Predicted risk of renal replacement therapy at arteriovenous fistula referral in chronic kidney disease.

BACKGROUND AND OBJECTIVES: Optimal timing of arteriovenous fistula placement in chronic kidney disease remains difficult and contributes to high central venous catheter use at initial hemodialysis. We tested whether a prediction model for progression to renal replacement therapy developed at Kaiser Permanente Northwest may help guide decisions about timing of referral for arteriovenous fistula placement. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: A total of 205 chronic kidney disease stage 4 patients followed by nephrology referred for arteriovenous fistula placement were followed for up to 2 years. Patients were censored if they died or discontinued Kaiser Permanente Northwest coverage. Survival analyses were performed for overall progression to renal replacement therapy divided by quartiles based on 2-year risk for renal replacement therapy and estimated glomerular filtrate rate at time of referral. RESULTS: By 2 years, 60% progressed to renal replacement therapy and 11% had died. 80% in the highest risk versus 36% in the lowest risk quartile progressed to renal replacement therapy (predicted risk 84% vs 17%). 75% in the lowest estimated glomerular filtrate rate versus 56% in the highest estimated glomerular filtrate rate quartile progressed to renal replacement therapy (mean estimated glomerular filtrate rate 13 mL/min vs 21 mL/min). The hazard ratio was significantly higher for each consecutive higher renal replacement therapy quartile risk while for estimated glomerular filtrate rate, the hazard ratio was only significantly higher for the lowest compared to the highest quartile. The extreme quartile risk ratio was higher for 2-year risk for renal replacement therapy compared to estimated glomerular filtrate rate (4.0 vs 2.4). CONCLUSION: In patients with chronic kidney disease stage 4 referred for arteriovenous fistula placement, 2-year renal replacement therapy risk better discriminated progression to renal replacement therapy compared to estimated glomerular filtrate rate at time of referral.

Comparison of a Kidney Replacement Therapy Risk Score Developed in Kaiser Permanente Northwest vs Estimated Glomerular Filtration Rate in Advanced Chronic Kidney Disease Using Decision Curve Analysis.

INTRODUCTION: Use of kidney replacement therapy (KRT) prediction models for guiding arteriovenous fistula (AVF) referrals in advanced chronic kidney disease (CKD) is unknown. We aimed to compare a hypothetical approach using a KRT prediction model developed in Kaiser Permanente Northwest to estimated glomerular filtration rate (eGFR) for AVF referrals. METHODS: Our retrospective cohort consisted of patients with stage G4 CKD in Kaiser Permanente Northwest followed by nephrology. Two-year KRT risk was calculated at each nephrology visit up to 2 years from entrance into cohort based on a previously published model. We calculated sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) based on several 2-year KRT risk and eGFR cutoffs for outcome of hemodialysis at 18 months. We compared an approach of AVF referral using 2-year KRT risk and eGFR cutoffs using decision curve analysis. RESULTS: Two-year KRT risk better discriminated progression to hemodialysis compared to eGFR < 15 mL/min (AUC 0.60 vs 0.69 at 2-year KRT risk > 20% and 0.69 at 2-year KRT risk > 40%, p = 0.003 and 0.006, respectively) but not to eGFR of 20 mL/min (AUC 0.64, p = 0.16 and 0.19, respectively). Decision curve analysis showed that AVF referral guided by 2-year KRT risk score resulted in higher net benefit compared to eGFR at low thresholds for referral. CONCLUSION: In stage G4 CKD, a 2-year KRT risk model better predicted progression to KRT at 18 months compared to an eGFR of 15 mL/min but not to 20 mL/min and may improve timely referral for AVF placement in patients at lower thresholds for referral.

Association Between Social and Economic Needs With Future Healthcare Utilization.

INTRODUCTION: Unmet social and economic needs are associated with poor health outcomes, but little is known about how these needs are predictive of future healthcare utilization. This study examined the association of social and economic needs identified during medical visits with future hospitalizations and emergency department visits. METHODS: Individuals with electronic health record-coded social and economic needs during a primary care, emergency department, or urgent care visit at Kaiser Permanente Northwest from October 1, 2016 to November 31, 2017 (case patients) were identified, as well as individuals who had visits during that time period but had no electronic health record-coded needs (control patients). The 2 groups were compared on sociodemographic characteristics, comorbidities, and healthcare utilization in the prior year. Finally, logistic regression assessed the relationship between documented needs and hospitalizations and emergency department visits in the 12 months following the index visit, controlling for sociodemographic characteristics, comorbidities, and prior healthcare utilization. Statistical analysis was completed in April 2019. RESULTS: Case patients differed significantly from control patients on sociodemographic characteristics and had higher rates of comorbidities and prior healthcare utilization. Social and economic needs documented during the index visit were associated with significantly higher rates of hospitalization and emergency department visits in the 12 months following the visit, controlling for sociodemographic characteristics, comorbidities, and prior utilization. CONCLUSIONS: These results demonstrate that documented social and economic needs are a powerful predictor of future hospitalization and emergency department use and suggest the need for research into whether interventions to address these needs can influence healthcare utilization.

Rural-urban differences in colorectal cancer screening capacity in Arizona.

Colorectal cancer can be prevented via screening by the detection and removal of colorectal adenomas. Few data exist on screening capacity by rural/urban areas. Therefore, the aims of this work were to evaluate current colorectal cancer endoscopy screening capacity and to estimate potential volume for rural and urban regions in Arizona. Gastroenterologists and colorectal surgeons practicing in Arizona completed a survey (n = 105) that assessed current colonoscopy and sigmoidoscopy screening and estimated future capacity. Resources needed to increase capacity were identified, and differences between rural and urban regions were examined. Responders were more likely to practice in an urban region (89.5%). Physicians reported performing 8,717 endoscopic procedures weekly (8,312 in urban and 405 in rural regions) and the vast majority were colonoscopies (91% in urban and 97% in rural regions). Urban physicians estimated being able to increase their capacity by 35.7% (95% confidence interval 34.7-35.7) whereas rural physicians estimated an increase of 53.1% (95% confidence interval 48.1-58.0). The most commonly cited resource needed to increase capacity was a greater number of physicians in urban regions (52.1%); while the top response in rural areas was appropriate compensation (54.6%). Lastly, 27.3% of rural physicians noted they did not need additional resources to increase their capacity. In conclusion, Arizona has the ability to expand colorectal cancer screening endoscopic capacity; this potential increase was more pronounced in rural as compared to urban regions.

SPSS and SAS programming for the testing of mediation models.

BACKGROUND: Mediation modeling can explain the nature of the relation among three or more variables. In addition, it can be used to show how a variable mediates the relation between levels of intervention and outcome. The Sobel test, developed in 1990, provides a statistical method for determining the influence of a mediator on an intervention or outcome. Although interactive Web-based and stand-alone methods exist for computing the Sobel test, SPSS and SAS programs that automatically run the required regression analyses and computations increase the accessibility of mediation modeling to nursing researchers. OBJECTIVES: To illustrate the utility of the Sobel test and to make this programming available to the Nursing Research audience in both SAS and SPSS. METHODS: The history, logic, and technical aspects of mediation testing are introduced. The syntax files sobel.sps and sobel.sas, created to automate the computation of the regression analysis and test statistic, are available from the corresponding author. RESULTS: The reported programming allows the user to complete mediation testing with the user's own data in a single-step fashion. A technical manual included with the programming provides instruction on program use and interpretation of the output. CONCLUSION: Mediation modeling is a useful tool for describing the relation between three or more variables. Programming and manuals for using this model are made available.