Royal Prince Alfred Hospital Royal Prince Alfred Hospital
Allergy Unit

Student Research


The analysis of group and single person food intolerance reactions

by
Tim Watkins
Master of Biostatistics (MBiostat)
The University of Sydney

Supervisor: Patrick Kelly
February 2012

pdf Full Text (Part 2 only) - PDF (1,842 KB)

Brief summary

Part 1 of this project used mixed effects logistic regression to analyse food chemical capsule challenge results from patients of the RPAH Allergy Unit suspected of having food intolerance, to test if any of these chemicals triggered skin reactions that appeared to improve on an elimination diet. Most patients took multiple challenges, often more than once, and very few took every challenge which resulted in multiple as well as missing values and some within-patient correlation of outcomes. The aim was to determine if the active challenges were more likely to trigger skin reactions than the placebo challenges. A number of patient characteristics such as sex and age were added to the model as potential confounders.

In Part 2, a control chart is firstly used to analyse a single patient’s elimination diet response. Then an ARIMA time series model is developed to analyse a single food intolerant person’s long term diet and related health data in an attempt to determine factors contributing to or protective of a particular recurring symptom. The analysis had the sole aim of providing health advice to that person.