Figure 1From: Categorisation of continuous risk factors in epidemiological publications: a survey of current practiceExample from the survey: categorical results displayed as a figure. Relative risk (& 95% CI) for coronary events by quintiles of NO2 (μg/m3) exposure [17]. Reference category is bottom fifth, trend line is fitted. More emphasis given to quantitative analysis. This image is reproduced with permission from Epidemiology.Back to article page