Prescribing rates for psychotropic medication amongst east London general practices: low rates where Asian populations are greatest.

OBJECTIVES: The aim of this study was to examine the contribution of Asian ethnicity to the variation in rates of practice prescribing for antidepressant and anxiolytic medication, taking into account other population and practice organizational factors.
METHODS: A practice-based cross-sectional survey was carried out of the prescribing of antidepressants and anxiolytics (daily defined dosages) in 164 general practices. The study was set in East London and the City Health Authority, which includes the multiethnic inner London boroughs of Hackney, Tower Hamlets, Newham and the City of London. The main outcome measures were the annual prescribing rates for each group of drugs, calculated as the total annual daily defined dosages divided by the practice population, and the ratio of antidepressant/ anxiolytic annual prescribing rates.
RESULTS: Prescribing rates for antidepressants showed a 25-fold variation between practices; this was greater for anxiolytics. The median annual prescribing rate for all antidepressants combined was 4.13 (interquartile range 2.50-5.88). For all anxiolytics and hypnotics combined the median annual prescribing rate was 3.55 (interquartile range 1.71-6.36). Univariate analysis showed that Asian ethnicity alone accounted for 28% of the variation in antidepressant prescribing and 20.5% of the variation in the anxiolytic prescribing. A backwards multiple regression model using 10 explanatory practice and population variables accounted for 47.7% of the variance in antidepressant prescribing and 34% of the variance in the anxiolytic prescribing.
CONCLUSION: In practices where the proportion of Asian patients is high, both antidepressant and anxiolytic prescribing is low. This is important for understanding interpractice prescribing variation and for setting levels of drug budgets. This study confirms that the low rates of non-psychotic disorders presented by Asian populations is not a selective feature of access to secondary care, but is evident in the prescribing behaviour of GPs. Uncertainty remains as to how much this is due to a lower prevalence rate, "culture-bound syndromes" or practical difficulties in diagnosis and management within the general practice setting.