Table 2

Dyspnoea-12 measurement properties for the Swedish Dyspnoea-12

Validation tests for Dyspnoea-12	All patients	Patients with COPD (n=45)	Patients with non-COPD (n=137)
Internal consistency, Cronbach’s alpha
Total	0.938	0.936	0.939
Physical domain score	0.843	0.830	0.846
Affective domain score	0.800	0.808	0.797
Test–retest reliability over 2 weeks, ICC (95% CI)
Total	0.81 (0.70 to 0.88)	0.81 (0.43 to 0.94)	0.81 (0.69 to 0.89)
Physical domain score	0.78 (0.67 to 0.86)	0.79 (0.49 to 0.93)	0.78 (0.65 to 0.87)
Affective domain score	0.75 (0.62 to 0.84)	0.73 (0.32 to 0.90)	0.76 (0.62 to 0.85)
Concurrent validity, Pearson’s correlation coefficients of Dyspnoea-12 total score with:
FEV₁ % of predicted	−0.297	−0.397	−0.266
mMRC	0.565	0.598	0.552
CAT l	0.616	0.537	0.658
EQ5D-index	−0.612	−0.605	−0.616
HADS total	0.329	0.370	0.310
HADS anxiety	0.449	0.535	0.419
HADS depression	−0.094	−0.247	−0.062
FACIT-Fatigue	−0.649	−0.636	−0.659
Dyspnoea-12 physical score with:
FEV₁ %pred	−0.351	−0.435	−0.324
mMRC	0.545	0.554	0.542
CAT	0.620	0.562	0.658
EQ5D-index	−0.589	−0.596	−0.590
HADS total	0.262	0.281	0.249
HADS anxiety	0.342	0.343	0.338
HADS depression	−0.053	−0.083	−0.057
FACIT-Fatigue	−0.609	−0.567	−0.636
D-12 affective score with:
FEV₁ %pred	−0.225	−0.354	−0.197
mMRC	0.519	0.582	0.496
CAT	0.530	0.451	0.566
EQ5D-index	−0.565	−0.507	−0.583
HADS total	0.358	0.348	0.356
HADS anxiety	0.513	0.599	0.483
HADS depression	−0.147	−0.083	−0.082
FACIT-Fatigue	−0.588	−0.606	−0.582

Measurement properties for all patients and for patients with COPD or other conditions as main cause of breathlessness. Test–retest reliability was analysed between 2 weeks and baseline in people who rated their breathlessness as unchanged.
CAT, COPD Assessment Test; COPD, chronic obstructive pulmonary disease;EQ-5D-5L, Euro-QoL-5 Dimensions-5 Levels; FACIT-Fatigue, Functional Assessment of Chronic Illness Therapy-Fatigue; FEV1%pred, forced expiratory volume in 1 s in percentage of predicted value; HADS, Hospital Anxiety and Depression Scale; ICC, intraclass correlation coefficient; mMRC, modified Medical Research Council.