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Se abordan las razones que motivan que los resultados de la investigación realizada sobre poblaciones hospitalarias en ocasiones no sea consistente con la practicada en la comunidad. En la base de las diferencias se encuentran el proceso de selección de los pacientes y la recogida de datos por la historia clínica (su falta de uniformidad y el tratamiento de los «no consta»). Se estructura la razón de las discrepancias en función del tipo de pregunta de investigación: frecuencia, diagnóstico, etiología, pronóstico y tratamiento-prevención. Es el proceso de selección el que justifica las diferencias en frecuencia y pronóstico. En relación con el diagnóstico, las discrepancias se deben a la prevalencia de la enfermedad. En el estudio de asociaciones de causalidad ciertos errores son más frecuentes en los estudios hospitalarios, como los sesgos de detección, protopático (ambos exageran la asociación), y el de inclusión (reduce la asociación). Se analizan ejemplos publicados de cada una de ellas. En relación con el tratamiento-prevención, los problemas son sobre todo de validez externa, ya que la metodología del ensayo clínico previene las amenazas a la validez interna; se analiza con un ejemplo de valoración de la eficacia vacunal en pacientes y población sana. La frecuencia de citación de los sesgos se midió en una búsqueda en Medline; en los estudios hospitalarios se mencionó con más frecuencia el sesgo de detección ([RR] = 2,71; intervalo de confianza [IC] del 95%, 1,69-4,37) y el sesgo de confusión por indicación (RR = 1,76; IC del 95%, 0,90-3,42). Por último, se da una serie de recomendaciones destinadas a aumentar la validez de los estudios realizados en el medio hospitalario. The goal of this review is to delineate some of reasons that justify the lack of consistency between hospital-based and community research. The main reasons for the differences are the selection of the hospital population and information based on clinical chart (its lack of uniformity and the treatment of the «not available» data). The reasons for lack of consistency are divided according to the type of research question: frequency, diagnosis, etiology, prognosis and treatment-prevention. The way a hospital population is selected justifies discrepancies regarding frequency and prognosis. As regards diagnosis, differences are mainly due the prevalence of disease. In the ascertainment of causality several biases are more common in hospital-based research, such as detection bias, protopathic (both producing an away-from-null estimate), and inclusion bias (diminishing the strength of association). Examples taken from the medical literature are offered to illustrate each bias. Regarding treatment-prevention problems arise from external validity, as clinical trials are less prone to bias; this latter situation is exemplified with an assessment of vaccine efficacy in both patients and healthy population. The frequency of citation of bias was assessed by a Medline search; in hospital studies detection bias and confounding by indication were more often quoted than in non-hospital research (RR = 2.71; 95% CI; 1.69-4.37; RR = 1.76; 95% CI, 0,90-3,42, respectively). Lastly, several recommendations are given to increase the validity of hospital-based research.

The assessment of the methodological quality of controlled clinical trials (CCTs) carried out in Spain and published in international journals and the comparison with those published in widely read general journals of medicine (N Engl J Med, Lancet, JAMA, BMJ) may help establishing their limitations and improving quality in future studies.Search in Medline of CCTs. Studies were evaluated according to a structured questionnaire (J Clin Epidemiol 1992; 45:225-265). The odds ratio and their 95% confidence intervals were used to compare spanish studies with the remaining studies. The following variables were considered as confounders and controlled for by logistic regression analysis: number of participating centers, sample size, funding source, and the inclusion of epidemiologists in the research team. The journal's impact factor was taken into account.Spanish CTTs had a smaller sample size, were mostly monocentric, reported les frequently the source of funding, and exhibited a lower participation of epidemiologists. The informed consent and the approval by the ethics committee were more frequently omitted. The major methodological differences with the other studies were: lack of pre-study sample size and statistical power estimation, lack of inclusion criteria, poor explanation of patients' flow in the selection process, lack of explanation for unmasked procedures, poor description of methods to assess intervention compliance, under-reporting confidence intervals, and less frequent use of the intention-to-treat principle. The quality score of spanish studies was lower (9.4 +/- 1.7 vs 10.7 +/- 1.5; p0.001). These limitations improved with higher journal's impact factor, the quality score was 8.5 in journals with an impact factor1.5, and 10.6 in those with an impact factor4.5. This last figure is almost identical to the average of CCTs published in general journals of medicine.Most spanish studies achieved a good quality score. Nevertheless, there are still issues which can be overcome easily. If this goal is achieved, the results will obtain a higher repercussion, as a better quality is observed in those published in journals with the highest impact factor.

