Table 3.

Relative risk of selected signs and symptoms among patients infected with different influenza virus types, subtypes, and lineages

First author, y	Setting	Age group or range	Fevera	Coughb	Rhinitisc	Sore throat	Headache	Dyspnoead	GI symptomse	Myalgia	Age‐adjusted
A vs. B
Hite, 2007 40	Hosp	<19	ns & nr	ns & nr	ns & nr	ns & nr	ns & nr	ns & nr	ns & nr	0.34 (0.13‐0.91)	Unclear
A(H1N1)p vs. B
Yap, 2012 43	Non‐hosp	Young adults	0.51 (0.29‐0.92)	2.1 (1.25‐3.54)	0.54 (0.34‐0.86)	0.44 (0.24‐0.80)	ns & nr	‐	‐	ns & nr	Yes
Gutiérrez‐Pizarraya, 2012 41	Non‐hosp	Adults	2.5 (1.2‐5.4)	‐	‐	‐	‐	‐	ns & nr	‐	Unclear
A(H3N2) vs. B
Yap, 2012 43	Non‐hosp	Young adults	ns & nr	ns & nr	ns & nr	ns & nr	ns & nr	‐	‐	ns & nr	Yes
Cohen, 2014 30	Hosp	All ages	ns & nr	ns & nr	‐	‐	‐	ns & nr	‐	‐	Yes
A(H1N1)p vs. A(H3N2)
Yap, 2012 43	Non‐hosp	Young adults	0.33 (0.11‐0.99)	ns & nr	ns & nr	ns & nr	ns & nr	‐	‐	ns & nr	Yes
Cohen, 2014 30	Non‐hosp	All ages	ns & nr	ns & nr	‐	‐	‐	ns & nr	‐	‐	Yes
Dangi, 2014 10	Non‐hosp	All ages	‐	‐	‐	2.27 (1.22‐4.22)	ns & nr	ns & nr	ns & nr	ns & nr	Unclear
B Victoria vs. B Yamagata
Dangi, 2014 10	Non‐hosp	All ages	‐	‐	‐	ns & nr	ns & nr	12.0 (2.4‐59.8)	9.6 (1.0‐19.4)	ns & nr	Unclear
Sočan, 2014 31	Non‐hosp	All ages	1.6 (0.5‐5.1)	1.1 (0.4‐3.0)	0.6 (0.3‐1.1)	1.1 (0.6‐1.9)	0.7 (0.3‐1.4)	‐	1.1 (0.5‐2.3)	1.5 (0.9‐2.7)	Yes
	Hosp		0.7 (0.3‐1.6)	0.7 (0.3‐1.8)	‐	‐	‐	0.9 (0.3‐1.8)	‐	‐	Yes

Ns, not statistically significant; nr, not reported; Hosp, hospital‐based studies, that is, in which all included patients were hospitalized. Non‐hosp, studies that included both hospitalized and non‐hospitalized patients.

^aFever, high fever.

^bCough (not specified), dry cough.

^cRhinitis, rhinorrhea, coryza, running nose.

^dDyspnoea, wheezing, shortness of breath.

^eGastrointestinal (GI) symptoms not specified, vomiting, diarrhea.

Bold value indicates the significant findings (p < .05).