Appendix 2 - A glossary of epidemiological terms

Summary

Introduction

This glossary contains a sample of the terms used in epidemiology. The definitions given below are based on those provided by Last (1988). For further details, other sources should be consulted (Stedman, 1982; Friedman, 1980; Lilienfeld & Lilienfeld, 1980; Kendall & Buckland, 1982; Abramson, 1984; Murphy, 1985; Pressat, 1985; Last, 1986; Schuman, 1986; Jammal et al., 1988).

Glossary of terms

Adjustment a procedure in which potentially misleading effects of differences in the composition of populations being compared have been minimized – as much as is possible – by statistical methods. The mathematical procedure commonly used to adjust incidence or mortality rates for age differences is direct or indirect standardization.

Age-specific rate a rate calculated for a specific age-group, i.e., the numerator and denominator refer to the same age group. A multiplier, usually 100,000, is chosen to produce a rate that can be expressed as a convenient number.

Analytical study a study designed to examine hypothesized causal relationships. An analytical study is usually concerned with identifying the health effects of specific risk factors. In this type of study, individuals are classified either according to the absence or presence of a specific disease and/or according to the presence or absence of risk factors presumed to influence disease occurrence.