Elsevier

Journal of Anxiety Disorders

Volume 52, December 2017, Pages 25-33
Journal of Anxiety Disorders

Review
Systematic review and meta-analysis of dropout rates in individual psychotherapy for generalized anxiety disorder

https://doi.org/10.1016/j.janxdis.2017.10.001Get rights and content

Highlights

  • A meta-analysis explored dropout rates in psychotherapy for Generalized Anxiety Disorder.

  • The weighted mean dropout rate was 16.99%, approximately one in six patients.

  • Dropout rate was not significantly moderated by client, therapist or treatment variables.

Abstract

Background

Despite being a relatively prevalent and debilitating disorder, Generalized Anxiety Disorder (GAD) is the second least studied anxiety disorder and among the most difficult to treat. Dropout from psychotherapy is concerning as it is associated with poorer outcomes, leads to service inefficiencies and can disproportionately affect disadvantaged populations. No study to date has calculated a weighted mean dropout rate for GAD and explored associated correlates.

Methods

A systematic review was conducted using PsycINFO, Medline and Embase databases, identifying studies investigating individual psychotherapies for adults with GAD. Forty-five studies, involving 2224 participants, were identified for meta-analysis.

Results

The weighted mean dropout rate was 16.99% (95% confidence interval 14.42%–19.91%). The Q-statistic indicated significant heterogeneity among studies. Moderator analysis and meta-regressions indicated no statistically significant effect of client age, sex, symptom severity, comorbidity, treatment type, study type (randomized trial or not), study quality, number of sessions or therapist experience.

Conclusions

In research investigating psychotherapy for GAD, approximately one in six clients can be expected to drop out of treatment. Dropout rate was not significantly moderated by the client, therapist or treatment variables investigated. Future research should specify the definition of dropout, reasons for dropout and associated correlates to assist the field’s progression.

Introduction

Generalized Anxiety Disorder (GAD) consistently falls behind all other anxiety disorders, with the exception of specific phobias, in terms of quantity of research publications (Dugas, Anderson, Deschenes, & Donegan, 2010). This is concerning, given that GAD has a 12-month prevalence of 1.7–3.4% (Wittchen et al., 2011), can have a chronic course with multiple associated psychiatric comorbidities, and is associated with an elevated risk of suicide (Andrews et al., 2010; Wehry, Beesdo-Baum, Hennelly, Connolly, & Strawn, 2015). Yet, GAD is one of the least successfully treated anxiety disorders (Waters & Craske, 2005). Consequently, this diagnosis warrants further treatment research.

Despite these challenges, reviews and practice guidelines have described the established efficacy of pharmacological treatments such as selective serotonin reuptake inhibitors (SSRIs), and psychological treatments such as Cognitive Behavioral Therapy (CBT) for GAD (Allgulander & Baldwin, 2013; Baldwin, Woods, Lawson, & Taylor, 2011; NICE, 2011). In fact, a recent meta-analysis (Cuijpers et al., 2014) of psychological therapies for GAD found a significant overall effect (Hedges g = 0.84), which can be considered a large effect size (Durlak, 2009). This is consistent with a number needed to treat (NNT) of 2.23, indicating that approximately two patients need to be treated with psychological therapy to generate one positive outcome (Cuijpers et al., 2014). A Cochrane review found no significant difference in outcomes between different psychological treatments for GAD (Hunot, Churchill, Silva de Lima, & Teixeira, 2007). There has also been some suggestion that psychotherapy may be preferable to pharmacotherapy due to reduced treatment discontinuation (Mitte, 2005), however there is also evidence that pharmacological treatments are associated with larger effect sizes than psychotherapy for GAD (Bandelow et al., 2015).

Treatment dropout is an important indicator of treatment acceptability and client engagement. Individuals that drop out of therapy tend to have poorer outcomes (Klein, Stone, Hicks, & Pritchard, 2003; McMurran, Huband, & Overton, 2010). Dropout can dilute the benefits of treatment, and interfere with the dissemination of evidence based treatments (Di Bona, Saxon, Barkham, Dent-Brown, & Parry, 2014). Dropout can also influence therapist morale, impact organizations revenue and lead to inefficiencies in service delivery systems (Barrett et al., 2009, Klein et al., 2003, McMurran et al., 2010).

