Personalising Outcomes after Child Cardiac Arrest (POCCA): design and recruitment challenges of a multicentre, observational study by Elizabeth Hunt, Katie Smith, Neha Patel, Ericka L Fink, Robert S B Clark, Ashok Panigrahy, Rachel Berger, Jessica Wisnowski, Stefan Bluml, David Maloney, Pamela Rubin, Tamara Haller, Hulya Bayir, Sue R Beers, Patrick M Kochanek, Anthony Fabio, Patrick Kochanek, Robert Clark, Sue Beers, Tony Fabio, Karen Walson, Alexis Topjian, Christopher JL Newth, Jordan Duval-Arnould, Binod Balakrishnan, Michael T Meyer, Melissa G Chung, Anthony Willyerd, Lincoln Smith, Jesse Wenger, Stuart Friess, Jose Pineda, Ashley Siems, Jason Patregnani, John Diddle, Aline Maddux, Lesley Doughty, Juan Piantino, Beena Desai, Maureen G Richardson, Cynthia Bates, Darshana Parikh, Janice Prodell, Maddie Winters, Jeni Kwok, Adriana Cabrales, Ronke Adewale, Pam Melvin, Sadaf Shad, Katherine Siegel, Katherine Murkowski, Mary Kasch, Josey Hensley, Lisa Steele, Danielle Brown, Brian Burrows, Lauren Hlivka, Deana Rich, Amila Tutundzic, Tina Day, Lori Barganier, Ashley Wolfe, Mackenzie Little, Elyse Tomanio, Diane Hession, Yamila Sierra, Ruth Grosskreuz, BS Kevin Van, Rhonda Jones, Laura Benken, Beata Dyar, Laura Mishler, Jonathan Elmer, Subramanian Subramanian, Julia Wallace, Tami Robinson, Andrew Frank, Keri Feldman, Avinash Vemulapalli, Linda Ryan, Scott Szypulski, Christopher Keys