Table 5.

Multivariable Linear Regression for Severe Exacerbation Frequency

GOLD	Classic CB			SGRQ CB			SGRQ vs Classic
	β Coeffa	SE	P Value	β Coeffa	SE	P Value	P Value
All	0.032	0.016	.054	0.065	0.014	< .0001	.077
0	0.027	0.018	.139	0.035	0.015	.017	.655
1, 2	0.033	0.026	.199	0.054	0.023	.018	.520
3, 4	0.038	0.051	.462	0.121	0.047	.011	.092

Probability values in boldface indicate significance. See Table 1 and 4 legends for expansion of abbreviations.

^aAge, race, sex, pack-year history, current smoking, oxygen use, modified Medical Research Council dyspnea score, % emphysema, prior exacerbation frequency, FEV₁% predicted, 6-min walk distance, and BMI as covariates.