An aid in assessing whether a risk factor might be a worthwhile screening test

Risk-Screening Converter (RSC2)

Many risk factors for disease are suggested as screening tests when there is no prospect that they could be useful in screening. To avoid this it is useful to know the quantitative equivalence between the value of a risk factor and its screening performance in terms of the detection rate (sensitivity) for a specified false-positive rate.

Here is an interactive risk-screening converter that does this. It is intended for people engaged in research into risk factors and disease and for those who give advice on applying such research findings into medical practice. It should help to distinguish effective screening methods from relatively ineffective ones and so improve clinical guidelines relating to screening and the prediction of disease.

The Risk-Screening Converter was first described in: Wald, N.J. and Morris, J.K., 2011. Assessing risk factors as potential screening tests: a simple assessment tool. Archives of internal medicine, 171(4), pp.286-291. This was the first version of the Risk-Screening Converter, RSC1

A Risk-Screening Converter (RSC2) with additional features was made available from 14th January 2022 which complements the original converter RSC1. The converter was developed by Steve Vale (Logical Medical Systems Ltd) and Nicholas Wald (University College London) with contributions from Joan Morris, Glenn Palomaki and Aroon Hingorani.

The Risk-Screening Converter (RSC2) can be accessed here.

The additional features in RSC2 compared to RSC1 include:

• RSC2 also allows the area under curve (AUC) and the odds ratio per standard deviation as well as odds ratio comparing highest group with lowest group to be entered as risk measures.
• RSC2 adds flexibility in the inter-conversion between risk measures and measures of screening performance (detection rate and false positive rate).
• RSC2 allows the standard deviations of the unaffected and affected test variable distributions to be different.
• RSC2 can be used on any computer with a web browser and does not require Microsoft Excel on the computer.

Risk Screening Converter (RSC1)

As indicated above, RSC1 is described in: Wald, N.J. and Morris, J.K., 2011. Assessing risk factors as potential screening tests: a simple assessment tool. Archives of internal medicine, 171(4), pp.286-291. In order to maintain consistency with the publication we retain RSC1 here and provide instructions on how it can be accessed and used.

Download the risk-screening converter here.

If you are using Chrome™ for your Internet browser, click the 'riskscreeningconverter' icon at the bottom-left corner of the screen.

If you are using Internet Explorer for your Internet broswer, click the 'Open' button at the bottom of the screen.

Then choose the option you want by clicking the appropriate pink box, enter the numbers you select in the green boxes and press the 'Return' key or click anywhere on the screen to complete the risk-screening conversion.