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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 |
|---|---|---|---|
Occlusal splint vs Palatal splint Preference (device preferred by participants) · People with sleep bruxism (tooth grinding or clenching); children (greater than 1 year old) and adults; diagnosis… Occlusal splints for treating sleep bruxism (tooth grinding) (2007) · Cochrane | Occlusal splint versus palatal splint, preference (Dube 2004): all participants preferred the palatal splint rather than the occlusal splint; 71% felt the occlusal splint offered greater protection for their teeth. At… | 1 study | Ungraded |
Third generation cephalosporins vs conventional therapy Death · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 19 studies · 1496 participants | Ungraded |
Third generation cephalosporins vs conventional therapy Death · patients treated for meningococcal meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 13 studies · 477 participants | Ungraded |
Third generation cephalosporins vs conventional antibiotics (high and low/middle‐income countries) Death · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 19 studies · 1301 participants | Ungraded |
Third generation cephalosporins vs conventional antibiotics (high and low/middle‐income countries) Death: high‐income countries · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 9 studies · 510 participants | Ungraded |
Third generation cephalosporins vs conventional antibiotics (high and low/middle‐income countries) Death: Low/middle‐income countries · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 10 studies · 791 participants | Ungraded |
Third generation cephalosporins vs conventional antibiotics (high and low/middle‐income countries) Deafness · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 10 studies · 501 participants | Ungraded |
Third generation cephalosporins vs conventional antibiotics (high and low/middle‐income countries) Deafness: high‐income countries · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 6 studies · 380 participants | Ungraded |
Third generation cephalosporins vs conventional antibiotics (high and low/middle‐income countries) Deafness: low‐income countries · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 4 studies · 121 participants | Ungraded |
Third generation cephalosporins vs conventional therapy Deafness · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 10 studies · 501 participants | Ungraded |
Third generation cephalosporins vs conventional therapy Culture positivity 10 to 48 hours start of treatment · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 12 studies · 442 participants | Ungraded |
Third generation cephalosporins vs conventional therapy Diarrhoea · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 12 studies · 750 participants | Ungraded |
Third generation cephalosporins vs conventional therapy Neutropenia · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 10 studies · 472 participants | Ungraded |
Third generation cephalosporins vs conventional therapy Skin rash · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 8 studies · 533 participants | Ungraded |
Third generation cephalosporins vs conventional therapy Treatment failure (either death or deafness) · patients treated for acute bacterial meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 19 studies · 1496 participants | Ungraded |
Cephalosporins vs conventional therapy Death · patients treated for H. influenzae meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 10 studies · 318 participants | Ungraded |
Third generation cephalosporins vs conventional antibiotics Death · patients treated for S. pneumoniae meningitis Third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis (2007) · Cochrane | no estimate extracted | 11 studies · 129 participants | Ungraded |
Photodynamic therapy with verteporfin vs photodynamic therapy with 5% dextrose Loss of 3 or more lines (15 or more letters) visual acuity ETDRS chart · patients with neovascular age‐related macular degeneration Photodynamic therapy for neovascular age‐related macular degeneration (2007) · Cochrane | RR 0.8 [0.73, 0.88] | 4 studies · 1381 participants | High |
