TABLE 1.
Clinical Characteristics of the Study Samplea
| Characteristics | Discovery sample | ||
|---|---|---|---|
| Patients with CH (n = 840) | Controls (n = 1,457) | p valueb | |
| Men | 579 (68.9) | 636 (43.7) | < 0.001 |
| Current daily smoking | 440 (52.4) | 202 (13.9) | < 0.001 |
| Episodic cluster headache | 577 (68.7) | ‐ | ‐ |
| Chronic cluster headache | 233 (27.7) | ‐ | ‐ |
| Migraine comorbidity | 106 (12.6) | ‐ | ‐ |
Data are expressed as numbers (percentages) unless otherwise stated.
a
Numbers and proportions may not add up to total of 100 due to rounding or missing values.
b
The p values of chi‐square test for categorical variables.
CH = cluster headache.