Table 1.

Characteristics of Pneumonia Etiology Research for Child Health (PERCH) Controls With Any Respiratory Symptom Subsequently Enrolled as PERCH Cases at 4 Study Sites—Kilifi, Kenya; Nakhon Phanom and Sa Kaeo^a, Thailand; and Matlab, Bangladesh

Site	Age, mo	Symptoms Present at Control Enrollment	Days Between Enrollment as Control and as Case	Duration of Longest Symptom at Time of Case Enrollment, d	Days Between Control Symptoms and Case Symptoms	Chest Radiograph Result During Hospitalization as a Caseb
Kilifi, Kenya	4	Cough, runny nose	223	14	209	Normal
Nakhon Phanom, Thailand	9	Rashc, tachypneac,d	207	7	200	Abnormal
Nakhon Phanom, Thailand	5	Coughc, runny nose	271	2	269	Normal
Matlab, Bangladesh	16	Cough, tachypneac,d	74	4	70	Uninterpretable
Matlab, Bangladesh	5	Cough	72	1	71	Abnormal
Matlab, Bangladesh	19	Coughc, runny nose	69	3	66	Abnormal

^aNo PERCH controls were later enrolled as cases in Sa Kaeo, Thailand.

^bAbnormal chest radiograph result: presence of alveolar consolidation and/or other infiltrate.

^cSymptom observed or measured by PERCH staff upon clinical examination at enrollment. All other symptoms reported by parent or guardian.

^d Tachypnea was defined as a respiratory rate ≥60 breaths per minute on clinical examination for children 1–2 months of age, ≥50 for children 2–11 months, and ≥40 for children 12–59 months.