Veracity of Calculators: was ....... Question on doubling time

[Guest guest]

PSA doubling time calculators do not depend upon 'studyies', but rather just the

math in calculating the representation of log PSA versus time. There can be

small differences from calculator to calculator depending upon how they handle

the timer series for multiple PSA readings.

Calculators estimating odds of recurrence for various treatments, usually called

'nomograms', do depend upon the study data used to derive them. The reliable

ones will have references as to their data sources.

The Best to You and Yours!

Jon in Nevada

>

> Apart from the fact that this still does not address Lynn's question, I

> think care should be taken in using any calculators, especially where it is

> not clear upon what data they have been based. There was one calculator I

> looked some time back that seemed to have been developed from a study with

> less than 50 men in it. Not a very sound basis for extrapolation of data.