scholarly journals Prognostic role of BNP in children undergoing surgery for congenital heart disease: analysis of prediction models incorporating standard risk factors

2015 ◽  
Vol 53 (11) ◽  
Author(s):  
Massimiliano Cantinotti ◽  
Raffaele Giordano ◽  
Marco Scalese ◽  
Sabrina Molinaro ◽  
Francesca della Pina ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Risk Prediction ◽  
Proportional Hazards ◽  
Prediction Models ◽  
Proportional Hazards Model ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Pediatric Cardiac Surgery ◽  
Hazards Model ◽  
Hazard Ratios

AbstractThe routine use of brain natriuretic peptide (BNP) in pediatric cardiac surgery remains controversial. Our aim was to test whether BNP adds information to predict risk in pediatric cardiac surgery.In all, 587 children undergoing cardiac surgery (median age 6.3 months; 1.2–35.9 months) were prospectively enrolled at a single institution. BNP was measured pre-operatively, on every post-operative day in the intensive care unit, and before discharge. The primary outcome was major complications and length ventilator stay >15 days. A first risk prediction model was fitted using Cox proportional hazards model with age, body surface area and Aristotle score as continuous predictors. A second model was built adding cardiopulmonary bypass time and arterial lactate at the end of operation to the first model. Then, peak post-operative log-BNP was added to both models. Analysis to test discrimination, calibration, and reclassification were performed.BNP increased after surgery (p<0.001), peaking at a mean of 63.7 h (median 36 h, interquartile range 12–84 h) post-operatively and decreased thereafter. The hazard ratios (HR) for peak-BNP were highly significant (first model HR=1.40, p=0.006, second model HR=1.44, p=0.008), and the log-likelihood improved with the addition of BNP at 12 h (p=0.006; p=0.009). The adjunction of peak-BNP significantly improved the area under the ROC curve (first model p<0.001; second model p<0.001). The adjunction of peak-BNP also resulted in a net gain in reclassification proportion (first model NRI=0.089, p<0.001; second model NRI=0.139, p=0.003).Our data indicates that BNP may improve the risk prediction in pediatric cardiac surgery, supporting its routine use in this setting.

scholarly journals Outcomes of Constrained Prostheses in Primary and Revision TKR

2017 ◽  
Vol 5 (5_suppl5) ◽  
pp. 2325967117S0016
Author(s):  
Ben Parkinson ◽  
Michelle Lorimer ◽  
Peter Lewis
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Survival Rates ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Knee Prostheses ◽  
Hazards Model ◽  
Kaplan Meier ◽  
Hazard Ratios ◽  
Total Knee

Introduction: The decision to use varus/valgus constrained or hinge knee prostheses in complex Total Knee Replacement (TKR) cases is difficult. There are few publications that compare survival rates, to aid this decision-making. This study compares the survival rates of unlinked fully constrained and hinge constrained prostheses in the primary and revision settings. Methods: Data from the AOANJRR to 31st of December 2013 was analysed to determine the survival rate of unlinked and hinge constrained TKR in the primary and revision settings (excluding the diagnosis of tumour and infection). Only first-time revisions of a known primary TKR were included in the revision analysis. Kaplan-Meier estimates of survivorship were calculated for the two categories of constraint and were matched for age and diagnosis in both primary and revision TKR situations. Hazard ratios using the Cox proportional-hazards model were used. The survivorship of individual prosthesis models was determined. Results: There were 3237 prostheses implanted during the study period that met the inclusion criteria. Of these, 1896 were for primary TKR and 1341 for revision TKR. There were 1349 unlinked fully constrained and 547 hinge prostheses for primary TKR and 991 unlinked fully constrained and 350 hinge prostheses for revision TKR. In both the primary and revision settings when matched by age, there was no difference in rates of revision for either level of constraint. When matched by indication in the primary setting, there was no difference in the rates of revision for either level of constraint. The rate of revision for both categories of constrained prosthesis was significantly higher in younger patients <55 years of age (p < 0.05). There were no differences in survival rates of individual models of constrained TKR. Conclusions: The survival rates of unlinked constrained and hinge knee prostheses are similar when matched by age or diagnosis. In complex TKR instability cases, surgeons should feel confident in choosing the appropriate prosthesis to gain a stable knee and need not be concerned that a hinge prosthesis may carry a higher revision rate.

