Variations in antidepressant prescribing suggest disparities in provision of care
SEPTEMBER 01, 2008
Researchers from the Institute of Psychiatry have published the results of a study to explore the relationship between physical illness, social deprivation, ethnicity, practice characteristics and the volume of antidepressants prescribed in primary care.
The study, published in the September issue of the British Journal of Psychiatry, reveals that higher volumes of antidepressants are prescribed by general practices in economically deprived areas, and by practices serving areas with a high prevalence of chronic illness. It also shows GPs prescribe lower volumes of antidepressants in areas with more Black or South Asian people, suggesting possible disparities in the provision of care.
They used data derived from the Quality and Outcomes Framework, a system established in 2004 which gives financial incentives to GPs for achieving certain performance targets. Prescribing data for antidepressant medicines were collected from national Prescribing Analyses and CosT data for 2004-2005. Ethnicity and deprivation data were provided by the Informatics Collaboratory of the Social Sciences.
Analysis showed that the greatest predictors of the volume of antidepressants prescribed were social deprivation, the prevalence of chronic illness (asthma, chronic obstructive pulmonary disease (COPD) and epilepsy) and ethnic density.
Overall, socio-economic status, ethnic density, asthma, COPD and epilepsy explained 44% of the variance in the volume of antidepressants prescribed.
The researchers claim the reason that more antidepressants are prescribed in socio-economically deprived areas is because of higher levels of depression in these areas.
Chronic illness is also associated with higher rates of depression, which may account for the increased volumes of prescriptions in practices with a higher prevalence of these illnesses.
Surprisingly, the way that GP surgeries are organised and run did not seem to influence prescribing volumes. The researchers had predicted that practices where appointments last at least 10 minutes, and those which have a lower number of patients per GP, would prescribe higher volumes of antidepressants because cases of depression are more likely to be recognised. However, organisational factors appeared to have little influence on the volumes of antidepressants prescribed.
The study’s authors say that further research is now needed to determine the clinical impact of these variations in antidepressant prescribing.
Reference:
Walters P, Ashworth, M and Tylee A (2008) Ethnic density, physical illness, social deprivation and antidepressant prescribing in primary care: ecological study. British Journal of Psychiatry, 193: 235-239
For further information, please contact Dr Paul Walters, Institute of Psychiatry. Tel: 0207 848 5070. E-mail: p.walters@iop.kcl.ac.uk