Study protocol for a randomised controlled trial examining the effect of blood and plasma donation on serum perfluoroalkyl and polyfluoroalkyl substance (PFAS) levels in firefighters.

Introduction: Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a diverse group of compounds that have been used in hundreds of industrial applications and consumer products including aqueous film-forming foam (AFFF) for many years. Multiple national and international health and environmental agencies have accepted that PFAS exposures are associated with numerous adverse health effects. Australian firefighters have been shown to have elevated levels of PFAS in their blood, specifically perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS), due to the historical use of AFFF.

Do patients who take part in stroke research differ from non-participants? Implications for generalizability of results.

Background: Stroke is one of the most disabling neurological conditions. Clinical research is vital for expanding knowledge of treatment effectiveness among stroke patients. However, evidence begins to accumulate that stroke patients who take part in research represent only a small proportion of all stroke patients.