Photodynamic therapy with verteporfin vs photodynamic therapy with 5% dextrose Loss of 6 or more lines (30 or more letters) visual acuity ETDRS chart · patients with neovascular age‐related macular degeneration Photodynamic therapy for neovascular age‐related macular degeneration (2007) · Cochrane | RR 0.66 [0.53, 0.83] | 4 studies · 1381 participants | High |
Photodynamic therapy with verteporfin vs photodynamic therapy with 5% dextrose Gain of 3 or more lines (15 or more letters) · patients with neovascular age‐related macular degeneration Photodynamic therapy for neovascular age‐related macular degeneration (2007) · Cochrane | RR 2.23 [1.19, 4.19] | 3 studies · 941 participants | High |
Photodynamic therapy with verteporfin vs photodynamic therapy with 5% dextrose Adverse effects: acute severe visual acuity decrease · patients with neovascular age‐related macular degeneration Photodynamic therapy for neovascular age‐related macular degeneration (2007) · Cochrane | RR 3.75 [0.87, 16.12] | 3 studies · 1075 participants | Moderate |
Photodynamic therapy with verteporfin vs photodynamic therapy with 5% dextrose Adverse effects: infusion‐related back pain · patients with neovascular age‐related macular degeneration Photodynamic therapy for neovascular age‐related macular degeneration (2007) · Cochrane | RR 9.93 [2.82, 35.02] | 4 studies · 1439 participants | High |
Cryopreservation vs fresh embryos transfer Moderate and or severe OHSS · patients with risk of ovarian hyperstimulation syndrome Embryo freezing for preventing ovarian hyperstimulation syndrome (2007) · Cochrane | OR 0.12 [0.01, 2.29] | 1 study · 125 participants | Low |
Cryopreservation vs fresh embryos transfer Clinical pregnancies · patients with risk of ovarian hyperstimulation syndrome Embryo freezing for preventing ovarian hyperstimulation syndrome (2007) · Cochrane | OR 1.08 [0.54, 2.19] | 1 study · 125 participants | Low |
Cryopreservation vs fresh embryos transfer Number of livebirths (livebirth rate) · patients with risk of ovarian hyperstimulation syndrome Embryo freezing for preventing ovarian hyperstimulation syndrome (2007) · Cochrane | OR 1.03 [0.5, 2.12] | 1 study · 125 participants | Low |
Cryopreservation vs intra‐venous albumin Moderate and or severe OHSS · patients with risk of ovarian hyperstimulation syndrome Embryo freezing for preventing ovarian hyperstimulation syndrome (2007) · Cochrane | OR 5.33 [0.51, 56.24] | 1 study · 26 participants | Very low |
Cryopreservation vs intra‐venous albumin Nil and or mild OHSS · patients with risk of ovarian hyperstimulation syndrome Embryo freezing for preventing ovarian hyperstimulation syndrome (2007) · Cochrane | OR 0.38 [0.08, 1.9] | 1 study · 26 participants | Low |
Cryopreservation vs intra‐venous albumin Clinical pregnancies · patients with risk of ovarian hyperstimulation syndrome Embryo freezing for preventing ovarian hyperstimulation syndrome (2007) · Cochrane | OR 0.06 [0, 1.17] | 1 study · 26 participants | Low |
Intervention NR Hospital admission/re‐admission · Adults who attend the emergency room for acute asthma Education interventions for adults who attend the emergency room for acute asthma (2007) · Cochrane | RR 0.5 [0.27, 0.91] | 5 studies · 572 participants | High |
Intervention NR Presentation at emergency department · Adults who attend the emergency room for acute asthma Education interventions for adults who attend the emergency room for acute asthma (2007) · Cochrane | RR 0.72 [0.47, 1.11] | 8 studies · 946 participants | Low |
Intervention NR Quality of life (SGRQ) ‐ Total scores SGRQ units. Scale from: 0 to 100. · Adults who attend the emergency room for acute asthma Education interventions for adults who attend the emergency room for acute asthma (2007) · Cochrane | no estimate extracted | 2 studies · 356 participants | Low |
Intervention NR Mental state: 1a. Overall no clinically important improvement (BPRS) ‐ short term 25‐30% change BPRS1,2 ( · people with schizophrenia Morita therapy for schizophrenia (2007) · Cochrane | RR 0.36 [0.13, 1.03] | 1 study · 66 participants | Low |
