Association between proximity to the attending nephrologist and mortality among patients receiving hemodialysis

Abstract

Background: Many Canadian patients who receive hemodialysis live far from their attending nephrologist, which may affect clinical outcomes. We investigated whether patients receiving hemodialysis who live farther from their attending nephrologist are more likely to die than those who live closer. Methods: We studied a random sample of 18 722 patients who began hemodialysis between 1990 and 2000 in Canada. We calculated the distance between each patient9s residence location at the start of dialysis and the practice location of their attending nephrologist. We used Cox proportional hazards models to examine the adjusted relation between distance and clinical outcomes (death from all causes, infectious causes and cardiovascular causes) over a follow-up period of up to 14 years. Results: During the follow-up period (median 2.5 yr, interquartile range 1.0–4.7 yr), 11 582 (62%) patients died. Compared with patients who lived within 50 km of their nephrologist, the adjusted hazard ratio of death among those who lived 50.1–150 km away was 1.06 (95% confidence interval [CI] 1.01–1.12), 1.13 (95% CI 1.04–1.22) for those who lived 150.1–300 km away and 1.13 (95% CI 1.03–1.24) for those who lived more than 300 km from their nephrologist (p for trend < 0.001). The risk of death from infectious causes increased with greater distance from the attending nephrologist (p for trend < 0.001). The risk of death from cardiovascular causes did not increase with distance from the attending nephrologist (p for trend = 0.21). Compared with patients who lived within 50 km of their nephrologist, the adjusted hazard ratio of death among those who lived more than 300 km away was 1.75 (95% CI 1.32–2.32) for infectious causes and 0.93 (95% CI 0.79–1.09) for cardiovascular causes. Conclusions: Mortality associated with hemodialysis was greater among patients who lived farther from their attending nephrologist, as compared with those who lived closer. This was especially evident for death from infectious causes.