HSS 2381 Chapter Notes - Chapter 4: Absolute Risk Reduction, Relative Risk Reduction, Odds Ratio

• School: University of Ottawa
• Department: Health Sciences
• Course: HSS 2381
• Professor: Eleanor Riesen

Document Summary

Chapter 4: bivariate description: crosstabulation, risk indexes, and correlation. Bivariate descriptive statistics: are used to describe relationships between 2 variables. Examples: 1) height & weight & 2)smoking status & lung cancer incidence. App(cid:396)op(cid:396)iate statisti(cid:272) depe(cid:374)ds o(cid:374) the (cid:448)a(cid:396)ia(cid:271)les" le(cid:448)el of (cid:373)easu(cid:396)e(cid:373)e(cid:374)t. Researchers crosstabulate frequencies of all categories of 2 variables in 2-dimensional frequency distribution & results are displayed in a contingency table (crosstab table) Crosstabulated variables should be nominal level (or ordinal level with a small # of categories) Crosstab tables: described by number of categories of 1st variable [x by 2nd variable categories] Number of cells in the table is the product of the two sets of categories: Ex: 2 dichotomous variables (male/female/nonsmoker) summarized by 2 x 2 counts/: dichotomous: 2 x 2 table =4 cell; 3x3 table=9. Get column % by dividing variable column by column total x 100. Example of a crosstab table: how to read cells in a crosstab table: