Characteristics associated with SF-36 in alpha-1 antitrypsin deficiency-associated COPD: a cross-sectional analysis

Table 2 Univariate associations between demographic and clinical characteristics and MCS and PCS of SF-36

	MCS^a			PCS^a
	Unadjusted coefficient	95% CI	p-value	Unadjusted coefficient	95% CI	p-value
Age, years
<50	REF			REF
50-65	3.12	(2.33; 3.91)	<0.0001	0.65	(-0.08; 1.38)	0.0797
>65	5.82	(4.89; 6.75)	<0.0001	1.45	(0.59; 2.31)	0.0009
Sex
Male	REF			REF
Female	0.71	(0.06; 1.36)	0.0318	0.07	(-0.51; 0.66)	0.8043
mMRC^b
0	REF			REF
1	-0.62	(-1.86; 0.61)	0.3203	-3.61	(-4.59; -2.63)	<0.0001
2	-2.34	(-1.86; -1.07)	0.0003	-8.70	(-9.70; -7.69)	<0.0001
3	-3.32	(-4.55; -2.08)	<0.0001	-11.85	(-12.83; -10.86)	<0.0001
4	-6.36	(-7.56; -5.16)	<0.0001	-14.85	(-15.81; -13.90)	<0.0001
Frequency of exacerbations in the past year
0	REF			REF
1	-1.10	(-2.06; -0.14)	0.0243	-1.92	(-2.78; -1.08)	<0.0001
2 or more	-4.56	(-5.35; -3.78)	<0.0001	-6.34	(-7.03; -5.64)	<0.0001
Regular use of oxygen in the past year
No	REF			REF
Yes	-0.96	(-1.61; -0.32)	0.0034	-5.97	(-6.53; -5.42)	<0.0001
Daily productive cough for at least 3 months each year over the past 2 years
No	REF			REF
Yes	-2.63	(-3.27; -1.99)	<0.0001	-3.69	(-4.27; -3.11)	<0.0001

^aMCS (Mental Component Summary score) and PCS (Physical Component Summary score) have a mean of 50 (±10) in the general US population. Higher scores indicate better HRQoL
^bmodified Medical Research Council scale: 0 -I only get breathless with strenuous exercise; 1 -I get short of breath when hurrying on level ground or walking up a slight hill; 2 -On level ground, I walk slower than people of the same age because of breathlessness or have to stop for breath when walking; 3 -I stop for breath after walking about 100 yards or after a few minutes on level ground; 4 -I am too breathless to leave the house, or I am breathless when dressing

ISSN: 1471-2466