Table 4.
Relationships between serum sodium levels at hospital admission and length of hospitalization among those discharged to home (stratified by eGFR/age)
| Natremia Statusa at Hospital Admission | Length of Stay among those Discharged to Home (N=1,664,500) | |
|---|---|---|
| Median, Interquartile Range | Coefficient and 95% Confidence Interval | |
| Normonatremia | 2.9 (1.9–4.6) | Reference |
| Hypernatremia | ||
| Mild | 3.3 (2.1–5.4) | 0.1 (0.1 to 0.1) |
| Moderate | 4.1 (2.7–7.0) | 0.3 (0.2 to 0.3) |
| Severe | 4.7 (3–7.7) | 0.4 (0.3 to 0.4) |
| eGFR level, ml/min per 1.73 m2 | ||
| Normonatremia | ||
| <15 | 4 (2.6–6.5) | 0.2 (0.2 to 0.3) |
| 15–29 | 3.5 (2.2–5.6) | 0.1 (0.1 to 0.1) |
| 30–59 | 3 (2–4.9) | 0.05 (0.04 to 0.05) |
| 60–89 | 2.9 (1.9–4.4) | −0.01 (-0.02 to 0.01) |
| ≥90 | 2.9 (1.9–4.4) | Reference |
| Mild hypernatremia | ||
| <15 | 4.3 (2.8–6.9) | 0.3 (0.2 to 0.3) |
| 15–29 | 4 (2.6–6.1) | 0.2 (0.2 to 0.3) |
| 30–59 | 3.4 (2.2–5.6) | 0.1 (0.1 to 0.2) |
| 60–89 | 3.2 (2.2–5.2) | 0.1 (0.1 to 0.1) |
| ≥90 | 3.2 (2–5.3) | 0.1 (0.1 to 0.1) |
| Moderate hypernatremia | ||
| <15 | 5.4 (3.7–9.1) | 0.4 (0.3 to 0.6) |
| 15–29 | 5 (3.3–7.7) | 0.4 (0.3 to 0.5) |
| 30–59 | 4.2 (2.8–7.0) | 0.3 (0.2 to 0.4) |
| 60–89 | 4 (2.5–6.9) | 0.3 (0.2 to 0.3) |
| ≥90 | 3.8 (2.2–6.3) | 0.2 (0.2 to 0.3) |
| Severe hypernatremia | ||
| <15 | 7 (4.9–12.4) | 0.6 (0.4 to 0.8) |
| 15–29 | 5 (3.7–7.5) | 0.4 (0.3 to 0.6) |
| 30–59 | 4.3 (2.9–6.9) | 0.3 (0.2 to 0.4) |
| 60–89 | 4.5 (3–8.5) | 0.4 (0.3 to 0.5) |
| ≥90 | 4 (2.7–6.8) | 0.3 (0.1 to 0.5) |
| Age group, yr | ||
| Normonatremia | ||
| 18–45 | 2.9 (1.9–4.4) | 0 (N/A) |
| 46–65 | 3 (1.9–4.7) | Reference |
| 66–75 | 3 (1.9–4.7) | −0 (N/A) |
| 76–89 | 3 (2–4.7) | 0 (N/A)b |
| ≥90 | 3 (2–4.6) | 0 (N/A)c |
| Mild hypernatremia | ||
| 18–45 | 3.1 (2–5.3) | 0.1 (0.9 to 0.1) |
| 46–65 | 3.4 (2.1–5.7) | 0.1 (0.1 to 0.1) |
| 66–75 | 3.3 (2.1–5.4) | 0.1 (0.1 to 0.1) |
| 76–89 | 3.3 (2.1–5.3) | 0.1 (0.1 to 0.1) |
| ≥90 | 3.3 (2.1–5.2) | 0.1 (0 to 0.2) |
| Moderate hypernatremia | ||
| 18–45 | 3.8 (2.4–6.1) | 0.2 (0.2 to 0.3) |
| 46–65 | 4.2 (2.7–7.2) | 0.3 (0.2 to 0.3) |
| 66–75 | 4.4 (2.5–7.9) | 0.3 (0.2 to 0.4) |
| 76–89 | 4.7 (3–6.9) | 0.3 (0.2 to 0.4) |
| ≥90 | 3.9 (2.8–6.1) | 0.2 (0.1 to 0.4)d |
| Severe hypernatremia | ||
| 18–45 | 4.3 (3.2–7.8) | 0.4 (0.2 to 0.5) |
| 46–65 | 4.7 (2.8–7.9) | 0.4 (0.2 to 0.5) |
| 66–75 | 4.4 (2.9–7.8) | 0.3 (0.8 to 0.5) |
| 76–89 | 4.8 (3.4–7.1) | 0.4 (0.2 to 0.5) |
| ≥90 | 5.8 (3–6.7) | 0.3 (0.1 to 0.5) |
Normonatremia: Na >135–145 mEq/L; hypernatremia: Na >145 mEq/L (mild hypernatremia: Na >145–150 mEq/L; moderate hypernatremia: Na >150–155 mEq/L; severe hypernatremia: Na >155 mEq/L). IQR, interquartile range.
a
Na levels corrected by adding 1.6 mEq/L for each 100 mg/dl above 100 mg/dl of the concomitantly measured serum glucose levels.
P<0.01 for all categories, except bP=0.87, cP=0.43, and dP=0.01.