PT  - JOURNAL ARTICLE
AU  - D H Staniforth
AU  - D Rose
TI  - Statistical analysis of the lactulose/breath hydrogen test in the measurement of orocaecal transit: its variability and predictive value in assessing drug action.
AID  - 10.1136/gut.30.2.171
DP  - 1989 Feb 01
TA  - Gut
PG  - 171--175
VI  - 30
IP  - 2
4099  - http://gut.bmj.com/content/30/2/171.short
4100  - http://gut.bmj.com/content/30/2/171.full
SO  - Gut1989 Feb 01; 30
AB  - The variability in the orocaecal transit time as measured by the lactulose/breath hydrogen method has been studied for three conditions: lactulose given with a meal, subjects sitting; lactulose given with a meal, subjects semirecumbent; lactulose given in aqueous solution, subjects semirecumbent. Thirty three healthy subjects attended on up to 12 occasions. It was found that administration of the lactulose with a meal significantly reduced the variability (p less than 0.05) and that adoption of the semirecumbent position further reduced variability. A power analysis was used to predict the number of subjects who would be required to show a given percentage change in orocaecal transit time at specified probabilities and powers. A graph and a table for use in the prediction of subject numbers at a probability of 5% and for powers of 50-99% is presented. A dose response curve for metoclopramide using the lactulose/breath hydrogen method is given for doses of 10, 15, and 20 mg.