The association of uveitis and systemic disease is well known. Patients suffering from uveitis often undergo a extensive battery of tests in order to detect underlying disease, but the efficiency of such screening is uncertain. The aim of this study was to investigate useful clinical data for recognizing secondary uveitis.We conducted a prospective analysis of 115 patients with uveitis of unknown etiology. All of them were included in an extensive protocol study. Four groups were considered: specific ocular disease (SOD), idiopathic uveitis, HLA-B27 associated uveitis without arthritis (HLA-B27-AU) and secondary uveitis. Groups were compared by analysis of variance for continuous variables, and chi 2 test or Student's t-test for discrete variables. A stepwise multiple discriminant analysis was performed for ranking the variables in order of their usefulness for distinguishing idiopathic and secondary uveitis.We diagnosed 11 SOD (9.6%), 54 idiopathic uveitis (47%), 6 HLA-B27-AU (5.2%) and 41 secondary uveitis (35.7%). The discriminant analysis showed that age, an elevated erythrocyte sedimentation rate, presence of cutaneous lesion, joint pain and genital ulcers are the strongest predictors of secondary uveitis. This model classification functions detected 92.5% of idiopathic uveitis and 72% of secondary uveitis. The global percentage of patients with a correct diagnosis was 84.6%.Anamnesis, physical examination and basic laboratory tests are sufficient tools for the diagnostic approach of the majority of patients with uveitis. Subsequent diagnostic procedures must be planned in each patient to confirm a specific disease.

Han sido estudiados algunos polvos de talco por métodos opticos. La investigación de las formas y tamaños de las partículas, ha servido para establecer dos índices que hemos denominado, grado de redondearniento y grado de finura. Estos resultados son muy interesantes en la aplicación tópica de los polvos de talco, porque permiten la estimación de una posible acción irritante de la piel., Some dusting powders tale have been studied by optic methods. The investigation of the shapes and sizes of the particles, has served to establish two index, which we are named roundish rate and fmeness rateo These results are very interesting at the topie aplication of the dusting powders tale, because they permit to appreciate a possible irritative action in the skin.

En este trabajo estudiamos los manantiales que presentan una pequeña cantidad de sales disueltas, el estudio abarca la composición química, ciclo geoquímico y aplicaciones terapéuticas. De igual modo hacemos una discusión general de todas las muestras, tanto las correspondientes a este trabajo, como a la primera parte del mismo., At the present study, we have studied the che mi cal composition geochemical cycle, and therapeutic applications of the sources whi ch contain smal l quantities of disolved salts. In the same way a general discussi on of the studi ed samples mainly as a relati on-ships wi th those of the Part 1 is made.

En este trabajo, tratamos de buscar las posibles aplicaciones terapéuticas de los manantiales de la provincia de Málaga según su composición química, ya que son las sales disueltas las que le dan su acción, para comprobar los resultados obtenidos, las hemos comparado con todos los manantiales en explotación que hay en España y Europa, observando que existe una estrecha relación entre la composición, y las aplicaciones., In the present paper, the possibles therapeutics applications of the sour­ces from the province of Malaga (Spain), as a funtion of their chemical compositions is reported. Analogously, we compared the obtained results with those found in other sources from Spain and Europe finding a close relationship between chemical composition and therapeutic application., Departamento de Edafología. Universidad de Granada

Se describe una síntesis geológica y edáfica de la provincia de Jaén, así como la localización y toma de muestra de los manantiales de la provincia, que presentan una mineralización superior a los 1.500 mg/litro y al conocer la composición química buscar su relación con los distintos materiales que atraviesa en su ciclo hidrológico, así como las posibles aplicaciones terapéuticas según su composición., It has been described a geologic and edaphic sy nthesis of the province of Jaén (Spain) as well as a location and sampling of the sources with a mineralisation higher than 1500 mg/l. On the other hand a relation between the materials involved in the hydrological cycle of these sources with their chemical compositions and their therapeutic applications are also accomplished.