Structural equation modelling of the role of cognition in functional interference and treatment nonadherence among haemodialysis patients.

BACKGROUND AND OBJECTIVES: Cognitive impairment is common in haemodialysis patients and associated with adverse health outcomes. This may be due to cognitive impairments interfering with daily functioning and self-care, but evidence is limited. This cross-sectional study aims to explore the interrelationships between cognition and functional outcomes in haemodialysis patients. METHODS: Haemodialysis patients completed measures of objective cognitive function (Montreal Cognitive Assessment), everyday problem-solving skills (scenario-based task), and subjective cognitive complaints (self-report). Participants also self-reported sociodemographic information, functional interference, treatment nonadherence, and mood and fatigue symptoms. Patients' clinical data including comorbidities and lab results were extracted from medical record. Structural equation modelling was performed. RESULTS: A total of 268 haemodialysis patients (mean age = 59.87 years; 42.5% female) participated. The final model showed satisfactory fit: CFI = 0.916, TLI = 0.905, RMSEA = 0.033 (90% confidence interval 0.024 to 0.041), SRMR = 0.066, χ2(493) = 618.573 (p < .001). There was a negative association between objective cognitive function and subjective cognitive complaints. Cognitive complaints were positively associated with both functional interference and treatment nonadherence, whereas objective performance was not. Everyday problem-solving skills emerged as a distinct aspect of cognition not associated with objective performance or subjective complaints, but had additive utility in predicting functional interference. CONCLUSIONS: Subjective cognitive complaints and everyday problem-solving skills appear to be stronger predictors of functional variables compared to objective performance based on traditional tests. Routine screening of everyday cognitive difficulties may allow for early identification of dialysis patients at risk of cognitive impairment, functional interference, treatment nonadherence, and poor clinical outcomes.

Randomized Controlled Clinical Trial of the Effect of Treatment with Vitamin K2 on Vascular Calcification in Hemodialysis Patients (Trevasc-HDK).

Introduction: Vitamin K deficiency among patients on hemodialysis (HD) affects the function of matrix GLA protein (MGP), a potent vitamin K-dependent inhibitor of vascular calcification (VC). Methods: We conducted a single-center randomized controlled trial (RCT) on maintenance HD patients to examine if vitamin K2 supplementation can reduce progression of coronary artery calcification (CAC) over an 18-month study period. Patients were randomized to vitamin K2 group receiving menaquinone-7360 µg 3 times/wk or control group. The primary outcome was CAC scores at the end of the study period. The secondary outcomes were aortic valve calcification (AVC), carotid-femoral pulse wave velocity (cfPWV), aortic augmentation index (AIx), dephosphorylated undercarboxylated MGP (dp-ucMGP) levels, major adverse cardiac events (MACE), and vascular access events. Results: Of the 178 patients randomized, follow-up was completed for 138 patients. The CAC scores between the 2 groups were not statistically different at the end of 18 months (relative mean difference [RMD] 0.85, 95% CI 0.55-1.31). The secondary outcomes did not differ significantly in AVC (RMD 0.82, 95% CI 0.34-1.98), cfPWV (absolute mean difference [AMD] 0.55, 95% CI -0.50 to 1.60), and AIx (AMD 0.13, 95% CI -3.55 to 3.80). Supplementation with vitamin K2 did reduce dp-ucMGP levels (AMD -86, 95% CI -854 to -117). The composite outcome of MACE and mortality was not statistically different between the 2 groups (Hazard ratio = 0.98, 95% CI 0.50-1.94). Conclusion: Our study did not demonstrate a beneficial effect of vitamin K2 in reducing progression of VC in this population at the studied dose and duration.

Risk assessment of failure during transitioning from in-centre to home haemodialysis.

