Gap finder
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.
1,886 questions in 74 reviews · Skin
current versionsNo studies 542 · 28.7%Ungraded 130 · 6.9%Very low 326 · 17.3%Low 434 · 23%Moderate 348 · 18.5%High 106 · 5.6%
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 |
|---|---|---|---|
Azelaic acid vs adapalene Participants' global self‐assessment of acne improvement Improved to very much improved(long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 0.89 [0.68, 1.17] | 1 study · 55 participants | Very low |
Azelaic acid vs clindamycin Withdrawal for any reason (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.3 [0.48, 3.56] | 2 studies · 329 participants | Low |
Azelaic acid vs clindamycin Total number of participants who experienced at least one minor adverse event (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.5 [0.67, 3.35] | 1 study · 100 participants | Low |
Azelaic acid vs clindamycin Quality of life · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Azelaic acid vs tretinoin Participants' global self‐assessment of acne improvement Good to excellent improvement (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 0.94 [0.78, 1.14] | 1 study · 289 participants | Moderate |
Azelaic acid vs tretinoin Withdrawal for any reason (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 0.66 [0.29, 1.47] | 2 studies · 309 participants | Low |
Azelaic acid vs tretinoin Total number of participants who experienced at least one minor adverse event · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Azelaic acid vs tretinoin Quality of life · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Salicylic acid vs benzoyl peroxide Participants' global self‐assessment of acne improvement · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Salicylic acid vs benzoyl peroxide Withdrawal for any reason (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | 1 study · 41 participants | Very low |
Salicylic acid vs benzoyl peroxide Total number of participants who experienced at least one minor adverse event (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 0.21 [0.01, 4.11] | 1 study · 41 participants | Very low |
Azelaic acid vs adapalene Withdrawal for any reason (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 2.64 [0.33, 20.99] | 1 study · 55 participants | Very low |
Salicylic acid vs benzoyl peroxide Quality of life ARQL (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | 1 study · 41 participants | Very low |
Salicylic acid vs pyruvic acid Participants' global self‐assessment of acne improvement Good to excellent improvement (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.12 [0.68, 1.84] | 1 study · 86 participants | Very low |
Salicylic acid vs pyruvic acid Withdrawal for any reason (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 0.89 [0.53, 1.5] | 1 study · 86 participants | Low |
Salicylic acid vs pyruvic acid Total number of participants who experienced at least one minor adverse event · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Salicylic acid vs pyruvic acid Quality of life · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Salicylic acid vs tretinoin Participants' global self‐assessment of acne improvement Moderate to excellent improvement (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1 [0.92, 1.09] | 1 study · 46 participants | Low |
Salicylic acid vs tretinoin Withdrawal for any reason (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | 2 studies · 74 participants | Low |
Salicylic acid vs tretinoin Total number of participants who experienced at least one minor adverse event (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.37 [0.66, 2.87] | 2 studies · 74 participants | Very low |
Salicylic acid vs tretinoin Quality of life AQOL (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | 1 study · 46 participants | Very low |
Nicotinamide vs clindamycin Participants' global self‐assessment of acne improvement · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Azelaic acid vs adapalene Total number of participants who experienced at least one minor adverse event (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.16 [0.47, 2.85] | 1 study · 55 participants | Very low |
Nicotinamide vs clindamycin Withdrawal for any reason (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.12 [0.49, 2.6] | 3 studies · 216 participants | Low |
Nicotinamide vs clindamycin Total number of participants who experienced at least one minor adverse event (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.2 [0.73, 1.99] | 3 studies · 216 participants | Low |
Nicotinamide vs clindamycin Quality of life · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Nicotinamide vs erythromycin Participants' global self‐assessment of acne improvement · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Nicotinamide vs erythromycin Withdrawal for any reason (medium term: treatment duration from 5 to 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.4 [0.46, 4.22] | 1 study · 158 participants | Low |
Nicotinamide vs erythromycin Total number of participants who experienced at least one minor adverse event · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Nicotinamide vs erythromycin Quality of life · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Glycolic acid (alpha‐hydroxy acid) vs salicylic‐mandelic acid Participants' global self‐assessment of acne improvement Fair to good improvement (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.06 [0.88, 1.26] | 1 study · 40 participants | Low |
