Table 2

Test characteristics of signs and symptoms of radiographic pneumonia

Symptom or sign*	Sample size, n	Sign or symptom present, n	Radiographic pneumonia, n	Sensitivity	Specificity	Positive likelihood ratio (95% CI)	Negative likelihood ratio (95% CI)
Cough48–51 53–55 57	4961	4405	1060	0.77	0.08	0.83 (0.81 to 0.86)	3.1 (2.65 to 3.57)
Fever19 50 51 53 54 57	5472	4531	1076	0.82	0.17	0.98 (0.95 to 1.01)	1.10 (0.96 to 1.25)
Difficulty breathing48–51 53–55	4061	3566	772	0.70	0.08	0.76 (0.73 to 0.79)	3.98 (3.41 to 4.65)
Vomiting50 51 53 54	2688	349	101	0.12	0.87	0.94 (0.76 to 1.17)	1.01 (0.98 to 1.04)
Poor feeding48–50 54	2905	265	65	0.14	0.91	1.67 (1.29 to 2.16)	0.94 (0.90 to 0.98)
Respiratory rate (RR) WHO cut off†19 48 49 51–55 57	12 478	9754	2006	0.79	0.22	1.01 (0.99 to 1.04)	0.96 (0.88 to 1.04)
RR WHO cut-off+5‡19 48 49 51–55 5⁷	12 478	8012	1648	0.65	0.36	1.02 (0.99 to 1.06)	0.96 (0.91 to 1.02)
RR WHO cut-off +10§^{19 48–55 57}	12 478	6140	1301	0.51	0.51	1.05 (1.004 to 1.09)	0.95 (0.91 to 0.997)
Lower chest indrawing48–50 52–57	12 546	10 388	2509	0.74	0.15	0.87 (0.85 to 0.89)	1.74 (1.61 to 1.88)
Temperature >38°C19 48–50 52–57	14 188	5940	1894	0.54	0.60	1.36 (1.31 to 1.41)	0.77 (0.74 to 0.80)
Rales/crepitations19 48–50 52 54 55 57	11 416	8584	1596	0.82	0.26	1.09 (1.07 to 1.12)	0.73 (0.66 to 0.80)
Unable to drink50 54	1769	429	75	0.29	0.76	1.17 (0.95 to 1.45)	0.95 (0.87 to 1.03)
Convulsions52 54	1324	160	22	0.14	0.88	1.24 (0.82 to 1.88)	0.97 (0.90 to 1.04)
Cyanosis48–50 52–54 56	5618	228	112	0.06	0.96	1.52 (1.19 to 1.94)	0.98 (0.97 to 0.99)
Head nodding/bobbing50 54 57	2757	169	63	0.11	0.94	1.84 (1.38 to 2.45)	0.95 (0.92 to 0.98)
Irritable48 49 54	2298	115	21	0.05	0.95	1.34 (0.88 to 2.19)	0.98 (0.95 to 1.01)
Abnormally sleepy/lethargy48–50 52 54 56	4999	349	76	0.05	0.93	0.72 (0.56 to 0.92)	1.02 (1.01 to 1.04)
Nasal flaring50 54 55 57	2898	439	117	0.18	0.85	1.24 (1.03 to 1.50)	0.96 (0.92 to 1.00)
Grunting19 50 54 57	4554	183	53	0.06	0.96	1.72 (1.27 to 2.33)	0.97 (0.95 to 0.99)
Wheeze19 50–52 54 55 57	10 801	2928	571	0.29	0.73	1.05 (0.97 to 1.13)	0.98 (0.95 to 1.01)
Oxygen saturation (SpO₂) <95%19 48–55 57	11 967	7298	1687	0.67	0.40	1.11 (1.08 to 1.15)	0.83 (0.78 to 0.88)
SpO₂ <90%19 48–55 57	11 967	3048	810	0.32	0.75	1.30 (1.22 to 1.39)	0.90 (0.87 to 0.93)
SpO₂ <85%19 48–55 57	11 967	1216	373	0.15	0.90	1.42 (1.27 to 1.59)	0.95 (0.93 to 0.97)
Any danger signs¶19 48–57	14 732	4399	1049	0.28	0.70	0.67 (0.60 to 0.75)	1.06 (1.40 to 1.07)

Bold values are statistically significant.
*Following missing values were excluded from the analysis: 373 (7%) for cough, 358 (6%) for fever, 218 (5%) for difficult breathing, 326 (11%) for vomiting, 50 (2%) for poor feeding, 286 (2%) for lower chest indrawing, 440 (3%) for temperature readings, 316 (3%) for rales/crepitations, 33 (2%) for unable to drink, 31 (2%) for convulsions, 243 (4%) for cyanosis, 65 (2%) for head nodding/bobbing, 106 (4%) for irritability, 63 (1%) for abnormally sleepy/lethargy, 71 (2%) for nasal flaring, 64 (1%) for grunting, 179 (2%) for wheeze, 977 (8%) for SpO₂ readings, 297 (2%) for any danger sign.
†RR of ≥60 per minute in infants <2 months old, >50 per minute in infants 2–11 months old or >40 per minute in children 12–59 months old.
‡RR of ≥65 per minute in infants <2 months old, >55 per minute in infants 2–11 months old or >45 per minute in children 12–59 months old.
§RR of ≥70 per minute in infants <2 months old, >60 per minute in infants 2–11 months old, >50 per minute in children 12–59 months old.
¶Any danger sign included: unable to drink, convulsions, cyanosis, head nodding/bobbing, irritability, abnormally sleepy, lethargy, nasal flaring, grunting, and SpO₂ <90%.