Gambichler 2001.

Study characteristics
Methods	Two‐group parallel split‐body, randomised controlled trial with paired comparison of right versus left elbow Setting: single‐centre study located in Germany recruiting out‐patients during autumn and winter Duration of enrolment: not reported Follow‐up time: not reported
Participants	Inclusion criteria of the trial Psoriasis patients of both sexes, over 18 years of age, with skin types II and III and symmetric psoriasis plaques of equal severity on both elbows Exclusion criteria of the trial Patients with antipsoriatic therapy within the last 2 months prior to the study and patients using photosensitising and psoriasis‐provoking agents. Characteristics Age: mean age in years (range): 36 (28 to 49) Gender (M/F, %): 4 (40%) / 6 (60%) Skin type (N, %): I: 0, II: 6 (60%), III: 4 (40%) Severity: PASI not reported Previous treatment: not reported Duration of condition: mean duration of 2.5 years ranging from 1 to 4.5 years
Interventions	Intervention (n = 10, one elbow) Saline salt bath : one elbow of each patient was soaked in 24% NaCl solution. Concentration: 240 g/L NaCl dissolved in tap water. Artificial broadband UVB : irradiation was applied using the following device: TL/12, Philips, Hamburg, Germany. The spectrum of this UV source ranges from 280 nm to 365 nm, with a peak at 306 nm. UVB intensity was 2 mW/cm2 at a lamp‐to‐site distance of 30 cm. The initial UVB dose for skin type II was 0.02 J/cm2 and for skin type III, 0.03 J/cm2. The UVB doses were gradually increased up to 50% to 75% of the initial UVB doses after each treatment session. The mean maximal UVB dose was 0.4 J/cm2 and the mean cumulative UVB dose was 7.2 J/cm2. Control intervention (n = 10, the other elbow) Tap water bath : the other elbow of each patient was soaked in tap water containing 0.02% sodium chloride Artificial broadband UVB alone : the same conditions as reported for the intervention. Both elbows were simultaneously exposed to the solution by bandaging the sites with soaked cotton wool. The interventions were applied to both elbows once a day, three to five days a week, for up to eight weeks, and reaching a maximum number of 30 applications. Duration of UV irradiation was not reported.
Outcomes	Outcomes of the trial not classified as primary or secondary The clinical evaluation was based on a severity score with respect to desquamation, erythema, and infiltration of the psoriatic target plaques of the elbows. Severity was assessed on a 5‐point scale and graded as follows: severest possible (4); severe (3); moderate (2); slight (1); none (0). The assessment was performed before commencing treatment and after 10, 20, and 30 treatments (end of treatment at 8 weeks after start of treatment).
Notes	Funding not reported Conflicts of interest: issue not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote (page 22): "A prospective, randomized, one‐blind, right/left comparison, investigating the efficacy of BPT in psoriasis with highly concentrated salt water versus tap water, was performed in an out‐patient setting during autumn and winter." Comment: sequence generation not clear
Allocation concealment (selection bias)	Unclear risk	Comment: allocation concealment not clear
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote (page 22): "A prospective, randomized, one‐blind, right/left comparison, investigating the efficacy of BPT in psoriasis with highly concentrated salt water versus tap water, was performed in an out‐patient setting during autumn and winter." "Both elbows were simultaneously exposed to these liquids (30°C) by bandaging the sites with soaked cotton wool." Comment: partially blinding of people or limbs
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote (page 23): "To avoid interobserver variation, all patients were clinically assessed by one physician who was not informed which pretreatment had been used prior to phototherapy." Comment: blinding of outcome assessment achieved
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: we did not identify a noteworthy proportion of dropouts and judged a low risk of attrition bias.
Selective reporting (reporting bias)	Unclear risk	Comment: we did not identify a selective reporting issue and judged an unclear risk of bias.
Other bias	Unclear risk	Comment: we did not identify other bias such as design‐specific risks of bias, baseline imbalance, blocked randomisation in unblinded trials, and differential diagnostic activity.