weibull regression model
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2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Verena Gotta ◽  
Olivera Marsenic ◽  
Andrew Atkinson ◽  
Marc Pfister

Abstract Background and Aims Hemodialysis (HD) adequacy is currently assessed based on weight-normalized small solute clearance (spKt/V), with same targets in both adult and pediatric patients on chronic thrice weekly hemodialysis, despite lack of pediatric studies to support this. It has been hypothesised that pediatric patients of small size may require higher spKt/V targets, due to higher ratio of body surface area (BSA) to body weight and/or greater post-dialysis urea rebound. Ultrafiltration rates (UFR) >10-13 mL/kg/h, associated with increased mortality in adults, are furthermore routinely exceeded in pediatric patients with uncertain consequences. We aimed to characterize how different delivered HD adequacy metrics and UFR are associated with survival in a large cohort of patients who started HD in childhood. Method Retrospective analysis on a cohort of patients <30y on chronic HD since childhood (<19y), having received thrice-weekly HD 2004-2016 in outpatient DaVita dialysis centers. Mean delivered dialysis dose (spKt/V) and alternative measures of HD adequacy and fluid balance, including eKt/V, body-surface normalized Kt (Kt/BSA) and ultrafiltration rate (UFR), were investigated as predictors of survival in a Weibull regression model. Results A total of 1780 patients were included (age at initiation of HD: 0-12y: n=321, >12-18y: n=1459), with median spKtV=1.55, eKt/V=1.31, Kt/BSA=31.2 L/m2 and UFR=10.6 mL/kg/h. Kt/BSA was a better predictor of survival than spKt/V or eKt/V (P<0.001 versus P=0.002, respectively). UFR was associated with survival (P<0.001), with increased mortality <10/>18 mL/kg/h. Associations remained significant after adjusting for age, ethnicity, and etiology of kidney disease. Conclusion We found that targeting Kt/BSA>30 L/m2 in children and young adults on maintenance HD is associated with improved long-term outcomes, corresponding to spKt/V>1.4 (>12 years) and >1.6 (<12 years), respectively. Relatively high UFR of 10-18 ml/kg/h appears to be risk-free in this HD population.


Author(s):  
Verena Gotta ◽  
Olivera Marsenic ◽  
Andrew Atkinson ◽  
Marc Pfister

Abstract Background Hemodialysis (HD) dose targets and ultrafiltration rate (UFR) limits for pediatric patients on chronic HD are not known and are derived from adults (spKt/V>1.4 and <13 ml/kg/h). We aimed to characterize how delivered HD dose and UFR are associated with survival in a large cohort of patients who started HD in childhood. Methods Retrospective analysis on a cohort of patients <30 years, on chronic HD since childhood (<19 years), having received thrice-weekly HD 2004–2016 in outpatient DaVita centers. Outcome: Survival while remaining on HD. Predictors: (I) primary analysis: mean delivered dialysis dose stratified as spKt/V ≤1.4/1.4–1.6/>1.6 (Kaplan–Meier analysis), (II) secondary analyses: UFR and alternative dialysis adequacy measures [eKt/V, body-surface normalized Kt/BSA] on continuous scale (Weibull regression model). Results A total of 1780 patients were included (age at the start of HD: 0–12y: n=321, >12–18y: n=1459; median spKt/V=1.55, eKt/V=1.31, Kt/BSA=31.2 L/m2, UFR=10.6 mL/kg/h). (I) spKt/V<1.4 was associated with lower survival compared to spKt/V>1.4–1.6 (P<0.001, log-rank test), and spKt/V>1.6 (P<0.001), with 10-year survival of 69.3% (59.4–80.9%) versus 83.0% (76.8–89.8%) and 84.0% (79.6–88.5%), respectively. (II) Kt/BSA was a better predictor of survival than spKt/V or eKt/V. UFR was additionally associated with survival (P<0.001), with increased mortality <10/>18 mL/kg/h. Associations did not alter significantly following adjustment for demographic characteristics (age, etiology of kidney disease, and ethnicity). Conclusions Our results suggest usefulness of targeting Kt/BSA>30 L/m2 for best long-term outcomes, corresponding to spKt/V>1.4 (>12 years) and >1.6 (<12 years). In contrast to adults, higher UFR of 10–18 ml/kg/h was not associated with greater mortality in this population.


