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Search review questions
Each row is one question a systematic review asked: who, what, compared with what, and which outcome, with the effect it found and how certain that is. Words match anywhere in the field.
780 questions in 55 reviews · Public Health
current versionsNo studies 162 · 20.8%Ungraded 52 · 6.7%Very low 231 · 29.6%Low 191 · 24.5%Moderate 122 · 15.6%High 22 · 2.8%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
| Question | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Staple foods fortified with vitamin A vs same unfortified staple foods Subclinical vitamin A deficiency (serum/plasma retinol 70 μmol/L or less) · general population above 2 years of age Fortification of staple foods with vitamin A for vitamin A deficiency (2019) · Cochrane | RR 0.45 [0.19, 1.05] | 2 studies · 993 participants | Very low |
Staple foods fortified with vitamin A vs same unfortified staple foods Clinical vitamin A deficiency (defined as night blindness) · general population above 2 years of age Fortification of staple foods with vitamin A for vitamin A deficiency (2019) · Cochrane | RR 0.11 [0.01, 1.98] | 1 study · 581 participants | Very low |
Staple foods fortified with vitamin A vs same unfortified staple foods All‐cause mortality · general population above 2 years of age Fortification of staple foods with vitamin A for vitamin A deficiency (2019) · Cochrane | no estimate extracted | NR | No studies |
Staple foods fortified with vitamin A vs same unfortified staple foods All‐cause morbidity · general population above 2 years of age Fortification of staple foods with vitamin A for vitamin A deficiency (2019) · Cochrane | no estimate extracted | NR | No studies |
Staple foods fortified with vitamin A vs same unfortified staple foods Any adverse effects (e.g. hypervitaminosis A, as defined by the trialists) · general population above 2 years of age Fortification of staple foods with vitamin A for vitamin A deficiency (2019) · Cochrane | no estimate extracted | NR | No studies |
Staple foods fortified with vitamin A plus other micronutrients vs same unfortified staple foods Serum/plasma retinol (μmol/L) · general population over 2 years of age Fortification of staple foods with vitamin A for vitamin A deficiency (2019) · Cochrane | no estimate extracted | 4 studies · 1009 participants | Low |
Staple foods fortified with vitamin A plus other micronutrients vs same unfortified staple foods Subclinical vitamin A deficiency (serum/plasma retinol 0.70 μmol/L or less) · general population over 2 years of age Fortification of staple foods with vitamin A for vitamin A deficiency (2019) · Cochrane | RR 0.27 [0.16, 0.49] | 3 studies · 923 participants | Moderate |
Staple foods fortified with vitamin A plus other micronutrients vs same unfortified staple foods Clinical vitamin A deficiency (as defined by night blindness) · general population over 2 years of age Fortification of staple foods with vitamin A for vitamin A deficiency (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Death (all‐cause) · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Mental development · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Cognitive function and motor skill development · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Cretinism · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Hypothyroidism · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Adverse effects (RCT) · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 1 study · 33 participants | Low |
Intervention NR Urinary iodine concentration (RCT) · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 6 studies · 2032 participants | Moderate |
Intervention NR Urinary iodine concentration (non‐RCT) · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 262 participants | Very low |
Intervention NR Thyroid‐stimulating hormone concentration · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Serum thyroglobulin concentration · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Goitre prevalence (RCT) · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 1 study · 1 participants | Very low |
Intervention NR Goitre prevalence (non‐RCT) · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | OR 1.6 [0.6, 4.31] | 83 participants | Very low |
Intervention NR Physical development measures (non‐RCT) · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR a. Weight · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 83 participants | Very low |
Intervention NR b. Height assessment tool not reported · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 83 participants | Very low |
Intervention NR c. Weight‐for‐age computed from weight and age values · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 83 participants | Very low |
Intervention NR d. Height‐for‐age computed from height and age values · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 83 participants | Very low |
Intervention NR e. Weight‐for‐height computed from weight and height values · all populations, including pregnant women, from any country Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders (2019) · Cochrane | no estimate extracted | 83 participants | Very low |
Interventions targeting vehicular sources vs practice All‐cause mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Low |
Interventions targeting industrial sources vs practice Respiratory mortality · General population, as well as age‐specific subgroups (< 1 year; < 14 years; > 65 years) Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting industrial sources vs practice Particulate matter (PM10) · General population, as well as age‐specific subgroups (< 1 year; < 14 years; > 65 years) Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting industrial sources vs practice Fine particulate matter (PM2.5) · General population, as well as age‐specific subgroups (< 1 year; < 14 years; > 65 years) Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Low |
Interventions targeting industrial sources vs practice Coarse particulate matter · General population, as well as age‐specific subgroups (< 1 year; < 14 years; > 65 years) Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting industrial sources vs practice Combustion‐related particulate matter · General population, as well as age‐specific subgroups (< 1 year; < 14 years; > 65 years) Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting residential sources vs practice All‐cause mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting residential sources vs practice Cardiovascular mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Low |
Interventions targeting residential sources vs practice Respiratory mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting residential sources vs practice Particulate matter (PM10) · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting residential sources vs practice Fine particulate matter (PM2.5) · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting vehicular sources vs practice Cardiovascular mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Low |
Interventions targeting residential sources vs practice Coarse particulate matter · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting residential sources vs practice Combustion‐related particulate matter · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting multiple sources vs practice All‐cause mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting multiple sources vs practice Cardiovascular mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting multiple sources vs practice Respiratory mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting multiple sources vs practice Particulate matter (PM10) · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting multiple sources vs practice Fine particulate matter (PM2.5) · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting multiple sources vs practice Coarse particulate matter · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting multiple sources vs practice Combustion‐related particulate matter · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | No studies |
Interventions targeting vehicular sources vs practice Respiratory mortality · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Low |
Interventions targeting vehicular sources vs practice Particulate matter (PM10) · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Very low |
Interventions targeting vehicular sources vs practice Fine particulate matter (PM2.5) · General population Interventions to reduce ambient particulate matter air pollution and their effect on health (2019) · Cochrane | no estimate extracted | NR | Low |