Figure 3From: The impact of attrition on the representativeness of cohort studies of older people Changes to prevalence of the hypothetical risk factor, assuming no association between the risk factor and the risk of death, in the population or the cohort; an association between the risk factor and non-death attrition in the cohort. Figure 3A assumes no bias and Figure 3B assumes lower prevalence of the risk factor at the beginning of the study.Back to article page