Popular Statistical Tests for Investigating the Relationship between Two Variables in Medical Research

Dear Editor in Chief, Recently, using statistical tests as useful and ubiquitous tools in medical data analysis is increasing (1). However, some researchers are using statistical methods without sufficient knowledge. The purpose of this letter is to provide applied information on some of the most commonly used statistical tests. All statistical tests examine a hypothesis. A hypothesis is defined as a claim that its accuracy or inaccuracy is unknown (2). In general, variables are divided into quantitative and qualitative categories (3). Some popular statistical tests that examine the relationship between two or more variables are summarized bellow according to the main purpose of this article.