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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.
75,239 questions in 5,342 reviews
current versionsNo studies 15,213 · 20.2%Ungraded 10,323 · 13.7%Very low 17,528 · 23.3%Low 17,951 · 23.9%Moderate 11,190 · 14.9%High 3,034 · 4%
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 |
|---|---|---|---|
Intermittent use of iron supplements vs placebo or no intervention Anaemia (haemoglobin below a cut‐off defined by trialists, taking into account the age and altitude) Â · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | RR 0.51 [0.37, 0.72] | 10 studies · 1824 participants | Moderate |
Intermittent vs daily use of iron supplements Iron status (ferritin (µg/L) · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | no estimate extracted | 10 studies · 902 participants | Low |
Intermittent vs daily use of iron supplements Iron deficiency anaemia · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | no estimate extracted | 0 studies · 0 participants | Ungraded |
Intermittent vs daily use of iron supplements Mortality · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | no estimate extracted | 0 studies · 0 participants | Ungraded |
Intermittent use of iron supplements vs placebo or no intervention Haemoglobin (g/L) · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | MD 5.2 [2.51, 7.88] | 19 studies · 3032 participants | Low |
Intermittent use of iron supplements vs placebo or no intervention Iron deficiency (using ferritin concentrations) · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | RR 0.24 [0.06, 0.91] | 3 studies · 431 participants | Very low |
Intermittent use of iron supplements vs placebo or no intervention Iron status (ferritin (μg/L) · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | MD 14.17 [3.53, 24.81] | 5 studies · 550 participants | Low |
Intermittent use of iron supplements vs placebo or no intervention Iron deficiency anaemia · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | no estimate extracted | 0 studies · 0 participants | Ungraded |
Intermittent use of iron supplements vs placebo or no intervention All‐cause mortality · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | no estimate extracted | 0 studies · 0 participants | Ungraded |
Intermittent vs daily use of iron supplements Anaemia (haemoglobin below a cut‐off defined by trialists, taking into account the age and altitude) · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | RR 1.23 [1.04, 1.47] | 6 studies · 980 participants | Low |
Intermittent vs daily use of iron supplements Haemoglobin (g/L) · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | no estimate extracted | 19 studies · 2851 participants | Low |
Intermittent vs daily use of iron supplements Iron deficiency (using ferritin concentrations) · children under 12 years of age Intermittent iron supplementation for improving nutrition and development in children under 12 years of age (2011) · Cochrane | RR 4 [1.23, 13.05] | 1 study · 76 participants | Very low |
Intervention NR Health utilisation ‐ preventive care · Anyone using any type of health service in low‐ and middle‐income countries The impact of user fees on access to health services in low‐ and middle‐income countries (2011) · Cochrane | no estimate extracted | NR | Very low |
Intervention NR Health utilisation ‐ curative care · Anyone using any type of health service in low‐ and middle‐income countries The impact of user fees on access to health services in low‐ and middle‐income countries (2011) · Cochrane | no estimate extracted | NR | Very low |
Intervention NR Equity outcome ‐ health utilisation by quartile · Anyone using any type of health service in low‐ and middle‐income countries The impact of user fees on access to health services in low‐ and middle‐income countries (2011) · Cochrane | no estimate extracted | NR | Very low |
Intervention NR Health utilisation ‐ curative care · Anyone using any type of health service in low‐ and middle‐income countries The impact of user fees on access to health services in low‐ and middle‐income countries (2011) · Cochrane | no estimate extracted | NR | Very low |
Intervention NR Health utilisation ‐ preventive care · Anyone using any type of health service in low‐ and middle‐income countries The impact of user fees on access to health services in low‐ and middle‐income countries (2011) · Cochrane | no estimate extracted | NR | Very low |
