Table 2. Risks of recurrent VTE for minor persistent and minor transient risk factors.
| Risk factor | Reported risk of recurrent VTE HR unless otherwise stated (CI) |
Patient characteristics |
|---|---|---|
| Minor persistent risk factor | ||
| Renal impairment 58 59 | 5.32 (1.49–18.95) | Patients with renal impairment (eGFR <60 mL/min/1.73 m 2 ) versus those with normal renal function (eGFR ≥90 mL/min/1.73 m 2 ) after a previous episode of VTE |
| 2.84 (1.13–7.11) | Patients with renal impairment (eGFR 60–89 mL/min/1.73 m 2 ) versus those with normal renal function after a previous episode of VTE | |
| 1.61 (0.67–3.90) | Patients with a first lifetime VTE with chronic kidney disease versus those without chronic kidney disease at baseline (physician's diagnosis and creatinine level >175 μmol/L [2 mg/dL] for ≥3 months, or nephrotic syndrome) | |
| IBD 58 60 | 2.5 (1.4–4.2) | Patients with a history of VTE after IBD diagnosis versus those without IBD who had an unprovoked VTE. IBD diagnosis based on clinical, endoscopic, histological, and radiological criteria according to the European Crohn's and Colitis Organization guidelines |
| 2.37 (1.12–5.01) | Patients with a first lifetime VTE with IBD versus those without IBD at baseline | |
| Lower limb paralysis with extremity paresis 58 | 1.92 (1.33–2.77) | Patients with a first lifetime VTE with extremity paresis versus those without extremity paresis at baseline |
| Thrombophilia 61 62 | 1.9 (1.0–3.9) | Patients with prior VTE and deficiency of antithrombin versus those with no known defect |
| RR = 1.5 (1.1–1.9) | Patients with prior VTE with or without heterozygous factor-V Leiden mutation | |
| RR = 1.4 (1.0–1.8) | Patients with prior VTE with or without heterozygous prothrombin mutation | |
| 1.4 (0.9–2.2) | Patients with prior VTE and deficiency of protein S or protein C versus those with no known defect. | |
| CHD 58 | 1.43 (1.04–1.97) | CHF or other heart disease (congenital heart disease, cardiomyopathy, ischemic heart disease, or valvular heart disease). Patients with a first lifetime VTE with CHD versus those without at baseline |
| Family history 63 | 1.92 (1.44–2.58) | Patients with unprovoked VTE and both parents with history of VTE versus those without |
| 1.30 (1.14–1.49) | Patients with unprovoked VTE and a sibling with history of VTE versus those without | |
| 1.20 (1.10–1.32) | Patients with unprovoked VTE and one parent with history of VTE versus those without | |
| Obesity 58 64 | 1.6 (1.0–2.4) | Patients with a first unprovoked VTE with a BMI ≥30 kg/m 2 versus those with a BMI <25 kg/m 2 |
| 1.21 (0.92–1.60) | Patients with a first lifetime VTE with a BMI ≥30 kg/m 2 versus those with a BMI ≥20 to ≤25 kg/m 2 at baseline | |
| Minor transient risk factor | ||
| Oral estrogen therapy 27 65 a | 6.4 (1.5–27.3) | Average of 79-month follow-up of postmenopausal women stratified into users versus nonusers of oral estrogen-based hormone replacement therapy who had ceased anticoagulation treatment after a first confirmed VTE |
| RR = 3.5 (2.9–4.3) | Healthy women receiving combined oral contraceptives compared with nonusers | |
| Lower limb injury with impaired mobility 66 | OR = 4.5 (1.5–14.0) | Patients with a lower-leg cast within 3 months of a recurrent event versus patients with a cast during a random 3-month follow-up period without a recurrent event |
| Pregnancy 67 | RR: 3.5 (1.6–7.8) | Pregnant versus nonpregnant period in women who had experienced at least one pregnancy following a venous thromboembolic event |
| Immobilization 68 | RR = 2.9 (1.2–7.5) | Immobilized versus ambulant patients with a first episode of VTE receiving a minimum of 3 months of oral anticoagulation therapy |
| Minor surgery 12 | 4.6 (1.5–14.2) | Minor surgery versus no surgery in patients with a history of VTE up to 1 month after surgery |
| Puerperium 34 | RR = 1.4 (0.6–3.4) | Puerperium versus pregnant period in women who had experienced at least one pregnancy following a venous thromboembolic event |
| Travel >8 hours | Not reported | |
Abbreviations: BMI, body mass index; CHD, congestive heart disease; CHF, congestive heart failure; CI, confidence interval; eGFR, estimated glomerular filtration rate; HR, hazard ratio; IBD, inflammatory bowel disease; OR, odds ratio; RR, relative risk; VTE, venous thromboembolism.
a
Women receiving estrogen replacement therapy after menopause require a higher estrogen potency and have a different baseline level of VTE risk compared with younger women taking estrogen-containing contraceptives. 32