DEVELOPMENT AND VALIDATION OF A SIMPLIFIED DIETARY ASSESSMENT TOOL FOR CKD RISK SCREENING IN SINGAPORE

Chronic kidney disease (CKD) is a progressive condition associated with high mortality, particularly in advanced stages. Poor dietary quality represents a modifiable risk factor for CKD development. Traditional dietary assessment methods such as 24-hour dietary recalls and food frequency questionnaires are resource-intensive and less scalable for large population screenings. This study aimed to develop and validate a brief, self-administered dietary assessment tool specifically designed for individuals at high risk for CKD in Singapore’s multi-ethnic population.

Eating behaviours associated with CKD risk were identified through a literature review. A 9-item questionnaire was developed, targeting key dietary components: whole grains, fruits and vegetables, added sugar, salt, processed foods, saturated fat, and eating-out habits. Responses were scored on a 5-point frequency scale, with higher scores indicating better dietary quality. Scores were weighted according to their established association with diabetes and hypertension risk (total score range: 0-48, higher score indicating a superior dietary quality). The tool underwent two-phases validation: initial pilot testing in a CKD screening clinic (n=255), followed by refinement and validation in a larger cohort (n=746) between February 2022 and February 2025. Participants underwent comprehensive assessment including basic demographic, anthropometric measurements, biochemical testing (estimated glomerular filtration rate (eGFR) and HbA1c). Impaired kidney function was defined as eGFR <90 mL/min/1.73m2. Participants provided consent for the use of their results in the study. Internal consistency was evaluated using Cronbach’s alpha and associations between dietary scores and CKD risk were analysed using multivariable binary logistic regression. Statistical significance was set at p<0.05.

The validation cohort comprised 746 adults (mean age 48.4 ± 13.6 years, 56.2% female, 75.7% Chinese ethnicity). Baseline characteristics revealed mean body mass index (BMI) of 25.1 ± 5.0 kg/m², elevated mean waist circumference (females: 84.2 ± 11.7 cm and males: 92.4 ± 11.6 cm), mean HbA1C level of 5.43 ± 0.72%, and 33.1% had at least one comorbidity. Impaired kidney function was present in 35.7% of participants. The questionnaire demonstrated acceptable internal consistency (Cronbach’s alpha = 0.676). Based on the questionnaire, most participants reported healthier behaviours including requesting less or no added sugar in beverages (42.4%) and reduced salt or sauces in meals (48.4%). In multivariable analysis adjusting for age, gender, ethnicity, comorbidities, BMI, waist circumference and HbA1c, each one-point increase in dietary quality score was associated with a significant 2.7% reduction in odds of impaired kidney function (OR=0.97, 95% CI:0.95-1.00, p=0.028).

This novel 9-item dietary assessment questionnaire demonstrates moderate reliability and significant association with kidney function in a diverse Asian population. The tool offers a practical, scalable approach for dietary risk assessment in CKD prevention programmes and popular health screening initiatives. Further research should focus on enhancing reliability through item refinement and validating predictive capacity for CKD progression outcomes.