We directly compared convergent, discriminant and concurrent validity of the Dyspnoea-12 (D-12) and Multidimensional Dyspnoea Profile (MDP) in people with chronic obstructive pulmonary disease.
Breathlessness measures (D-12, MDP, visual analogue scales and descriptors) were completed for two focal periods (daily life and end of walk test). Instrument structure (D-12 and MDP item grouping) was assessed with factor analysis. Differences between airflow severity stage and focal periods (ANOVA, t-test and Chi-squared test), associations between D-12 and MDP (r, r2 for static pulmonary function, 6-min walk test and self-reported measures of impairment) and individual consistency for comparable items of the D-12 and MDP (McNemar's test) were assessed.
In 84 participants (mean±sd age 70±9 years, 47 males, forced expiratory volume in 1 s 48±17% predicted), item groupings were confirmed for both focal periods. Developer-recommended single and subdomain scores were highly correlated, and demonstrated similar convergent, discriminant and concurrent validity. Individual consistency differed between the D-12 and MDP according to item/item groups.
At the level of developer-recommended single and subdomain scores, the D-12 and MDP share similar psychometric properties, but these instruments serve different purposes, do not assess the same sensations or emotions and are not interchangeable.
The D-12 and MDP share similar psychometric properties but serve different purposes and are not interchangeable http://ow.ly/VXmX305OkdN
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Clinical trials: This study is registered at www.anzctr.org.au with identifier number ACTRN12611000292976.
Support statement: This study was supported by a National Health and Medical Research Council (NHMRC) Project Grant (1010309). The NHMRC did not have input or contribute to the development of the research or the manuscript. Funding information for this article has been deposited with the Open Funder Registry.
Conflict of interest: Disclosures can be found alongside this article at erj.ersjournals.com
- Received September 7, 2015.
- Accepted October 26, 2016.
- Copyright ©ERS 2017