Rheumatoid arthritis is associated with reduced kidney function, possibly due to chronic inflammation or the use of nephrotoxic therapies. However, little is known about the effects of using the newer novel non-nephrotoxic biologic agents on the risk of incident chronic kidney disease (CKD). To study this we used a cohort of 20,757 United States veterans diagnosed with rheumatoid arthritis with an estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73m² or more, recruited between October 2004 and September 2006, and followed through 2013. The associations of biologic use with incident CKD (eGFR under 60 with a decrease of at least 25% from baseline, and eGFR under 45 mL/min/1.73m²) and change in eGFR (<-3, -3 to <0 [reference], and ≥0 mL/min/1.73m²/year) were examined in propensity-matched patients based on their likelihood to initiate biologic treatment, using Cox models and multinomial logistic regression models, respectively. Among 20,757 patients, 4,617 started biologic therapy. In the propensity-matched cohort, patients treated (versus not treated) with biologic agents had a lower risk of incident CKD (hazard ratios 0.95, 95% confidence interval [0.82-1.10] and 0.71 [0.53-0.94] for decrease in eGFR under 60 and under 45 mL/min/1.73m², respectively) and progressive eGFR decline (multinomial odds ratios [95% CI] for eGFR slopes <-3 and ≥0 [versus -3 to <0] mL/min/1.73m²/year, 0.67 [0.58-0.79] and 0.76 [0.69-0.83], respectively). A significant deceleration of eGFR decline was also observed after biologic administration in patients treated with biologics (-1.0 versus -0.4 [mL/min/1.73m²/year] before and after biologic use). Thus, biologic agent administration was independently associated with lower risk of incident CKD and progressive eGFR decline.

Background

Mortality in the immediate post-hemodialysis transition period is extremely high. Many end-stage renal disease (ESRD) patients in the US start dialysis in an inpatient setting, but the characteristics of patients starting dialysis as inpatients, and the association of inpatient hemodialysis transition with mortality remain unclear.

Methods

We examined 48,261 US veterans who transitioned to hemodialysis between October 2007 and September 2011. Associations of inpatient hemodialysis starting with all-cause mortality were examined in Cox proportional hazard models, with adjustments for demographics, comorbidities, vascular access type, pre-dialysis nephrology care and medication use, and last pre-ESRD estimated glomerular filtration rate and hemoglobin.

Results

A total of 22,338 (46.3%) patients received the first hemodialysis treatment in an inpatient setting. Inpatient hemodialysis transition was associated with older age, presence of a tunneled catheter, higher comorbidity burden, and lack of pre-dialysis nephrology care. A total of 8,674 patients died (mortality rate 405/1,000 patient-years, 95% CI 397-413) during the first 6 months after transition to hemodialysis. The starting of inpatient vs. outpatient hemodialysis was associated with significantly higher crude all-cause mortality, but this association was attenuated after multivariable adjustments.

Conclusions

Transition to hemodialysis in an inpatient setting is more common in older and sicker individuals, and in patients without pre-dialysis nephrology care and those who used a catheter for vascular access. Future studies are needed to determine if a higher proportion of patients could start hemodialysis treatment in outpatient clinics, through interventions targeting modifiable risk factors such as timely vascular access placement or earlier nephrology referrals.