Trenkwalder 2007.

Methods	Randomised active controlled parallel‐group trial of levodopa versus cabergoline Dropouts/withdrawals: ITT (361) and PP (204) with premature discontinuations of 83 (levodopa) and 74 (cabergoline)
Participants	Included/analysed: long term: 361 patients (178 cabergoline, 183 levodopa), short term: 204 (104 cabergoline, 100 levodopa) Demographics: 46 (levodopa)/58 (cabergoline) male, age 56.9 (levodopa)/58.7 (cabergoline) Diagnosis: RLS according to IRLSSG, symptom severity on IRLS ≥ 10 and RLS‐6 "severity at night" ≥ 4. Setting: 51 centres in 4 European countries Baseline: IRLS score of 25.6 (levodopa) and 25.8 (cabergoline)
Interventions	Intervention 1: fixed uptitration of single dose cabergoline to 2.0 mg which could be increased to 3.0 mg (in 2 weeks), maintenance up to 6/ 8 weeks and to 24 weeks Intervention 2: fixed uptitration of single dose levodopa/benserazide 200 mg/50 mg (in 8 days) which could be increased to to 300 mg/75 mg, maintenance up to 6/ 8 weeks and to 24 weeks
Outcomes	Change of symptoms: IRLS, CGI‐I Self rated quality of sleep: RLS‐6 satisfaction with sleep Daytime tiredness: RLS‐6 daytime tiredness Quality of life: RLS‐QoL Safety: number of dropouts due to adverse events, number of patients with adverse events
funding source	The study was supported by Pfizer GmbH.
Notes	RLS‐QoL: Restless Legs Syndrome Quality of Life questionnaire
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	Sequentially assigned to one of the two treatments by the investigators using medication numbers in ascending order for each block of 4 which was allocated to the study site after central randomisation using the program SAS Proc. Plan Version v8.2.
Allocation concealment?	Low risk	Medication numbers in ascending order. See above.
Blinding? All outcomes	Low risk	Identical looking tablets.
Incomplete outcome data addressed? All outcomes	Low risk	Dropouts and reasons described.
Free of selective reporting?	Low risk	All results reported as prespecified with further report of short term data for secondary outcomes following request.
Free of other bias?	Low risk	Low indication of other bias.