MedWire News: A multicomponent protocol can lead to clinically significant increases in physical activity among patients with asthma, US researchers report.
The 12-month protocol consisted of making a contract to participate in a specific physical activity, increasing knowledge of exercise and asthma, and increasing self-efficacy through physiologic feedback from a pedometer, explain Carol Mancuso (Hospital for Special Surgery, New York, USA) and colleagues.
An additional intervention to increase positive affect and self-affirmation did not, however, increase physical activity above the control protocol, but may have had an incremental benefit in patients who required interval medical care during the trial.
The researchers explain that patients with asthma engage in less physical activity than their age-matched peers without asthma, and increasing such activity may require a conscious change in behavior.
Mancuso and team randomly assigned 258 asthma patients, aged 18 years and over, to the control protocol or the intervention protocol. At study enrollment, all participants completed a survey measuring energy expenditure and then received bimonthly follow-up telephone calls.
Participants in the intervention group also received instructions in fostering positive affect and self-affirmation, as well as small gifts every 2 months to increase positive affect.
The main outcome was the within-patient change in energy expenditure in kilocalories per week - measured with the Paffenbarger Physical Activity and Exercise Index - from enrollment to 12 months.
Clinical and demographic characteristics were similar between the groups at enrollment, and there was no significant difference in energy expenditure, at 1767 kcal/week among controls and 1860 kcal per week among intervention patients
By the end of the study, energy expenditure had increased significantly by 415 and 398 kcal per week in the control and intervention groups respectively, with no difference between the groups.
For both groups, physical activity increased to 4 months and was sustained through 12 months. Importantly, the gains were achieved without worsening asthma, and in most cases asthma improved.
Of note, 23 patients in the control group and 29 in the intervention group required interval medical care during the trial. Among these, energy expediture decreased by 198 kcal per week for controls but increased by 552 kcal per week for intervention patients.
This suggests that "positive affect and self-affirmation buffer patients from the psychological consequences of acute illness and help prevent abandoning elective healthy behaviors during periods of medical adversity," the researchers remark.
Indeed, in multivariate analysis, increased energy expenditure was significantly associated with the intervention among patients who required urgent asthma care. Less social support, decreased depressive symptoms, more follow-up calls, use of the pedometer, and fulfillment of the contract were also associated with increased physical activity.
Writing in the Archives of Internal Medicine, Mancuso and co-authors conclude: "These findings are clinically relevant because they address a dilemma faced by asthma patients: although patients acknowledge that physical activity is beneficial for cardiovascular health, many avoid it for fear it will exacerbate respiratory symptoms.
"This trial is the first to apply several tenets of health behavior theory to address this critical yet largely overlooked dilemma for [these] patients."
MedWire (http://www.medwire-news.md/) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
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