In studies of child development, the combined effect of multiple risks acting in unison has been represented in a variety of ways. This investigation builds upon this preceding work and presents a new procedure for capturing the combined effect of multiple risks. A representative sample of 2,899 British children had their cognitive development measured at 36 and 58 months of age along with 10 potential risks during this period of development. Comparing a cumulative index of these risks against the previously undocumented alternative of confirmatory factor analysis using formative measurement, this study found differences favouring the factor analysis. The factor analysis procedure demonstrated greater predictive power of children's cognitive development while it systematically tested two of the assumptions implicit in cumulative risk indices.