| Clinical characteristics | Clinically identified radiographic pneumonia | Clinically unrecognised radiographic pneumonia | p-value |
| Patients n | 41 | 99 | |
| Symptoms and signs | |||
| Runny nose | 44 | 64 | 0.031 |
| Fever | 90 | 41 | <0.001 |
| Chest pain | 68 | 52 | 0.068 |
| Comorbidity (pulmonary, cardiac or DM)# | 20 | 23 | 0.629 |
| Abnormal auscultation lungs | 83 | 50 | <0.001 |
| Diminished vesicular breathing | 15 | 20 | 0.441 |
| Crackles | 66 | 16 | <0.001 |
| Rhonchi | 27 | 23 | 0.652 |
| Heart rate >100 beats·min−1 | 24 | 7 | 0.004 |
| Breathing frequency >24 breaths·min−1 | 10 | 2 | 0.040 |
| Blood pressure <90/60 mmHg | 12 | 4 | 0.073 |
| Gradation of illness¶ | |||
| Severe cough | 30 | 43 | 0.143 |
| Severe breathlessness | 26 | 13 | 0.133 |
| Severe fever | 31 | 7 | 0.002 |
| Severe chest pain | 23 | 8 | 0.045 |
| Severe general unwellness | 25 | 26 | 0.912 |
| Severe interference with daily activities | 23 | 27 | 0.697 |
Data are presented as %, unless otherwise stated. DM: diabetes mellitus. #: pulmonary comorbidity was defined as history of asthma or chronic obstructive pulmonary disease and cardiac comorbidity was defined as history of heart failure or ischaemic heart disease; ¶: as judged by the patient.