Fig. 2
From: Domestic water hardness, genetic risk, and distinct phenotypes of cardiovascular disease
Restricted cubic spline for testing the hypothesis of non-linear correlation between CaCO3 and incident AF and three other cardiovascular phenotypes. Spline curves represent hazard ratios of (a) AF, (b) CHD, (c) HF, and (d) stroke adjusted for age, sex, ethnicity, education, the Townsend index, smoking status, ideal physical activity, healthy diet score, BMI, total cholesterol, ideal HbA1c, and ideal blood pressure. HR, hazard ratio; AF, atrial fibrillation; CHD, coronary heart disease; HF, heart failure; BMI, body mass index; HbA1c, hemoglobin A1c