Comparison of the incidence of schizophrenia in rural Dumfries and Galloway and urban Camberwell

Background Being born or living in urban areas is associated with high rate s of schizophrenia. However, few studies have compared the incidence in urb an/rural areas using the same methodology. Aims To compare service-based incidence rates for schizophrenia in rural Du mfries and Galloway in south-west Scotland with urban Camberwell in south-e ast London. Method Using Research Diagnostic Criteria diagnoses from the OPCRIT compute r algorithm, we compared the incidence of schizophrenia over 12 years (1979 -1984 and 1992-1997) using indirect standardisation techniques and Poisson regression modelling. Results The incidence was 61% higher in urban Camberwell than in rural Dumf ries and Galloway (standardised incidence ratio (SIR)=1.61; 95% Cl=1.42-1.8 1). There was no difference in incidence when we compared the White populat ion in Camberwell with Dumfries and Galloway (SIR=1.12; 95% Cl=0.86-1.43). Conclusions The incidence of schizophrenia in urban Camberwell was higher t han that in rural Dumfries and Galloway; the high incidence of non-Whites i n Camberwell largely explains the urban/rural difference.