Table 5 Comparison of study design and characteristics of the four studies investigating the thrombophilia–oral contraceptives–ischaemic stroke hypothesis.
| Aznar et al10 | Slooter et al11 | Martinelli et al12 | This study | |
|---|---|---|---|---|
| Study design | Case–control analysis | Case–control analysis | Case–control analysis | Case–control analysis |
| No of patients/controls | 34/68 | 193/767 | 105/293 | 108/216 |
| Patients | ||||
| Age, years, mean (SD) | 18–50 | 18–49, 38.6 (8.0) | Fertile age, 34.7 (9.1) | 18–45, 33.9 (7.4) |
| Diagnosis | Ischaemic stroke | First ever ischemic stroke | First ever ischaemic stroke | First ever ischaemic stroke |
| Inclusion criteria | Consecutive patients with cryptogenic stroke | Consecutive patients with acute stroke | Consecutive patients with history of stroke | Consecutive patients with acute stroke |
| Exclusion criteria | Atherosclerosis, heart disease, foramen ovale, occlusive vessel disease | TIA, cerebral venous sinus thrombosis, carotid artery dissection, history of cardiovascular or cerebrovascular disease, terminal illness, aphasia or cognitive impairment interfering with the questionnaire, not speaking Dutch | ||
| Controls | ||||
| Age, years, mean (SD) | <50 | 18–49, 39.7 (7.7) | Fertile age, 34.9 (8.6) | 34.6 (6.6) |
| Selection criteria | Not defined | From the general population by random digit dialling | From partners and friends who accompanied patients to the centre | From the hospital staff |
| Inclusion criteria | Age‐matched healthy subjects | Age‐matched subjects, no history of coronary heart disease, cerebrovascular event or peripheral vascular disease | Healthy subjects of fertile age | Age‐matched subjects (±3 years), no known history of vascular disease |
| Setting | Unit of thrombophilia | Stroke centre | Thrombosis centre | Stroke centre |
| OC users | Not defined | Within 1 month before the acute event | Within the 2 weeks before referral | Within 1 month before the acute event |
| Thrombophilic tests | FV G1691A | FV G1691A | FV G1691A | FV G1691A |
| PT G20210A | PT G20210A | PT G20210A | PT G20210A | |
| C677T MTHFR | C677T MTHFR | C677T MTHFR | ||
| Hyperhomocysteinaemia | ||||
| AT, PC, PS deficiency |
AT, anti‐thrombin; OC, oral contraceptive; PC, protein C; PS, protein S; TIA, transient ischaemic attack.