Intervention NR Mental state: 1a. Overall no clinically important improvement (BPRS) ‐ medium term 25‐30% change BPRS1,2 ( · people with schizophrenia Morita therapy for schizophrenia (2007) · Cochrane | RR 0.36 [0.14, 0.89] | 1 study · 76 participants | Low |
Itraconazole vs Fluconazole Death associated with fungal infection · Patients with cancer receiving chemotherapy or radiotherapy or both Interventions for preventing oral candidiasis for patients with cancer receiving treatment (2007) · Cochrane | RR 0.14 [0.01, 2.73] | 1 study · 202 participants | Ungraded |
Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs Attention control (attention/contact without an active psychological intervention) Self-reported flossing · Adults (aged 18 or over) diagnosed with periodontal disease (gingivitis or periodontitis) · 5 weeks (2 weeks post-intervention) Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal… (2007) · Cochrane | Stewart 1991: there were no differences between the attention control group and the cognitive behavioural (psychological) intervention group for self reported flossing; it cannot be concluded that the cognitive… | 1 study · 50 participants | Ungraded |
Itraconazole vs Fluconazole Good compliance · Patients with cancer receiving chemotherapy or radiotherapy or both Interventions for preventing oral candidiasis for patients with cancer receiving treatment (2007) · Cochrane | RR 0.95 [0.85, 1.05] | 1 study · 202 participants | Ungraded |
Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs No (active) intervention (usual/standard dental care or no-treatment control) Observed tooth brushing skill · Adults (aged 18 or over) diagnosed with periodontal disease (gingivitis or periodontitis) · 4 months Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal… (2007) · Cochrane | Little 1997 observed and rated participants on brushing skill; Analysis of Covariance found a significant difference favouring the intervention group (one of four measures on which significant differences were found… | 1 study · 107 participants | Ungraded |
Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs No (active) intervention (usual/standard dental care or no-treatment control) Dental knowledge · Adults (aged 18 or over) diagnosed with periodontal disease (gingivitis or periodontitis) Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal… (2007) · Cochrane | Stewart 1996: for dental knowledge the control group showed no change pre- and post-intervention, whereas the psychological intervention group improved dental knowledge significantly (both intervention groups improved… | 1 study · 117 participants | Ungraded |
Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs Educational intervention (oral hygiene education/instruction) Self-reported tooth brushing · Adults (aged 18 or over) diagnosed with periodontal disease (gingivitis or periodontitis) · 5 weeks (2 weeks post-intervention) Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal… (2007) · Cochrane | Stewart 1991: for self reported brushing only the comparison of the control group with the cognitive behavioural intervention was significant; the cognitive behavioural (psychological) intervention showed no… | 1 study · 50 participants | Ungraded |
Antifungal drugs partially absorbed from GI tract (miconazole, clotrimazole) vs Placebo or no treatment Empirical antifungal treatment · Patients with cancer receiving chemotherapy or radiotherapy or both Interventions for preventing oral candidiasis for patients with cancer receiving treatment (2007) · Cochrane | RR 3.38 [0.15, 77.12] | 1 study · 32 participants | Ungraded |
Paracetamol (single oral dose, any dose or formulation; subgroups up to 1000 mg and 1000 mg or more) vs Placebo Patients with one or more adverse events · Patients requiring surgical removal of a lower wisdom tooth or teeth, with baseline moderate to severe pain (surgery… · up to 7 days Paracetamol for pain relief after surgical removal of lower wisdom teeth (2007) · Cochrane | RR 1.19 [0.90, 1.57] | 17 studies · 1645 participants | Ungraded |
