Low radiant exposures delivered by high-frequency and/or long-pulsed diode laser energy output in hair reduction: an intrapatient comparative, randomized double-blind trial (D800RCS)

Study type

• Study type:
  Clinical trial
• Scope of the study:
  Effectiveness study (incl. comparative)

Clinical trials

• Clinical trial randomisation:
  Randomised clinical trial

Population studied

• Age groups:
  • Adults (18 to < 46 years)
  • Adults (46 to < 65 years)
• Estimated number of subjects:
  30

Study design details

• Main study objective:
  To show that the use of a low radiant exposure (6 J/cm2), standard pulse width (30 ms) and high repetition frequency (10 Hz) or the use of a medium radiant exposure (18 J/cm2), longer pulse width (100 ms) and medium repetition frequency (4 Hz) diode laser is equally efficacious but safer than standard diode laser hair reduction protocol (25-35 J/cm2, 12.5-30 ms, 1 Hz).
• Outcomes:
  The primary outcome parameter is reduction of hair growth evaluated 3 and 6 months following the last treatment. Secondary outcome parameters are treatment-related pain, adverse effects and treatment duration, as well as patient-rated efficacy evaluated 3 and 6 months following the last treatment.
• Data analysis plan:
  Primary outcome analysis is based on the reduction of hair growth at the follow-up visits in the intention-to-treat (ITT) population. ITT was defined as all patients who had received all 6 study treatments. Missing values at visit 8 were implemented using the conservative last-observation-carried-forward (LOCF) approach. Additionally, a per-protocol (PP) analysis was performed as a sensitivity analysis. The goal of the trial is to show non-inferiority of the new treatment protocols.All data were analysed with the paired two-sample Student’s t-test because the baseline data were normally distributed. All data are given as mean ± SD. A P-value below 0.05 was considered significant. To assess consistency in hair counts, a Mann–Whitney U-test was performed. The patient satisfaction were compared between two lasers by using Wilcoxon Signed-Rank test. The differences of treatment time and p