Objective: To discern the trend in the prevalence and population-adjusted rate of US office-based physician visits documenting a diagnosis of anxiety among patients ≥18 years of age.
Design: This was a retrospective study of data from a large national survey in the USA.
Methods: Data from the National Ambulatory Medical Care Survey for the years 1990 through 1997 were used for this analysis. Anxiety was defined as International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes 300.00 to 300.02. Subcategories included: (i) anxiety, unspecified type (300.00); (ii) panic disorder (300.01); and (iii) generalised anxiety disorder (GAD) [300.02]. Office visits resulting in a diagnosis of anxiety were partitioned into four time intervals for trend analysis: 1990 to 1991; 1992 to 1993; 1994 to 1995; 1996 to 1997.
Results: The annualised mean number of office visits documenting a diagnosis of anxiety increased from 5 739 390 in 1990–1991 to 8 429 413 in 1996–1997. The majority of patients were female, aged between 40 and 59 years, and White. On average, 44.4% of patients were prescribed an antianxiety medication. The proportion of patients with a concomitant diagnosis of depression increased from 7.1 to 12.8%. Use of antidepressants increased from 16.2 to 34.2% of patients, with use of a selective serotonin reuptake inhibitor increasing more than 5-fold. The proportion of patients prescribed both an antianxiety medication and an antidepressant increased from 7.4 to 13.8%. There existed a 1.4-fold increase in the population-adjusted rate of office visits documenting a diagnosis of anxiety, rising from 30.8 office visits per 1000 US population ≥18 years old in 1990–1991 to 42.8 per 1000 in 1996-1997; a 1.2-fold increase in anxiety of unspecified type, from 23.2 to 28.7 per 1000; panic disorder more than doubled, from 4.5 to 9.5 per 1000; and GAD increased from 3.3 to 5.2 per 1000.
Conclusion: The high prevalence of anxiety disorders, predominant in women, represents a major public health concern. Previous research suggests that anxiety disorders are associated with a decreased quality of life, an increased rate of cardiovascular/cerebrovascular events, and an increased risk of mortality due to suicide. Further research is required to discern the reasons for the growth in the prevalence of anxiety disorders, and to examine the effectiveness of medical management.