Local Control Phase Three:  EXPLORE

In the third (and most important) phase of LC analysis, the outcomes researcher performs

Systematic Sensitivity Analyses!

Specifically, he/she explores the implications of using alternative ways to form and use clusters.  For example, what are the effects of (simultaneously) varying the following four LC analysis decisions?

[1] choice of total number (size) of clusters,

[2] choice of clustering algorithm / strategy,

[3] choice of patient dissimilarity metric, and

[4] choice of subset (or weighting) of patient X-characteristics.

This third phase can be quite tedious and repetitive if the researcher has to specify each alternative analysis to be performed.  Ideally, software for LC Analysis would minimize the need for user input when performing sensitivity analyses ...via some form of “batch mode” processing.

The primary objective in Phase Three is to identify, say, the three most “interesting” LTD distributions that are typical (representative) of all of the salient LTD distributions that have been identified in sensitivity analyses.  For example, which distribution is typical of the salient distributions most favorable to a treatment?  Which distribution is most representative of the LTD distributions least favorable to a treatment?  And which LTD distribution is most typical of all salient LTD distributions?

Phase Four (REALIZE) analyses should concentrate upon these most typical LTD Distributions.