A new functional status outcome measure of dyspnea and anxiety for adults with lung disease: the dyspnea management questionnaire.

PURPOSE: To develop and psychometrically test the Dyspnea Management Questionnaire (DMQ), a new multidimensional measure of dyspnea in adults with chronic obstructive lung disease. PARTICIPANTS: Eighty-five participants were recruited with diagnoses of chronic obstructive pulmonary disease (COPD, n = 73) and asthma (n = 12). The total sample was predominately female (65%) and married (34%), with 64.9% white and a mean age of 75 years (SD = 9.6, n = 76), diagnosed with pulmonary disease 4.8 years ago (SD = 4.4), 32% requiring the use of supplemental oxygen. Participants were also African American (29.9%), Asian (2.6%), and Hispanic (2.6%); n = 77.
METHODS: An initial item pool of 74 items was drawn for the DMQ aided by qualitative interview data, literature review, and pilot testing with 3 adults with COPD. Several analyses were used to reduce the item pool. An interdisciplinary panel of 12 experts evaluated the content validity of the DMQ items. To evaluate test-retest reliability, respondents with stable COPD (n = 26) completed the questionnaire twice within a mean interval of 18 days (SD = 7.17). The DMQ was compared with the Medical Outcomes Study 12-Item Short-Form (SF-12) Health Survey, the Seattle Obstructive Lung Disease Questionnaire, and the Hospital Anxiety and Depression Scale.
RESULTS: The resulting DMQ is a 30-item scale that measures 5 conceptually derived dimensions: dyspnea intensity, dyspnea-related anxiety, fearful activity avoidance, self-efficacy for activity, and satisfaction with strategy use. It has a 7-point Likert-type scale and third Flesch-Kincaid reading grade level. A panel of 12 experts supported the content validity of the DMQ. It showed high internal consistency (alpha = .87 to .96) and test-retest reliability over 2.5 weeks (intraclass correlation coefficient = 0.71 to 0.95). Dyspnea intensity, dyspnea-related anxiety, and fearful activity avoidance subscales of DMQ-30 and composite score were moderately to highly correlated with 3 Seattle Obstructive Lung Disease Questionnaire dimensions (r = 0.44-0.83), Medical Outcomes Study 12-Item Short-Form scales (r = 0.41-0.57), and Hospital Anxiety and Depression Scale-Anxiety (r = -0.59 to -0.65). Two of DMQ's subscales, self-efficacy for activity and satisfaction with strategy use, correlated mildly with Seattle Obstructive Lung Disease Questionnaire (r = 0.28 and 0.27, respectively). Some very low correlations for DMQ-30's satisfaction with strategy use compared with the Medical Outcomes Study 12-Item Short-Form provided preliminary support for its divergent construct validity. The DMQ-30 discriminated adults with COPD requiring supplemental oxygen from those not requiring it.
CONCLUSIONS: The DMQ addresses the need for a more comprehensive, multidimensional assessment of dyspnea, especially for anxious patients with COPD, in order to better guide the appropriate application of dyspnea management interventions and measure pulmonary rehabilitation outcomes. The DMQ can help add insights into the benefit of adjunctive therapies such as psychoeducation, controlled breathing strategies, and cognitive-behavioral approaches in pulmonary rehabilitation for anxious patients with COPD.