Guidelines for reporting trial protocols and completed trials modified due to the COVID-19 pandemic and other extenuating circumstances: the CONSERVE 2021 statement by Orkin, AM, Gill, PJ, Ghersi, D, Campbell, L, Sugarman, J, Emsley, R, Steg, PG, Weijer, C, Simes, J, Rombey, T, Williams, HC, Wittes, J, Moher, D, Richards, DP, Kasamon, Y, Getz, K, Hopewell, S, Dickersin, K, Wu, T, Ayala, AP, Schulz, KF, Calleja, S, Boutron, I, Ross, JS, Golub, RM, Khan, KM, Mulrow, C, Siegfried, N, Heber, J, Lee, N, Kearney, PR, Wanyenze, RK, Hróbjartsson, A, Williams, R, Bhandari, N, Jüni, P, Chan, A-W