Barriers and potential solutions in the recruitment and retention of older patients in clinical trials - lessons learned from six large multicentre randomized controlled trials

Buttgereit Thomas, Andriko Palmowski, Noah Forsat, Maarten Boers, Miles D. Witham, Nicolas Rodondi, Elisavet Moutzouri, Antonio Jesus Quesada Navidad, Arnoud W J Van't Hof , Bart van der Worp, Laura Coll-Planas, Marieke Voshaar, Maarten de Wit, José da Silva, Sven Stegemann, Johannes W Bijlsma , Markus Koeller, Simon Mooijaart , Patricia M Kearney , Frank Buttgereit^*