Table 3.

Effect of Serum Bicarbonate Levels on 2-Year Adverse Kidney Outcomes/Mortality and on Log Cost PPPY, Adjusted for Covariates

Regression Parameter	Logistic Regression Model on DD40 Within 2 Years		Generalized Linear Model on Log Cost PPPY Assessed Over 2 Years
	OR (95% CI)	P	Parameter Estimates ± SE	P
Age, per 1-y increase	1.000 (0.998-1.002)	0.8460	−0.013 ± 0.0025	<0.001
Male (vs female)	1.197 (1.135-1.263)	<0.0001	−0.150 ± 0.0628	0.02
Race (vs White)
African American	1.436 (1.321-1.560)	<0.0001	0.302 ± 0.1100	0.006
Asian	0.845 (0.704-1.013)	0.0683	−0.690 ± 0.2368	0.004
Other/unknown race	1.094 (0.989-1.210)	0.0794	0.356 ± 0.1494	0.02
Baseline laboratory values, continuous
eGFR, per 1-mL/min/1.73 m2 increase	0.967 (0.965-0.969)	<0.0001	−0.003 ± 0.0029	0.25
Serum bicarbonate, per 1-mEq/L increase	0.873 (0.866-0.879)	<0.0001	−0.070 ± 0.0075	<0.001
ACR, log, per 1-unit increase	1.209 (1.190-1.229)	<0.0001	0.008 ± 0.0194	0.67
Baseline comorbidities (yes vs no)
Diabetes	0.924 (0.868-0.983)	0.0128	0.044 ± 0.0723	0.54
Hypertension	0.938 (0.871-1.011)	0.0938	−0.234 ± 0.0874	0.007
Heart failure	1.828 (1.711-1.953)	<0.0001	0.432 ± 0.0793	<0.001
Charlson Comorbidity Index score (vs 0)
1	1.157 (1.045-1.281)	0.0049	0.173 ± 0.1145	0.13
2	1.212 (1.100-1.334)	<0.0001	−0.026 ± 0.1150	0.82
≥3	1.739 (1.597-1.895)	<0.0001	0.524 ± 0.1032	<0.001
Other
Pharmacy insurance coverage (yes vs no)	NA		0.503 ± 0.0653	<0.001

Note: Covariates are age, sex, race, serum bicarbonate, eGFR, log ACR, diabetes, heart failure, hypertension, Charlson Comorbidity Index score, and pharmacy insurance coverage. P values: difference between the metabolic acidosis and normal serum bicarbonate groups.

Abbreviations and definitions: ACR, albumin-creatinine ratio (urinary); CI, confidence interval; DD40, death, dialysis, kidney transplantation, or a ≥40% decline in eGFR; eGFR, estimated glomerular filtration rate; GLM, generalized linear regression model; OR, odds ratio; PPPY, per-patient, per-year; SE, standard error.