TABLE 1

Characteristics of the Study Population, Overall and According to Pneumonia Severity

PredictorPneumonia SeverityaOverall, n = 2319
Mild, n = 1825Moderate, n = 316Severe, n = 178
Age, mo, median (IQR)30 (13–72)25 (10–73)17 (5–59)28 (12–71)
Male sex996 (55)172 (54)105 (59)1273 (55)
Race/ethnicity
 Non-Hispanic white701 (38)142 (45)73 (41)916 (40)
 Non-Hispanic black649 (36)75 (24)51 (29)775 (33)
 Hispanic336 (18)73 (23)35 (20)444 (19)
 Other139 (8)26 (8)19 (11)184 (8)
Comorbidityb
 Pulmonary639 (35)138 (44)47 (27)824 (36)
 Prematurity162 (9)33 (11)20 (11)215 (9)
 Neurologic110 (6)36 (11)27 (15)173 (7)
 Cardiovascular84 (5)33 (10)12 (7)129 (6)
 Genetic/metabolic89 (5)34 (11)12 (7)135 (6)
 Other100 (5)12 (4)7 (4)119 (5)
No. comorbidities
 0910 (50)123 (39)93 (53)1126 (49)
 1697 (38)128 (41)53 (30)878 (38)
 2175 (10)43 (14)25 (14)243 (10)
 3+43 (2)22 (7)7 (4)72 (3)
Household smoke exposurec637 (35)114 (36)64 (36)815 (35)
Season
 Winter623 (34)113 (36)69 (39)805 (35)
 Spring565 (31)119 (34)56 (31)730 (31)
 Summer263 (14)46 (15)27 (15)336 (14)
 Fall374 (21)48 (15)26 (15)448 (19)
Symptom duration, d, median, (IQR)c,d3 (2–6)3 (2–5)2 (1–4)3 (2–6)
Vomiting/feeding refusal1025 (56)149 (47)89 (51)1263 (54)
Temperature, °C, median (IQR)38 (37–39)38 (37–39)38 (37–39)38 (37–39)
Respiratory rate, median (IQR)40 (28–51)48 (36–60)42 (32–58)40 (30–52)
Heart rate, median (IQR)150 (130–167)158 (139–174)162 (143–182)152 (132–168)
Systolic blood pressure, median (IQR)d110 (101–120)110 (98–120)105 (92–118)110 (100–120)
PF ratio, median (IQR)d457 (434–474)423 (369–457)417 (297–457)451 (420–474)
Chest indrawingd896 (50)258 (82)111 (64)1265 (55)
Asymmetric breath sounds1163 (64)220 (70)121 (68)1504 (65)
Wheezing708 (39)173 (55)61 (34)942 (41)
Altered mental statusd21 (1)8 (3)29 (18)58 (3)
White blood cell count, median (IQR)e12 (9, 17)12 (8, 17)11 (8, 19)12 (9, 18)
Radiographic infiltrate patternf
 Consolidation, single lobar462 (25)46 (14)21 (12)529 (23)
 Consolidation, multilobar495 (27)93 (29)76 (43)664 (29)
 Other infiltrate735 (40)157 (49)66 (38)958 (41)
 Mixed129 (7)20 (6)15 (9)164 (7)
Pleural effusion247 (14)37 (12)25 (14)309 (13)
  • Data presented as no. (%) unless otherwise indicated; all predictors reflect assessments performed at the time of admission.

  • a Severe included children who required invasive mechanical ventilation and those with shock requiring vasoactive medications; moderate included children admitted to intensive care who did not meet criteria for severe pneumonia; the remaining children were classified as mild.

  • b Comorbidities present in <5% of children were grouped into a single “other” variable, which includes hematologic, endocrine, and hepatic/renal comorbidities.

  • c Before admission.

  • d Missing data for <2% of observations.

  • e Missing data for 397 observations (17%).

  • f Infiltrate pattern was not defined for 4 children because of the presence of a large pleural effusion.