Table 1.

Model Inputs: Parameters

Parameter	Value	Range	References
Odds Ratio (OR) for Effect of Obesity on Prevalence/ Incidence
GERD Symptoms Prevalence	1.94	1.0–4.0	(2–3, 6, 8, 24–26)
BE Prevalence	*	0.99–4.0	(9, 24, 27–33)
EAC Incidence	2.78	1.0–5.4	(6–7, 20, 34–38)
Population Prevalence (%)
GERD Symptoms Prevalence	18.6	17.6–19.9	(39–49)
BE Prevalence	4.2	0.8–25	(40, 50–58)
Annual Transition Rates Between Health States
Normal to GERD Symptoms	Derived From Calibration	Derived From Calibration
Normal to BE	``	``
GERD to BE	``	``
BE to Undetected EAC	``	``
Undetected EACs detected (per year)	25%	11–100%	(59–60)

This table describes the literature-derived values and ranges used as model input parameters. Population prevalences of GERD and BE are not themselves model parameters, but they are used to derive values for transition or progression from the “Normal” state to the “GERD” and “BE” states, respectively.

^*A meta-analysis³² could not find any statistically significant association between the effect of obesity and BE Prevalence; the effect is uncertain as published results have produced a wide range of result. Consequently, we did not use the OR for the effect of obesity on developing BE as part of our simulation selection criteria, but checked the OR to ensure that it was within the published range.

Abbreviations GERD=gastroesophageal reflux disease; BE=Barrett’s esophagus; EAC=esophageal adenocarcinoma; OR=Odds Ratio