TESTING
TREATMENTS - BETTER RESEARCH
FOR BETTER HEALTHCARE
CHAPTER V - Excerpt
CLINICAL RESEARCH: THE GOOD,
THE BAD, AND THE UNNECESSARY
Regrettably,
research is not always well done or relevant. Take the example of a
distressing condition known as tardive dyskinesia. This is a serious
side-effect associated with long-term use of drugs called neuroleptics
(antipsychotics) which are prescribed for psychiatric disorders,
and especially schizophrenia. The most prominent features of tardive
dyskinesia are repetitive, involuntary movements of the mouth and face
grimacing, lip smacking, frequent poking out of the tongue, and
puckering or blowing out of the cheeks. Sometimes this is accompanied
by twitching of the hands and feet. One in five patients taking a
neuroleptic for more than three months experiences these side-effects.
In the 1990s a group of researchers began exploring, systematically,
what treatments had been used for tardive dyskinesia over the preceding
30 years. Writing in 1996, they were rather surprised to have
identified about 500 randomised controlled trials involving 90
different drug treatments. Yet none of these trials had produced any
useful data. Some of the trials had included too few patients to give
any reliable results; in others the treatments had been given so
briefly as to be meaningless.77
The same research group went on to publish a comprehensive survey of
the content and quality of controlled trials relevant to the treatment
of schizophrenia in general. They looked at 2,000 trials and were
disappointed in what they found. Over the years, drugs have certainly
improved the prospects for people with schizophrenia in some respects.
For example, most patients can now live at home or in the community.
Yet, even in the 1990s (and still today), most drug trials were done on
patients in hospital, so their relevance to outpatient treatment is
uncertain. On top of that, the
inconsistent way in which outcomes of treatment were assessed was
astonishing. The researchers discovered that over 600 treatments –
mainly drugs but also psychotherapy, for example – were tested in the
trials, yet 640 different scales were used to rate the results and 369
of these were
used only once. Comparing outcomes of different trials was therefore
severely hampered and the results were virtually uninterpretable by
doctors or patients. Among a catalogue of other problems, the
researchers identified many studies that were too small or short term
to give useful
results. And new drug treatments were often compared with a drug well
known for its side-effects – an obviously unfair test. The authors of
this review concluded that half a century of studies of limited
quality, duration, and clinical utility left much scope for
well-planned, properly conducted,
and competently reported trials.78
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BEING BETTER INFORMED
‘Even if evidence for the efficacy of interventions is lacking, or of
poor quality, it is important to avoid nihilism. By undertaking
systematic reviews and highlighting what high quality evidence does –
or does not – exist, clinicians, researchers, policy-makers and
patients will, at least, be better informed.’
Soares K,
McGrath J, Adams C. Evidence and tardive dyskinesia.
Lancet 1996;347;1696-7.
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