Koopman et al (referring to Harrell) developed a risk score starting from the odds or hazard ratios for a study.
Points made by Harrell with respect to developing a score:
(1) odds ratios should be multipled, not added together.
(2) logarithms can be added
Starting point: study with odds or hazard ratios
Protocol:
(1) Take the natural logarithm for the odds or hazard ratio.
(2) Multiply this by 10.
(3) Round to the nearest integer.
