What do systematic reviews say?

Oral vs IV antibiotics

Oral showed no clear difference in mortality compared with intravenous antibiotic therapy (moderate certainty).

• Oral versus intravenous antibiotic treatment for febrile neutropenia in cancer patients 2013 · Cochrane Headline outcomes only
  RR 0.95 [0.54, 1.68]
  9 studies · 1392 participants
  Moderate

Oral vs intravenous acetylcysteine

• Interventions for paracetamol (acetaminophen) overdose 2018 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 66 participants
  Very low

Summary of findings table ‐ Combined mechanical and oral antibiotic bowel preparation vs oral antibiotics

Summary of findings table ‐ Combined mechanical and oral antibiotic… showed no clear difference in mortality compared with oral antibiotics alone (low certainty).

• Preoperative combined mechanical and oral antibiotic bowel preparation for preventing complications in elective… 2023 · Cochrane Headline outcomes only
  RR 1.02 [0.3, 3.5]
  2 studies · 709 participants
  Low

Oral iron vs inactive control

It is very uncertain whether oral iron changes mortality compared with inactive control (very low certainty).

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  RR 1.05 [0.68, 1.61]
  4 studies · 659 participants
  Very low

Oral direct thrombin inhibitors (DTIs) vs conventional anticoagulation

Oral DTIs showed no clear difference in all‐cause mortality (7 months) compared with conventional anticoagulation (moderate certainty).

• Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of… 2023 · Cochrane Headline outcomes only
  OR 0.66 [0.41, 1.08]
  1 study · 2489 participants
  Moderate

Direct oral anticoagulant (DOAC) prophylaxis vs no prophylaxis

Direct oral anticoagulant (DOAC) prophylaxis showed no clear difference in mortality compared with no prophylaxis (moderate certainty).

• Oral anticoagulation in people with cancer who have no therapeutic or prophylactic indication for anticoagulation 2021 · Cochrane Headline outcomes only
  RR 0.94 [0.64, 1.38]
  3 studies · 1440 participants
  Moderate

Summary of findings table ‐ Combined mechanical and oral antibiotic bowel preparation vs no bowel preparation

Summary of findings table ‐ Combined mechanical and oral antibiotic… showed no clear difference in mortality compared with no bowel preparation (low certainty).

• Preoperative combined mechanical and oral antibiotic bowel preparation for preventing complications in elective… 2023 · Cochrane Headline outcomes only
  RR 0.2 [0.01, 4.22]
  1 study · 396 participants
  Low

Summary of findings table ‐ Combined mechanical and oral antibiotic bowel preparation vs mechanical bowel preparation alone

Summary of findings table ‐ Combined mechanical and oral antibiotic… showed no clear difference in mortality compared with mechanical bowel preparation alone (moderate certainty).

• Preoperative combined mechanical and oral antibiotic bowel preparation for preventing complications in elective… 2023 · Cochrane Headline outcomes only
  RR 0.87 [0.27, 2.82]
  3 studies · 639 participants
  Moderate

Oral etoposide vs ABV

Oral etoposide showed no clear difference in mortality compared with ABV (moderate certainty).

• Treatment of severe or progressive Kaposi's sarcoma in HIV‐infected adults 2014 · Cochrane Headline outcomes only
  RR 1.08 [0.98, 1.19]
  1 study · 178 participants
  Moderate

Intravenous iron with oral iron vs oral iron

The review found no eligible studies for this question.

• Treatment for women with postpartum iron deficiency anaemia 2015 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Subcutaneous EPO with oral iron vs oral iron

• Treatment for women with postpartum iron deficiency anaemia 2015 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 40 participants
  GRADE not reported

Summary of findings for resveratrol plus oral anti‐diabetic drugs vs placebo plus oral anti‐diabetic drugs

• Resveratrol for adults with type 2 diabetes mellitus 2020 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 50 participants
  Very low

Avoralstat vs placebo

The review found no eligible studies for this question.

• Interventions for the long‐term prevention of hereditary angioedema attacks 2022 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Oral factor Xa inhibitors vs conventional anticoagulation

Oral factor Xa inhibitors showed no clear difference in all‐cause mortality compared with conventional anticoagulation (moderate certainty).

• Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of… 2023 · Cochrane Headline outcomes only
  OR 1.16 [0.79, 1.7]
  1 study · 4817 participants
  Moderate

Oral nutritional supplements vs multivitamin and mineral supplement

Oral nutritional supplements showed no clear difference in mortality compared with multivitamin and mineral supplement (low certainty).

• Perioperative nutrition for the treatment of bladder cancer by radical cystectomy 2019 · Cochrane Headline outcomes only
  RR 0.97 [0.06, 14.78]
  1 study · 61 participants
  Low

Oral plus intravenous acetylcysteine vs intravenous acetylcysteine

• Interventions for paracetamol (acetaminophen) overdose 2018 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 40 participants
  Very low

Summary of findings for resveratrol plus oral anti‐diabetic drugs vs placebo plus oral anti‐diabetic drugs

• Resveratrol for adults with type 2 diabetes mellitus 2020 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 50 participants
  Very low

Preoperative oral nutritional support vs normal diet

It is very uncertain whether preoperative oral nutritional support changes mortality compared with normal diet (very low certainty).

• Perioperative nutrition for the treatment of bladder cancer by radical cystectomy 2019 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 28 participants
  Very low

DOAC vs variable dose warfarin

Direct oral anticoagulants (DOAC) showed no clear difference in all‐cause mortality compared with warfarin (moderate certainty).

• Direct oral anticoagulants versus warfarin for preventing stroke and systemic embolic events among atrial fibrillation… 2017 · Cochrane Headline outcomes only
  RR 0.91 [0.78, 1.05]
  4 studies · 9595 participants
  Moderate

Oral direct thrombin inhibitors (DTIs) vs conventional anticoagulation

The review found no eligible studies for this question.

• Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of… 2023 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found