Efforts have been made to develop treatment protocols for GAD aimed at increasing retention (Behar and Borkovec, 2010, Newman et al., 2011; Westra, Antony, & Constantino, 2016). These efforts need to be supported by a clear understanding of the typical dropout rate in psychotherapy for GAD, as well as a specification of what factors are associated with dropout, including characteristics of patients, therapists and treatment modality. Understanding differential dropout rates across GAD treatments can also elucidate whether certain types of treatment pose particularly difficulties in terms of patient engagement. This type of analysis has been conducted in other disorder groups including depression (Cooper & Conklin, 2015), borderline personality disorder (Barnicot, Katsakou, Marougka, & Priebe, 2011) and post-traumatic stress disorder (Imel, Laska, Jakcupcak, & Simpson, 2013) but not with GAD.

The relevant published data addressing dropout in GAD are limited. In their Cochrane Review of outcomes of psychological therapy for GAD, Hunot et al. (2007) found a dropout rate of 15.6%. Yet, this review calculated an overall mean dropout rate rather than a weighted mean that accounts for sample size. Additionally, the analysis was limited to randomized controlled trials and there is evidence that less controlled settings may have higher rates of dropout. For example, one small uncontrolled study of GAD in a community setting found a dropout rate of 72% (Kehle, 2008). Another review of dropout across multiple diagnoses found a similar rate of dropout in GAD of 15.2% (Swift & Greenberg, 2014). That review also included pharmacological treatments and group-based treatments as well as some participants under the age of 18. A focus on individual psychotherapy for adults excluding the potentially confounding effects of medication might yield a more precise estimate of dropout rates in GAD. Furthermore, no study to date has investigated moderators of dropout in GAD.

The present study had two aims. The first was to conduct a systematic review and meta-analysis of the research on individual psychotherapy for GAD and identify a weighted mean dropout rate. The second aim was to determine whether participant, therapist, treatment or study factors might influence dropout rates and account for any heterogeneity across studies in rates of dropout.

Section snippets

Method

This systematic review was conducted in accordance with PRISMA guidelines (Moher et al., 2015).

Results

A summary of the 45 studies included in the meta-analysis is presented in Table 1. There were a total of 2224 participants included in the analysis, with a mean age of 41.62. Studies were predominantly conducted in North America (64%) and Europe (31%), and most were randomized trials (82%). The sample sizes ranged from 8 to 135 and involved majority females (71%), which is consistent with the epidemiology of GAD (Kessler, Petukhova, Sampson, Zaslavsky, & Wittchen, 2012). The modal number of

Discussion

The 16.99% weighted mean dropout rate found in this study suggests that in research studies investigating individual psychological therapy for GAD, approximately one in six clients can be expected to drop out of therapy. This dropout rate is similar to other studies that have examined dropout in treatment for GAD, which have found mean rates in the range of 15.2–15.6% (Hunot et al., 2007, Swift and Greenberg, 2014). A comprehensive review of dropout in adult psychotherapy studies across

References (85)

  • P. Knekt et al.

    Effectiveness of short-term and long-term psychotherapy on work ability and functional capacity—A randomized clinical trial on depressive and anxiety disorders

    Journal of Affective Disorders

    (2008)
  • M. McMurran et al.

    Non-completion of personality disorder treatments: A systematic review of correlates, consequences and interventions

    Clinical Psychology Review

    (2010)
  • T.J. Meyer et al.

    Development and validation of the Penn State Worry Questionnaire

    Behavior Research and Therapy

    (1990)
  • J. Mohlman et al.

    Standard and enhanced cognitive-behavior therapy for late-life generalized anxiety disorder: Two pilot investigations

    The American Journal of Geriatric Psychiatry

    (2003)
  • L.G. Ost et al.

    Applied relaxation vs. cognitive therapy in the treatment of generalized anxiety disorder

    Behaviour Research and Therapy

    (2000)
  • M.D. Provencher et al.

    Efficacy of problem-solving training and cognitive exposure in the treatment of generalized anxiety disorder: A case replication series

    Cognitive and Behavioral Practice

    (2004)
  • L. Roemer et al.

    An open trial of an acceptance-based behavior therapy for generalized anxiety disorder

    Behavior Therapy

    (2007)
  • M.A. Stanley et al.

