Oral antipsychotic prescribing and association with neighbourhood-level socioeconomic status: analysis of time trend of routine primary care data in England, 2011-2016.

BACKGROUND

Increasing rates of antipsychotic prescribing have been reported previously, particularly for second-generation antipsychotics (SGAs), which are generally better tolerated than the older first-generation antipsychotics (FGAs). Prescribers, however, may exert bias, favouring prescriptions of novel drugs for patients of higher socioeconomic status (SES). We aimed to examine time trends in: (1) prescriptions of oral FGAs vs. SGAs and (2) associations between antipsychotic prescriptions and neighbourhood-level SES in England between 2011 and 2016.

METHODS

We used publicly available data for prescriptions made in primary care and linked general practices' postcodes with the Index of Multiple Deprivation (IMD) as a measure for neighbourhood-level SES. Absolute numbers of antipsychotic prescriptions were calculated. Linear regression analysis was used to examine the association of SGA vs. FGA prescription pattern with time and with SES.

RESULTS

A total of 27,486,000 oral antipsychotics were prescribed during the study period, mostly SGAs (n = 21,700,000; 78.9%). There was a significant increase in the ratio of SGA/FGA prescriptions over time (β = 0.376, 95% CI 0.277-0.464, P < 0.001). Individual FGAs were increasingly prescribed in areas of lower SES and the converse for SGAs except amisulpride. During the study period, a significantly larger proportion of total SGA prescriptions relative to total FGAs were made in areas of higher SES (β = 0.182, 95% CI 0.117-0.249, P < 0.001).

CONCLUSION

Prescriptions of antipsychotics continue to rise overall, with SGAs taking preference especially in areas of higher SES. The pattern of antipsychotic prescription favouring people in areas of lower social deprivation carries implications on inequalities even among sub-groups of people with mental disorders.