Tabriz University of Medical Sciences Journal of Cardiovascular and Thoracic Research 2008-5117 15 2 2023 06 29 Analysis of covariance and sample size calculation for comparing means in randomized controlled trials 131 131 10.34172/jcvtr.2023.30497 EN Yousef Alimohamadi https://orcid.org/0000-0002-4480-9827 Mojtaba Sepandi https://orcid.org/0000-0001-6441-5887 LETTER 10.34172/jcvtr.2023.30497 2022 01 13 2023 05 21