Immediate, Short-term, Medium-term, and Long-term effects of Acceptance and Commitment Therapy for Smoking Cessation: A Systematic Review and Meta-Analysis

Introduction Acceptance and commitment therapy (ACT) is increasingly being studied as a treatment for smoking cessation. However, its immediate, short-, and long-term effects have rarely been reviewed. Methods This systematic review aimed to evaluate the effectiveness of immediate, short-, medium-, and long-term smoking cessation rates in ACT and comparators at less than 3-month, 3 to 4-month, 6-, and 12-month follow-ups. Randomized controlled trials (RCTs) were searched in eight databases until April 20, 2023. We assessed the quality of RCTs and the certainty of evidence of outcomes. Results Nineteen RCTs involving 7885 smokers across six countries were included. The majority (72.81%) of RCTs were graded as low risk across six domains. For complete-case outcomes, meta-analyses were conducted, and the results revealed a significant effect in favor of ACT [risk ratio: 1.70-1.80 at <3-month, 3 to 4-month, and 6 months follow-up] compared with comparators. For outcomes using missing data management, meta-analyses found an overall effect in favor of ACT, but a significant effect was found at 3 to 4-months only. However, 12-month follow-ups revealed no significant reduction in smoking cessation for both outcomes. Moderate and substantial heterogeneities were found among four meta-analyses that may lead to inaccurate estimates of effects. The certainty of evidence of all outcomes was rated as low and very low. Conclusion ACT may be an effective intervention for smoking cessation with immediate, short-term, and medium-term effects. Caution must be applied in the interpretation of the results due to the limited trials and low certainty of evidence. Implication ACT can be implemented adjuvant to the usual treatment for smoking cessation. Additional RCTs with follow-up data using biochemically verified measures in non-US countries are warranted.