Postcode prescribing for schizophrenia [Abstract]

Data on antipsychotic drug expenditure in primary care for all English health authorities (total pop 52,072,048) during the 2nd quarter of 1999 was released by the Prescription Pricing Authority (PPA) after permission was obtained from each health authority to access this information. Data on typical antipsychotics excluded depot preparations (5% of total antipsychotic expenditure in 1999). Expenditure data was normally distributed. Adjusted spending figures showed an 11-fold variation in per capita atypical spending across English health authorities. The highest atypical to typical spending ratio was 7.64 : 1 and the lowest ratio 0.97 : 1. The variation in per capita atypical expenditure was three times higher than that for per capita typical expenditure. Population need was hypothesised to explain this variation, with drug use reflecting varying rates and severity of psychotic illness between different communities. The expenditure data was set against that health anthority's York Psychiatric Need Index score. As predicted, population-adjusted antipsychotic spending correlated significantly with the health authorities' level of psychiatric need. Significant correlations were found between population-adjusted atypical spending and psychiatric need (r=.49, p <.001); population-adjusted typical spending and psychiatric need (r=.33, p <.001); and between population-adjusted total antipsychotic spending and psychiatric need (r=.51, p <.001). This significant relationship remained when outliers were removed. The York Psychiatric Need Index explained 23.7% of the variance of per capita atypical expenditure. Local population need is known to be a predictor ofresource use in other aspects of mental health care and it appears also to account for about a quarter of the variance in per capita antipsychotic expenditure.