Summary of findings 2. Diagnostic value of clinical symptoms and signs ‐ pooled results with 95% confidence intervals.

Clinical feature (n = number of studies)	Sensitivity	Specificity	Positive likelihood ratio	Negative likelihood ratio
Cough (n = 5)	0.89 (0.67 to 0.97)	0.15 (0.05 to 0.37)	1.04 (0.95 to 1.13)	0.78 (0.44 to 1.39)
Wheeze (n = 6)*	0.25 (0.17 to 0.36)	0.67 (0.56 to 0.76)	0.76 (0.60 to 0.97)	1.12 (1.02 to 1.23)
Coryza (n = 4)	0.32 (0.08 to 0.72)	0.66 (0.28 to 0.91)	0.95 (0.71 to 1.26)	1.03 (0.90 to 1.17)
Crepitations (n = 5)**	0.84 (0.78 to 0.88)	0.22 (0.14 to 0.32)	1.06 (0.96 to 1.18)	0.77 (0.52 to 1.12)

*The absence of wheeze remained a statistically significant diagnostic indicator when M. pneumoniae was diagnosed based on serology only (pooled LR+ 0.68, 95% CI 0.50 to 0.92; pooled LR‐ 1.24, 95% 1.03 to 1.51) (Chan 2001; Somer 2006). However, the absence of wheeze was no longer a statistically significant diagnostic indicator based on data from studies which used other laboratory tests alongside serology to diagnose M. pneumoniae (pooled LR+ 0.84, 95% CI 0.63 to 1.12; pooled LR‐ 1.06, 95% CI 0.96 to 1.18).

**Our sensitivity analysis excluding data from Agarwal 2009 found that the presence of crepitations was a weak diagnostic indicator of borderline statistical significance (pooled LR+ 1.10, 95% CI 0.99 to 1.23; pooled LR‐ 0.66, 95% CI 0.46 to 0.96).