Summary of risk factors using GRADE
| Risk factor | n (primary studies) Type of primary studies | GRADE | Absolute effect OR (95% CI) | I2 (%) | |
| Vascular | Atrial fibrillation10 41 42 | 1394 (5‡) L (+2) | ⨁⨁⨁◯ Moderate Due to the magnitude of effect | 3.01 (1.96 to 4.61)*† | 0 |
| 2425 (7‡) L (+2) | ⨁⨁⨁◯ Moderate Due to magnitude of effect | 2.4 (1.7 to 3.5)* | 10 | ||
| 3647 (13) L (+2) | ⨁⨁◯◯ Low Due to magnitude of effect and inconsistency | 2.0 (1.4 to 2.8)* | 55 | ||
| Diabetes42 | 4809 (19) L (+2) | ⨁⨁◯◯ Low | 1.4 (1.2 to 1.7) * | 10 | |
| Hypertension42 | 4800 (19) L (+2) | ⨁◯◯◯ Very low Due to imprecision | 1.1 (0.9 to 1.3) | 0 | |
| Smoking42 | 4163 (16) L (+2) | ◯◯◯◯ Critically low Due to imprecision and inconsistency | 1.0 (0.8 to 1.2) | 54 | |
| Moderate alcohol consumption42 | 2822 (9) L (+2) | ⨁◯◯◯ Very low Due to imprecision | 0.8 (0.6 to 1.0) | 45 | |
| Ischaemic heart disease42 | 3739 (14) L (+2) | ⨁◯◯◯ Very low Due to imprecision | 1.0 (0.8 to 1.3) | 46 | |
| Previous TIA42 | 3411 (11) L (+2) | ⨁◯◯◯ Very low Due to imprecision | 1.0 (0.8 to 1) | 27 | |
| Demographic | Female sex42 | 5707 (24) L (+2) | ⨁⨁◯◯ Low | 1.3 (1.1 to 1.6) * | 49 |
| White42 | 1245 (3) L (+2) | ⨁⨁◯◯ Low | 0.6 (0.4 to 0.8)* | 1 | |
| Low education42 | 2787 (11) L (+2) | ⨁⨁◯◯ Low | 2.5 (1.8 to 3.4) * | 56 | |
| Stroke related | Haemorrhagic stroke42 | 1252 (9) L (+2) | ⨁⨁◯◯ Low | 1.4 (1.1 to 1.9)* | 2 |
| Dysphasia42 | 2223 (7) L (+2) | ⨁⨁◯◯ Low Due to inconsistency and magnitude of effect | 3.6 (2.1 to 6.1)* | 71 | |
| Left hemisphere stroke42 | 4599 (17) L (+2) | ⨁⨁◯◯ Low | 1.4 (1.1 to 1.7)* | 48 | |
| Brainstem stroke42 | 3042 (9) L (+2) | ◯◯◯◯ Critically low Due to imprecision and inconsistency | 0.7 (0.4 to 1.2) | 75 | |
| Lacunar stroke42 | 2895 (10) L (+2) | ⨁◯◯◯ Very low Due to imprecision | 0.8 (0.7 to 1.0) | 0 | |
| Previous stroke42 | 2766 (10) L (+2) | ⨁⨁◯◯ Low | 1.9 (1.5 to 2.3)* | 0 | |
| Multiple strokes42 | 2730 (9) L (+2) | ⨁⨁⨁◯ Moderate Due to magnitude of effect | 2.5 (1.9 to 3.1)* | 16 | |
| Recurrent stroke42 | 947 (4) L (+2) | ⨁⨁⨁◯ Moderate Due to magnitude of effect | 2.3 (1.5 to 3.5)* | 14 | |
| Silent strokes42 | 775 (5) L (+2) | ◯◯◯◯ Critically low Due to imprecision and inconsistency | 1.8 (0.9 to 3.5) | 63 | |
| Stroke complications | Hypoxic ischaemic episode42 | 169 (2) L (+2) | ⨁⨁◯◯ Low Due to publication bias and magnitude of effect | 2.4 (1.4 to 4.2)* | 0 |
| Incontinence42 | 2291 (7) L (+2) | ⨁⨁◯◯ Low Due to inconsistency and magnitude of effect | 6.4 (4.5 to 9.2)* | 52 | |
| Acute confusion42 | 339 (2) L (+2) | ⨁⨁◯◯ Low Due to publication bias and magnitude of effect | 2.8 (1.5 to 5.3)* | 0 | |
| Early seizures42 | 169 (1) L (+2) | ⨁⨁◯◯ Low Due to publication bias and magnitude of effect | 5.4 (2.4 to 12.1)* | NA | |
| Abnormal EEG42 | 180 (1) L (+2) | ⨁⨁◯◯ Low Due to publication bias and magnitude of effect | 2.7 (1.4 to 4.9)* | NA | |
| Brain imaging | Leukoaraiosis42 | 1300 (7) L (+2) | ⨁⨁⨁◯ Moderate Due to magnitude of effect | 2.5 (1.9 to 3.4)* | 37 |
| Atrophy42 | 998 (5) L (+2) | ⨁◯◯◯Very low Due to inconsistency | 2.6 (1.1 to 6.3)* | 80 | |
| MTLA42 | 481 (2) L (+2) | ⨁⨁◯◯ Low Due to publication bias and magnitude of effect | 2.7 (1.8 to 4.2)* | 0 |
Our certainty level of each outcome is presented using GRADE.24
*Statistically significant.
†Relative risk.
‡Subset.
EEG, electroencephalogram; GRADE, Grading of Recommendations, Assessment, Development and Evaluations; L, longitudinal observational study; MTLA, medial temporal lobe atrophy; NA, not available; TIA, transient ischaemic attack.