Findings

What do systematic reviews say?

Refine by population, intervention, comparison or outcome
More filters
Evidence found and GRADE certainty

4,756 questions · 13,493 findings · 1,305 reviews · Headline outcomes only

No studies found 2,594 · 19.2%GRADE not reported 728 · 5.4%Very low 2,868 · 21.3%Low 3,777 · 28%Moderate 2,620 · 19.4%High 906 · 6.7%

Ranked among the 5,000 newest matching findings; add words or filters to narrow the search.

Vitamin C vs placebo

Incidence of pneumonia Defined as patient admitted to hospital with a diagnosis of pneumonia Dose: 2 g per day · school‐aged children (6 to 15 years) and marine corps recruits (mean age 18.5 years)

It is very uncertain whether vitamin C changes incidence of pneumonia Defined as patient admitted to hospital with… compared with placebo (very low certainty).

1 finding from 1 review

Vitamin C vs placebo

Adverse effects (urticaria) Defined as participants reporting urticaria (hives) Dose: 2 g per day · school‐aged children (6 to 15 years) and marine corps recruits (mean age 18.5 years)

It is very uncertain whether vitamin C changes adverse effects (urticaria) Defined as participants reporting… compared with placebo (very low certainty).

1 finding from 1 review