Case reports versus literature reviews: indicators of change in the dominant model for sharing medical knowledge

Aims: The crisis in the medical paradigm was seen at the end of the 20th century in the variability of practices, uncertainty of medical-decision making and difficulties in defining normality. Using changes in knowledge production as a marker, our aim was to characterize this paradigm crisis and to foresee its evolution. Methods: We reviewed Medline annually between 1976 and 2004, and counted the number of published case reports versus the number of literature reviews and clinical trial articles. Results : Our results show that of the articles indexed each year the proportion of literature review articles in 1994 was greater than case reports. This proportion is currently increasing. The proportion of case reports articles has fallen by half over the last twenty years. Clinical trial articles are increasing regularly and may exceed case reports in the next decade. Conclusions : The measurement of changes in the medical paradigm provided by our results show changes in the previous equilibrium: - the qualitative approach to disease is giving way to a quantitative approach; - knowledge development is moving towards a scientific process. From being inductive it is becoming deductive. This knowledge is changing and is stratifying through accumulation and review of primary knowledge from different teams; - research into etiologic certainties specific to the mechanistic paradigm is clashing with complexity, which is translated in the use of probabilities. Beyond large numbers, however, the clinical approach and human skills of the doctor remain fundamental prerequisites for care.