Tai chi or cognitive behavioural therapy for treating insomnia in middle aged and older adults: randomised non-inferiority trial.

OBJECTIVE: To assess whether tai chi is non-inferior to cognitive behavioural therapy for insomnia (CBT-I), the first line treatment, for managing chronic insomnia in middle aged and older adults. DESIGN: Randomised, assessor masked, non-inferiority trial. SETTING: A single research site in Hong Kong with participants recruited from the local community between 18 May 2020 and 14 July 2022. PARTICIPANTS: Chinese participants aged ≥50 years with chronic insomnia diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. INTERVENTIONS: Tai chi and CBT-I interventions were delivered in group format over three months, consisting of one hour sessions twice a week for a total of 24 sessions. MAIN OUTCOME MEASURES: The primary outcome was the change in perceived insomnia severity measured by the Insomnia Severity Index after the intervention (month 3) and at 12 month follow-up (month 15). To assess whether tai chi is non-inferior to CBT-I, a threshold of four points was used as the margin of non-inferiority. RESULTS: 200 participants were randomised (1:1) to receive tai chi (n=100) or CBT-I (n=100). The per protocol principle was adopted. At month 3, the tai chi group showed a reduction of 6.67 (95% confidence interval 5.61 to 7.73) in Insomnia Severity Index scores, while the CBT-I group had a reduction of 11.19 (10.06 to 12.32), resulting in a between group difference of 4.52 (-∞ to 5.81). Tai chi was deemed inferior to CBT-I at month 3 because the upper confidence limit exceeded the non-inferiority margin. At month 15, the reductions for tai chi and CBT-I were 9.51 (8.47 to 10.54) and 10.18 (8.97 to 11.40), respectively, with a between group difference of 0.68 (-∞ to 2.00). At this point, tai chi was considered non-inferior to CBT-I because the upper confidence limit fell within the non-inferiority margin. Results from the intention-to-treat analysis were consistent with the per protocol findings. No adverse events occurred during the intervention period. CONCLUSION: Tai chi was inferior to CBT-I at month 3 but non-inferior at month 15. This finding supports the use of tai chi as an alternative approach for the long term management of chronic insomnia in middle aged and older adults. TRIAL REGISTRATION: ClinicalTrials.gov NCT04384822.