Study designs of evaluations included in the review
Controlled trials that presented sufficient data to permit an intention-to-treat analysis based on the original number randomised were eligible for inclusion. All of the included studies were randomised controlled trials (RCTs).
Specific interventions included in the review
Studies that directly compared CBT with control treatments were eligible for inclusion. Studies using only exposure or specific elements of CBT were excluded. The studies had to use a credible control treatment, defined as medication, waiting-list or placebo. The included studies used the following interventions: CBT alone; fluvoxamine with and without CBT; placebo plus CBT; moclobemide with CBT; moclobemide plus clinical management; CBT plus placebo; placebo plus clinical management; imipramine with and without CBT; CBT plus placebo; and placebo pills alone. Acute treatments lasted 10 to 12 weeks; one study included a 6-month maintenance treatment phase.
Participants included in the review
Studies of general samples of adults (18 years or more) with panic disorder were eligible for inclusion. Studies of special samples of patients (such as those who failed pharmacotherapy) were excluded.
Outcomes assessed in the review
The studies had to follow up patients for 6 months or more and present results using a clearly defined binary measure for patients who maintained remission. The studies also had to report relapses and use of treatment between follow-up interviews. In the review, these 'survivors' were defined as patients who were still present, were doing well using standardised criteria (as defined in the primary study), or did not require any additional treatment. The included studies measured remission using the Hamilton Anxiety Scale, Sheffield Symptom Rating Test, Fear Questionnaire-Agoraphobic subscale, Panic Disorder Severity Scale and the Clinical Global Impression Scale.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.