The prevalence of anxiety in adult endocrinology outpatients: A systematic review and meta-analysis

Introduction: Anxiety disorders and anxiety symptoms are common mental disorders in the medically unwell and have significant impacts on patients' quality of life and engagement with psychiatric and medical services. Several systematic reviews have examined the prevalence of anxiety in specific endocrinology settings with estimates varying significantly from study to study. No meta-analysis has examined anxiety rates across the endocrinology outpatient setting. The aim of this meta-analysis is to provide endocrinologists with a precise estimate of the prevalence of anxiety - and impacting factors - in their outpatient clinics. Method: PubMed, Embase, Cochrane and PsycINFO databases and Google Scholar were searched to identify studies that assessed anxiety prevalence in endocrinology outpatients published up to 23 January 2023. This was part of a larger systematic review search of anxiety prevalence in common medical outpatient clinics. Data characteristics were extracted independently by two investigators. Studies of patients 16 years and older and representative of the clinic were included. The point prevalence of anxiety or anxiety symptoms was measured using validated self-report questionnaires or structured interviews. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. Pooled estimates were analysed under the random-effects model and subgroup analyses on relevant variables were conducted under a mixed-effects model. Heterogeneity was assessed using the I2 statistic. Results: Fifty-nine studies with a total of 25,176 participants across 37 countries were included in this study. The overall pooled prevalence of anxiety or anxiety symptoms was 25.1% (95%CI 21.4-29.2; 6372/25,176; n = 59). Subgroup analyses revealed no difference in prevalence between outpatients with diabetes mellitus compared to other grouped endocrine disorders. Generalized Anxiety Disorder (GAD) was the most frequent clinical diagnosis 11.7% (95%CI 8.1-16.7; I2=87.93%; 443/4604; n = 17), while panic disorder was significantly higher in the non-diabetes group 9.5% (95%CI 5.9-14.9; I2=57.28%; 56/588; n = 8), compared to the diabetes group 5.2% (95%CI 3.7-7.3; I2=32.18%; 184/3669; n = 6). Estimates of prevalence were higher when assessed with a selfreport scale 32.4% (95%CI 25.6-40.0; I2=96.06%; 1565/4675; n = 21) compared to diagnostic interview 17.6% (95%CI 12.2-24.7; I2=94.39%; 636/5168; n = 21). Outpatients in developing countries had higher rates of anxiety than those in developed countries. Female diabetes patients reported higher rates of anxiety compared to males. Conclusion: Our study provides evidence that anxiety occurs frequently amongst endocrinology outpatients and at a higher rate than is estimated in the general population. Given the impact anxiety has on patient outcomes, it is important that effective management strategies be developed to support endocrinologists in identifying and treating these conditions in their outpatient clinics.