[Rheumatology research. Analysis of Spanish papers published in 1990-1996 in 9 foreign journals in the field].

Background: A relevant increase in the spanish biomedical production has occurred in the last few years. The magnitude, evolution and characteristics of the Spanish scientific production in Rheumatology is here analyzed through the published papers in foreign specialty journals.
Methods: Location in spanish documents published from 1990 to 1996 in nine foreign rheumatology journals of great visibility in MEDLINE. Classification of documents according to type of publication, specialty of authors and type of design. Estimation of bibliometric and collaboration indicators. Analysis of their evolution and comparison with data published for 1987.
Results: The number of Spanish documents from 1990 to 1996 doubled and from 1987 to 1996 tripled, with a 54% increase for the four journals with more visibility. In 1996, the spanish documents reached 5% of the total of published documents in several journals. From 1990 to 1996 original papers increased almost four times more than letters, the analytical studies increased almost eight times more than descriptive studies, and the mean expected impact factor of the originals multiplied by 1.6. The published documents by spanish rheumatologists had a more favorable profile--higher ratios for originals: letters, analytical studies: descriptive studies--than publications performed by other specialists in this area. The number of authors by document (median) increased from 5 to 6 during the analyzed period. Seventy-two percent of documents was signed by more than one department and 75% by only one institution.
Conclusions: A relevant increase has occurred in the number and quality spanish documents published in the rheumatology area during the last ten years. To note a lack of collaboration between different institutions and few analytical studies of great complexity: cohort studies and controlled clinical trials.