Advertisement

Development and validation of a food frequency questionnaire to assess potassium intake of patients on hemodialysis

Published:October 18, 2022DOI:https://doi.org/10.1053/j.jrn.2022.10.002
      This paper is only available as a PDF. To read, Please Download here.

      Abstract

      Objective

      To develop and to validate a food frequency questionnaire (FFQ) to assess potassium intake of patients on hemodialysis (HD).

      Methods

      This is a cross-sectional study that included 41 patients in the FFQ development step and 53 patients in the FFQ validation step. In the FFQ development step, the patients completed a three-day food record (used as a reference method). Total potassium intake and potassium from each food item were calculated. Food items that contributed up to 90% of the total potassium intake were considered to be included in the FFQ food list. Then the FFQ was applied in person through the google-forms platform. The result of potassium intake obtained by the FFQ was compared with that obtained by the three-day food record.

      Results

      A total of 94 patients were included, 53.2% women; age 55.7±15.0 years; 47.9% had diabetes; body mass index 25.0±4.5 kg/m2 and dialysis vintage 34.5 (17.0-68.2) months. Demographic, clinical and laboratory parameters did not differ between the development and validation groups. From the 255 registered food items, 85 comprised the FFQ. The standardized Cronbach’s alpha obtained was 0.71. No difference was found between the potassium intake obtained by the FFQ and by the three-day food record (1,438.5±659.4 mg/d vs. 1,464.8±529.4mg/d; p=0.753 respectively) with an intraclass correlation coefficient of 0.66 (p=0.001). No systematic bias or proportionality bias between the methods was observed in the Bland-Altman graphical analysis.

      Conclusion

      The quantitative FFQ presented strong relative validity and may constitute a practical tool in the analysis of potassium intake of patients on hemodialysis.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Journal of Renal Nutrition
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect