Burden of CKD and Cardiovascular Disease on Life Expectancy and Health Service Utilization: a Cohort Study of Hong Kong Chinese Hypertensive Patients

Background The relative effects of combinations of CKD, heart disease, and stroke on risk of mortality, direct medical costs, and life expectancy are unknown. Methods In a retrospective cohort study of 506,849 Chinese adults in Hong Kong with hypertension, we used Cox regressions to examine associations between all-cause mortality and combinations of moderate CKD (eGFR of 30-59 ml/min per 1.73 m(2)), severe CKD (eGFR of 15-29 ml/min per 1.73 m(2)), heart disease (coronary heart disease or heart failure), and stroke, and modeling to estimate annual public direct medical costs and life expectancy. Results Over a median follow-up of 5.8 years (2.73 million person-years), 55,666 deaths occurred. Having an increasing number of comorbidities was associated with incremental increases in mortality risk and medical costs and reductions in life expectancy. Compared with patients who had neither CKD nor cardiovascular disease, patients with one, two, or three conditions (heart disease, stroke, and moderate CKD) had relative risk of mortality increased by about 70%, 160%, and 290%, respectively; direct medical costs increased by about 70%, 160%, and 280%, respectively; and life expectancy at age 60 years decreased by about 5, 10, and 15 years, respectively. Burdens were higher with severe CKD. Conclusions This study demonstrated extremely high mortality risk and medical cost increases for severe CKD, exceeding the combined effects from heart disease and stroke. Mortality risks and costs for moderate CKD, heart disease, and stroke were similar individually and roughly multiplicative for any combination. These findings suggest that to reduce mortality and health care costs in patients with hypertension, CKD prevention and intervention merits priority equal to that of cardiovascular disease.