Table 3.

Associations between drinking natural water and all-cause mortality (natural water vs. tap water).

Analysis	HR (95% CI), p
No. of deaths/no. of participants at risk (%) a
To tap water	8,945/11,421 (98.5%)
To natural water	12,434/15,267 (97.5%)
Crude analysis	0.95 (0.92–0.98), <0.001
Multivariable analysisb	0.94 (0.91–0.97), <0.001
Propensity-score analyses
With PSM (univariable)	0.92 (0.89–0.95), <0.001
With PSM (multivariable)b	0.94 (0.91–0.97), <0.001
With IPTW (univariable)	0.96 (0.94–0.99), 0.013
With IPTW (multivariable)b	0.94 (0.91–0.97), <0.001
With overlap weighting (univariable)	0.96 (0.94–0.99), 0.011
With overlap weighting (multivariable)b	0.94 (0.91–0.97), <0.001
Adjusted for propensity score (univariable)c	0.96 (0.93–0.99), 0.008
Adjusted for propensity score (multivariable)d	0.94 (0.91–0.97), <0.001

Values are n (%) or HR (95% CI) with p-value.

^aCumulative incidence of all-cause mortality.

^bAdjustment for sex, age, education, marital status, residence, co-residence, fresh fruits, fresh vegetables, taking meat, reading books/newspapers, current smoking, current drinking, current regular exercise, hypertension, diabetes, heart diseases, cerebrovascular diseases, respiratory diseases, cancer, self-rated health, and places of birth.

^cOnly adjustment for propensity score.

^dAdjustment for propensity score, and sex, age, education, marital status, residence, co-residence, fresh fruits, fresh vegetables, taking meat, reading books/newspapers, current smoking, current drinking, current regular exercise, hypertension, diabetes, heart diseases, cerebrovascular diseases, respiratory diseases, cancer, self-rated health, and places of birth.

CI, confidence interval; HR, hazard ratio; IPTW, inverse probability treatment weighting; PSM, propensity score matching.