This study is a pilot trial to determine the feasibility of conducting a subsequent large multi-centre RCT.
The objectives of this pilot trial are:
Primarily:
- To establish the proportion of eligible participants and their willingness to be randomised to home NB-UVB
Secondarily:
- To establish participants' adherence and satisfaction in using home phototherapy
- To assess success of blinding of both participants and outcome assessors by using an identical placebo unit with visible light fluorescence bulb instead of NB-UVB bulb.
- To establish possible short term side effects i.e. if the device is suitable for home use with limited medical supervision
- To manualise the treatment intervention, i.e. prepare package educating participants in how to use the intervention and to deal with possible side effects.
- To define and test the primary and secondary outcome measures and the methods of data collection for the main RCT
Trial Configuration:
Parallel groups-Three arms study
- Group A: active hand held NB-UVB unit (Dermfix 1000)
- Group B: active hand held NB-UVB unit (Waldmann)
- Group C: placebo hand held NB-UVB unit (placebo Dermfix 1000) The allocation to the active or placebo group will be 2:1. This trial configuration will reflect the participants' allocation to active and placebo groups in the main RCT (75% of the participants will receive active treatment), as the latter is most likely to be a three arm or a factorial trial. Subsequently, the results obtained from this pilot trial regarding the participants' willingness to be randomised will be a more precise estimate of the main RCT.
Setting:
Participants will primarily be indentified in secondary care (Nottingham, Leicester, Derby and Mansfield) and by direct advertising. Recruitment will be extended to include primary care if time and resources allow.
Sample size estimate:
This is a pilot study, with sample size being resource driven in terms of available subjects in a reasonable time frame, for which no formal statistically based sample size estimate is applicable.
For this pilot study, 21 participants (7 in each group) will allow the investigators to measure the recruitment rate from each site; n=21 will also give a reasonable estimate of acceptability and completeness of outcome data.
Number of participants:
The investigators estimate to recruit 21 participants, 7 in each group; however the recruitment will depend on time and resources available.
Description of interventions:
The hand held NB-UVB unit is a portable and light weight NB-UVB device that is slightly larger than a usual hairbrush.
These units are CE marked and are being used within their licensing authorisations.
The hand held device is held above any small area of the skin (10-12cm x 6.5-4 cm) and spacers are provided in order to standardise the distance from the skin. Hand held NB-UVB units are suitable for small lesions making phototherapy available for participants with limited disease, and for participants who find it difficult to attend hospital-based phototherapy units 2 to 3 times a week.
The lamp is held still above the vitiliginous lesion. If the size of the lesion is bigger than mentioned above i.e. 10-12 cm X 6.5-4 cm, the participant (or their parent or legal guardian for younger participants) will be asked to move the lamp slowly above the area in circular movements.
In this trial the investigators will explore 2 similar hand held NB-UVB (311nm) phototherapy devices with the same output, but a slighly different size of treatment window, weight of the device and cable length. By doing this the investigators will be able to monitor and assess which of the 2 units is best tolerated in terms of participants' satisfaction and minimisation of side effects. The information gathered will assist in the choice of device for the main RCT.
Device A: Dermfix 1000 NB-UVB Device B: Waldmann UV 109 Both devices are manual units with an on/off switch and an external digital timer. The user of this device has to follow the written treatment protocol, set and re-set the timer each time manually and to keep an accurate diary of exposure times.
The devices need to be connected to a socket all the time.
Placebo Device: Placebo Dermfix 1000, same as Device A The placebo device to be used is identical to the active device Dermfix with the only difference that it will not emit 311nm NB-UVB.
Duration of study:
The recruitment is planned to commence as soon as approvals (ethics and R&D) are in place and should take approximately 6 months. Each participant will participate in the study for 4 months. Participants will be assessed at face to face visits at the beginning of the screening stage-baseline, 8th week and 16th week. Outcomes will be assessed at the same time points.
Follow up telephone calls will be made at weeks 1, 2 and 12.
Randomisation and blinding:
Participants will be blinded to which device they have received, (intervention groups A or B or control group C).
The research nurse will be blinded to which group the participants are allocated (intervention groupS A or B or control group C).
The randomisation will be based on a computer generated pseudo-random code using random permuted blocks of randomly varying size, created by the Nottingham Clinical Trials Unit (CTU) in accordance with their standard operating procedure (SOP) and held on a secure server. The randomisation will be stratified by 3 groups (Group A, B and C) and 2 recruiting sites.
Statistical methods:
Demographic, baseline data and measure of compliance will be summarised by descriptive statistics (number[n], mean, standard deviation [SD], median, minimum and maximum) or frequency tables, stratified by treatment.
Also, calculation of the re-pigmentation rate, spread & cessation of the vitiligo lesions will be conducted for all of the 3 devices. This information will be vital for the sample size calculation for the definitive trial.
