Background: Self-report questionnaires play an important role as outcome measures in shoulder research. Having an estimate of the measurement error of these ...

Our aim was to evaluate the reproducibility of a food-frequency questionnaire (FFQ) developed in a French population, and its validity against four 24-h dietary recalls (24-HRs). For most nutrients, ...

Despite extensive use over 40 years, physical activity questionnaires still show limited reliability and validity. Measurements have value in indicating conditions where an increase in physical ...