Characteristics of participants
| Characteristics | Needle aspiration | Chest tube drainage (CTD) |
| Patients n | 64 | 63 |
| Men | 54 (84.4) | 53 (84.1) |
| Age years | 40.5±21.5 | 40.9±19.5 |
| Height cm | 177.1±10.5 | 179.4±9.6 |
| BMI kg·m−2 | 21.3±3.2 | 22.1±3.2 |
| Current smoker | 30 (47.6) | 27 (44.3) |
| Smoking history pack-years | 6.5 (0.0–17.5) | 10.8 (1.8–20.0) |
| First episode of pneumothorax | 38 (69.1) | 42 (72.4) |
| Size of pneumothorax % | 47.5±19.8 | 57.0±25.0 |
| Secondary pneumothorax | 22 (34.4) | 26 (41.3) |
| Right-sided pneumothorax | 39 (60.9) | 36 (57.1) |
| Hours from first symptoms until treatment | 20.5 (6.0–60.0) | 15.5 (5.0–72.0) |
Data are presented as n (%), mean±sd or median (interquartile range), unless otherwise stated. Data on height was missing for 7 subjects (5 from aspiration), on BMI for 9 subjects (6 from aspiration), on current smoking status for 3 subjects (1 from aspiration), on pack-years for 11 subjects (6 from aspiration), on first episode of pneumothorax for 14 subjects (9 from aspiration), on size of pneumothorax for 3 subjects (2 from aspiration) and on hours from first symptoms until treatment for 1 subject (from drainage).