Table 2.
Evidence profile for VTE-related prognostic factors
| No. of studies | Certainty assessment domains | Overall certainty in the evidence about this prognostic factor | Relative effect (95% CI) | |||||
|---|---|---|---|---|---|---|---|---|
| Study design | Risk of bias | Indirect | Inconsistent | Imprecise | Publication bias | |||
| Age (>60 y vs <60 y)7,25-27,29,31,34,37,39 | ||||||||
| 9* | Observational | Serious† | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 1.34 (95% CI, 1.17-1.55) |
| MODERATE | ||||||||
| Sex (male vs female)27,34-37 | ||||||||
| 5 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 1.03 (95% CI, 0.80-1.33) |
| MODERATE | ||||||||
| CRP (>10 mg/L vs <10 mg/L)35 | ||||||||
| 1 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 10.10 (95% CI, 1.93-52.85) |
| MODERATE | ||||||||
| D-dimer (>500 ng/mL vs <500 ng/mL at baseline; and increase vs no increase)36,39 | ||||||||
| 2 | Observational | Serious† | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | Categorical: OR, 2.46 (95% CI, 1.19-5.10) |
| MODERATE | Continuous: OR, 3.45 (95% CI, 2.01-5.92) | |||||||
| Heart rate (elevated >100 beats per minute vs nonelevated <100 beats per minute)27 | ||||||||
| 1 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 2.48 (95% CI, 1.66-3.71) |
| MODERATE | ||||||||
| Thrombocytosis (platelet count >350 × 109/L vs <350 × 109/L)27,28 | ||||||||
| 2 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 2.16 (95% CI, 1.40-3.35) |
| MODERATE | ||||||||
| Leukocytosis (WBC ≥11 × 109/L vs <11 × 109/L)27 | ||||||||
| 1 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 1.91 (95% CI, 1.24-2.94) |
| MODERATE | ||||||||
| Fever (body temperature >38°C-38.5°C vs <38°C-38.5°C)27,28 | ||||||||
| 2 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 1.88 (95% CI, 1.10-3.21) |
| MODERATE | ||||||||
| Leg edema (presence vs absence)28,31 | ||||||||
| 2 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 1.88 (95% CI, 1.23-2.90) |
| MODERATE | ||||||||
| Varicose veins (presence vs absence)29,31 | ||||||||
| 2 | Observational | Serious† | Not serious | Not serious | Serious‡ | Undetected | ⊕⊕○○ | OR, 1.53 (95% CI, 0.85-2.76) |
| LOW | ||||||||
| Obesity (BMI >30 kg/m2 vs <30 kg/m2)27,29,34 | ||||||||
| 3 | Observational | Serious† | Not serious | Not serious | Serious‡ | Undetected | ⊕⊕○○ | OR, 1.34 (95% CI, 0.94-1.91) |
| LOW | ||||||||
| Fibrinogen levels (elevated levels >400 mg/dL) vs no elevated levels35 | ||||||||
| 1 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 0.18 (95% CI, 0.04-0.81) |
| MODERATE | ||||||||
| BI score ≤9 vs >937,39 | ||||||||
| 2 | Observational | Serious† | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 8.30 (95% CI, 2.70-25.52) |
| MODERATE | ||||||||
| Immobility: defined as confinement to bed for >72 h or >7 d or bedridden or nonambulatory (yes vs no)7,26-29,31,37,39 | ||||||||
| 8 | Observational | Serious† | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 3.17 (95% CI, 2.18-4.62) |
| MODERATE | ||||||||
| Paresis (yes vs no)7,25,26,37 | ||||||||
| 4 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 2.97 (95% CI, 1.20-7.36) |
| MODERATE | ||||||||
| Previous VTE (yes vs no)7,25-27,29-31,36 | ||||||||
| 8 | Observational | Serious† | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 6.08 (95% CI, 3.71-9.97). |
| MODERATE | ||||||||
| Thrombophilia (familial or acquired disorder of the hemostatic system; yes vs no)7,25,26,29,34 | ||||||||
| 5 | Observational | Serious† | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 5.88 (95% CI, 2.80-12.35) |
| MODERATE | ||||||||
| Malignancy (active malignancy, defined as the presence of cancer on admission or within the past year, vs no active malignancy; and history vs no history of malignancy)7,25-28,30,31,34,36,37 | ||||||||
| 10 | Observational | Serious | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | Active cancer: OR, 2.65 (95% CI, 1.79-3.91) |
| MODERATE | History of cancer: OR, 3.20 (95% CI, 2.14-4.79) | |||||||
| Critical illness: defined as ICU or CCU stay, or need for resuscitation (yes vs no)7,25-27,29,34,36 | ||||||||
| 7 | Observational | Serious† | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | OR, 1.65 (95% CI, 1.39-1.95) |
| MODERATE | ||||||||
| Infections: including cellulitis, pneumonia, and sepsis (yes vs no)28,31 | ||||||||
| 5 | Observational | Serious† | Not serious | Not serious | Not serious | Undetected | ⊕⊕⊕○ | Any infection: OR, 1.48 (95% CI, 1.16-1.89) |
| MODERATE | Acute infection: OR, 1.59 (95% CI, 1.23-2.06) | |||||||
