Background: There is increasing emphasis on primary care services for individuals with severe mental illnesses (SMI), including schizophrenia, bipolar disorder, and other non-organic psychotic disorders. However we lack information on how many people receive these different diagnoses in primary care. Primary care databases offer an opportunity to explore the recording of new SMI diagnoses in representative general practices.
Methods: We used data from The UK Health Improvement Network (THIN) primary care database including longitudinal patient records for individuals aged over 16 years from 437 general practices. We determined the annual GP recorded rate of first diagnosis of SMI by age, gender, social deprivation and urbanicity between 2000 and 2010.
Results: We identified 10,520 individuals with a first record of schizophrenia, bipolar disorder or other non-organic psychosis among 4,164,794 patients. This corresponded to a rate of first diagnosis of 46.4 per 100,000 person years at risk (PYAR) (95% CI 45.4 to 47.4) in the 16-65 age group. The rate of first record of schizophrenia was 9.2 per 100,000 PYAR (95% CI 8.7 to 9.6) in this age group, bipolar disorder was 15.0 per 100,000 PYAR (95% CI 14.4 to 15.5) and other non-organic psychotic disorder was 22.3 per 100,000 PYAR (95% CI 21.6 to 23.0).
Conclusions: The rates of GP recorded SMI in primary care records were broadly comparable to incidence rates from previous epidemiological studies of SMI and show similar patterns by socio-demographic characteristics. However there were some differences by specific diagnoses. GPs may be recording rates that are higher than those used to commission services.