BACKGROUND: Introducing a de-novo home haemodialysis (HHD) program often raises safety concerns as errors could potentially lead to serious adverse events. Despite the complexity of performing haemodialysis at home without the supervision of healthcare staff, HHD has a good safety record. We aim to pre-emptively identify and reduce the risks to our new HHD program by risk assessment and using failure mode and effects analysis (FMEA) to identify potential defects in the design and planning of HHD. METHODS: We performed a general risk assessment of failure during transitioning from in-centre to HHD with a failure mode and effects analysis focused on the highest areas of failure. We collaborated with key team members from a well-established HHD program and one HHD patient. Risk assessment was conducted separately and then through video conference meetings for joint deliberation. We listed all key processes, sub-processes, step and then identified failure mode by scoring based on risk priority numbers. Solutions were then designed to eliminate and mitigate risk. RESULTS: Transitioning to HHD was found to have the highest risk of failure with 3 main processes and 34 steps. We identified a total of 59 areas with potential failures. The median and mean risk priority number (RPN) scores from failure mode effect analysis were 5 and 38, with the highest RPN related to vascular access at 256. As many failure modes with high RPN scores were related to vascular access, we focussed on FMEA by identifying the risk mitigation strategies and possible solutions in all 9 areas in access-related medical emergencies in a bundled- approach. We discussed, the risk reduction areas of setting up HHD and how to address incidents that occurred and those not preventable. CONCLUSIONS: We developed a safety framework for a de-novo HHD program by performing FMEA in high-risk areas. The involvement of two teams with different clinical experience for HHD allowed us to successfully pre-emptively identify risks and develop solutions.

Treatment to reduce vascular calcification in hemodialysis patients using vitamin K (Trevasc-HDK): A study protocol for a randomized controlled trial.

INTRODUCTION: End stage renal failure patients on hemodialysis have significant vascular calcification This is postulated to be related to sub-clinical vitamin K deficiency, which is prevalent in hemodialysis patients. Vitamin K deficiency result in the failure of the matrix GLA protein (MGP) to undergo carboxylation. MGP is a natural local inhibitor of vascular calcification and the lack of functional carboxylated MGP may contribute to increase vascular calcification. Vitamin K supplement should therefore correct this anomaly and decrease the rate or severity of vascular calcification in this population of patients on long-term maintenance hemodialysis. Our study seeks to evaluate the prevalence and the progression of vascular calcification in a cohort of maintenance hemodialysis patients. It will also evaluate the efficacy of vitamin K supplementation in reducing the progression of vascular calcification in this group of patients. METHODS: This will be a single-center randomized, prospective and open-label interventional clinical trial of end stage renal failure patients on hemodialysis. We aim to recruit 200 patients. Eligible patients will be randomized to either the standard care arm or active treatment arm. Active treatment arm patients will receive standard care plus supplementation with oral vitamin K2 isoform 360 mcg 3 times weekly for a total duration of 18 months. Primary outcome measured will be absolute difference in coronary artery calcification score at 18-month between control and intervention arms. Secondary outcomes will be to compare absolute difference in aortic valve calcification, percentage of patients with regression of coronary artery calcification of at least 10%, absolute difference in aortic and systemic arterial stiffness, mortality from any cause and major adverse cardiovascular over the same period. DISCUSSION: Evidence of successful regression or retardation of vascular calcification will support the conduct of larger and longer-term trials aimed at reducing cardiovascular disease mortality and major adverse cardiovascular events in this high-risk population using a safe and inexpensive strategy TRIAL REGISTRATION:: ClinicalTrials.gov NCT02870829. Registered on 17 August 2016 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02870829National University Hospital's Institutional Review Board (2015/01000).

Comparison of combination therapy of high-dose oral N-acetylcysteine and intravenous sodium bicarbonate hydration with individual therapies in the reduction of Contrast-induced Nephropathy during Cardiac Catheterisation and Percutaneous Coronary Intervention (CONTRAST): A multi-centre, randomised, controlled trial.

