COPD: Dyspnea Questionnaire Does Not Determine Physical Activity

Chronic obstructive pulmonary disease (COPD) can majorly limit physical activity and impair quality of life. A system believed to predict activity level proved to not be helpful after all.

Dyspnea, or difficulty breathing, is a characteristic symptom of COPD. Cristino Oliveira, PhD, from La Trobe University in Melbourne, and colleagues hypothesized that the Dyspnea-12 questionnaire (D-12) would greatly coordinate with level of physical activity. However, they discovered that that’s not the case and dissected the findings at the CHEST 2015 meeting in Montréal, Canada.

“Dyspnea has a complex nature,” Oliveira began during the presentation. There are two parts to the symptom, the physical component and affective component. The D-12 questionnaire measures dyspnea and is made up of 12 questions with the first 7 evaluating the physical component and the other five addressing the affective component. To directly measure the affective component, such as intensity and severity, the researchers used the Borg scale (0 to 10) and visual analogue scale (VAS).

“So we investigated 63 people with COPD,” Oliveira continued. “The objective of this study was to explore the associations between the D-12 as comprehensive assessment of dyspnea and levels of activity.”

The researchers studied each of the participants’ physical activity for one week at some point from December 2013 to March 2015. All patients had an oxygen saturation of less than 90% and the average 6-minute test measured in around 400 meters. Data was also collected from the endurance shuttle walk test (ESWT).

“There was no correlation with light physical activity,” Oliveira verified. This also held true for moderate to severe physical activity. The Borg score taken after the ESWT, however, had a statistically significant correlation with dyspnea. The researchers clarified that they were unable to predict physical activity with any dyspnea measure.

“The hypothesis was not confirmed,” Oliveira concluded. “The D-12 comprehensive dyspnea assessment was not associated with physical activity in COPD.” These outcomes suggest that predicting physical activity in COPD is much more complex and needs additional research.

Notably, the results could bring doubt that the D-12 is an effective scale to measure components of COPD. However, Oliveira explained that the measurement is oblique and reassured that it has a high correlation with other commonly used hospital scales. Additional journal analyses have confirmed the reliable usage of D-12 as well.