Analysis of longitudinal changes in dyspnea of patients with chronic obstructive pulmonary disease: an observational study

Table 4 Results of stepwise regression analyses to best predict the changes in dyspnea

	OCD (/year)	mMRC (/year)	CRQ dyspnea (/year)	SGRQ activity (/year)
Body mass index (kg/m²/year)			-
FEV₁ (ml/year)	0.05	0.06	0.08	0.19
DL_CO (%predicted/year)	0.05	0.08	0.07	0.04
Peak V₂ (ml/min/kg/year)	-	0.07
Peak V (l/min/year)	-	-	-	-
Peak V (%predicted VC/year)		-		-
HADS anxiety (/year)	-	-	-	0.14
HADS depression (/year)	0.17	0.17	0.16	-
Cumulative r²	0.27	0.38	0.32	0.37

Values indicate correlation of determination (r²). Missing values (-) indicate that independent variables were not statistically significant. FEV₁ forced expiratory volume in one second; FRC functional residual capacity, DL_CO diffusing capacity for carbon monoxide, $V ˙ O 2$ oxygen uptake, $V ˙ E$ minute ventilation, $VT$ tidal volume, VC vital capacity, HADS Hospital Anxiety and Depression Scale, OCD Oxygen Cost Diagram, mMRC modified Medical Research Council dyspnea scale, CRQ Chronic Respiratory Disease Questionnaire, SGRQ St. George’s Respiratory Questionnaire.

ISSN: 1465-993X