Table 5.

Effect of antibiotic prescribing strategy subgroup variable interactions on mean symptom severity score two to four days after consultation for delayed versus no antibiotics, and delayed versus immediate antibiotics

Subgroup	No of studies	No of participants	Interaction (95% CI)	P	Adjusted* mean difference (95% CI)
Delayed v no antibiotics
Previous duration
Median and above	6	1835	0.05 (−0.23 to 0.34)	0.70	0.008 (−0.21 to 0.23)
Below median		1589			0.03 (−0.22 to 0.28)
Age (years)
0-4	9	749	0.11 (−0.02 to 0.24)	0.11	−0.20 (−0.24 to −0.15)
5-15		637			0.12 (0.07 to 0.16)
16-64		2153			−0.03 (−0.14 to 0.08)
>65		368			0.07 (−0.36 to 0.51)
Fever
≥37.5ºC	8	1436	0.01 (−0.16 to 0.18)	0.88	−0.03 (−0.15 to 0.09)
<37.5ºC		2211			−0.02 (−0.19 to 0.16)
Comorbidity
Any lung disease	9	438	0.14 (−0.05 to 0.34)	0.15	0.15 (−0.12 to 0.42)
No lung disease		2598			−0.01 (−0.15 to 0.13)
Baseline severity
Median and above	9	1972	−0.05 (−0.28 to 0.19)	0.69	−0.09 (−0.31 to 0.13)
Below median		1935			−0.14 (−0.33 to 0.04)
Delayed v immediate antibiotics
Previous duration
Median and above	6	1516	−0.07 (−0.41 to 0.27)	0.68	−0.04 (−0.38 to 0.29)
Below median		1526			0.02 (−0.17 to 0.21)
Age (years)
0-4	9	729	−0.10 (−0.17 to −0.03)	0.005†	0.10 (0.03 to 0.18)
5-15		548			0.09 (−0.11 to 0.30)
16-64		2107			−0.09 (−0.27 to 0.09)
>65		366			−0.19 (−0.62 to 0.25)
Fever
≥37.5ºC	8	1765	−0.05 (−0.32 to 0.23)	0.80	−0.01 (−0.42 to 0.40)
<37.5ºC		1662			0.03 (−0.06 to 0.11)
Comorbidity
Any lung disease	9	483	0.01 (−0.16 to 0.19)	0.87	0.13 (−0.27 to 0.53)
No lung disease		2554			0.12 (−0.14 to 0.38)
Baseline severity
Median and above	9	2286	0.35 (−0.23 to 0.93)	0.24	0.10 (−0.57 to 0.77)
Below median		1466			−0.27 (−0.34 to −0.19)

^*Adjusted for baseline severity, age, and condition.

^†Statistically significant interaction term.