Development and validation of a risk prediction model for gastroesophageal reflux disease: Gastroesophageal Reflux Disease Risk Scoring System

Table 1 Significance and strength of association for each risk factor of gastroesophageal reflux disease

Factor	Continuous variables		Categorical variables
	Spearman ‘rho’	P value	Fischer’s test	Cramer’s v value	Strength of association
Age	0.573	< 0.0011	< 0.0011	0.646	Strong
Body mass index	0.749	< 0.0011	< 0.0011	0.745	Strong
Smoking	-		< 0.0011	0.476	Relatively strong
Alcoholism	-		< 0.0011	0.434	Relatively strong
Sleep	0.710	< 0.0011	< 0.0011	0.642	Strong
Diet	0.492	< 0.0011	< 0.0011	0.639	Strong
Stress	0.289	< 0.0011	< 0.0011	0.727	Strong
Community2	-		0.129	0.0900	Very weak
Socio-economic status2	-		0.932	0.0465	Very weak

¹Indicates significance.

²Categorical data.

Table 2 Coefficients of factors in the logistic regression model for gastroesophageal reflux disease

Factor	Coefficient β
Age	0.01123340
Body mass index	0.05075936
Smoking	-0.01586711
Alcoholism	-0.03592046
Sleep	0.09640941
Diet	0.00588875
Stress	0.03304126

Table 3 Gastroesophageal reflux disease Risk Scoring Scale (Gastroesophageal Reflux Disease Risk Scoring System)

Factor	Parameter	Score
Age (years)	Less than 20	3
	21-40	5
	41-60	8
	61-80	11
	Greater than 81	13
Body mass index	Less than 18	3
	18-22.9	7
	23-24.9	10
	More than 25	13
Smoking	Non-smoker	0
	Smoker < 5 pack years	0.2
	Smoker > 5 pack years	0.4
Alcohol score	Non-alcoholic	0
	0–6	0·2
	7–12	1.4
Diet score	< 4	2
	4–8	1.5
	8–12	1
	> 12	0.5
Stress score	< 4.5	1
	4.5–6	2
	> 6	2.5
Sleep score	< 4	3
	4–8	6
	> 8	9