Table 2.

Mechanisms of reduced 6-min walk distance after COVID-19 illness.

			Unadjusted analysis			Adjusted analysis
Model	Outcome	Primary predictor(s)	Coefficient	95%CI	P-value	Coefficient	95%CI	P-value	Prespecified covariates
1a	6MWD	BORG dyspnea	−22	−33, −12	<0.001	−17	−27, −8	<0.001	Age, sex, smoker, BMI, timea
1b	6MWD	BORG fatigue	−5	−13, 4	0.277	−4	−11, 4	0.298	Age, sex, smoker, BMI, time
1c	6MWD	End-exercise SpO2	8	4, 11	<0.001	8	4, 12	<0.001	Age, sex, smoker, BMI, time
2	6MWD	BORG dyspnea	−18	−29, −7	<0.001	−13	−22, −3	0.009	Age, sex, smoker, BMI, time
		End-exercise SpO2	6	2, 10	0.004	7	3, 10	<0.001

Abbreviations: 6MWD, 6-min walk distance; BMI, body mass index; CI, confidence interval, SpO₂, oxygen saturation by pulse oximetry.

^aTime from symptom onset.