASTOCK/PHOTONICA
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Reporting of clinical trials of drugs shows bias
Results from clinical studies sponsored by the pharmaceutical industry that
reach the public domain are subject to bias, according to a study by Melander
and colleagues (p 1171). They
investigated 42 placebo controlled studies of selective serotonin reuptake
inhibitors submitted to the Swedish drug regulatory authority in 1983-99 and
compared the published results with the results in the full reports of the
studies. A major cause of bias was the tendency to publish only the more
favourable per protocol results, rather than intention to treat analyses.
Other causes were extensive duplicate publication and a preference for
publishing only studies showing significant effects of the drug.
"Opt-out" consent increases uptake of HIV screening
Introducing routine serological testing increases the acceptability and
uptake of HIV screening in genitourinary medicine clinics. Stanley and
colleagues (p 1174) audited
the introduction of routine rather than selective HIV screening in 400
patients and found that uptake was almost doubled. Including HIV in the
package of screening tests did not reduce the uptake of syphilis screening.
These findings supplement those of Read and Winceslaus
(
BMJ
2003;326:
1066-7[Free Full Text]) who found, when reviewing
their genitourinary clinic database, that replacing the usual lengthy oral
counselling with a shorter, written explanation of the main points about
testing doubled the rate of uptake of HIV
testing.
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BSIP/FILIN, HERRERA/SPL
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Evidence on stage based approach to smoking cessation is limited
Though services aimed at smoking cessation have made extensive use of the
stage based approach, only limited evidence exists for its effectiveness. In a
systematic review, Riemsma and colleagues
(p 1175) identified 23
randomised controlled trials evaluating a stage based approach for helping
people to quit smoking. They found wide variation in the quality of methods
and in the theories justifying the interventions used. Few studies reported
that the instruments used to assess participants' stage of change had been
validated. As a result, the authors say, more rigorous studies are needed
before stage based approaches to smoking cessation are considered
credible.
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KENNY TRICE/PHOTONICA
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© 2003 BMJ Publishing Group Ltd