    Cognitive-behavior therapy for late-life generalized anxiety disorder in primary care: Preliminary findings

    The American Journal of Geriatric Psychiatry

    (2003)
  • C. van der Heiden et al.

    Randomized controlled trial on the effectiveness of metacognitive therapy and intolerance-of-uncertainty therapy for generalized anxiety disorder

    Behaviour Research and Therapy

    (2012)
  • A. Wells et al.

    Metacognitive therapy for generalized anxiety disorder: An open trial

    Journal of Behavior Therapy and Experimental Psychiatry

    (2006)
  • A. Wells et al.

    A pilot randomized trial of metacognitive therapy vs applied relaxation in the treatment of adults with generalized anxiety disorder

    Behaviour Research and Therapy

    (2010)
  • H.A. Westra et al.

    Adding a motivational interviewing pretreatment to cognitive behavioral therapy for generalized anxiety disorder: A preliminary randomized controlled trial

    Journal of Anxiety Disorders

    (2009)
  • J.L. Wetherell et al.

    Acceptance and commitment therapy for generalized anxiety disorder in older adults: A preliminary report

    Behavior Therapy

    (2011)
  • H.U. Wittchen et al.

    The size and burden of mental disorders and other disorders of the brain in Europe 2010

    European Neuropsychopharmacology

    (2011)
  • R.E. Zinbarg et al.

    Dyadic predictors of outcome in a cognitive-behavioral program for patients with generalized anxiety disorder in committed relationships: A “spoonful of sugar” and a dose of non-hostile criticism may help

    Behaviour Research and Therapy

    (2007)
  • C. Allgulander et al.

    Pharmacotherapy of generalized anxiety disorder

  • G. Andrews et al.

    Generalized worry disorder: A review of DSM-IV generalized anxiety disorder and options for DSM-V

    Depression and Anxiety

    (2010)
  • D. Baldwin et al.

    Efficacy of drug treatments for generalised anxiety disorder: Systematic review and meta-analysis

    British Medical Journal

    (2011)
  • B. Bandelow et al.

    The efficacy of treatments for anxiety disorders: A meta-analysis

    International Clinical Psychopharmacology

    (2015)
  • K. Barnicot et al.

    Treatment completion in psychotherapy for borderline personality disorder: A systematic review and meta-analysis

    Acta Psychiatrica Scandinavica

    (2011)
  • M.S. Barrett et al.

    Early withdrawal from mental health treatment: Implications for psychotherapy practice

    Psychotherapy: Theory, Research, Practice, Training

    (2009)
  • E. Behar et al.

    Avoiding treatment failures in generalized anxiety disorder

  • G. Belleville et al.

    Sequential treatment of comorbid insomnia and generalized anxiety disorder

    Journal of Clinical Psychology

    (2016)
  • M. Borenstein et al.

    Introduction to meta-analysis

    (2009)
  • M. Borenstein et al.

    Comprehensive meta-analysis: A computer program for research synthesis (Version 3)

    (2014)
  • T.D. Borkovec et al.

    Efficacy of applied relaxation and cognitive-behavioral therapy in the treatment of generalized anxiety disorder

    Journal of Consulting and Clinical Psychology

    (1993)
  • T.D. Borkovec et al.

    The effects of relaxation training with cognitive or nondirective therapy and the role of relaxation-induced anxiety in the treatment of generalized anxiety

    Journal of Consulting and Clinical Psychology

    (1987)
  • T.D. Borkovec et al.

    A component analysis of cognitive-behavioral therapy for generalized anxiety disorder and the role of interpersonal problems

    Journal of Consulting & Clinical Psychology

    (2002)
  • G. Butler et al.

    Comparison of behavior therapy and cognitive behavior therapy in the treatment of generalized anxiety disorder

    Journal of Consulting and Clinical Psychology

    (1991)
  • D.L. Chambless et al.

    Defining empirically supported therapies

    Journal of Consulting and Clinical Psychology

    (1998)
  • H. Cousineau et al.

    Insomnia symptoms following treatment for comorbid panic disorder with agoraphobia and generalized anxiety disorder

    Journal of Nervous and Mental Disease

    (2016)
  • P. Crits-Christoph et al.

    An open trial of brief supportive-expressive psychotherapy in the treatment of generalized anxiety disorder

    Psychotherapy

    (1996)
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