Gender differences in outpatients with anxiety disorders: the Leiden Routine Outcome Monitoring Study

Background. Data from the general population show higher prevalence of different anxiety disorders in women as compared with men. We analysed gender differences in a naturalistic sample of outpatients with anxiety disorders in a mental healthcare setting. Method. Routine outcome monitoring data were collected from 1333 patients (age: 18-65; 63.3% women) fulfilling Diagnostic and Statistical Manual of Mental Disorders IV criteria of current anxiety disorder according to the Mini-International Neuropsychiatric Interview between 2004 through 2006. Data included Comprehensive Psychopathological Rating Scale, Brief Symptom Inventory (BSI), Short Form Health Survey (SF-36), Mood and Anxiety Symptom Questionnaire (MASQ). Chi-squared test and t-test were used to compare women with men for variables with parametric distributions, and Mann-Whitney test for non-parametric distribution. Adjustments for potential confounders (age, level of education, ethnicity and comorbidites) were made by logistic regression models (for discrete variables) or analysis of covariance. Results. The female-to-male ratio (i.e., 844 women, 489 men) for any anxiety disorder was 1.73 : 1 (95% confidence interval [CI]: 1.63-1.83), with the strongest skewness for post-traumatic stress disorder (2.80 : 1) and the smallest one for social phobia (1.18 : 1). Compared with men, women reported more severe self-rating scores on the BSI (on average, the scores were 12.3% higher on 3 of 9 subscales: somatisation, interpersonal sensitivity and anxiety), SF-36 (self-reported generic health status was lower on 5 of 8 subscales: physical functioning, social functioning, physical problems, vitality and bodily pain) and MASQ (on average, the scores were 6.6% higher on 4 of 5 subscales: anxious arousal, general distress, general distress depression, general distress anxiety). On the contrary, no gender difference was found in the severity of anxiety symptoms measured by the Brief Anxiety Scale. Women were more likely to suffer from comorbid depression and bulimia nervosa, and less likely from substance abuse. Conclusions. In a treatment-seeking population the prevalence rate of anxiety disorders was 1.7 times higher in female compared with men. Female outpatients were more severely affected on self-rated but not on observer-rated scales.