Post and core restoration with a ferrule vs Post and core restoration without a ferrule Outcome NR · Participants with permanent endodontically-treated (root-filled) teeth for which a post is indicated to retain the… · Minimum 6 months (planned) Root canal posts for the restoration of root filled teeth (2007) · Cochrane | No included trial evaluated the presence of a ferrule (a planned secondary comparison); no eligible study identified. | 0 studies | No studies |
Non-metal carbon-fibre post and core (Category III; Composipost) vs Metal custom-cast post and core (Category I; gold alloy) Clinical/technical failure (root fracture) · Participants with permanent endodontically-treated (root-filled) teeth for which a post is indicated to retain the… · 48 months (4 years) Root canal posts for the restoration of root filled teeth (2007) · Cochrane | RR 0.05 [0.00, 0.90] | 1 study · 195 participants | Ungraded |
Antifungal drugs absorbed from GI tract vs Antifungal drugs not absorbed from GI tract Death associated with fungal infection · Patients with cancer receiving chemotherapy or radiotherapy or both Interventions for preventing oral candidiasis for patients with cancer receiving treatment (2007) · Cochrane | RR 1.25 [0.38, 4.13] | 3 studies · 981 participants | Ungraded |
Occlusal splint vs Palatal splint Number of bruxism episodes per hour of sleep (Epi/h) · People with sleep bruxism (tooth grinding or clenching); children (greater than 1 year old) and adults; diagnosis… Occlusal splints for treating sleep bruxism (tooth grinding) (2007) · Cochrane | MD 0.54 [-10.95, 12.93] | 1 study | Ungraded |
Paracetamol (single oral dose, any dose or formulation; subgroups up to 1000 mg and 1000 mg or more) vs Placebo Achieving at least 50% pain relief at 6 hours (using pain relief measurements / TOTPAR) · Patients requiring surgical removal of a lower wisdom tooth or teeth, with baseline moderate to severe pain (surgery… · 6 hours Paracetamol for pain relief after surgical removal of lower wisdom teeth (2007) · Cochrane | RR 3.32 [1.88, 5.87] | 13 studies · 1155 participants | Ungraded |
Paracetamol (single oral dose, any dose or formulation; subgroups up to 1000 mg and 1000 mg or more) vs Placebo Achieving at least 50% pain relief at 4 hours (using pain relief measurements / TOTPAR) · Patients requiring surgical removal of a lower wisdom tooth or teeth, with baseline moderate to severe pain (surgery… · 4 hours Paracetamol for pain relief after surgical removal of lower wisdom teeth (2007) · Cochrane | RR 2.85 [1.89, 4.29] | 16 studies · 1498 participants | Ungraded |
Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs No (active) intervention (usual/standard dental care or no-treatment control) Self-efficacy beliefs (tooth brushing) · Adults (aged 18 or over) diagnosed with periodontal disease (gingivitis or periodontitis) Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal… (2007) · Cochrane | Stewart 1996: the psychological intervention had no discernible effect on self efficacy beliefs concerning tooth brushing; the data on perceived self efficacy for tooth brushing were not analysed due to ceiling effects… | 1 study · 117 participants | Ungraded |
Potassium nitrate/polycarboxylate cement (KNO3/PCa) vs Polycarboxylate cement (PCa) alone Clinical success (absence of periapical pathology, tenderness to pressure and fistula formation) at 24 months · Adults with asymptomatic vital pulpal exposures from caries · 24 months Pulp management for caries in adults: maintaining pulp vitality (2007) · Cochrane | Hodosh 2003 (Analysis 3.1): 9/17 in the KNO3/PCa group and 10/12 in the PCa group developed clinical symptoms requiring endodontic therapy or extraction. No significance test reported for this specific contrast; no… | 1 study · 29 participants | Ungraded |
Life (calcium hydroxide pulp-capping material) vs Dycal (calcium hydroxide pulp-capping material) Clinical symptoms at 12 months · Adults (aged 20 to 60 years, mean 27) with deep carious lesions in permanent teeth (indirect or direct pulp capping,… · 12 months, Indirect pulp capping Pulp management for caries in adults: maintaining pulp vitality (2007) · Cochrane | Analysis 2.1 (clinical symptoms at 12 months following indirect pulp capping, Life vs Dycal). Fitzgerald 1991: 151 teeth in 55 patients (analysis at tooth level, not patient level); substantial attrition (11 teeth lost… | 1 study · 151 participants | Ungraded |