Summary of key and auxiliary independent variables for experiments 1, 2 and 3
| Experiments 1 and 2 key variables | Experiment 3 key variables | Auxiliary variables for experiments 1–3 |
| Age (2–59 months) | Age (2–59 months) | Gender (male/female) |
| Indrawing (present/absent) | Indrawing (present/absent) | Cough duration (days) |
| History of cough (yes/no) | History of cough (yes/no) | Crackles (present/absent) |
| Difficulty breathing (present/absent) | Difficulty breathing (present/absent) | Weight (kg) |
| Level of consciousness: AVPU (alert/verbal response/pain response/unresponsive) | Level of consciousness: AVPU (alert/verbal response/pain response/unresponsive) | Pallor (0, +, +++) |
| Oxygen ordered (yes/no) | Capillary refill (immediate, 1–2 s, 3–6 s, >6 s) | |
| Cyanosis (present/absent) | Fever (present/absent) | |
| Inability to drink/breastfeed (yes/no) | Diarrhoea (present/absent) | |
| Grunting (present/absent) | Convulsions (present/absent) | |
| Respiratory rate (breaths/min) | Vomiting (yes/no) | |
| Referral (yes/no) | ||
| Length of illness (days) | ||
| Number of fits | ||
| Thrush (present/absent) | ||
| Quinine/artesunate (prescribed/not prescribed) | ||
| Weight for age z-score | ||
| Wheeze (present/absent) | ||
| Comorbidities (malaria and or diarrhoea) |
Experiment 3 has more key variables than experiment 2 as it usespatient populations with ‘very severe, severe and non-severe pneumonia’—as classified in the previous WHO and Kenyan treatment guidelines. Therefore, in addition to variables used to classify severe pneumonia, other variables used to classify very severe and non-severe pneumonia are considered.