Home > DARE Reviews > Number needed to treat analyses of drugs...

PubMed Health. A service of the National Library of Medicine, National Institutes of Health.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

Number needed to treat analyses of drugs used for maintenance treatment of bipolar disorder

D Popovic, M Reinares, B Amann, M Salamero, and E Vieta.

Review published: 2011.

Link to full article: [Journal publisher]

CRD summary

The authors concluded that all pharmacological agents assessed were effective in prevention of any kind of mood episode, but different efficacy profiles were found for prevention of manic and/or depressive relapses. The reliability of the conclusions is uncertain given the potential for publication bias, risk of reviewer error and bias and unclear study quality.

Authors' objectives

To compare the efficacy of pharmacological treatments for maintenance treatment of bipolar disorder by means of the number needed to treat (NNT).

Searching

PubMed was searched up to May 2010 (abstract and text differed) for relevant studies published in English. Search terms were reported. Reference lists of identified publications were handsearched.

Study selection

Randomised controlled trials (RCTs) of drugs used for the treatment of any phase of bipolar disorder compared to placebo were eligible for inclusion if they had a minimum duration of six months and the patients were over 18 years old. Studies with small sample sizes (median sample inferior to 16.5 patients in each study arm), study samples that were not composed exclusively of bipolar patients and studies that used rating scales that were not validated in bipolar disorder patients were excluded.

Most of the included patients had bipolar 1 disorders. Study durations ranged from 24 to 104 weeks. Treatments assessed included aripiprazole, olanzapine, quetiapine, risperidone long-acting injection, lithium, lamotrigine and divalproex, valproate, oxcarbazepine and ziprasidone; doses varied. All studies included an acute treatment phase followed by a relapse-prevention (maintenance) treatment phase.

The authors did not state how many reviewers assessed studies for inclusion.

Assessment of study quality

The authors did not state that they assessed study quality.

Data extraction

Data were extracted to enable calculation of NNTs (treatment and placebo relapse rates) and 95% confidence intervals (CIs).

The authors did not state how may reviewers extracted data.

Methods of synthesis

NNTs and CIs were calculated by taking reciprocals of differences between rates of outcomes for comparison interventions. The authors considered NNTs of less than 10 to be clinically meaningful.

Results of the review

Fifteen RCTs (n=5,200 participants, range 99 to 1,172) were included.

Aripiprazole (one RCT), olanzapine alone (one RCT), quetiapine alone or in combination (three RCTs), risperidone long-acting injection (two RCTs), lithium alone or in combination (six RCTs), lamotrigine (two RCTs) and divalproex in combination (three RCTs) were significantly superior to placebo for prevention of relapse into any mood episode (all ≥10% advantage over placebo) based on NNT.

Quetiapine alone or in combination (three RCTs), lithium (six RCTs), risperidone long-acting injection (two RCTs), aripiprazole (one RCT) and olanzapine (one RCT) were significantly superior to placebo in manic recurrence prevention based on NNT.

Lamotrigine (one RCT), quetiapine alone or in combination (three RCTs) and lithium (one RCT) were significantly superior to placebo for prevention of depressive relapses based on NNT.

Authors' conclusions

All of pharmacological agents assessed were effective in prevention of any kind of mood episode, but different efficacy profiles were found for prevention of manic and/or depressive relapses.

CRD commentary

The review question was clearly stated with regard to eligible study designs, interventions and patient groups. Eligible outcomes were not pre-specified. Only one database was searched and papers written in languages other than English were excluded, so some relevant papers may have been missed. It was unclear whether review processes were conducted in duplicate, so reviewer error and bias could not be excluded. Quality of the included studies was unclear as there was no validity assessment. Statistical methods used to combine study results appeared appropriate. Individual results were supported by small numbers of studies.

The reliability of the authors’ conclusion is uncertain given a number of weaknesses in the review process (potential for publication bias, incomplete reporting of details of review process and unclear study quality).

Implications of the review for practice and research

Practice: The authors stated that comparison of NNT values of the available medicaments may represent a useful adjuvant in clinical settings to facilitate implementation of long-term pharmacological interventions in patients with bipolar disorder.

Research: The authors stated that future placebo-controlled randomised trials should assess long-term effectiveness of combination treatments (such as lamotrigine as add-on treatment), carbamazepine, oxcarbazepine, valproate and amisulpride, asenapine or paliperidone.

Funding

Not stated.

Bibliographic details

Popovic D, Reinares M, Amann B, Salamero M, Vieta E. Number needed to treat analyses of drugs used for maintenance treatment of bipolar disorder. Psychopharmacology 2011; 213(4): 657-667. [PubMed: 21052983]

Indexing Status

Subject indexing assigned by NLM

MeSH

Antipsychotic Agents /therapeutic use; Bipolar Disorder /drug therapy /physiopathology; Humans; Randomized Controlled Trials as Topic /methods; Recurrence /prevention & control; Sample Size; Time Factors; Treatment Outcome

AccessionNumber

12011002119

Database entry date

26/10/2011

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 21052983

Download

PubMed Health Blog...

read all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...