INTRODUCTION: N-acetylcysteine (NAC) and sodium bicarbonate (SOB) therapies may prevent contrast-induced nephropathy (CIN). However, the efficacy of using combination over individual therapies was not established, and there was no large randomised study comparing abbreviated SOB therapy with conventional sustained saline pre-hydration with oral NAC. METHODS: In a multi-centre, open-label, randomised, controlled trial (NCT00497328), we prospectively enrolled 548 patients with at least moderate renal impairment undergoing cardiac catheterisation with or without percutaneous coronary intervention. Patients were randomly assigned to 3 groups: 1) NAC: 154 mEq/L sustained sodium chloride regime (1 mL/kg/h 12 h before, during and 6h after the procedure) with oral NAC at 1.2g bid for 3 days (n=185); 2) SOB: 154 mEq/L abbreviated SOB regime at 3 mL/kg/h 1h before the procedure, and 1 mL/kg/h during and 6h after the procedure (n=182); and 3) COM: combination of abbreviated SOB regime and oral NAC (n=181). The primary end point was incidence of CIN. The secondary end points were rise in serum creatinine, hospitalisation duration, haemodialysis, morbidity and mortality within 30 days. RESULTS: The 3 groups had similar baseline characteristics: age 68 ± 10 years, 76% male, 48% diabetic and baseline glomerular filtration rate (GFR) 47.7 ± 13.0 mL/min. There were 41 (8.8%) patients with GFR<30. The CIN incidences were NAC 6.5%, SOB 12.8% and COM 10.6%. The COM regimen was not superior to either the NAC (relative risk (RR)=1.61, 95% confidence interval (CI): 0.76 to 3.45, p=0.225) or SOB (RR=0.83, 95% CI: 0.44 to 1.56, p=0.593) regimens. The CIN incidence was lower in the NAC group than the SOB group (adjusted odds ratio (OR)=0.40, 95% CI: 0.17 to 0.92; p=0.032). Multivariate analysis showed contrast volume (OR=1.99, 95% CI: 1.33 to 2.96, p<0.001 per 100mL), female (OR=2.47, 95% CI: 1.22 to 5.00, p=0.012) and diabetes (OR=2.03, 95% CI: 1.03 to 3.99, p=0.041) were independent risk predictors. There were no differences in the secondary outcomes among the 3 groups. CONCLUSION: The combination regimen was not superior to individual regimens in preventing CIN in patients with baseline renal impairment. There was a trend suggesting that the 12-hour sustained sodium chloride pre-hydration regimen was more protective than the 1-hour abbreviated SOB regimen.

Validation of the English version of the Kidney Disease Quality of Life questionnaire (KDQOL-36) in haemodialysis patients in Singapore.

BACKGROUND: To validate a widely used health outcomes instrument for patients with chronic kidney disease and on dialysis, the Kidney Disease Quality of Life questionnaire (KDQOL-36), in English-speaking haemodialysis patients in Singapore. METHODS: This study is a secondary data analysis using the KDQOL-SF (version 1.3) data collected from a cross-sectional survey of haemodialysis patients in Singapore. Cronbach's α was used to test internal consistency reliability. Multi-item scales were assessed using item-to-scale correlation and factor analysis. Both confirmatory and exploratory factor analyses were performed separately for generic and disease-targeted scales. Construct validity was assessed by correlation between disease-targeted and generic scales. Criterion validity was assessed by correlation of the physical component summary (PCS-12) and mental component summary (MCS-12) from KDQOL-36 with the corresponding PCS-36 and MCS-36 from the KDQOL-SF. RESULTS: Three hundred ninety-four patients who completed the interviews in English [male 55.8 %, mean age (SD) 52.4 (11.7) years] were involved. Kidney disease scales exhibited desirable internal consistency (Cronbach's α 0.822-0.906) and item-to-scale correlation (range 0.763-0.903), and a three-factor model fit the data well [comparative fit index (CFI) 0.934, root mean square error of approximation (RMSEA) 0.085]. For the generic Short Form 12 Health Survey (SF-12) items, a two-factor model (physical and mental) showed poor overall fit, but a three-factor structure (role, physical and mental functions) achieved good model fit (CFI 0.999, RMSEA 0.027). Correlation between disease-targeted and generic scales was weak to moderate (range 0.286-0.418). Correlation between SF-12 and SF-36 was 0.750 for PCS and 0.797 for MCS. CONCLUSION: The English version of the KDQOL-36 appears to be reliable and valid to measure quality of life for haemodialysis patients in Singapore.