Study designs of evaluations included in the review
Prospective studies that used standardised methods for diagnosing delirium and evaluating severity were eligible for inclusion. Studies of delirium associated with a specific state of intoxication or withdrawal were ineligible.
Specific interventions included in the review
Studies were eligible for inclusion if antipsychotic drugs were used to treat delirium. The included drugs were haloperidol, olanzapine, risperidone, quetiapine, chlorpromazine, lorazepam and mianserin. The mean daily dose ranged from 36 to 325 mg chlorpromazine equivalents. The duration of treatment varied. A few studies included pharmacologic cointerventions.
Participants included in the review
The included participants were patients from medical, surgical, cancer, intensive care unit and AIDS populations. The patients were aged from 19 to 92 years. Most of the patients were referred for psychiatry; some patients were recruited who had screened positive for delirium.
Outcomes assessed in the review
Studies that diagnosed delirium and assessed its severity using validated instruments were eligible for inclusion. The included outcomes were delirium severity, response to treatment, remission, time to improvement, and treatment-emergent serious and minor adverse events. Severity scales included the Delirium Rating Scale (DRS), the DRS 1998 revision, the Memorial Delirium Assessment Scale and the Delirium Index.
How were decisions on the relevance of primary studies made?
Two of the authors reviewed all of the retrieved studies. The decision to include a study was reached by consensus. The authors of primary studies were contacted for clarification when needed.