Is progressive muscle relaxation (PMR) effective on reducing cigarette craving and withdrawal symptoms among experienced smokers?
Date of publication of the randomized controlled trial: March 2015
Design
Randomized controlled trial (RCT).
Participants
32 cigarette-dependent smokers aged 18 or more who met Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for cigarette dependence (mean age: 35.4 years in PMR group, 30.7 years in control group, male %: 87.5% in PMR group, 100% in control group).
Intervention
The intervention group was instructed to practice PMR individually in a quiet, private, air-conditioned room for about 20 minutes, following a PMR audiotape developed by the Thai Bureau of Mental Health Technical Development.
Comparator
Comparison: PMR versus control activity. Control activity referred to reading current newspaper for 20 minutes in the same room and sitting in the same chairs that used for PMR practice.
Major Outcomes
Outcome 1: Cigarette craving as assessed by the Thai version of the Penn Alcohol Craving Scale (PACS) after the 1-session intervention;
Outcome 2: Cigarette withdrawal symptoms as assessed by Visual Analog Scale (VAS) after the 1-session intervention.
Settings
This study was performed in an outpatient setting.
Comparison    PMR versus control activity
Main Results
Compared to control activity, PMR showed significantly lower levels of craving (p<0.001). PMR also significantly reduced withdrawal symptoms including stimulation (p=0.008), anxiety (p=0.043) and hunger(p=0.002).
Comparison: PMR versus control activity in experienced smokers
Outcome No. of studies (Total number of participants) Mean score (SD)/No. of participants Heterogeneity test (I2) MD (95%CI) p value Overall quality of evidence*
Intervention Comparator
1 1 (32) 7.2 (5.5)/16 15.2 (5.2)/16 Not applicable as there is only 1 study. Not reported <0.001 Low
2 1 (32) 1.8 (2.7)/16 3.6 (2.4)/16 Not applicable as there is only 1 study. Not reported 0.043 Low
Keys: SD = standard deviation; CI = confidence intervals.
Comparison    PMR versus control activity
Main Results
Compared to control activity, PMR showed significantly lower levels of craving (p<0.001). PMR also significantly reduced withdrawal symptoms including stimulation (p=0.008), anxiety (p=0.043) and hunger(p=0.002).
Comparison: PMR versus control activity in experienced smokers
Outcome 1 2
No. of studies (Total number of participants) 1 (32) 1 (32)
Mean score (SD)/No. of participants Intervention 7.2 (5.5)/16 1.8 (2.7)/16
Comparator 15.2 (5.2)/16 3.6 (2.4)/16
MD (95%CI) Not reported Not reported
p value <0.001 0.043
Overall quality of evidence* Low Low
Keys: SD = standard deviation; CI = confidence intervals.
Conclusion
Benefits
Compared to control activity, PMR significantly reduced cigarette craving and withdrawal symptoms (feeling anxiety, anxiety and hunger) among smokers undergoing acute abstinence. For all outcomes, the overall quality of evidence is low. Further research is likely to have an important impact on our confidence in this estimate of effect.
Harms
The authors did not mention details of adverse events.
Link to Original Article
https://www.ncbi.nlm.nih.gov/pubmed/ 26420821
The synopsis is based on the following article:
Limsanon T, Kalayasiri R. Preliminary effects of progressive muscle relaxation on cigarette craving and withdrawal symptoms in experienced smokers in acute cigarette abstinence: a randomized controlled trial. Behav Ther. 2015 Mar;46(2):166-76. doi: 10.1016/j.beth.2014.10.002. Epub 2014 Nov 7.


* Interpretation of quality assessment results:
• Very low: Further research is most likely to have an important impact on our confidence in this estimate of effect.
• Low: Further research is likely to have an important impact on our confidence in this estimate of effect.
• Moderate: Further research is fairly likely to have an important impact on our confidence in this estimate of effect.
• High: Further research is unlikely to have an important impact on our confidence in this estimate of effect.
• Very high: Further research is most unlikely to have an important impact on our confidence in this estimate of effect.

Details of assessment method can be found at Chung VC, Wu XY, Ziea ET, Ng BF, Wong SY, Wu JC. Assessing internal validity of clinical evidence on effectiveness of CHinese and integrative medicine: Proposed framework for a CHinese and Integrative Medicine Evidence RAting System (CHIMERAS). European Journal of Integrative Medicine. 2015 Aug 31;7(4):332-41.