Table 3. Multivariate logistic regression analysis on the risk factors for GERD.

Variables	OR [95% CI]	P-value
Age
18–30 years vs. Under 18 years	0.815 [0.553–1.202]	0.302
30–40 years vs. Under 18 years	3.025 [2.147–4.261]	<0.001*
40–50 years vs. Under 18 years	4.484 [3.145–6.393]	<0.001*
Over 50 years vs. Under 18 years	1.128 [0.731–1.739]	0.557
Education level
High school vs. Primary	0.698 [0.550–0.885]	0.003*
University vs. Primary	2.804 [2.090–3.761]	<0.001*
Ethnic group
Han vs. Tibetan	0.230 [0.183–0.289]	<0.001*
Others vs. Tibetan	0.304 [0.239–0.386]	<0.001*
Altitude of residence, n (%)
3.0–3.5 km vs. 2.5–3.0 km	1.174 [0.842–1.635]	0.344
3.5–4.0 km vs. 2.5–3.0 km	1.275 [0.926–1.756]	0.136
4.0–4.5 km vs. 2.5–3.0 km	2.469 [1.714–3.556]	<0.001*
Length of residence
<5 years vs. ≥5 years	2.218 [1.836–2.679]	<0.001*
Sweet tea
Yes vs. No	2.158 [1.782–2.613]	<0.001*
Barley wine
Yes vs. No	1.271 [1.060–1.523]	0.009*
Dried meat
Yes vs. No	1.278 [1.067–1.532]	0.008*
Staying up late
Yes vs. No	1.229 [1.026–1.472]	0.025*
Family history of GERD
Yes vs. No	1.173 [0.979–1.406]	0.083

Note:

An asterisk indicated the significant risk factor (P < 0.05).