Estimating the prevalence of schizophrenia in Spain using a disease model

There are two main sources of information on the epidemiology of schizophrenia: prevalence and incidence studies. Prevalence rates can be estimated from incidence figures, and vice versa. The present article aims to provide an estimate of the prevalence of schizophrenia in Spain, calculated from epidemiological and demographic data, using a disease model of schizophrenia which applies the specific methodology of the WHO Global Burden of Disease project. Our model assumes a causal relationship between incidence and prevalence, but takes into account other competing risk factors of mortality; this approach is more realistic than one assuming a simple linear relationship between both parameters. Our findings indicate an estimated mean prevalence of 3.0 per 1000 inhabitants per year for men, but slightly lower for women: 2.86 per 1000. Our model enables us to compare incidence figures with those provided by prevalence studies and obtain accurate estimates of the distribution of schizophrenia in the general population, which can be used to better identify treatment needs and the consequent allocation of resources.