Performance feedback on the quality of care in hospitals performing thrombectomy for ischemic stroke (PERFEQTOS): protocol of a stepped wedge cluster randomized trial oleh Marzyeh Amini, Sanne J. den Hartog, Nikki van Leeuwen, Frank Eijkenaar, Laurien S. Kuhrij, Lotte J. Stolze, Paul J. Nederkoorn, Hester F. Lingsma, Adriaan C. G. M. van Es, Ido R. van den Wijngaard, Aad van der Lugt, Diederik W. J. Dippel, Bob Roozenbeek, on behalf of the PERFEQTOS Investigators