What do systematic reviews say?

Low molecular weight heparin vs no thromboprophylaxis

Low‐molecular‐weight heparin probably leads to lower symptomatic PE compared with no thromboprophylaxis (moderate certainty).

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.6 [0.42, 0.88]
  8 studies · 5324 participants
  Moderate

Low molecular weight heparin vs active control

Low‐molecular‐weight heparin showed no clear difference in symptomatic PE compared with with active control (1); GRADE not reported.

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 2.89 [0.12, 66.75]
  Studies not reported
  GRADE not reported
• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.13 [0.02, 1.03]
  2 studies · 781 participants
  Moderate
• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.11 [0.01, 2.06]
  1 study · 439 participants
  Low

Low molecular weight heparin vs no thromboprophylaxis

Low‐molecular‐weight heparin leads to lower symptomatic DVT compared with no thromboprophylaxis (high certainty).

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.48 [0.35, 0.67]
  9 studies · 5408 participants
  High

Low molecular weight heparin vs active control

Low‐molecular‐weight heparin showed no clear difference in symptomatic VTE compared with with active control (1) (low certainty).

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 2.89 [0.12, 66.75]
  1 study · 51 participants
  Low
• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.51 [0.22, 1.17]
  2 studies · 781 participants
  Moderate
• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.33 [0.14, 0.83]
  1 study · 439 participants
  High

Low molecular weight heparin vs active control

The review found no eligible studies for this question.

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found
• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.81 [0.32, 2.04]
  2 studies · 781 participants
  Moderate
• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.43 [0.17, 1.1]
  1 study · 439 participants
  Moderate

Low molecular weight heparin vs no thromboprophylaxis

Low‐molecular‐weight heparin leads to lower symptomatic VTE compared with no thromboprophylaxis (high certainty).

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.62 [0.46, 0.83]
  11 studies · 3931 participants
  High

Ultra‐low‐molecular‐weight heparin vs placebo

Ultra‐low‐molecular‐weight heparin showed no clear difference in symptomatic PE compared with placebo (moderate certainty).

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.48 [0.22, 1.01]
  1 study · 3212 participants
  Moderate

Low molecular weight heparin vs placebo or no prophylaxis

Low molecular weight heparin may leads to lower symptomatic venous thromboembolism compared with no prophylaxis or placebo (low certainty).

• Low molecular weight heparin for prevention of venous thromboembolism in patients with lower‐limb immobilization 2017 · Cochrane Headline outcomes only
  OR 0.4 [0.21, 0.76]
  6 studies · 2924 participants
  Low

Ultra‐low‐molecular‐weight heparin vs placebo

Ultra‐low‐molecular‐weight heparin leads to lower symptomatic VTE compared with placebo (high certainty).

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.36 [0.22, 0.6]
  1 study · 3212 participants
  High

Ultra‐low‐molecular‐weight heparin vs placebo

Ultra‐low‐molecular‐weight heparin leads to lower symptomatic DVT compared with placebo (high certainty).

• Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy 2020 · Cochrane Headline outcomes only
  RR 0.32 [0.16, 0.63]
  1 study · 3212 participants
  High

Combined NMES and low‐dose heparin vs no prophylaxis

• Neuromuscular electrical stimulation for the prevention of venous thromboembolism 2017 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 32 participants
  GRADE not reported

Low molecular weight heparin vs no prophylaxis

It is very uncertain whether low‐molecular‐weight heparin changes asymptomatic DVT: compared with no prophylaxis (very low certainty).

• Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy 2022 · Cochrane Headline outcomes only
  RR 0.14 [0.03, 0.61]
  2 studies · 369 participants
  Very low

Combined NMES and low‐dose heparin vs no prophylaxis

• Neuromuscular electrical stimulation for the prevention of venous thromboembolism 2017 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 32 participants
  GRADE not reported

Heparin prophylaxis vs no treatment/placebo

It is very uncertain whether antenatal (± postnatal) prophylaxis: heparin (LMWH or UFH) changes symptomatic PE ( compared with no treatment/placebo (very low certainty).

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  RR 0.33 [0.02, 7.14]
  3 studies · 187 participants
  Very low

Heparin prophylaxis vs no treatment/placebo

It is very uncertain whether antenatal (± postnatal) prophylaxis: heparin (LMWH or UFH) changes symptomatic DVT ( compared with no treatment/placebo (very low certainty).

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  RR 0.33 [0.04, 3.1]
  4 studies · 227 participants
  Very low

Low molecular weight heparin vs control

Does low molecular weight heparin prevent central venous… showed no clear difference in symptomatic CVC‐related thrombosis ( compared with control (low certainty).

• Low molecular weight heparin for prevention of central venous catheter‐related thrombosis in children 2020 · Cochrane Headline outcomes only
  RR 1.03 [0.21, 4.93]
  1 study · 158 participants
  Low

Low molecular weight heparin vs control

Does low molecular weight heparin prevent central venous… showed no clear difference in asymptomatic CVC‐related thrombosis ( compared with control (low certainty).

• Low molecular weight heparin for prevention of central venous catheter‐related thrombosis in children 2020 · Cochrane Headline outcomes only
  RR 1.17 [0.45, 3.08]
  1 study · 158 participants
  Low

Low molecular weight heparin vs vitamin K antagonist (VKA)

It is very uncertain whether low‐molecular‐weight heparin (LMWH) changes symptomatic catheter‐related thrombosis (up to 3 months) compared with vitamin K antagonist (VKA) (very low certainty).

• Anticoagulation for people with cancer and central venous catheters 2018 · Cochrane Headline outcomes only
  RR 1.83 [0.44, 7.61]
  2 studies · 327 participants
  Very low

Low molecular weight heparin vs no LMWH

Low‐molecular‐weight heparin (LMWH) probably leads to lower symptomatic catheter‐related thrombosis (up to 3 months) compared with no LMWH (moderate certainty).

• Anticoagulation for people with cancer and central venous catheters 2018 · Cochrane Headline outcomes only
  RR 0.43 [0.22, 0.81]
  5 studies · 1089 participants
  Moderate

Heparin prophylaxis vs no treatment/placebo

It is very uncertain whether antenatal (± postnatal) prophylaxis: heparin (LMWH or UFH) changes symptomatic thromboembolic events ( compared with no treatment/placebo (very low certainty).

• Venous thromboembolism prophylaxis for women at risk during pregnancy and the early postnatal period 2021 · Cochrane Headline outcomes only
  RR 0.39 [0.08, 1.98]
  4 studies · 476 participants
  Very low