Flora Z Statistic


I am a Post-Graduate Surgical Resident working on my Thesis. I need to analyze my data using the 'Flora Z Statistic'. Unfortunately even the statisticians I have met with have no idea what this is. Earlier studies that have used this method give their results but not how to actually use the formula.

I am in urgent need of assistance as my whole Thesis depends on this. I hope one of you can give me the correct formula and how to calculate it. As much information as possible please.

Hoping for your help.

The following is the formula for flora Z statistics.

Z = Actual survival - predicted survival
sqrt(predicted survival * predicted deaths)

I hope you might be using this for trauma cases.In that case you will have to use TRISS method to calculate the predicted survival and predicted deaths


Yes, my Thesis is on "efficacy of trauma scoring systems in predicting survival outcome" at my hospital. I have to calculate the Probability of survival using Revised Trauma Score (RTS) and Injury Severity Score(ISS).

RTS is the physiologic component of TRISS. In order to calculate it, I need to use the Abbreviated Injury Scale (AIS 90) coding system. I have been able to dig up most if the codes from several articles and sites on the internet. But so far failed to get a complete list of the codes in one place that I can give a reference to in my Thesis. Even those I have got are not the full codes.

If you are aware of any way I can get this, I would be most grateful.

Thanks again.
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