Development and validation of the Cancer Dyspnoea Scale: a multidimensional, brief, self-rating scale

Abstract

Summary Dyspnoea is one of the most frequent and refractory symptoms in cancer patients. Lack of an appropriate assessment tool for dyspnoea seems to disturb establishment of management strategy. The purpose of this study was to develop and validate a brief self-rating scale to assess the multidimensional nature of dyspnoea in cancer patients. We developed a 12-item scale, the Cancer Dyspnoea Scale (CDS), composed of three factors (sense of effort/sense of anxiety/sense of discomfort), by using factor analysis. One hundred and sixty-six patients with advanced or recurrent lung cancer participated in the validation phase. The CDS showed good feasibility (average time required to complete it was 140 s). Construct validity, confirmed by repeating factor analysis, was good. Convergent validity, confirmed by a relation to Visual Analogue Scale of dyspnoea and modified Borg's scale, was also good (average: r = 0.57 and 0.52, respectively, and both P < 0.001). The CDS had good internal consistency (average Cronbach's alpha = 0.86) and stability (average test-retest reliability r = 0.66, P < 0.005). The present study demonstrated that the CDS is a brief, valid and feasible scale for assessing the multidimensional nature of dyspnoea in cancer patients.

Validation of a Swedish Version of the Cancer Dyspnea Scale

“…The influence of dyspnea on daily life activities has been measured by the Shortness of Breath Questionnaire (Eakin et al 1998). The Cancer Dyspnea Scale (CDS) assesses different parts of the physical dyspnea experience in cancer patients (Tanaka et al 2000). It consists of twelve items which could be grouped into three factors: a physical factor called sense of effort, a psychological factor called sense of anxiety and a factor reflecting the uncomfortable feeling at rest called sense of discomfort.…”

“…Dyspnea qualities were measured by the Cancer Dyspnea Scale (CDS). The CDS consists of 12 items, with a 5-point scale ranging from 1 (not at all) to 5 (very much), which may be grouped into three factors according to the original validation analysis (Tanaka et al 2000). The factors include a physical factor called sense of effort (5 items), a psychological factor called sense of anxiety (4 items), and a factor reflecting the uncomfortable feeling at rest called sense of discomfort (3 items).…”

“…The factors include a physical factor called sense of effort (5 items), a psychological factor called sense of anxiety (4 items), and a factor reflecting the uncomfortable feeling at rest called sense of discomfort (3 items). Completion times average 140 s (Tanaka et al 2000). The construct validity of the original instrument was determined by factor analysis and the factor loadings ranged from 0.61 to 0.94 within the factors.…”

“…The construct validity of the original instrument was determined by factor analysis and the factor loadings ranged from 0.61 to 0.94 within the factors. Convergent validity was demonstrated by comparing the factors as well as the total CDS score with a visual analogue scale (VAS) of dyspnea, the Borg's scale, the physical status as indicated by performance status and oxygen saturation, the State-Trait Anxiety Inventory (STAI), and the presence of patophysiological causes of dyspnea as evaluated by the physician (Tanaka et al 2000). Internal consistency was good, with Cronbach's alpha ranging from 0.81 to 0.93 for the three subscales.…”

“…Concerning total dyspnea (total CDS score), 80% scored above zero. If zero were considered a cut-off point -although not specified as such by Tanaka et al (2000), then CDS may be considered to be a more sensitive instrument than VAS-D. Symptom distress includes the degree of discomfort experienced in response to the symptom (McDaniel & Rhodes 1995).…”