One of the requirements of Modified Condition and Decision Coverage (MCDC) is that test cases should be selected to demonstrate that a condition can independently affect the outcome of a decision. However, it is known that test cases cannot be selected to satisfy this <i>"independently-affect"</i> requirement when a decision contains strongly coupled conditions. Researchers have proposed various forms of MCDC in addressing this issue. In last 20 years, these variant MCDC forms have been discussed and applied as test data adequacy criteria in white-box testing, and as fault revealing techniques in empirical studies. In this paper, we performed a systematic literature review (SLR) on these MCDC variants. By clarifying the existing meanings of these variants, we are able to define another MCDC form. Moreover, we performed an empirical study to compare the fault detecting ability of this new form with other existing MCDC variants. The results showed that this new form of MCDC has a higher fault detecting ability than the others.