Leheta 2014b.
| Methods | A randomised multiple‐arm single‐blinded, hospital‐based study. Duration of the study from start until the end of follow‐up 17 months (from July‐2009 through December‐2010) | |
| Participants | 39 participants with Skin Phototype III and IV with atrophic acne scars were enrolled Exclusion: "pregnancy, lactation, diabetes, history of keloids or hypertrophic scars, active infection, cancers, receiving treatment for more than 6 months" |
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| Interventions | Trial arm 1 (n = 13): 6 sessions (4 weeks apart) of percutaneous collagen induction with 20% TCA Trial arm 2 (n = 13): 6 sessions (4 weeks apart) of 1540 nm fractional photothermolysis laser system Trial arm 3 (n = 13): 6 alternating sessions (4 weeks apart) of PCI with 20% TCA (3 sessions) and fractional photothermolysis (3 sessions) |
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| Outcomes | Improvement of acne scar (investigator and participant) (12 months), using a quartile grading scale (0 = minimal improvement < 25%; 1 = mild improvement 25% – 50%; 2 = moderate improvement 51% – 75%; 3 = significant improvement > 75% improvement) Side effects (12 months) Timing: at baseline, and at week 48 |
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| Funding source | No funding source | |
| Declaration of interest | Nothing to be declared | |
| Notes | Egypt | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Computer‐generated random sequence prepared by a statistician" Comment: Probably done |
| Allocation concealment (selection bias) | Low risk | Quote: "Sequentially numbered, sealed, opaque envelopes, and kept by a nurse not involved in the study" Comment: Probably done |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Quote: "Patients were randomly divided into three equal groups; group 1: received six sessions …. of PCI …Group 2: received six sessions of 1540 nm fractional photothermolysis ….laser …. Group 3: received combined alternating sessions of the previously mentioned two modalities …" Comment: Probably not done. Given that the control arm was easily distinguished from the treatment arm during treatment, participants and the treating dermatologist were not blinded |
| Blinding of outcome assessment (detection bias) Investigator‐ assessed | Low risk | Quote: "The assessor was blinded to the intervention used." Comment: Probably done |
| Blinding of outcome assessment (detection bias) Participant‐reported | High risk | Quote: "Patients were randomly divided into three equal groups; group 1: received six sessions …. of PCI …Group 2: received six sessions of 1540 nm fractional photothermolysis ….laser …. Group 3: received combined alternating sessions of the previously mentioned two modalities …" Comment: No blinding of participants and the outcome assessment is likely to be influenced by lack of blinding |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Number of participants enrolled: 39. Number of participants with missing data or lost during follow‐up: 1 |
| Selective reporting (reporting bias) | Low risk | The study protocol was obtained by contacting the investigators. The published reports include all expected outcomes that are of interest in the review |
| Other bias | Low risk | The study appears to be free of other sources of bias |