Association of varicosities and concomitant deep venous thrombosis in patients with superficial venous thrombosis, a systematic review

Figures & data

Figure 1. Flow chart search strategy. DVT, deep venous thrombosis; SVT, superfical venous thrombosis.

Table 1. Critical appraisal: assessment of risk of bias of individual studies selected for qualitative synthesis. All studies mentioned in the table had a cross-sectional study design, or contained at least a cross-sectional element.

	External validity (relevance)			Internal validity
				Completeness of data			Standardization
Study (ref no.)	Domain	Determinant	Outcome	Varicosities	Ultrasound/phlebography	Blinding	Varicosities	Ultrasound/phlebography
28	±	+	+	+	+	?	?	±
21	±	+	+	+	+	?	?	+
29	−	+	+	+	+	?	?	+
30	−	+	±	+	+	?	?	?
31	−	+	+	+	+	?	+	+
32	−	±	+	+	+	?	?	+
27	±	+	+	+	+	?	?	+
25 (excluded)	−	+	±	+	−	?	?	+
26 (excluded)	−	+	±	−	−	?	±	+

Domain, pre-referred patients with clinically suspected SVT of lower extremities; Determinant, presence of varicosities; Outcome, presence of DVT as diagnosed with ultrasound or phlebography; Completeness of data, assessment of varicosities in all patients; Ultrasound or phlebography performed in all patients; Blinding, assessment of varicosities is blinded from outcome; Standardization, standardized assessment of varicosities; standardized ultrasound or phlebography procedure.

+ Yes, criterion satisfied.

− No, criterion not satisfied.

± Criterion partially satisfied.

? No information reported.

Table 2. Probability of concomitant DVT in patients with SVT: Prior, in absence and in presence of varicosities.

Study (ref no.)	28		21		29		30		31		32
Inclusion criteria	Clinically suspected SVT		Clinically suspected SVT		SVT confirmed by ultrasound		SVT confirmed by ultrasound		SVT confirmed by ultrasound		SVT confirmed by ultrasound
Exclusion criteria	Catheter related SVT		Catheter related SVT, previous VTE, thrombocytosis, coagulation disorders, malignancy		Incomplete records, lack of follow-up, chronic SVT		Age < 18, surgery < 10 days, SVT after sclerotherapy < 30 days, follow-up not feasible		Age < 18, DVT and/or PE without SVT, non-lower limb SVT, follow-up not feasible		Age < 18, inability to give informed consent, short life expectancy, anticoagulation therapy
Setting	Emergency department		Surgical department		Outpatient department		Outpatient department		Outpatient department		Outpatient department
Age	Range 26–84		Range 29–85		Range 24–86		IQR 50–74		IQR 51–75		Mean 62 ± 14
Sex (% women)	63%		60%		62%		65%		64%		64%
Diagnosis DVT	Phlebography		Phlebography		Ultrasound		Ultrasound		Ultrasound		Ultrasound
Total patients with SVT	56		57		60		844		783		138
Diagnostic 2 × 2 table
A | B	1	37	4	37	4	44	143	547	118	388	44	80
C | D	8	10	7	9	4	8	67	87	109	168	3	11
Prior probability of DVT % (95% CI)	16 (8–28)		19 (10–32)		13 (6–25)		25 (22–28)		29 (26–32)		34 (26–43)
Probability of DVT in absence of varicosities % (95% CI)	44 (22–70)		44 (20–70)		33 (10–65)		44 (36–52)		39 (34–45)		21 (5–51)
Probability of DVT in presence of varicosities % (95% CI)	3 (0–14)		10 (3–23)		8 (2–20)		20 (18–24)		23 (20–27)		35 (27–45)

DVT, deep venous thrombosis; SVT, superficial venous thrombosis; VTE, venous thromboembolism; PE, pulmonary embolism; 95% CI, 95% confidence interval; IQR, interquartile range; diagnostic 2 3 2 table: A, patients with presence of both DVT and varicosities; B, patients with absence of DVT and presence of varicosities; C, patients with presence of DVT and absence of varicosities; D, patients with absence of both DVT and varicosities.