Publication
Estimating mean population salt intake in Fiji and Samoa using spot urine samples
Publisher:
Springer Science and Business Media LLC
Date:
10-09-2019
DOI:
10.1186/S12937-019-0484-9
Abstract: There is an increasing interest in finding less costly and burdensome alternatives to measuring population-level salt intake than 24-h urine collection, such as spot urine s les. However, little is known about their usefulness in developing countries like Fiji and Samoa. The purpose of this study was to evaluate the capacity of spot urine s les to estimate mean population salt intake in Fiji and Samoa. The study involved secondary analyses of urine data from cross-sectional surveys conducted in Fiji and Samoa between 2012 and 2016. Mean salt intake was estimated from spot urine s les using six equations, and compared with the measured salt intake from 24-h urine s les. Differences and agreement between the two methods were examined through paired s les t-test, intraclass correlation coefficient analysis, and Bland-Altman plots and analyses. A total of 414 participants from Fiji and 725 participants from Samoa were included. Unweighted mean salt intake based on 24-h urine collection was 10.58 g/day (95% CI 9.95 to 11.22) in Fiji and 7.09 g/day (95% CI 6.83 to 7.36) in Samoa. In both s les, the INTERSALT equation with potassium produced the closest salt intake estimate to the 24-h urine (difference of − 0.92 g/day, 95% CI − 1.67 to − 0.18 in the Fiji s le and + 1.53 g/day, 95% CI 1.28 to 1.77 in the Samoa s le). The presence of proportional bias was evident for all equations except for the Kawasaki equation. These data suggest that additional studies where both 24-h urine and spot urine s les are collected are needed to further assess whether methods based on spot urine s les can be confidently used to estimate mean population salt intake in Fiji and Samoa.