{Reference Type}: Journal Article
{Title}: Number needed to treat (NNT) for ketamine and esketamine in adults with treatment-resistant depression: A systematic review and meta-analysis.
{Author}: Calder CN;Kwan ATH;Teopiz KM;Wong S;Rosenblat JD;Mansur RB;Rhee TG;Ho R;Cao B;McIntyre RS;
{Journal}: J Affect Disord
{Volume}: 356
{Issue}: 0
{Year}: 2024 Jul 1
{Factor}: 6.533
{DOI}: 10.1016/j.jad.2024.04.039
{Abstract}: <B>BACKGROUND: </B>Ketamine has been established as efficacious in adults living with Treatment-resistant Depression (TRD). Toward providing a quantifiable estimate of the clinical meaningfulness of the therapeutic benefit of ketamine, herein, we conduct a systematic review that aims to report the Number Needed to Treat (NNT) and the Number Needed to Harm (NNH).<BR><B>METHODS: </B>This systematic review searched Embase, Medline/Pubmed, PsycINFO and ClinicalTrials.gov from inception up to October 15th 2023, for placebo-controlled, Randomized Controlled Trials (RCTs) assessing racemic ketamine or esketamine therapy for unipolar TRD. We calculated NNT and NNH for ketamine treatments over various time points.<BR><B>RESULTS: </B>A total of 21 studies with 2042 participants were included. Racemic ketamine treatments had pooled NNTs for response of 7 at 4 h, 3 from one day to one week and 9 for studies at four weeks. Esketamine treatment was found to have a similar efficacy with an NNT of 2 at one day and 11 at four weeks. NNH values indicated low risk for ketamine treatments.<BR><B>CONCLUSIONS: </B>Limitations in the data used include the possibility of functional unblinding and selective reporting bias. Moreover, the meta-analysis may have been limited in its precision by including low threshold definitions of treatment resistance (≥ 1 failed antidepressant) and low-dose ketamine treatments.<BR><B>CONCLUSIONS: </B>Herein, we determined that the NNT for ketamine treatment in adults living with TRD across different intervals of observation was <10. We conclude that the NNTs observed herein are highly clinically meaningful in this difficult to treat disorder.