CARE 2013 explanations and elaborations: Reporting guidelines for case reports by Riley, D, Barber, M, Kienle, G, Aronson, J, von Schoen-Angerer, T, Tugwell, P, Kiene, H, Helfand, M, Altman, D, Sox, H, Werthmann, P, Moher, D, Rison, R, Shamseer, L, Koch, C, Sun, G, Hanaway, P, Sudak, N, Kaszkin-Bettag, M, Carpenter, J, Gagnier, J