Simple Likelihood Ratio Calculations Farrokh Alemi, PhD 10/1/2018 2:51 PM
Weighted Average for Patients SELECT SUM(Data.LOS*CAST (N AS FLOAT)) / SUM(CAST (N AS FLOAT) AS AvgLOS INTO AvgMI FROM Data;
Count Combination of MI & Stay SELECT SUM(Data.N) AS Number-Cases , Sum(N*[MI]*IIf([LOS]>[AvgLOS],1,0)) AS MIandLong , Sum(N*[MI]*IIf([LOS]<=[AvgLOS],1,0)) AS MIandShort , Sum(N*(1-[MI])*IIf([LOS]>[AvgLOS],1,0)) AS NotMIandLong , Sum(N*(1-[MI])*IIf([LOS]<=[AvgLOS],1,0)) AS NotMIandShort INTO CountCombination FROM AvgMI, Data;
Calculate Likelihood Ratio SELECT ([MIandLong]/([MIandLong]+[NotMIandLong])) / ([MIandShort]/([MIandShort]+[NotMIandShort])) AS LRforMI FROM CountCombination;