TABLE 3.

Linear regression model for log CFU, adjusting for clustering of repeated measures in a single participant using robust standard errors^a

Log CFU	Coefficient	SE	P	95% CIb
Constantc	5.560	0.099	<0.001	5.366 to 5.754
Day on treatment	−0.082d	0.005	<0.001	−0.091 to −0.072
Vol (ml)e
6–10	0.265	0.090	0.003	0.088 to 0.442
>10	0.490	0.108	<0.001	0.278 to 0.701

^an = 5,067; number of clusters, 435; F (3.434) = 113.38; P < 0.001; R² = 0.1235; root mean squared error (MSE), 1.1028.

^b95% CI, 95% confidence interval.

^cThe constant represents the expected log CFU in the smallest volume category (<6 ml) when the time on treatment is zero.

^dEach day of increase in treatment duration decreases the log CFU by 0.082.

^eFor the expected log CFU when the sputum volume changes from <6 ml to a higher volume category, add the corresponding volume coefficient.