Trends in the registration of anxiety in Belgian primary care from 2000 to 2021: a registry-based study

Background: Anxiety is frequently encountered in general practice, but figures regarding prevalence and incidence in this healthcare setting remain scarce. Aim: To provide insight in the trends of prevalence and incidence of anxiety in Belgian general practice, as well as the comorbidities and treatment of anxiety in this context. Design and setting: A retrospective cohort study using the INTEGO morbidity registration network, collecting clinical data of over 600.000 patients in Flanders, Belgium. Methods: Trends in age-standardized prevalence and incidence of anxiety from 2000 to 2021, as well as prescriptions in prevalent anxiety cases, were analysed with joinpoint regression. Comorbidity profiles were analysed using the Cochran-Armitage test and the Jonckheere-Terpstra test. Results: During the 22-year study period, we identified 8 451 unique patients with anxiety. The prevalence of anxiety diagnoses rose significantly during this period, from 1.1% in 2000 to 4.8% in 2021. The incidence rate rose from 1.1/1000 patient-years (PY) in 2000 to 9.9/1000 PY in 2021. The average chronic disease count per patient increased significantly during the study period, from 1.5 to 2.3 chronic conditions. The most frequent comorbidities in patients with anxiety were malignancy (20.1%), hypertension (18.2%) and irritable bowel syndrome (13.5%). The proportion of patients treated with psychoactive medication rose from 25.7% to almost 40% over the study period. Conclusion: We found a significantly increasing prevalence and incidence of physician-registered anxiety in our study. Patients with anxiety tend to become more complex, with more comorbidities. Treatment for anxiety in Belgian primary care is very dependent on medication.