Validation and reproducibility of a semi-qualitative food frequency questionnaire for assessment of sodium intake in Iranian population

Abstract

Background Few semi-quantitative food frequency questionnaires (SFFQ)s has yet been developed to assess sodium intake in Middle East region. This study was performed to validate a SFFQ for assessment of sodium consumption and food groups΄ contribution to sodium intake. Methods This study was performed on 219 healthy participants including 113 adults aged ≥19 years and 106 children aged 6–18 years in Isfahan, Iran. They were administered two SFFQ at the beginning and after 1 year to evaluate the reproducibility. The validity of SFFQ for assessment of sodium intake was compared with 24-h urine sodium and twelve 24-h dietary recalls which were completed monthly during a year as two standard methods. Results Correlation coefficient between the contribution of food groups to sodium intake based on SFFQ and 24-h dietary recalls varied from 0.04 for legumes (P = 0.667) to 0.47 for added salt (P < 0.001). There was a significant correlation between the estimated total sodium intake based on SFFQ and both standard methods (P < 0.01). Intraclass correlation coefficient (95% CI) between first and second SFFQ had a diverse range from 0.10 (-0.05, 0.17) for fats and oils to 0.49 (0.28, 0.69) for bread. According to the Bland-Altman plots, we observed an acceptable level of agreement between the two methods for sodium intake. Conclusions The SFFQ was a relatively valid and reproducible method for estimating sodium intake. Combination of this SFFQ with a valid prediction of 24-h urinary sodium excretion can be useful in achieving more accurate results.

Be aware of the sodium intake outside student canteens: development and validation of a sodium food frequency questionnaire in Chinese undergraduates

“…Consistency with the previous works ( 14 , 15 , 17 , 24 , 25 , 33 , 34 , 37 , 41 ), the correlation coefficient between the Sodium-FFQ and 3-day dietary records were 0.393 ( Spearman ) and 0.485 (de-attenuated), respectively. The correlation coefficients between Sodium-FFQ and 24 h U Na were lower than Sodium-FFQ with dietary records; this was in line with the existing studies (ranging from 0 to 0.37) ( 15 , 24 , 25 ).…”

“…The current study demonstrated an acceptable reproducibility of the Sodium-FFQ, consistent with those of other studies ( 12 , 34 ). The intra-group correlation coefficient ( ICC ) also revealed a moderate association between the test and retest of 0.571, within the range of previous studies from 0.43 to 0.97 ( 33 , 34 , 37 ). The ICC varies significantly among studies might be because of the test–retest interval ( 25 ), sample size ( 10 , 24 ), dietary disparities ( 38 ), and sex and age differences of subjects ( 13 , 33 ).…”

“…The intra-group correlation coefficient ( ICC ) also revealed a moderate association between the test and retest of 0.571, within the range of previous studies from 0.43 to 0.97 ( 33 , 34 , 37 ). The ICC varies significantly among studies might be because of the test–retest interval ( 25 ), sample size ( 10 , 24 ), dietary disparities ( 38 ), and sex and age differences of subjects ( 13 , 33 ). In our study, taking the day-to-day variation of sodium intake and excretion ( 39 , 40 ), as well as the possibility of high compliance ( 10 ), 2 weeks were chosen ( 12 , 30 , 34 ) to represent the short-term stability of it.…”

“…Moreover, the difference between 24 h U Na and dietary records were consistently observed in previous studies ( 12 , 15 , 29 ). The extensive distribution of sodium in natural foods, variation in the proportion of salt retained in food, the widespread utility of sodium compounds in food process and medication, as well as uncommon foods unlisted in food composition tables, could contribute to such a difference, too ( 25 , 32 , 33 ).…”

A Need for Improvement in the Definition of Resistant Arterial Hypertension

“…The sixth shortcoming is the absence of a criterion describing the degree in which healthy lifestyle measures need to be fulfilled to allow us to say it is sufficient to change the diagnosis from "apparent treatment-resistant HTN" to the "resistant HTN". For example, how should we check patients' salt intake in everyday practice: 24-h urinary sodium excretion, food frequency questionnaire, spot urine collection, or another tool [33,[37][38][39][40]? How realistic are self-reports?…”