Summary of findings 1. Laser therapy compared with no treatment for treating hypertrophic and keloid scars.
| Laser therapycompared with no treatment for treating hypertrophic and keloid scars | ||||||
| Patient or population: patients with hypertrophic and keloid scars Setting: outpatient Intervention: laser therapy (various types ‐ 585‐nm Pulsed‐Dye Laser (PDL), Non‐Ablative Fractional Laser (NAFL), Fractional CO2) Comparison: no treatment | ||||||
| Outcomes | Anticipated absolute effects (95% CI) | Relative effect (95% CI) | № of scar segment (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with no treatment | Risk with Laser therapy | |||||
| Scar severity ‐ 585‐nm Pulsed‐Dye Laser (PDL) versus no treatment ‐ patient self‐assessment of scar improvement of 50% or higher ‐ hypertrophic and keloid scars ‐ follow‐up: 32 weeks | Study population | RR 1.96 (1.11 to 3.45) | 60 (2 studies) | ⊕⊕⊝⊝1,2 Low | There may be more hypertrophic and keloid scar improvement (that is scars are less severe) in 585‐nm PDL‐treated scars compared with no treatment after 32 weeks. |
|
| 400 per 1000 | 784 per 1000 | |||||
| Incidence and severity of treatment‐related adverse effects ‐ 585‐nm PDL versus no treatment ‐ mild to moderate discomfort or pain related to treatment ‐ hypertrophic and keloid scars ‐follow‐up: 32 weeks | Two split‐scar trials (n = 60) reported this outcome. In these studies, participants reported mild to moderate discomfort or pain in 10 out of 30 (10/30) (33%) PDL treated areas versus 0 out of 30 (0/30) (0%) no treatment areas (RR 8.62; 1.10 to 67.39). | ⊕⊝⊝⊝2,3 Very low | It is uncertain whether there is any difference in the incidence and severity of treatment‐related adverse effects in 585‐nm PDL‐treated hypertrophic and keloid scars compared with no treatment after 32 weeks. | |||
| Incidence and severity of treatment‐related adverse effects ‐ 585‐nm PDL versus no treatment ‐ purpura ‐ hypertrophic and keloid scars ‐ follow‐up: 32 weeks | Two split‐scar trials (n = 60) reported this outcome. In these studies, purpura was observed in 40 out of 40 (40/40) (100%) PDL treated areas versus 0 out of 20 (0/20) (0%) no treatment areas (RR 21.32; 3.14 to 144.86). | ⊕⊝⊝⊝2,3 Very low | ||||
| Scar severity ‐ Non‐Ablative Fractional Laser (NAFL) versus no treatment ‐ health professional global assessment measured on a visual analogue scale (VAS) ranging from 0 to 100 mm (0 = as normal skin and 100 = worst possible scar) ‐ hypertrophic scars ‐ follow‐up: 3 months | Study population | RR 2.00 (0.85 to 4.69) |
36 (1 study) |
⊕⊝⊝⊝3,4 Very low | It is uncertain whether there is any difference in the scar severity in NAFL‐treated hypertrophic scars compared with no treatment after 3 months. | |
| 278 per 1000 | 556 per 1000 |
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| Scar severity ‐ NAFL versus no treatment ‐ patient global assessment measured on a VAS ranging from 0 to 100 mm (0 = as normal skin and 100 = worst possible scar) ‐ hypertrophic scars ‐ follow‐up: 3 months | One split‐scar trial (n = 36) reported this outcome. In this study, the authors reported an improvement in scar severity in NAFL treated hypertrophic scars compared with no treatment on the patient global assessment at 1 month (reported P = 0.006) and 3 months (reported P = 0.02). | ⊕⊝⊝⊝5,6 Very low | ||||
| Scar severity ‐ NAFL versus no treatment ‐ Patient and Observer Scar Assessment Scale (POSAS) (higher scores = worse scar appearance) ‐ hypertrophic scars ‐ follow‐up: up to 3 months | One split‐scar trial (n = 36) reported this outcome. In this study, the authors reported an improvement in scar severity in NAFL treated hypertrophic scars compared with no treatment on the participant part of the scale at 1 month and 3 months. The size of the difference was not reported and no data for the observer part of the scale was presented. | ⊕⊝⊝⊝5,6 Very low | ||||
| Incidence and severity of treatment‐related adverse effects ‐ NAFL versus no treatment ‐ scar worsening ‐ hypertrophic scars ‐ follow‐up: 3 months | One split‐scar trial (n = 20) reported this outcome. In this study, 3 out of 10 (3/10) (30%) NAFL treated areas versus 0 out of 10 (0/10) (0%) no treatment areas were considered by the patients to have worsened (RR 7.00; 0.41 to 120.16). | ⊕⊝⊝⊝3,7 Very low | It is uncertain whether there is any difference in the incidence and severity of treatment‐related adverse effects in NAFL‐treated hypertrophic scars compared with no treatment after 3 months. | |||
