Comparing healthy controls and patient's with Barrett's oesophagus using automated cluster analysis

Dr K R. Haylett et al. see  recent AGIP/IPEM presentation  for details:

Contents

Results of Barretts v Control study including Example 1

This example shows how the visualisation technique together with post cluster classification can be used to compare clinical groups. The figures below show the results of comparing the ambulatory manometry between patients with confirmed Barrett's oesophagus (red) and healthy controls (blue). Three simple post cluster classifications were used i.e. the overall plot shows Primary, Secondary and Non peristaltic events between the two groups.

It can easily be seen that the groups form different clusters, with a small degree of overlap. It can be hypothesised that the outliers in the healthy controls group (volunteers with no known problem) should be screened or monitored for Barrett's i.e. this technique could be used a tool to identify candidates at a risk of developing Barrett's that require entry into a screening programme etc. The statistical tests are shown below.
 

Overall plot

 

Comparison of number of primary swallows

Mean number of primary swallows
Barrett's =   334.6875, Controls =   1054.1
Results of Student T-test (= var) P =  2.5578e-004
Results of Student T-test (# var) P =  7.2077e-005

 

Comparison of number of secondary swallows

Mean number of secondary persistaltic
Barrett's =   190.2500, Controls =   591.6923
Results of Student T-test (= var), P =  2.5578e-004
Results of Student T-test (# var), P =  7.2077e-005

 

Comparison of number of non peristaltic events

Mean number of non peristaltic
Barrett's =   3.5285e+003 Controls =   2.5925e+003
Results of Student T-test (= var) P =   2.5578e-004
Results of Student T-test (# var) P =  7.2077e-005

Box plot comparing selected example with Barretts & Controls

Primary	= 1062, Secondary = 606, Unclassified	= 2983
(distance between cluster centre and example)
d1 = 3.0402e+003 
d2 = 1.9865e+003
Conclusion: Closer to normal than Barrett's

Back to http://www.medeng.net