Table 1

Uses of predictive risk algorithms in the population setting

 Uses Calculation method Projection Estimate the number of people who will develop a disease or condition (for people without the disease) or disease complication (for people with the disease) Calculate baseline risk for a population-based sample of people Description Describe the level of risk diffusion in the population—whether population risk is diffused or concentrated Plot baseline risk for population deciles and/or calculate gini coefficient and related terms Describe the change in population risk over time Calculate baseline risk at different time periods Identify target populations at high baseline risk Calculate baseline risk for a population-based sample of people Categorise the population into different levels of baseline risk Evaluation Estimate the population health benefit of interventions Population health benefit = target population size × baseline risk × relative bvenefit Estimate the population health benefit of risk factor reduction Recalculate population baseline risk assuming risk factor exposure is reduced or eliminated; or, the same as the estimate of health benefit of interventions: population risk factor reduction benefit = target population size × baseline risk × relative reduction of outcome per unit of risk factor reduction × units of risk factor reduction Estimating the contribution of risk factor levels on future population risk Same as above