Short-term effect of motivational interviewing on clinical and psychological outcomes and health-related quality of life in cardiac rehabilitation patients with poor motivation in Hong Kong: A randomized controlled trial

Background: Motivational interviewing (MI) is effective in promoting behavioural changes in patients with substance abuse and smoking. However, its effectiveness on health outcomes in cardiac rehabilitation patients is unclear. Design: A randomized controlled trial.Method: A total of 146 patients assessed as having poor motivation attended a cardiac rehabilitation programme from February 2008 to June 2010. Patients (n = 73) in the control group received usual care while those in the experimental group (n = 73) received usual care plus four sessions of MI, each lasting 30-45 min. Clinical and psychological outcomes and health-related quality of life were measured at baseline and 3 months after entering the programme. Descriptive statistics, independent t-test, Pearson Chi-squared test, and generalized estimating equations models were used to analyse the data.Results: There was no significant difference between the two groups on clinical outcomes (all p-values >0.05). Patients in the experimental group had higher increases in health-related quality of life (SF-36) scores in the aspects of general health (4.74, 95% CI 0.04-9.44; p = 0.048) and role limitation due to emotional problems (8.80, 95% CI 1.16-16.43; p = 0.024). However, they reported significantly higher increases in anxiety levels (Hospital Anxiety and Depression Scale) than those in the control group (0.96, 95% CI 0.09-1.83; p = 0.030). Conclusion: The short-term effectiveness of MI on clinical outcomes and health-related quality of life in poorly motivated cardiac rehabilitation patients is limited. MI, however, was shown to increase anxiety levels of patients during the study period (3 months). More evidence is needed to better understand this phenomenon in the future studies.