Intervention NR Health service utilisation ‐ preventive care · Anyone using any type of health service in low‐ and middle‐income countries The impact of user fees on access to health services in low‐ and middle‐income countries (2011) · Cochrane | no estimate extracted | NR | Very low |
Intervention NR Health service utilisation ‐ curative care · Anyone using any type of health service in low‐ and middle‐income countries The impact of user fees on access to health services in low‐ and middle‐income countries (2011) · Cochrane | no estimate extracted | NR | Very low |
Intervention NR Health service utilisation ‐ curative and preventive care · Anyone using any type of health service in low‐ and middle‐income countries The impact of user fees on access to health services in low‐ and middle‐income countries (2011) · Cochrane | no estimate extracted | NR | Very low |
Bisphosphonates vs placebo or no intervention All‐cause mortality · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | RD 0 | 2 studies · 46 participants | Very low |
Bisphosphonates vs another bisphosphonate Adverse events · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | RR 0.95 [0.31, 2.94] | 2 studies · 62 participants | Very low |
Bisphosphonates vs another bisphosphonate Lumbar spine bone mineral density (g/cm²) · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 50 participants | Very low |
Bisphosphonates vs another bisphosphonate Proximal femur bone mineral density (g/cm²) · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 49 participants | Very low |
Bisphosphonates vs another bisphosphonate The procollagen type I N‐terminal propeptide (PINP) (ng/ml) · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 48 participants | Very low |
Bisphosphonates vs another bisphosphonate The urinary amino telopeptides of collagen I (NTx) (nmol bone collagen equivalents /mmol creatinine) · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 46 participants | Very low |
Bisphosphonates vs placebo or no intervention Fractures · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | RR 0.87 [0.29, 2.66] | 3 studies · 106 participants | Very low |
Bisphosphonates vs placebo or no intervention Adverse events · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | RR 1 [0.49, 2.04] | 2 studies · 46 participants | Very low |
Bisphosphonates vs placebo or no intervention Lumbar spine bone mineral density (g/cm²) · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 3 studies · 100 participants | Very low |
Bisphosphonates vs placebo or no intervention Proximal femur bone mineral density (g/cm²) · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 3 studies · 100 participants | Very low |
Bisphosphonates vs placebo or no intervention Serum osteocalcin (ng/ml) · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 3 studies · 100 participants | Very low |
Bisphosphonates vs placebo or no intervention The urinary amino telopeptides of collagen I (NTx) (nmol bone collagen equivalents/mmol creatinine) · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 88 participants | Moderate |
Bisphosphonates vs another bisphosphonate All‐cause mortality · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 62 participants | Very low |
Bisphosphonates vs another bisphosphonate Fractures · patients with primary biliary cirrhosis. Bisphosphonates for osteoporosis in primary biliary cirrhosis (2011) · Cochrane | RR 0.95 [0.18, 5.06] | 2 studies · 62 participants | Very low |
Hormone replacement vs placebo or no intervention All‐cause mortality · women with primary biliary cirrhosis. Hormone replacement for osteoporosis in women with primary biliary cirrhosis (2011) · Cochrane | RD 0 | 2 studies · 49 participants | Very low |
Hormone replacement vs placebo or no intervention Fractures · women with primary biliary cirrhosis. Hormone replacement for osteoporosis in women with primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 49 participants | Very low |
Hormone replacement vs placebo or no intervention Adverse events · women with primary biliary cirrhosis. Hormone replacement for osteoporosis in women with primary biliary cirrhosis (2011) · Cochrane | RR 5.26 [1.26, 22.04] | 2 studies · 49 participants | Very low |
Hormone replacement vs placebo or no intervention Change in % of lumbar spine bone mineral density (BMD) per year (g/cm2 year‐1) · women with primary biliary cirrhosis. Hormone replacement for osteoporosis in women with primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 36 participants | Very low |