| Incidence and severity of treatment‐related adverse effects ‐ NAFL versus no treatment ‐ hyperpigmentation ‐ hypertrophic scars ‐ follow‐up: 3 months | One split‐scar trial (n = 36) reported this outcome. In this study, hyperpigmentation was observed in 1 out of 18 (1/18) (6%) NAFL treated areas versus 0 out of 18 (0/18) (0%) no treatment areas (RR 3.00; 0.13 to 69.09). | ⊕⊝⊝⊝3,5 Very low | ||||
| Scar severity ‐ Fractional Carbon Dioxide (CO2) Laser versus no treatment ‐ Vancouver Burn Scar (VBS) scale (higher scores = worse scar appearance) ‐ hypertrophic scars ‐ follow‐up: up to 3 months | Study population | NA | 104 (2 studies) |
⊕⊝⊝⊝6,8 Very low | It is uncertain whether there is any difference in the scar severity in Fractional CO2‐treated hypertrophic and keloid scars compared with no treatment after up to 3 months, and in Fractional CO2‐treated hypertrophic scars compared with no treatment after at least 1 month. | |
| Baseline mean in the no treatment group was 7.6 | MD 1.30 lower (4.32 lower to 1.71 higher) | |||||
| Scar severity ‐ Fractional CO2 Laser versus no treatment ‐ VBS (higher scores = worse scar appearance) ‐ keloid scars ‐ follow‐up: 3 months | Study population | NA | 24 (1 study) |
⊕⊝⊝⊝6,9 Very low | ||
| Baseline mean in the no treatment group was 7.6 | MD 1.90 lower (3.02 lower to 0.78 lower) | |||||
| Scar severity ‐ Fractional CO2 Laser versus no treatment ‐ POSAS scale (higher scores = worse scar appearance) ‐ hypertrophic scars ‐ follow‐up: at least 1 month | Study population | NA | 80 (1 study) |
⊕⊝⊝⊝6,10 Very low | ||
| Baseline mean in the no treatment group was 29.9 | MD 4.13 higher (1.24 lower to 9.50 higher) | |||||
| *The risk in the intervention group (and its 95% confidence interval) is based on the mean risk in the comparison group and the relative effect of the intervention (and its 95% CI). ƚThe assumed risk in the comparison group is based on the event rate observed in the control arms of included trials. Where no events occurred, the risk was not calculated. VAS: visual analogue scale ‐ ranging from 0 to 100 mm (0 = normal skin and 100 = worst possible scar); Patient self‐assessment ‐ based on a 4‐point scale (1 = 0 to 25% improvement, 2 = 25 to 50% improvement, 3 = 50 to 75% improvement, and 4 = 75% or greater improvement); POSAS: Patient and Observer Scar Assessment Scale ‐ the lowest score (6) reflects normal skin, and the highest score (60) reflects the worst imaginable scar; VBS: Vancouver Burn Scar Assessment Scale ‐ severity of scar was determined by numeric value from a minimum of 0 to 13 as the most severe form. CI: Confidence Interval; CO2: carbon dioxide;LDTA: (Low‐Density Treatment Arm of NAFL), HDTA: (High‐Density Treatment Arm of NAFL); MD: Mean Difference; NAFL: Non‐Ablative Fractional Laser ;PDL: Pulsed‐Dye Laser; RR: Risk Ratio; VBS: Vancouver Burn Scar Assessment Scale. | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect. | ||||||
1 Downgraded 1 level for serious imprecision due to small number of events.
2 Downgraded 1 level for serious risk of bias (lack of blinding of participants and assessors (patient‐reported outcome), and unclear sequence generation and allocation concealment).
3 Downgraded 2 levels for very serious imprecision due to small number of events and large confidence interval.
4 Downgraded 1 level for serious risk of bias (lack of blinding of participants).
5 Downgraded 1 level for serious risk of bias (lack of blinding of participants and assessors (patient‐reported outcome)).
6 Downgraded 2 levels for very serious imprecision due to small sample size and large confidence interval.
7 Downgraded 1 level for serious risk of bias (lack of blinding of participants and assessors (patient‐reported outcome), incomplete outcome data, and unclear allocation concealment).
8 Downgraded 1 level for serious risk of bias (selective reporting in one study, and lack of blinding of participants and incomplete outcome data in 2 studies).
9 Downgraded 1 level for serious risk of bias (lack of blinding of participants, incomplete outcome data and selective reporting).
10 Downgraded 1 level for serious risk of bias (lack of blinding of participants and assessors (patient‐reported outcome) and incomplete outcome data).