| Sepsis: OR, 1.07 (95% CI, 0.70-1.62) | ||||||||
| Heart failure (HF) (acute HF vs no acute HF; history of HF vs no history of HF)28,29,31,35,36 | ||||||||
| 5 | Observational | Serious | Not serious | Not serious | Serious‡ | Undetected | ⊕⊕○○ | Acute heart failure: OR, 0.82 (95% CI, 0.42-1.60) |
| LOW | History of heart failure: OR, 2.68 (95% CI, 1.11-6.44) | |||||||
| Autoimmune disease: including rheumatological diseases and inflammatory diseases (yes vs no)27,29,31,35 | ||||||||
| 4 | Observational | Serious† | Not serious | Serious | Not serious | Undetected | ⊕⊕○○ | OR, 2.33 (95% CI, 1.13-4.83) |
| LOW | ||||||||
| CVC (presence vs absence)31,34 | ||||||||
| 2 | Observational | Serious | Not serious | Serious§ | Not serious | Undetected | ⊕⊕○○ | OR, 2.05 (95% CI, 0.74-5.65) |
| LOW | ||||||||
| Severe stroke: defined as acute ischemic stroke (yes vs no)29,31,32,36 | ||||||||
| 4 | Observational | Serious† | Not serious | Not serious | Serious‡ | Undetected | ⊕⊕○○ | Acute ischemic stroke: OR, 1.79 (95% CI, 0.77-4.18) |
| LOW | When stroke was assessed in terms of the NIHSS, we found consistent results.¶ | |||||||
| Tobacco (current use vs no current use; previous use vs no previous use)35 | ||||||||
| 1 | Observational | Serious | Not serious | Not serious | Serious‡ | Undetected | ⊕⊕○○ | Current tobacco use: OR, 1.59 (95% CI, 0.28-9.03) |
| LOW | Previous tobacco use: OR, 0.97 (0.24-3.92) | |||||||
| Hormone use: defined as estrogen intake (yes vs no)31 | ||||||||
| 1 | Observational | Serious | Not serious | Not serious | Serious‡ | Undetected | ⊕⊕○○ | OR, 0.80 (95% CI, 0.36-1.78). |
| LOW | ||||||||
| Renal failure (yes vs no)36 | ||||||||
| 1 | Observational | Serious || | Not serious | Not serious | Very Serious‡,# | Undetected | ⊕○○○ | OR, 0.76 (95% CI, 0.18-3.18) |
| VERY LOW | ||||||||
| Respiratory failure (yes vs no)27,29,31,36 | ||||||||
| 4 | Observational | Serious† | Not serious | Not serious | Serious‡ | Undetected | ⊕⊕○○ | Any respiratory failure: OR, 1.04 (95% 0.69-1.58). |
| LOW | Acute respiratory failure: OR, 1.18 (95% CI, 0.76-1.84) | |||||||
| Chronic respiratory failure: OR, 0.58 (95% 0.30-1.10) | ||||||||
| Coronary artery disease (yes vs no)29,31,36,37 | ||||||||
| 4 | Observational | Serious† | Not serious | Serious§ | Not serious | Undetected | ⊕⊕○○ | OR, 1.01 (95% CI, 0.33-3.09) |
| LOW | ||||||||
Question: prognostic factors for medical patients; outcome: VTE; setting: inpatient.
BI, Barthel Index; WBC, white blood cell count.
Certainty in evidence was downgraded for risk of bias, given a follow-up time of more than 3 months in the included studies that may cause an overestimation of the magnitude of the association (Zhou et al29: 6 mo after discharge and Yi 2012: 12 mo after discharge).
Certainty in evidence was downgraded for imprecision, given that the confidence interval suggests that there may be no association.
Certainty in evidence was downgraded for risk of bias, given that the results of each prognostic factor in the multivariate analysis were not reported and we therefore had to rely on the unadjusted measures of association. Also, the multivariate analysis included only factors statistically significant in the univariate analysis.
Certainty in evidence was downgraded for inconsistency but not imprecision, given that the inconsistency is the likely cause for the imprecision.
Certainty in evidence was downgraded for imprecision, given the small number of events (n = 32).
Bembenek et al35 assessed the severity of a stroke experienced by an individual by using the NIHSS, a diagnostic tool; results were consistent with the meta-analysis that severe stroke may result in an increase in risk of any DVT (OR, 2.11; 95% CI,: 0.50-8.90) for NIHSS >7 compared with a NIHSS score <7. Also, severe stroke may result in an increase in risk of any DVT (OR, 1.34; 95% CI,: 0.25-7.18) for NIHSS >14 compared with a NIHSS <14. When NIHSS was assessed continuously, results showed that severe stroke may result in an increase in risk of any DVT (OR, 1.21; 95% CI,: 0.86-1.70) for each additional 4 points on the NIHSS.
Fan et al,36 with 458 patients older than 60 y of which 45 patients had any VTE, presented age as a continuous variable and showed no association between age and any VTE (OR, 1.03; 95% CI, 0.98-1.08). Bembenek et al,35 with 299 patients of which 9 had any DVT, 7 of which were distal, presented age per 10-y increase and showed a decrease in risk per 10-y increase in age with any DVT (OR, 0.64; 95% CI, 0.33-1.24).