Influences on the use of antidepressants in primary care: All England general practice-level analysis of demographic, practice-level and prescriber factors

Introduction: General practice (GP) antidepressants (ADs) prescribing in England has almost doubled in the past decade: how does location, GP characteristics, and prescribing selection influence antidepressant prescribing rate (ADPR) and growth. Methods: Stepwise multivariate regression analysis was applied to national public relevant data for each general practice to establish associations between these factors and ADPR. The regression coefficient was applied to the actual change in the number of different ADs and costs/dose to extrapolate the impact of these on growth. Results: In 2017–2018, 2.1 billion doses of antidepressant were prescribed into a population of 52 million people in 6,146 larger practices. In the model, location demographics accounted for 62% of the variation in ADPR: including practice size and health raised this to 71%, and local prescribing behaviour to 80%. Practices using more different drugs and lower-cost/dose had higher ADPR. Extrapolation showed that 40% of growth in ADPR could be attributed to the historic changes in these factors. Conclusions: While practice location factors do impact on AD prescription rates, local long-term physical health condition prevalence and prescribing behaviours are almost as important. We hope that our findings can provide insights that are helpful to local clinical behaviour and medicines management.