Knowles et al developed a scoring system for evaluating a patient with consitpation. The authors are from St. Bartholomew's, Royal London School of Medicine and Dentistry, Queen Mary and Westfield College and the Royal College of Surgeons of England.
Patient selection: constipation (age range not specified)
Parameters:
(1) duration of constipation: from 0 to 4
(2) laxative use: from 0 to 3
(3) frequency of bowel movement: from 0 to 3
(4) abdominal pain: from 0 to 4
(5) time taken in the lavatory per attempt in minutes: from 0 to 3
|
Parameter
|
Slow Transit Constipation Coefficient
|
Mixed Coefficient
|
Rectal Evacuation Disorder Coefficient
|
|
duration
|
1.766
|
1.475
|
0.969
|
|
laxative use
|
0.666
|
0.882
|
-0.005
|
|
frequency
|
0.447
|
-0.007
|
-1.484
|
|
abdominal pain
|
1.039
|
1.035
|
1.899
|
|
time taken
|
0.339
|
1.169
|
2.003
|
discriminant value for slow transit constipation
= SUM((score for parameter) * (coefficient)) - 6.566
discriminant value for mixed
= SUM((score for parameter) * (coefficient)) - 6.233
discriminant value for rectal evacuation disorder =
= SUM((score for parameter) * (coefficient)) - 5.813
Interpretation:
• The disorder with the maximum discriminant value is the diagnosis.
Performance:
• The area under the ROC curve for rectal evacuation disorder was 0.91.