Author(s):  
Ms Valdemiro Piedade Vigas ◽  
Maíra Blumer Fatoretto ◽  
Giovana Simão Slanzon ◽  
Edwin Moises Marcos Ortega ◽  
Clarice Garcia Borges Demétrio ◽  
...  

2021 ◽  
pp. 097215092098865
Author(s):  
Amare Wubishet Ayele ◽  
Abebaw Bizuayehu Derseh

The contributions of small and medium-sized enterprises (SMEs) to socio-economic development are generally recognized, but they have faced several obstacles that impede their sustainability. This manuscript seeks to identify factors for the survival of SMEs in the East Gojjam Zone, Ethiopia. The prospective study design was employed. Both descriptive and inferential statistics, particularly families of parametric survival regression models, have been used. Of the 650 enterprises included in this study, 330 (50.8%) were censored (sustained enterprises) and the remaining 320 (49.2%) were events or withdrawn enterprises. The findings of this study revealed that the incidence of termination or withdrawal of SMEs in the study area is relatively common. The results from multivariable Weibull regression model revealed that woreda, sector, manger profile (gender, age, educational status, experience (in year) and source of experience), working place, marketing channel and profitability district status of enterprise were found to be statistically significant factors for the sustainability of enterprises in the study area. The bodies concerned, in particular the enterprise administrative offices at various levels, should work with collaborative organizations to develop a strong marketing platform (network), should be able to make workplaces accessible with the required infrastructure at minimal rental costs, and should prioritize the type of sector that has the highest customer needs at the onset, for instance, agriculture and service sectors.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii136-ii136
Author(s):  
Stephanie Boisclair ◽  
Shenae Samuels ◽  
Luis E Raez ◽  
Delia A Wietecha ◽  
Alejandro Lopez Cohen ◽  
...  

Abstract Gliosarcoma (GS), a rare variant of glioblastoma, accounts for less than 5% of CNS tumors. Due to its low incidence and prevalence, very few comprehensive, large-scale studies are reported in the literature that describe prognostic elements and treatment outcomes. The objective of the study was to examine patient and treatment characteristics to identify significant predictors of survival. METHODS: Data on patients with GS, diagnosed between 2004-2016, was extracted from the National Cancer Database (NCDB). Univariate analysis and a multivariate Weibull regression model was used to determine prognostic factors of survival (months). Kaplan-Meier (KM) method with log-rank test was used to compare and estimate overall survival rates between various groups. RESULTS: There was a total of 2,656 GS patients identified in the NCDB between the years of 2004-2016 with median age of 62 years old. In multivariable Weibull regression model, increasing age (HR=1.04, p=0.000) and increasing comorbidities were independent predictors of increased hazard of death. Having 3 or more comorbidities had the strongest association with increased hazard of death (HR=1.44; P=0.001). The OS has minimally improved over the period of 2004-2016; median OS was highest among those diagnosed between 2012 and 2016 at 11.4 months followed by an OS of 10.6 months between 2004 and 2007, and 9.1 months between 2008 and 2011 (P=0.001). Although current clinical guidelines recommend chemotherapy and radiation within 30 days of surgery, there was no statistically significant difference in median OS between patients who had chemotherapy initiated within 30 days, between 30 and 60 days or later than 60 days (P=0.109). There is also no statistically significant difference in OS for time of radiation initiation categories (P=0.752). In a disease with such low OS and limited treatment options, palliative care use was found in only 45 (1.7%) patients.


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