Comprehensive Exercise Therapy Program Motivates Physical Activity Post-PCI

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After percutaneous coronary intervention (PCI), patients who are treated with ‘positive affect’ intervention are able to achieve a sustained and clinically significant increase in physical activity by 1 year compared with those who only receive exercise education, according to results from a study published online January 23, 2012, ahead of print in the Archives of Internal Medicine.

Janey C. Peterson, EdD, MS, RN, of Weill Cornell Medical College (New York, NY), and colleagues randomized patients who had undergone PCI within 1 year to patient education (n = 118) or an intervention focused on positive affect and self-affirmation (n = 124). All patients received an educational workbook and pedometer and agreed to a behavioral contract for a physical activity goal. In addition, the positive-affect group received a workbook chapter on the technique, bimonthly induction of positive affect by telephone, and 5-6 small mailed gifts. Positive affect induction was designed to remind patients to “think about things that make you feel good,” according to the authors.

Follow-up was maintained for 1 year. Overall mortality was 2.1%, and attrition was 4.5%.

The Positive Effect of Positive Affect

More patients in the positive affect group achieved the main study outcome of an increase of 336 kcal/wk or more of energy expenditure at 1 year than did those who received ordinary exercise education (54.9% vs. 37.4%; P = 0.007). Multivariate analysis confirmed that the main predictors of not meeting that target were stress (OR 0.96; P = 0.03) and sustaining an interval medical condition or procedure (OR 0.30; P = 0.01), while the positive affect intervention made patients more likely to reach this goal compared with education only (OR 1.7; P = 0.02).

After adjusting for baseline characteristics, positive affect still predicted a change in kilocalories expended at 1 year (P = 0.01). Moreover, patients who underwent the more intensive regimen saw nearly double the improvement in extra kilocalories burned per week by 1 year compared with those who received education alone (602 vs. 328 kcal/week; P = 0.14). The trend became significant when the researchers controlled for factors including the number of interval medical conditions/procedures and diabetes (P = 0.03).

Despite these differences, positive affect therapy failed to significantly influence clinical outcome by 1-year follow-up. The rate of combined cardiovascular morbidity and all-cause mortality was 12.3% for the intervention group and 19.1% in the education group (P = 0.15).  However, the study was not powered to detect differences in clinical outcomes.

In addition, subanalyses of patients with extremely high comorbidity and depressive symptoms showed differences in results between the 2 randomization groups. Among patients with a Charlson Comorbidity Index of 8 or greater, considered high, 87.5% in the intervention group burned an extra 336 kcal/wk or more at 12 months compared with 20.0% in the control group (P = 0.03). Positive affect patients were twice as likely to recover from high baseline depressive symptoms by 12 months compared with controls (OR 2.58; 95% CI 1.08-6.19).

‘A Tall Order’

Commenting on the benefits of positive affect intervention, Dr. Peterson told TCTMD in an e-mail communication that in experimental studies, positive affect has been shown to “increase enjoyment of tasks and improve intrinsic motivation.” It has also been shown to promote the processing of health information “even when the message conveys high personal risk,” she said.

Dr. Peterson was impressed by the rates of Kcal expenditure obtained by 1 year, which were impressive for a telephone-based behavioral intervention.

“Bringing a promising basic behavioral science intervention like positive affect from a laboratory setting to the real world setting to motivate behavior change in people with a clinical disease is a tall order,” she said. “We spent several years creating this intervention. And it paid off.”

Dr. Peterson and her team have copyrighted their workbooks for the purpose of distribution, so the intervention is “very easy and quick to deliver,” she noted, adding, “This intervention is scripted and it can be delivered in less than a minute over the telephone.” 

Because this study was not powered to detect differences in clinical outcomes, Dr. Peterson advocated longer-term studies that could demonstrate the impact of positive affect intervention on physical activity maintenance and hard outcomes. “The key with any behavior change is long-term maintenance.  We were focused on motivating physical activity over the course of a year and were surprised to see early differences in clinical outcomes. Longer studies need to be conducted. ” she said.

Study Details 

Patients were primarily older and male. They reported a high burden of comorbidity with 23.1% scoring 4 or more on the Charlson Comorbidity Index. Approximately three-quarters were overweight or obese. No baseline differences in psychosocial characteristics were found.

 

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Source:
Peterson JC, Charlson ME, Hoffman Z, et al. Randomized controlled trial of positive affect induction to promote physical activity after percutaneous coronary intervention. Arch Intern Med. 2012;Epub ahead of print.

 

 

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