Validation and reliability of a simplified food frequency questionnaire:A cross sectional study among physical health examination adults in southwest region of China
Abstract Background: In China, many people are apt to participate in regular physical examination as a prevention. Some simplified food frequency questionnaire have been designed and used. However, the accuracy of questionnaire is absent. This study was conducted to examine the reliability and validity of simplified food frequency questionnaire (SFFQ) used among physical examination adults in southwest region of China.Methods: This study was a cross sectional study among physical health examination adults in Southwest region of China. A total of 239 participants aged 20-65 were conducted during February to June in 2019. The performance of the SFFQ was evaluated by the mean of three-day 24-hour dietary record (3R24). The relative validity and agreement was assessed by the Pearson`s correlation and intra-class correlation coefficients(ICC) respectively. Results: The median energy-adjusted ICC of food groups between SFFQ2 and SFFQ1 was 0.59 (range: 0.49-0.73) and the ICC of nutrients was 0.47(range: 0.39-0.76). The Pearson correlation showed the validity between the SFFQ1 and 3R24, which ranged from -0.086 to 0.93 for food and and 0.21 to 0.71 for nutritions, respectively. Energy-adjustment slightly increased the correlation coefficients.Conclusions: The reliability and validity of the SFFQ was acceptable. It could be an appropriate dietary assessment tool for future epidemiological studies among physical health examination adults in southwest China.Trial registration:CHiCTR, ChiCTR1900020934, Registered 22 January 2019, http://www.chictr.org.cn/edit.aspx?pid=35414&htm=4.