Methods |
|
Participants |
Country: USA
Setting: clinical research centre
Diagnostic criteria: eGFR of 15‐59 mL/min/1.73 m2 on the basis of the Modification of Diet in Renal Disease equation, and had normal phosphate levels (2.5 to 4.6 mg/dL)
Number: treatment group A (10); control group A (10); treatment group B (8); control group B (11)
Mean age ± SD (years): treatment group A (56.2 ± 10.1); control group B (55.1 ± 12.6); treatment group B (56.1 ± 10.0); control group B (54.3 ± 9.8)
Sex (M/F): treatment group A (7/3); control group A (5/5); treatment group B (5/3); control group B (8/3)
Comorbidity: not reported
Exclusion criteria: hyperphosphataemia; rapidly advancing CKD, primary hyper‐ or hypoparathyroidism or prior parathyroidectomy; malabsorption; malnutrition, liver disease; cholestasis; anaemia; received prior counselling by a nutritionist within 6 months; taking phosphate binders; hospitalised within the previous 4 weeks; pregnant or breastfeeding mothers; unable to provide written informed consent
|
Interventions |
All participants met with the dietitian, who provided personalized dietary recommendations during a 60‐minute session at the randomisation visit and at 30‐minute follow‐up visits during weeks 2, 8, and 12, when adherence with the dietary intervention was reassessed with 3‐day food records. Dietitian used the food records to counsel participants to follow a diet tailored to their randomisation group. Treatment group A
Control group A
Treatment group B
Control group B
|
Outcomes |
Serum phosphorus (mg/dL)
FGF‐23 (RU/mL)
PTH (pg/mL)
|
Notes |
Funding: "supported by a grant from Shire Pharmaceuticals and by grants from the National Institutes of Health and the National Institute of Diabetes and Digestive and Kidney Diseases: K23DK087858 (T.I.), R01DK076116 (M.W.) and R01DK081374 (M.W.)"
"Shire Pharmaceuticals gave full rights of publication to the investigators. Shire did review the manuscript but did not participate in the conceptual design, data analysis, interpretation of the results, or writing of the manuscript"
|
Risk of bias |
Bias |
Authors' judgement |
Support for judgement |
Random sequence generation (selection bias) |
Unclear risk |
Not reported |
Allocation concealment (selection bias) |
Unclear risk |
Not reported |
Blinding of participants and personnel (performance bias)
All outcomes |
High risk |
Dietitian and participants were unblinded to the assigned dietary counselling group |
Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
The investigators remained blinded to the dietary group |
Incomplete outcome data (attrition bias)
All outcomes |
High risk |
Imbalance in numbers and reasons for missing data across intervention groups |
Selective reporting (reporting bias) |
High risk |
Data did not show all of the study's pre‐specified primary outcomes |
Other bias |
Unclear risk |
Insufficient information to permit judgement |