%0 Journal Article
%T Number needed to treat (NNT) for ketamine and esketamine in adults with treatment-resistant depression: A systematic review and meta-analysis.
%A Calder CN
%A Kwan ATH
%A Teopiz KM
%A Wong S
%A Rosenblat JD
%A Mansur RB
%A Rhee TG
%A Ho R
%A Cao B
%A McIntyre RS
%J J Affect Disord
%V 356
%N 0
%D 2024 Jul 1
%M 38636712
%F 6.533
%R 10.1016/j.jad.2024.04.039
%X BACKGROUND: 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).
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
CONCLUSIONS: 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.