Chronic respiratory disease: an unrecognized risk factor in dialysis.

Background: Few studies have analysed the impact of chronic respiratory disease (CRD) on outcomes in dialysis. We therefore sought to describe patients with CRD and end-stage renal disease and their outcomes after dialysis start, compared with patients without CRD, focusing especially on causes of death, access to renal transplantation and causes of hospital admissions.

Methods: The study included 52 797 adults aged 18 years and older who began dialysis from 2008 to 2013 and are recorded in the French national REIN registry. Survival, specific mortality and access to the waiting list and to renal transplantation were analysed, with adjustment for various comorbidities and consideration of competitive risks. The numbers of hospitalizations and hospital days, together with their causes, were analysed through an indirect link between the REIN database and the national French hospital discharge database.

Results: The frequency of CRD at dialysis start was 12% and was associated with various other comorbidities, including obesity and tobacco use. After adjustment for those comorbidities, CRD remained associated with a higher risk of death [hazard ratio (HR) 1.20, 95% confidence interval (CI) 1.16-1.25]. Patients with CRD were 30% less likely to undergo transplantation (HR 0.67, 95% CI 0.6-0.7) than patients without CRD. Their risk of dying from a respiratory disease was 8.8 times higher; their risk of dying from infection was also higher. Patients with CRD had a higher rate of admissions and more hospital days, for all causes and for every cause, except cancer.

Conclusions: CRD was associated with higher risks of death and hospital admissions and with lower likelihoods of being wait-listed for and undergoing renal transplantation. Increasing clinical awareness by patients and doctors and encouragement of spirometry use should promote more accurate clinical diagnosis and better preventive care for CRD.