Table 3.

Worsening of illness according to subgroup in amoxicillin versus placebo group

	Amoxicillin	Placebo	Interaction terma (95% CI)	P-value	Odds ratio for subgroupa (95% CI)	P-value
Whole cohort	162/1021	194/1006			0.79 (0.63 to 0.99)	0.043
Green sputum	40/221	43/185	0.93 (0.53 to 1.61)	0.787	0.73 (0.45 to 1.18)	0.202
Current smoker	47/304	45/269	1.21 (0.72 to 2.03)	0.482	0.91 (0.58,1.42)	0.680
Significant past historyb	44/257	47/243	1.11 (0.65 to 1.88)	0.692	0.86 (0.55 to 1.36)	0.520
Prior duration of illness >7 days	70/411	74/390	1.16 (0.73 to 1.86)	0.528	0.88 (0.61 to 1.26)	0.474
Fever at baseline	59/345	70/347	1.05 (0.65 to 1.69)	0.844	0.82 (0.56 to 1.20)	0.300
Minor chest signs	57/345	70/334	0.92 (0.57 to 1.49)	0.740	0.75 (0.51 to 1.10)	0.139

^aEstimates controlled for baseline symptom severity.

^bLung disease, heart disease, diabetes, or hospital admission.