With the exception of Egyptian physicians, research findings published in local journals are more likely to result in change in clinical practice relative to journals published in other regions followed closely by research findings published in North American journals. This was demonstrated by the fact that more than 80% of the physicians in this study chose the highest two influence categories indicating a high willingness to change practice in response to findings in local journals. This contrasted with approximately 60% for North American journals and less for European and regional publications.
The relative influence of research done in different regions is similar to the pattern for journal information. It is also clear that the physicians' impressions of the difference in research quality in different regions affect the degree to which they are willing to change their practices. This was evident from the fact that there was a statistically significant increase in influence scores for local and regional research if research quality is considered the same. The changes are most evident among the Kenyan and Egyptian physicians. The changes in impact scores for North American and European research are however not statistically significant. These contrasting findings suggest that developing world physicians think that the quality of medical research in North America and Europe is better than that in their own regions and countries.
This study also demonstrated that there is significant variation between countries in the likely influence of journals from and research studies done in different regions. Most physicians are likely to be influenced by North American publications. There is more variation with regard to the likely effects of European publications on physician practice: physicians from Kenya, Egypt and India are more likely to be influenced by European research relative to those sampled in China and in Thailand. This may directly relate to the relative contact between the medical establishment in Europe and those in these countries. Europe has had a longer history of influence in the medical establishments in Kenya, India and in Egypt relative to those in China and in Thailand. Differences in language may also add to this influence. This study also reveals that physicians working in tertiary care hospitals are more likely to be influenced by North American and European publications than physicians from secondary care hospitals. This may relate to the greater exposure these physicians have to publications and research done in North America and Europe.
There is also much variation with regard to the physicians' impressions of the likely impact of regional research and publication on their practice. Kenyan and Indian physicians are more likely to be influenced by their regional publications and research than are physicians from the other countries studied. Egyptian physicians are especially unlikely to be influenced by their regional journals
The design of this study involved random sampling of physicians after an initial random sampling of hospitals. This was however not carried out uniformly, and where random sampling was performed the method was left to the individual investigators. There is a strong possibility of selection bias being present in this study, thus limiting the interpretation of between-country differences in the results. It is unlikely, however, that any such selection would be related to the outcome factor examined (the relative importance of the source of the research or publication) and hence internal validity should not be compromised. In some centres all hospitals were used since there were only a few physicians located in each. In Kenya, a national sampling frame was used rather than identifying hospitals first, and the 48% response rate indicates uncertainty about the validity of the results.
We report answers to a questionnaire rather than observations on practice, and have not established the validity of the stated responses. It is possible that 'national pride' may explain the large difference seen between local and regional journals. The understanding of 'region' may also be difficult, we gave examples in the question of East Africa, Asia and Latin America. In addition, it is possible that the influence and credibility of various information sources may be different for different clinical problems in different settings. The study did not differentiate between type of research study – a randomized controlled trial would usually be more highly regarded than a descriptive study, wherever it was conducted or published. In order to allow for this issue, we asked the question about change in perceptions of the research if the quality were the same in all regions.
This is the first study to assess the differences in likely impact of medical research and medical journals published in different parts of the world on physicians' practices. The study was carried out in developing countries where few resources are available for doing local medical research and for guiding health policy , although the burden of disease is great . Insufficient numbers of clinical trials are performed in sub-Saharan Africa despite the heavy disease burden . Hepatitis B and C , the AIDS epidemic , the emergence of resistant strains of organisms to antibiotics , the need for culture specific and cost-effective methods for child care , and appropriate contraceptive methods  are only a few of the problems facing developing countries. Given these burdens and that so little financial resources are available for health, it is essential that doctors in developing countries use the most cost-effective methods of health management. Although the respondents to our survey reported high levels of access to medical libraries (Table 2), and also reported high levels of access to "up to date" medical journals, we do not know which journals they are or if they were read. Unfortunately, even in the 'best' settings worldwide, medical practice is not necessarily driven by peer-reviewed evidence. It is therefore important that we identify how physicians use evidence to guide their practice. This can in turn lead to appropriate education programs to guide developing world physicians on how to use evidence. Evidence-based practice needs to be taught to developing world medical practitioners . Initiatives like the International Clinical Epidemiology Network which build research and education capacity in evidence based medicine [7, 8] should therefore be encouraged and supported. In addition, given that physicians are more likely to respond to local research than research from other countries, local researchers need to be given support to improve the quality and quantity of local research output. This obviously makes sense since local research is more likely to be directly applicable to the population involved . However, it is neither sensible nor cost-effective to repeat every study in local settings. It is therefore important that the development of culturally sensitive evidence-based guidelines which guide physicians on how to use the results of research findings from settings other than their own be encouraged.