Association, cause, and correlation

Abstract

Anything one measures can become data, but only those data that have meaning can become information. Information is almost always useful; data may or may not be. This chapter will address the various ways one can measure the degree of association between an exposure and an outcome and will include a discussion of relative and absolute risk, odds ratios, number needed to treat, and related measures. In addition, this chapter will introduce the concept of causal inference.