Associations of geographic and climate parameters with outcomes after adjustment of patient clinical parameters
| Variable | All-cause readmission HR (95% CI), p values | HF-specific readmission HR (95% CI), p values |
| Altitude of patients’ residence (per 25 m) | 1.03 (1.00 to 1.05), p=0.02 | 1.04 (1.01 to 1.07), p=0.02 |
| Altitude of patients’ residence ≥200 m | 1.49 (1.12 to 1.96), p=0.006 | 1.97 (1.37 to 2.83), p<0.001 |
| Distance from patients’ residence to hospital* (per 1 km) | 0.99 (0.98 to 1.00), p=0.23 | 1.00 (0.98 to 1.01), p=0.76 |
| Population† (per 100 persons) | 0.98 (0.97 to 1.00), p=0.009 | 0.99 (0.97 to 1.00), p=0.11 |
| Proportion of the population ≥75 years† (per 1%) | 1.02 (1.00 to 1.03), p=0.04 | 1.01 (0.99 to 1.04), p=0.45 |
| Number of hospital or clinics† | 0.98 (0.91 to 1.05), p=0.54 | 0.98 (0.90 to 1.08), p=0.69 |
| Mean temperature in a day‡ (per 1°C) | 0.97 (0.64 to 1.46), p=0.87 | 0.84 (0.48 to 1.47), p=0.53 |
| Difference of temperature in a day‡ (per 1°C) | 1.01 (0.93 to 1.10), p=0.74 | 0.94 (0.85 to 1.04), p=0.23 |
All associations of study variables with outcomes were adjusted by age, sex, BMI, systolic blood pressure, heart rate, left ventricular ejection fraction, haemoglobin, BNP at discharge, hospitalisation in the prior year, history of HF admission, diabetes and creatinine >2.5 mg/dL.
P<0.008, significant based on Bonferroni correction.
*Kitaishikai Hospital.
†In the minor administrative district (Cho-Aza district) located at patients’ residence.
‡Average daily temperature from July 2006 to June 2014 in the major administrative district (Gun-City district) located at patients’ residence.
BMI, body mass index; BNP, B-type natriureticpeptide; HF, heart failure.