Marcus Tolentino
Farmacêutico/Consultor Técnico
DECIT/SCTIE/MS


-----Mensagem original-----
De: Rakesh Biswas, Malaysia [mailto:[log in to unmask]]
Enviada em: domingo, 28 de janeiro de 2007 06:25
Para: HIFA2015
Assunto: [hifa2015] Evidence Based Medicine and the developing world


Thought I would share this with the list (if it hasn't been already
shared)--rakesh

Full text open at:
http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0020107


Is Evidence-Based Medicine Relevant to the Developing World? Systematic
reviews have yet to achieve their potential as a resource for
practitioners in developing countries. Paul Chinnock, Nandi Siegfried,
Mike Clarke

HIFA2015 profile: Rakesh Biswas is Associate professor, Department of
Medicine, Melaka-Manipal Medical College, Melaka, Malaysia. He is a
physician academic trying to merge two worlds, the developing and
developed in his day to day practice. He has worked in India, Nepal and
Malaysia. His interests include Medical problem solving, education and
evidence based telemedicine.
http://www.manipal.edu/melaka/departments/departments.htm
rakesh7biswas AT gmail.com

[Note from Neil PW, HIFA2015 co-moderator: Many thanks, Rakesh. PLoS
Medicine is an open-access publication, so we are able to reproduce the
full text here for the benefit of HIFA2015 members with slow or unreliable
internet access:

Citation: Chinnock P, Siegfried N, Clarke M (2005) Is Evidence-Based
Medicine Relevant to the Developing World? PLoS Med 2(5): e107
doi:10.1371/journal.pmed.0020107

IS EVIDENCE-BASED MEDICINE RELEVANT TO THE DEVELOPING WORLD?

Although there is still some resistance to the evidence-based medicine
movement, evidence-based health care has now become widely accepted and
adopted. Systematic reviews of the effectiveness of health care
interventions are the engine room of evidence-based health care; much has
been written about how these reviews should be conducted and what they can
achieve [1,2]. If the case for the use of systematic reviews is good in
developed countries - and we think it is - then the case is even stronger
in the developing world. Wherever health care is provided and used, it is
essential to know which interventions work, which do not work, and which
are likely to be harmful. This is especially important in situations where
health problems are severe and the scarcity of resources makes it vital
that they are not wasted [3].

But are the systematic reviews that have so far been published relevant
and of practical use to those who provide health care in 'the majority
world' (i.e., in developing countries? In our view, the relevance of
systematic reviews to frontline health care workers in developing
countries has so far been limited, for a number of reasons.

Reasons Why the Relevance Is Limited:

CONDITIONS
Most of the reviews produced to date address health conditions that are
priorities in the developed world [4]. Many major health concerns in
developing nations have yet to be made the subject of a review, although
there are signs that this may be changing [5]. The introductory
discussions of most reviews focus on the impact of conditions in the
United States and Western Europe. This may be an indication of the
authors' own priorities and experience, or it may be because they have
made assumptions about the priorities of journal editors and readers.

INTERVENTIONS
Health care professionals in developing countries sometimes wonder whether
their reliance on older, cheaper, 'lower-tech' approaches has made their
practice quite distinct from that of their colleagues in richer regions
[6]. Yet the authors of systematic reviews seem, by and large, to prefer
to take on the task of assessing the evidence for more recent (and
generally more expensive) technologies. This is not to say that reviewers
should avoid high-tech interventions. Again, it is a question of setting
priorities, and of recognising the urgent need for more reviews on
interventions that are feasible in the majority world.

EXCLUSION OF STUDIES FROM THE DEVELOPING WORLD
Systematic reviews are based largely on research that has been done in
rich countries. One of the reasons for this is the relative lack of
research in developing countries. However, even when research has been
conducted in these countries, it might not be published [7] - or if it is
published, it might not be in a journal that is indexed in the widely used
bibliographic databases such as MEDLINE and EMBASE. Thus, despite the best
efforts of many reviewers, relevant studies may easily be missed.
Excluding studies on the basis of language or region is generally not
considered good practice in systematic reviewing [8], but the difficulties
of identifying and assessing such studies can make finding them and
including them in a review an unrealistic expectation.

QUALITY OF STUDIES FROM THE DEVELOPING WORLD
Once studies have been found, they are assessed for quality by the
reviewers. Only when the quality meets the criteria specified in the
review protocol (in most cases, this specifies randomised controlled
trials only) are they included in the analysis. The difficulties of
conducting randomized controlled trials in resource-poor situations result
in the exclusion of many developing country studies. Some have suggested
that the 'quality threshold' should be lowered, so that more studies from
developing countries can be included in systematic reviews. This question
is contentious, and indeed divides the authors of this essay, but it needs
to be recognised and debated openly.