Glycolic acid (alpha‐hydroxy acid) vs salicylic‐mandelic acid Withdrawal for any reason (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | 2 studies · 84 participants | Low |
Glycolic acid (alpha‐hydroxy acid) vs salicylic‐mandelic acid Total number of participants who experienced at least one minor adverse event (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.8 [0.72, 4.52] | 1 study · 44 participants | Very low |
Azelaic acid vs adapalene Quality of life Dermatology Life Quality Index (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | 1 study · 55 participants | Very low |
Glycolic acid (alpha‐hydroxy acid) vs salicylic‐mandelic acid Quality of life · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Azelaic acid vs benzoyl peroxide Participants' global self‐assessment of acne improvement Good or very good improvement (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 0.82 [0.72, 0.95] | 1 study · 351 participants | Moderate |
Azelaic acid vs benzoyl peroxide Withdrawal for any reason (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 0.88 [0.6, 1.29] | 1 study · 351 participants | Low |
Azelaic acid vs benzoyl peroxide Total number of participants who experienced at least one minor adverse event (short term: treatment duration ≤ 4 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 0.5 [0.05, 4.94] | 1 study · 30 participants | Very low |
Azelaic acid vs benzoyl peroxide Quality of life · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | no estimate extracted | NR | No studies |
Azelaic acid vs clindamycin Participants' global self‐assessment of acne improvement Good or very good improvement (long term: treatment duration > 8 weeks) · participants with acne Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha‐hydroxy acid) for acne (2020) · Cochrane | RR 1.13 [0.92, 1.38] | 1 study · 229 participants | Low |
Intervention NR Frequency of skin damage (as recorded by clinicians according to STAR Skin Tear Classification) Outcome measured during 6 months · people 60 years of age and older Hygiene and emollient interventions for maintaining skin integrity in older people in hospital and… (2020) · Cochrane | no estimate extracted | 1 study · 984 participants | Very low |
Intervention NR Side effects from intervention (as and when observed) Outcome measured up to day 56 ± 4 · people 60 years of age and older Hygiene and emollient interventions for maintaining skin integrity in older people in hospital and… (2020) · Cochrane | no estimate extracted | 1 study · 133 participants | Very low |
Intervention NR Transepidermal water loss (TEWL) Measured using temperature‐adjusted g/m²/h with the Tewameter TM 300 (Courage + Khazaka, Cologne, Germany) Hahnel 2017: measured at 56 ± 4 days Shishido 2017: measured 15 minutes after wiping the skin with a dry to... · people 60 years of age and older Hygiene and emollient interventions for maintaining skin integrity in older people in hospital and… (2020) · Cochrane | no estimate extracted | 2 studies · 147 participants | Low |
Intervention NR Stratum corneum hydration (SCH) (at baseline and day 56 ± 4) Hahnel 2017: measured at 56 ± 4 days in mid‐volar arm and lower leg in arbitrary units from 0 (no water) to 120 (on water) using the Corneometer CM 825 Gillis 2016: measured at 12 weeks ... · people 60 years of age and older Hygiene and emollient interventions for maintaining skin integrity in older people in hospital and… (2020) · Cochrane | no estimate extracted | 3 studies · 266 participants | Very low |
Intervention NR Erythema · people 60 years of age and older Hygiene and emollient interventions for maintaining skin integrity in older people in hospital and… (2020) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Clinical score of dryness Hahnel 2017: measured at day 56 ± 4 using the Overall Dry Skin Score Boccanfuso 1978: measured after 10 applications using a non‐validated General Foot Condition Questionnaire including a Dryness Scale (1 = oily; 2 = norm... · people 60 years of age and older Hygiene and emollient interventions for maintaining skin integrity in older people in hospital and… (2020) · Cochrane | no estimate extracted | 3 studies · 245 participants | Low |
Intervention NR Clinical score of itch · people 60 years of age and older Hygiene and emollient interventions for maintaining skin integrity in older people in hospital and… (2020) · Cochrane | no estimate extracted | NR | No studies |
Any systemic treatment vs placebo Infliximab · people with chronic plaque psoriasis Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis (2020) · Cochrane | RR 29.52 [19.94, 43.7] | 5 studies · 1651 participants | Moderate |
Any systemic treatment vs placebo Tildrakizumab · people with chronic plaque psoriasis Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis (2020) · Cochrane | RR 17.08 [12.93, 22.56] | 3 studies · 1903 participants | High |
Any systemic treatment vs placebo Oral tyrosine kinase 2 (TYK2) inhibitor · people with chronic plaque psoriasis Systemic pharmacological treatments for chronic plaque psoriasis: a network meta-analysis (2020) · Cochrane | RR 13.99 [1.99, 98.1] | 1 study · 267 participants | Low |