Assessing health status over time: impact of recall period and anchor question on the minimal clinically important difference of copd health status tools

Table 1 Baseline patient characteristics

	Baseline all patients N = 451	Patients with complete follow-up N = 309	Patients with incomplete follow-up N = 142	Significance testing
Age (years)^a	57.9 ± 6.6	58.1 ± 6.5	57.5 ± 6.6	p = 0.39
Gender (male)^b	65.0	63.8	67.6	p = 0.43
FEV₁%pred^a	50.4 ± 15.1	50.6 ± 14.9	50.0 ± 15.6	p = 0.72
GOLD II^b	227 (50.3)	158 (51.1)	69 (48.6)
GOLD III^b	176 (39.0)	121 (39.2)	55 (38.7)	p = 0.63
GOLD IV^b	48 (10.6)	30 (9.7)	18 (12.7)
Smoking pack years ^a	42.6 ± 23.5	41.1 ± 23.1	45.9 ± 24.0	p = 0.05
CAT ^a	20.2 ± 7.3	20.0 ± 7.6	20.8 ± 6.8	p = 0.28
CCQ Total^a	2.9 ± 1.2	2.8 ± 1.2	3.0 ± 1.1	p = 0.06
SGRQ Total^a	50.7 ± 17.3	49.6 ± 17.8	53.0 ± 16.2	p = 0.05

CAT COPD Assessment Test, CCQ Clinical COPD Questionnaire, FEV1%pred Forced Expiratory Volume in 1 Second % predicted, GOLD Global initiative for Chronic Obstructive Lung Disease, N Number of Patients, SGRQ St. George’s Respiratory Questionnaire
^aData expressed as mean ± SD
^bData expressed as frequencies (% of total)
Significance tested with independent t-tests or Chi Square tests at level p < 0.05

ISSN: 1477-7525