Faculty Bibliography

Prediction models for post-kidney transplantation mortality have had limited success (C-statistics ≤0.70). Adding objective measures of potentially modifiable factors may improve prediction and, consequently, kidney transplant (KT) survival through intervention. The Short Physical Performance Battery (SPPB) is an easily administered objective test of lower extremity function consisting of three parts (balance, walking speed, chair stands), each with scores of 0-4, for a composite score of 0-12, with higher scores indicating better function. SPPB performance and frailty (Fried frailty phenotype) were assessed at admission for KT in a prospective cohort of 719 KT recipients at Johns Hopkins Hospital (8/2009 to 6/2016) and University of Michigan (2/2013 to 12/2016). The independent associations between SPPB impairment (SPPB composite score ≤10) and composite score with post-KT mortality were tested using adjusted competing risks models treating graft failure as a competing risk. The 5-year posttransplantation mortality for impaired recipients was 20.6% compared to 4.5% for unimpaired recipients (p < 0.001). Impaired recipients had a 2.30-fold (adjusted hazard ratio [aHR] 2.30, 95% confidence interval [CI] 1.12-4.74, p = 0.02) increased risk of postkidney transplantation mortality compared to unimpaired recipients. Each one-point decrease in SPPB score was independently associated with a 1.19-fold (95% CI 1.09-1.30, p < 0.001) higher risk of post-KT mortality. SPPB-derived lower extremity function is a potentially highly useful and modifiable objective measure for pre-KT risk prediction.

BACKGROUND:Health-related quality of life (HRQOL) reflects a patient's perceived disease burden, treatment effectiveness, and health status. Given the time burden and physiologic effects of hemodialysis, patients who spend dialysis time (9-15 h/week) physically or intellectually engaged may have better HRQOL. We characterized the intradialytic activities and explored their association with HRQOL. METHODS:In a cross-sectional study of 431 hemodialysis patients, we ascertained kidney-disease-specific quality of life, measured frailty, and surveyed participants about their usual active intradialytic activities (reading, playing games, doing puzzles, chatting, or other) and passive intradialytic activities (watching TV or sleeping). We used adjusted ordered logistic regression to identify correlates of the activity index (the sum of active intradialytic activities) and adjusted linear regression to quantify the association between the activity index and physical-, mental-, and kidney-disease-specific HRQOL. RESULTS:The 2 most common intradialytic activities were passive activities (watching TV = 87.9%; sleeping = 72.4%). Participants who were female (aOR 1.85, 95% CI 1.28-2.66; p = 0.001), nonfrail (aOR 1.70, 95% CI 1.06-2.70; p = 0.03), and nonsmokers (aOR 2.61, 95% CI 1.39-4.90; p = 0.003) had a higher intradialytic activity index after adjustment. Higher intradialytic activity index was associated with better mental- (0.83 points, 95% CI 0.04-1.62; p = 0.04) and kidney-disease-specific HRQOL (1.70 points, 95% CI 0.47-2.93; p = 0.007), but not physical HRQOL. CONCLUSIONS:Hemodialysis patients with more active intradialytic activities report better mental and kidney-disease-specific HRQOL. These results should be confirmed in a prospective study with a broader cohort of hemodialysis patients. Dialysis providers may consider offering patients with low levels of activity additional support and opportunities to engage in beneficial intradialytic activities.

BACKGROUND:Up to 31% of kidney transplant (KT) recipients experience early hospital readmission (EHR). We hypothesized that EHR among older KT recipients is higher than younger recipients due to increased comorbidities and higher prevalence of frailty. METHODS:We identified 22,458 older (age ≥65) and 86,372 younger (18 to < 65) first-time KT recipients (December 1, 1999 - December 31, 2014) using United States Renal Data System data. We estimated the association between patient-level characteristics and EHR (30 days post-KT discharge) with modified Poisson regression among older and younger KT recipients, separately. We estimated the association between graft loss and mortality and EHR using Cox proportional hazards. RESULTS:EHR was more common in older KT recipients (30.1 vs. 27.6%; p < 0.001). Risk factors for EHR that differed by recipient age included female sex, African American race, diabetes, smoking, dialysis vintage, donor age, and length of stay. Risk of graft loss associated with EHR was greater among older KT recipients (adjusted hazard ratio [aHR] 1.64, 95% CI 1.51-1.77, p < 0.001) than younger KT recipients (aHR 1.43, 95% CI 1.38-1.48, p < 0.001; interaction p < 0.01). However, the risk of mortality associated with EHR was greater among younger recipients (aHR 1.52, 95% CI 1.47-1.57, p < 0.001) than that in older -recipients (aHR 1.40, 95% CI 1.34-1.47, p < 0.001; interaction p < 0.01). CONCLUSIONS:Older KT recipients are more likely to experience EHR and are at a higher risk of graft loss after EHR than younger recipients. Targeted interventions to prevent EHR and subsequent graft loss in this population should be identified.