A new ratio for protocol categorization (Q2262473)

Summary: The present review describes and validates a new ratio `` \(S\)'' created for matching predictability and balance between TP and TN. Validity of \(S\) was studied in a three-step process as follows: (i) \(S\) was applied to the data of a past study predicting cardiac output response to fluid bolus from response to passive leg raise (PLR); (ii) \(S\) was comparatively analyzed with traditional ratios by modeling different 2 * 2 contingency tables in 1000 hypothetical patients; (iii) precision of \(S\) was compared with other ratios by computing random fluctuations in the same patients. In comparison to other ratios, \(S\) performs better in predicting the cardiac response to fluid bolus and supports more directly the clinical conclusions. When the proportion of false responses is high, \(S\) is close to the coefficient correlation (CC). When the proportion of true responses is high, \(S\) is the unique ratio that identifies the categorization that balances the proportion of TP and TN. The precision of is close to that of CC. In conclusion, \(S\) should be considered for creating categories from quantitative variables; especially when matching predictability with balance between TP and TN is a concern.