Study designs of evaluations included in the review
Double-blind, placebo-controlled randomised clinical trials (RCTs) were included.
Specific interventions included in the review
Oral kava monopreparations with daily kavapyrone content ranging from 60 to 240 mg was compared with placebo. Doses of kava extract were generally given between two and four times daily. Duration of studies ranged from night before and morning of operation to 24 weeks. Settings included university outpatient clinic, gynaecological practice, general practice, university, university hospital, and general hospital. One study in which kava extract was combined with benzodiazepines and studies using kavain were excluded.
Participants included in the review
The following groups of patients with anxiety were included: outpatients with anxiety of nonpsychiatric origin including those with anxiety according to American Psychiatric Association DSM-III-R criteria; females; anxiety diagnosed on State Trait Anxiety Inventory; preoperative patients; and female patients between taking tissue sample and diagnosis.
Outcomes assessed in the review
Anxiety was measured using the total score on the Hamilton Rating for Anxiety (HAM-A), Zung anxiety status inventory, State Trait Anxiety Inventory, and a 10-item anxiety scale. Adverse reactions were also assessed.
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the reviewers performed the selection.