Trends, geographical variation and factors associated with prescribing of gluten-free foods in English primary care: a cross-sectional study

OBJECTIVES: There is substantial disagreement about whether gluten-free foods should be prescribed on the National Health Service. We aim to describe time trends, variation and factors associated with prescribing gluten-free foods in England. SETTING: English primary care. PARTICIPANTS: English general practices. PRIMARY AND SECONDARY OUTCOME MEASURES: We described long-term national trends in gluten-free prescribing, and practice and Clinical Commissioning Group (CCG) level monthly variation in the rate of gluten-free prescribing (per 1000 patients) over time. We used a mixed-effect Poisson regression model to determine factors associated with gluten-free prescribing rate. RESULTS: There were 1.3 million gluten-free prescriptions between July 2016 and June 2017, down from 1.8 million in 2012/2013, with a corresponding cost reduction from £25.4 million to £18.7 million. There was substantial variation in prescribing rates among practices (range 0 to 148 prescriptions per 1000 patients, IQR 7.3–31.8), driven in part by substantial variation at the CCG level, likely due to differences in prescribing policy. Practices in the most deprived quintile of deprivation score had a lower prescribing rate than those in the highest quintile (incidence rate ratio 0.89, 95% CI 0.87 to 0.91). This is potentially a reflection of the lower rate of diagnosed coeliac disease in more deprived populations. CONCLUSION: Gluten-free prescribing is in a state of flux, with substantial clinically unwarranted variation between practices and CCGs.