Revisión crítica de las fuentes de variabilidad en la medición de la prevalencia de esquizofrenia.

Epidemiologic research plays a very relevant role to know the prevalence of schizophrenia. However, sometimes data from different studies are compared without taking into account some methodological questions that influence the results. This paper reviews different methodological factors that influence variability of rates in schizophrenia prevalence. Also, we provide some generic recommendations for measuring prevalence. We have revised 52 studies which offer prevalence rates of schizophrenia. A big difference appears in the prevalence rates of schizophrenia which range between 1 to 45 per 1000 inhabitants. The factors founded can be summarized as follows: 1. type of prevalence; 2. denominator population; 3. place of selection of cases; 4. classification issue; 5. diagnoses categories and 6. methods of diagnoses. In conclusion, in the epidemiological studies about schizophrenia prevalence we have to take into account the methodological factors involved in order to interprete and compare results from different studies. [ABSTRACT FROM AUTHOR]