What do systematic reviews say?

Higher vs lower PUFA

It is very uncertain whether higher changes food allergy ‐ infant incidence compared with lower PUFA intake (very low certainty).

• Polyunsaturated fatty acid supplementation in infancy for the prevention of allergy 2016 · Cochrane Headline outcomes only
  RR 0.81 [0.56, 1.19]
  3 studies · 915 participants
  Very low

Higher vs lower PUFA

It is very uncertain whether higher changes all allergic disease ‐ childhood incidence compared with lower PUFA intake (very low certainty).

• Polyunsaturated fatty acid supplementation in infancy for the prevention of allergy 2016 · Cochrane Headline outcomes only
  RR 0.69 [0.47, 1.02]
  2 studies · 154 participants
  Very low

Higher vs lower PUFA

It is very uncertain whether higher changes asthma ‐ childhood incidence compared with lower PUFA intake (very low certainty).

• Polyunsaturated fatty acid supplementation in infancy for the prevention of allergy 2016 · Cochrane Headline outcomes only
  RR 0.45 [0.2, 1.02]
  1 study · 89 participants
  Very low

Higher vs lower PUFA

It is very uncertain whether higher changes dermatitis/eczema ‐ childhood incidence compared with lower PUFA intake (very low certainty).

• Polyunsaturated fatty acid supplementation in infancy for the prevention of allergy 2016 · Cochrane Headline outcomes only
  RR 0.65 [0.34, 1.24]
  2 studies · 154 participants
  Very low

Higher vs lower PUFA

It is very uncertain whether higher changes food allergy ‐ childhood incidence compared with lower PUFA intake (very low certainty).

• Polyunsaturated fatty acid supplementation in infancy for the prevention of allergy 2016 · Cochrane Headline outcomes only
  RR 2.27 [0.25, 20.68]
  1 study · 65 participants
  Very low

Higher national income (GNI per capita) vs Lower national income (GNI categories: middle <=$15,000 / high $15,001-25,000 / very high >$25,000)

Higher national income was strongly associated with lower odds of poor oral health (OR 0.10, 95% CI 0.03 to 0.37; about 90% lower odds); not GRADE-rated.

• Caries status in 12-year-old children, geographical location and socioeconomic conditions across European countries: A… 2025 All outcomes

  Cross-sectional (survey data 2011-2022) · European countries; ordinal logistic regression of DMFT category on socioeconomic indicators (adjusted) · Higher vs lower income (ordinal logistic regression, adjusted)
  OR 0.10 [0.03, 0.37]
  Studies not reported
  GRADE not reported

Higher‐dose vs lower‐dose nicotine patch

Higher‐dose showed no clear difference in smoking cessation ‐ 42/44 mg versus 21/22 mg (24‐hour patches) compared with lower‐dose nicotine patch (moderate certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 1.09 [0.93, 1.29]
  5 studies · 1655 participants
  Moderate
• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 1.19 [1, 1.41]
  3 studies · 3446 participants
  Moderate
• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 1.48 [1.06, 2.08]
  1 study · 537 participants
  Moderate

Higher‐dose vs lower‐dose nicotine patch

Higher‐dose showed no clear difference in overall SAEs ‐ 42/44 mg versus 21/22 mg (24 hr patches) compared with lower‐dose nicotine patch (low certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 5.01 [0.87, 28.82]
  2 studies · 1023 participants
  Low
• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 537 participants
  Low

Higher‐dose vs lower‐dose nicotine patch

Higher‐dose may leads to higher treatment withdrawals ‐ 42/44 mg versus 21/22 mg (24‐hour patches) compared with lower‐dose nicotine patch (low certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 4.99 [1.6, 15.5]
  2 studies · 554 participants
  Low

Higher‐dose vs lower‐dose nicotine patch

Higher‐dose showed no clear difference in treatment withdrawals ‐ 21 mg versus 14 mg (24‐hour patches) compared with lower‐dose nicotine patch (low certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 0.77 [0.36, 1.64]
  1 study · 537 participants
  Low

Higher‐dose vs lower dose

It is very uncertain whether higher dose changes deaths compared with lower dose (very low certainty).

• Oximes for acute organophosphate pesticide poisoning 2011 · Cochrane Headline outcomes only
  OR 0.38 [0.1, 1.47]
  4 studies · 479 participants
  Very low

Higher‐dose vs lower dose

It is very uncertain whether higher dose changes intermediate syndrome compared with lower dose (very low certainty).

• Oximes for acute organophosphate pesticide poisoning 2011 · Cochrane Headline outcomes only
  OR 0.94 [0.24, 3.62]
  3 studies · 283 participants
  Very low

Higher‐dose vs lower dose

It is very uncertain whether higher dose changes ventilated compared with lower dose (very low certainty).

• Oximes for acute organophosphate pesticide poisoning 2011 · Cochrane Headline outcomes only
  OR 0.72 [0.08, 6.35]
  2 studies · 272 participants
  Very low

Higher blood flow vs standard blood flow

• Non‐pharmacological interventions for preventing clotting of extracorporeal circuits during continuous renal… 2021 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 499 participants
  Low

Higher blood flow vs standard blood flow

The review found no eligible studies for this question.

• Non‐pharmacological interventions for preventing clotting of extracorporeal circuits during continuous renal… 2021 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Higher blood flow vs standard blood flow

The review found no eligible studies for this question.

• Non‐pharmacological interventions for preventing clotting of extracorporeal circuits during continuous renal… 2021 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Higher blood flow vs standard blood flow

The review found no eligible studies for this question.

• Non‐pharmacological interventions for preventing clotting of extracorporeal circuits during continuous renal… 2021 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Higher‐dose heparin vs standard‐dose heparin

Higher‐dose heparin showed no clear difference in VTE compared with standard‐dose heparin (low certainty).

• Pharmacological interventions for preventing venous thromboembolism in people undergoing bariatric surgery 2022 · Cochrane Headline outcomes only
  RR 0.55 [0.05, 5.99]
  4 studies · 597 participants
  Low

Higher‐dose heparin vs standard‐dose heparin

Higher‐dose heparin showed no clear difference in major bleeding compared with standard‐dose heparin (low certainty).

• Pharmacological interventions for preventing venous thromboembolism in people undergoing bariatric surgery 2022 · Cochrane Headline outcomes only
  RR 1.19 [0.48, 2.96]
  4 studies · 597 participants
  Low

Higher‐dose heparin vs standard‐dose heparin

• Pharmacological interventions for preventing venous thromboembolism in people undergoing bariatric surgery 2022 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 597 participants
  Low