The thorny issue of using questionnaires in health claim-targeted RCTs.

Questionnaires are often used in clinical and nutritional research to subjectively evaluate the effect of an intervention on an outcome measure or e.g. to select a study population with specific characteristics from a larger pool of potential study participants. Nevertheless, their thoughtless application in health claim-targeted studies have frequently resulted in EFSA dismissing the outcomes generated by these questionnaires. Validation […] >> read more