BACKGROUND: Coordinated Anxiety Learning and Management (CALM) is a model for delivering evidence-based treatment for anxiety disorders in primary care. Compared to usual care, CALM produced greater improvement in anxiety symptoms. However, mean estimates can obscure heterogeneity in treatment response. This study aimed to identify (1) clusters of participants with similar patterns of change in anxiety severity and impairment (trajectory groups); and (2) characteristics that predict trajectory group membership. METHODS: The CALM randomized controlled effectiveness trial was conducted in 17 primary care clinics in four US cities in 2006–2009. 1,004 English- or Spanish-speaking patients age 18–75 with panic, generalized anxiety, social anxiety, and/or posttraumatic stress disorder participated. The Overall Anxiety Severity and Impairment Scale was administered repeatedly to 482 participants randomized to CALM treatment. Group-based trajectory modeling was applied to identify trajectory groups and multinomial logit to predict trajectory group membership. RESULTS: Two predicted trajectories, representing about two-thirds of participants, were below the cut-off for clinically significant anxiety a couple of months after treatment initiation. The predicted trajectory for the majority of remaining participants was below the cut-off by 9 months. A small group of participants did not show consistent improvement. Being sicker at baseline, not working, and reporting less social support were associated with less favorable trajectories. CONCLUSIONS: There is heterogeneity in patient response to anxiety treatment. Adverse circumstances appear to hamper treatment response. To what extent anxiety symptoms improve insufficiently because adverse patient circumstances contribute to suboptimal treatment delivery, suboptimal treatment adherence, or suboptimal treatment response requires further investigation.

Context: Improving the quality of mental health care requires moving clinical interventions from controlled research settings into real-world practice settings. Although such advances have been made for depression, little work has been performed for anxiety disorders. Objective: To determine whether a flexible treatment-delivery model for multiple primary care anxiety disorders (panic, generalized anxiety, social anxiety, and posttraumatic stress disorders) would be better than usual care (UC). Design, Setting, and Patients: A randomized controlled effectiveness trial of Coordinated Anxiety Learning and Management (CALM) compared with UC in 17 primary care clinics in 4 US cities. Between June 2006 and April 2008, 1004 patients with anxiety disorders (with or without major depression), aged 18 to 75 years, English- or Spanish-speaking, were enrolled and subsequently received treatment for 3 to 12 months. Blinded follow-up assessments at 6, 12, and 18 months after baseline were completed in October 2009. Intervention: CALM allowed choice of cognitive behavioral therapy (CBT), medication, or both; included real-time Web-based outcomes monitoring to optimize treatment decisions; and a computer-assisted program to optimize delivery of CBT by nonexpert care managers who also assisted primary care clinicians in promoting adherence and optimizing medications. Main Outcome Measures: Twelve-item Brief Symptom Inventory (BSI-12) anxiety and somatic symptoms score. Secondary outcomes included proportion of responders ( 50% reduction from pretreatment BSI-12 score) and remitters (total BSI-12 score <6). Results: A significantly greater improvement for CALM vs UC in global anxiety symptoms was found (BSI-12 group mean differences of -2.49 [95% confidence interval {lcub}CI{rcub}, -3.59 to -1.40], -2.63 [95% CI, -3.73 to -1.54], and -1.63 [95% CI, -2.73 to -0.53] at 6, 12, and 18 months, respectively). At 12 months, response and remission rates (CALM vs UC) were 63.66% (95% CI, 58.95%-68.37%) vs 44.68% (95% CI, 39.76%-49.59%), and 51.49% (95% CI, 46.60%-56.38%) vs 33.28% (95% CI, 28.62%-37.93%), with a number needed to treat of 5.27 (95% CI, 4.18-7.13) for response and 5.50 (95% CI, 4.32-7.55) for remission. Conclusion: For patients with anxiety disorders treated in primary care clinics, CALM compared with UC resulted in greater improvement in anxiety symptoms, depression symptoms, functional disability, and quality of care during 18 months of follow-up.