Study design of the RAD-ON02 trial
The RAD-ON02 study is a prospective, double-blinded and placebo-controlled trial (EudraCT Nr. 2016-002085-31, DRKS-ID DRKS00016019). This is the follow-up study of the RAD-ON01 study, which had no control group (The study was carried out according to a cross-over design. Patients were randomized in two cohorts in a double-blinded manner; neither the treating physicians or the involved scientists nor the patient knew which treatment was performed. In the first year, one group first received thermal spa treatment while the other group received radon spa treatment with a radon concentration of 1200 bq/L at the state-certified health resort Bad Steben (Germany). Both groups received nine baths for 20 min in a period of three weeks. Before treatment (0 weeks), pain-related data were collected and blood was drawn from both groups. This was repeated in week 4 directly after the bath series as well as 12 and 24 weeks after the treatment. One year after the first bath treatment, the treatment was changed for both cohorts, so that the cohort that first received the radon spa treatment then received the thermal spa treatment and vice versa for the other cohort. Again, pain-related data were collected and blood was drawn the week before (0 weeks) and directly after (week 4) as well as 12 and 24 weeks after the second bath series (Study design of the prospective, double-blind and temporary placebo-controlled RAD-ON02 trial.In this work, subgroups of patients have been randomly analyzed. Characteristics of these patients are shown in Characteristics of patients (RAD-ON02 trial).