Better understanding of ‘don’t confuse absence of evidence with evidence of absence’

Abstract

| INTRODUCTION: In every single lecture or text book of Evidence-based Health-care and research synthesis, we invariably find references to the aphorism “absence of evidence does not mean absence of effect”. However, we have not rarely found those who forget, ignore or put this aphorism aside while interpreting results from research on healthcare. The objective of this text is to clarify the concepts underlying this aphorism, such as absence of evidence and absence of effect.