Factors associated with primary listener disagreement for cases and controls, stratified by lung examination result*
| Dichotomous lung examination group | Characteristic | Disagreement, n/N (%) | OR (95% CI) | p Value | Adjusted OR (95% CI)† | p Value |
| Abnormal or normal‡ | All cases and controls (n=987) | 262 (26.6) | – | – | – | – |
| Cases only (n=709) | 178 (25.1) | 0.77 (0.57 to 1.05) | 0.10 | 0.65 (0.47 to 0.90) | <0.01 | |
| Controls only (n=278) | 84 (30.2) | – | – | – | – | |
| Age 1–11 months (n=601) | 163 (27.1) | 1.08 (0.81 to 1.44) | 0.61 | – | – | |
| Age 12–59 months (n=386) | 99 (25.7) | – | – | – | – | |
| Tachypnoea§ (n=592) | 152 (25.7) | 0.92 (0.68 to 1.22) | 0.55 | – | – | |
| No tachypnoea (n=383) | 105 (27.4) | – | – | – | – | |
| >3 uninterpretable chest positions (n=344) | 121 (35.2) | 1.93 (1.45 to 2.58) | <0.001 | 2.05 (1.51 to 2.78) | <0.001 | |
| <3 uninterpretable chest positions (n=643) | 141 (21.9) | – | – | – | – | |
| Intermittent crying (n=514) | 161 (31.3) | 1.68 (1.26 to 2.24) | <0.001 | 1.56 (1.16 to 2.11) | <0.01 | |
| No intermittent crying (473) | 101 (21.4) | – | – | – | – | |
| Upper airway noises (n=607) | 189 (31.1) | 1.90 (1.40 to 2.59) | <0.001 | 2.23 (1.62 to 3.07) | <0.001 | |
| No upper airway noises (n=380) | 73 (19.2) | – | – | – | – | |
| PERCH site | – | – | 0.27 | – | – |
*Excludes uninterpretable primary listener lung examination results in both cases and controls. Eighty-three out of 792 cases and 23/301 controls were excluded. Primary listeners were the first two listeners randomly assigned to interpret a lung sound examination.
†Adjusted for all characteristics associated with disagreement at the significance level of 0.20.
‡Crackle and/or wheeze (abnormal) or no crackle and/or wheeze (normal).
§Tachypnoea defined as follows: <2 months: >60 breaths/minute; 2–11 months: >50 breaths/minute; 12–59 months: >40 breaths/minute.
PERCH, Pneumonia Etiology Research for Child Health.