TRANSFERABILITY
Practitioners in low-income countries have questioned the
'transferability' of evidence derived from studies conducted in richer
nations [9]. The basis of their concern is their awareness that there can
be many differences between patient populations and in the delivery of
health care. Forjuoh et al. have pointed out that some injury prevention
interventions will have broad transferability, while others will not [10].
They went on to make suggestions as to which intervention would be
transferable, but they did so on theoretical grounds without any
supporting data.

Features of the typical health care experience of a patient living in the
developing world, as compared with features of the typical health care
experience of a patient in a clinical trial in a developed country, are
shown [below]:

Features of the typical health care experience of a patient living in the
less developed world include:
- late presentation
- self-medication of 'prescription' drugs or traditional treatments
- poor facilities may delay diagnosis
- referral (if needed) not easily arranged
- if a child, may be malnourished
- if a woman, may be anaemic
- will experience problems because of shortages of trained staff,
- and because of poor infection control
- and because of a lack of follow-up care
- patient may be unable (e.g., because of lack of funds) to fully adhere
to treatment.

Features of the typical health care experience of a patient in a clinical
trial in a developed country include
- none of the above

There are also important differences in the way in which care is delivered
in developing and developed countries. In developing countries, treatments
that would be delivered by doctors elsewhere are often delivered by
medical assistants or clinical officers. This may or may not have an
impact on the effectiveness of the treatment. Similarly, legislation can
be considered a health care intervention for the prevention of road
traffic injury, but the 'delivery' of such legislation (i.e., its
enforcement) is often harder to achieve in developing countries for a
multitude of reasons.

As a result of such differences, the most effective treatment in a
randomised controlled trial may not be the most effective treatment when
provided in the developing world. Some treatments will retain much of
their effectiveness in a resource-poor context; others will not.

One recently updated Cochrane review on the primary repair of penetrating
colon injuries is a case in point [11]. The update involved the addition
of data from one study, which had been completed since the original
version of the review had been published. This addition introduced a much
greater level of heterogeneity. The likely explanation for this, in the
opinion of the reviewers, was that the new study was the only one in which
the intervention had been applied in a developing country, which had
imposed a number of limitations on its delivery.

Rather than implying that a review's conclusions are globally applicable,
perhaps this is one of those circumstances where it would be more
appropriate if reviewers concluded with statements such as, 'There is
evidence for the effectiveness of this intervention in the countries and
setting where the included studies were conducted, and in places that are
similar in terms of the resources available.'

WHAT CAN BE DONE?
It is, of course, vital that more research of quality and relevance is
conducted in developing countries, but the writers of systematic reviewers
also have much to do. We need to find ways to make a good product better,
and we must do more to make sure that people in the majority world are
able to access the reviews that are published. In order for progress to be
made, the following questions require more attention than they have
received up to now.

AUTHORS
How can we involve more people from developing countries in the writing
and peer reviewing of systematic reviews? For example, how can we continue
to build on progress made on international activity within the Cochrane
Collaboration [12]
[...]

CONTEXT
Should reviews focus on specific contexts in relation to the location of
the condition and the delivery of the intervention?

BACKGROUND SECTIONS
How can we encourage reviewers to look at conditions/interventions
globally, and not just as they affect the United States and Western
Europe?

SEARCH FOR STUDIES
How can we make it easier to find and review data from research done in
developing countries?

ANALYSIS
Should reviewers be encouraged to consider whether heterogeneity between
study results might be due to differences in underlying resources?

CONCLUSIONS
Should conclusions address whether any recommendations apply everywhere,
or just in settings similar to those in which the included studies were
done? Or is this beyond the recommendations of a review?

DISSEMINATION OF THE FINDINGS OF REVIEWS
Is this best done by circulating the reviews themselves, or are reviews
merely a stage in the production of more accessible evidence-based health
information materials? For example, the World Health Organization's
Reproductive Health Library, available on CD-ROM, includes selected
Cochrane reviews but also summaries and commentaries that have been
specially prepared to provide a developing world perspective. The BMJ's
Clinical Evidence produces other summaries of the evidence (for example,
often integrating the findings of Cochrane Reviews into answers to
clinical questions), and aims to prepare these in user-friendly formats
and languages. Are more initiatives like these needed?

RESEARCH
Research is needed on the impact of systematic reviews on practice in the
developing world. We need to assess: What proportion of reviews are
relevant to health care in low-resource settings? Are evidence-based
sources used to set policy in different countries? How widely are the
Cochrane Library and/or Cochrane reviews used by health care workers, and
what are the barriers to use? How widely are these resources used by other
people involved in decisions about health care, including patients, their
carers, and policy makers? Has the use of Cochrane evidence influenced
practice? What do these users and potential users think would make reviews
more useful?

CONCLUSION
When so-called developing countries first gained freedom from their
colonial oppressors, Ernst Schumacher pointed out that there was a need,
not for the 'best' technology, but for 'appropriate' technology [13]. When
it comes to health care, practitioners and patients of these countries
need and deserve nothing less than the most 'appropriate evidence'.

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