Hormone replacement vs placebo or no intervention Change in % of proximal femur bone mineral density (BMD) per year (g/cm2 year‐1) · women with primary biliary cirrhosis. Hormone replacement for osteoporosis in women with primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 36 participants | Very low |
Hormone replacement vs placebo or no intervention Liver‐related morbidity · women with primary biliary cirrhosis. Hormone replacement for osteoporosis in women with primary biliary cirrhosis (2011) · Cochrane | RR 1.07 [0.15, 7.63] | 2 studies · 49 participants | Very low |
Hormone replacement vs placebo or no intervention Bilirubin (µmol/L) · women with primary biliary cirrhosis. Hormone replacement for osteoporosis in women with primary biliary cirrhosis (2011) · Cochrane | no estimate extracted | 2 studies · 36 participants | Very low |
Blunt needles vs sharp needles glove perforations per surgeon per operation · surgical staff Blunt versus sharp suture needles for preventing percutaneous exposure incidents in surgical staff (2011) · Cochrane | RR 0.46 [0.38, 0.54] | 10 studies · 2961 participants | High |
Honey vs No treatment Oral mucositis (severe) · Patients with cancer receiving radiotherapy, chemotherapy or targeted therapies · Median 28 days Interventions for preventing oral mucositis for patients with cancer receiving treatment (2011) · Cochrane | RR 0.26 [0.13, 0.52] | 3 studies | Ungraded |
Oxygenated glycerol triester (OGT) spray vs Saliveeze (aqueous electrolyte) spray Oral health (overall mouth condition) · Adults seeking treatment for the symptom of dry mouth (xerostomia) due to any cause (e.g. medication, Sjogren's… Interventions for the management of dry mouth: topical therapies (2011) · Cochrane | Mouly 2007b: overall mouth condition improved in both groups; no significant differences between the treatment groups. | 1 study | Ungraded |
Hypnosis vs Relaxation Depression (short term) · Adults over 18 years of age with chronic orofacial pain (temporomandibular disorder (TMD)) · Short term Psychosocial interventions for the management of chronic orofacial pain (2011) · Cochrane | SMD -0.49 [-0.93, -0.04] | 2 studies · 81 participants | Ungraded |
Antibiotic pastille or paste (PTA) vs Placebo Oral mucositis (any severity) · Patients with cancer receiving radiotherapy, chemotherapy or targeted therapies · Median 28 days Interventions for preventing oral mucositis for patients with cancer receiving treatment (2011) · Cochrane | RR 0.87 [0.78, 0.96] | 2 studies · 356 participants | Ungraded |
Fluoride supplements (tablets, drops, lozenges or chewing gums) vs No fluoride supplement (placebo or no treatment) Fluorosis (adverse effect; % of children with fluorotic teeth, questionable to severe) · Children and adolescents (aged 16 years or less at baseline) · 55 months Fluoride supplements (tablets, drops, lozenges or chewing gums) for preventing dental caries in children (2011) · Cochrane | % of children with fluorotic teeth (questionable to severe), follow-up 55 months. Assumed risk 32/212 = 15%; corresponding risk 40/202 = 20% (APF once a day) and 43/197 = 22% (APF twice a day). Relative effect: Not… | 1 study · 611 participants | Very low |
Epidermal growth factor vs Placebo Oral mucositis (moderate to severe) · Patients with cancer receiving radiotherapy, chemotherapy or targeted therapies · Median 28 days Interventions for preventing oral mucositis for patients with cancer receiving treatment (2011) · Cochrane | RR 0.67 [0.45, 0.99] | 1 study · 103 participants | Ungraded |
Chewing gum vs No chewing gum Oral mucositis (any severity) · Patients with cancer receiving radiotherapy, chemotherapy or targeted therapies · Median 28 days Interventions for preventing oral mucositis for patients with cancer receiving treatment (2011) · Cochrane | RR 0.87 [0.71, 1.07] | 1 study · 140 participants | Ungraded |
Dentirol chewing gum (xylitol) vs Profylin lozenge (xylitol/sorbitol + CMC) Xerostomia (dry mouth relief) · Adults seeking treatment for the symptom of dry mouth (xerostomia) due to any cause (e.g. medication, Sjogren's… Interventions for the management of dry mouth: topical therapies (2011) · Cochrane | Risheim 1993 (crossover, high risk of bias, n=18, rheumatic patients): both products gave good subjective relief of dry mouth in slightly less than one third of participants; crossover design not accounted for, no… | 1 study · 18 participants | Ungraded |