Greenbaum 2007.

Methods	Study design: parallel RCT Time frame: 2001 to 2003 Follow‐up period: 12 weeks after 2 to 6 weeks washout Loss to follow‐up: 17 did not complete study but included in analysis 0% (0/29)
Participants	Country: USA Setting: national, multicentre HD for at least 1 month; PTH ≥ 300 pg/mL; Ca ≤ 10.5 mg/L, Ca x P ≤ 70 after 2 to 6 weeks run‐in Number (randomised/completed): treatment group (15/10); control group (14/2) Mean age ± SD (years): treatment group (13.6 ± 4.76); control group (14.3 ± 4.15) Sex (M/F): treatment group (13/2); control group (5/9) Exclusion criteria: allergy to paricalcitol or other vitamin D; pregnant; nursing; other major illness; AKI in previous 3 months; partial parathyroidectomy in previous 12 months; aluminium binders in past 3 months or likely to need binders; poor compliance; drugs likely to affect bone metabolism
Interventions	Treatment group IV paricalcitol: (0.04 µg/kg if PTH ≤ 500, and 0.08 µg/kg if PTH ≥ 500) 3 times/week for 12 weeks Dose altered according to Ca and P levels Control group IV placebo: 3 times/week for 12 weeks Dose altered according to Ca and P levels Co‐interventions Phosphate binders through study; dialysate Ca maintained at 2.5 mmol/L or 3 mmol/L through study
Outcomes	Proportion with > 30% fall in PTH on 2 consecutive occasions Mean change in PTH levels Mean changes in serum Ca, phosphorus, Ca x P levels
Notes	Patients discontinued after 4 weeks if had 2 PTH levels > 700 pg/mL 10 withdrawn from placebo and 4 from paricalcitol groups for increased PTH
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Central randomisation
Allocation concealment (selection bias)	Low risk	Central randomisation
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Placebo and active medication given IV after dialysis
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Placebo and active medication given IV after dialysis; Primary outcome was laboratory based
Incomplete outcome data (attrition bias) All outcomes	Low risk	12 (41%) prematurely withdrawn (5 treatment; 10 placebo) but these patients included in evaluation of primary outcome
Selective reporting (reporting bias)	Low risk	All relevant laboratory outcomes are included
Other bias	High risk	Supported by Abbott Laboratories