Comparison of Valvulopathy Risk with Lorcaserin and Phenterminetopiramate for Weight Loss

2019 ◽  
Vol 14 (1) ◽  
pp. 74-78
Author(s):  
Michael Guo ◽  
Mahyar Etminan ◽  
Bruce Carleton
Keyword(s):  
Weight Loss ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Adverse Outcome ◽  
The United States ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Hazards Model ◽  
Hazard Ratios ◽  
One Year

Background: Lorcaserin and phentermine-topiramate are two drugs marketed for obesity that have shown moderate efficacy after one year of use. However, concerns over risks of serious cardiovascular harms including valvulopathy have been brought up for both drugs, prompting an epidemiologic investigation to quantify this adverse outcome using real-world clinical data. </P><P> Objective: To compare rates of valvulopathy between the weight-loss drugs lorcaserin and phentermine-topiramate. </P><P> Methods: A retrospective cohort study using the PharMetrics database from the United States was conducted. From approximately 9 million subjects captured in the database from 2006 to 2016, we identified all patients who had received at least one prescription for lorcaserin or phentermine-topiramate. Users of either drug were followed to the first mutually exclusive diagnosis of non-congenital valvulopathy defined as having received an international classification for diseases, ninth revision clinical modification [ICD-9- CM] code for valvulopathy, or to the end of the study period. A Cox Proportional Hazards model was then constructed to compute adjusted hazard ratios (HRs) to compare the rates of valvulopathy between users of the two drugs. </P><P> Results: We identified 1,981 lorcaserin users and 1,806 phentermine-topiramate users. Rates of valvulopathy for lorcaserin and phentermine-topiramate cohorts were 26 and 24 per 1000-person-years, respectively. The crude and adjusted hazard ratios (HRs) comparing the two cohorts with respect to valvulopathy were 1.28 (95% CI: 0.73,2.26) and 1.16 (95% CI: 0.65-2.05), respectively. </P><P> Conclusion: Our analysis suggests comparable rates of valvulopathy between lorcaserin and phentermine-topiramate users. Clinicians are advised to consider the risk of valvular disease when medically managing obesity.

Beyond the Hazard Ratio: Generating Expected Durations from the Cox Proportional Hazards Model

2017 ◽  
Vol 50 (1) ◽  
pp. 303-320 ◽  
Author(s):  
Jonathan Kropko ◽  
Jeffrey J. Harden
Keyword(s):  
Political Science ◽  
Hazard Function ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Cox Model ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Hazards Model ◽  
Hazard Ratios ◽  
Quantities Of Interest

The Cox proportional hazards model is a commonly used method for duration analysis in political science. Typical quantities of interest used to communicate results come from the hazard function (for example, hazard ratios or percentage changes in the hazard rate). These quantities are substantively vague, difficult for many audiences to understand and incongruent with researchers’ substantive focus on duration. We propose methods for computing expected durations and marginal changes in duration for a specified change in a covariate from the Cox model. These duration-based quantities closely match researchers’ theoretical interests and are easily understood by most readers. We demonstrate the substantive improvements in interpretation of Cox model results afforded by the methods with reanalyses of articles from three subfields of political science.

scholarly journals Plasma Oxalate as a Predictor of Kidney Function Decline in a Primary Hyperoxaluria Cohort

2020 ◽  
Vol 21 (10) ◽  
pp. 3608 ◽  
Author(s):  
Ronak Jagdeep Shah ◽  
Lisa E. Vaughan ◽  
Felicity T. Enders ◽  
Dawn S. Milliner ◽  
John C. Lieske
Keyword(s):  
Kidney Disease ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Primary Hyperoxaluria ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Hazards Model ◽  
Hazard Ratios ◽  
End Stage

This retrospective analysis investigated plasma oxalate (POx) as a potential predictor of end-stage kidney disease (ESKD) among primary hyperoxaluria (PH) patients. PH patients with type 1, 2, and 3, age 2 or older, were identified in the Rare Kidney Stone Consortium (RKSC) PH Registry. Since POx increased with falling estimated glomerular filtration rate (eGFR), patients were stratified by chronic kidney disease (CKD) subgroups (stages 1, 2, 3a, and 3b). POx values were categorized into quartiles for analysis. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for risk of ESKD were estimated using the Cox proportional hazards model with a time-dependent covariate. There were 118 patients in the CKD1 group (nine ESKD events during follow-up), 135 in the CKD 2 (29 events), 72 in CKD3a (34 events), and 45 patients in CKD 3b (31 events). During follow-up, POx Q4 was a significant predictor of ESKD compared to Q1 across CKD2 (HR 14.2, 95% CI 1.8–115), 3a (HR 13.7, 95% CI 3.0–62), and 3b stages (HR 5.2, 95% CI 1.1–25), p < 0.05 for all. Within each POx quartile, the ESKD rate was higher in Q4 compared to Q1–Q3. In conclusion, among patients with PH, higher POx concentration was a risk factor for ESKD, particularly in advanced CKD stages.

Abstract 17609: Comparison of All-cause and Bleeding-related Hospitalizations Among Non-valvular Atrial Fibrillation Patients Receiving Oral Anticoagulants

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Steve Deitelzweig ◽  
Amanda Bruno ◽  
Kiran Gupta ◽  
Jeffrey Trocio ◽  
Natalie Tate
Keyword(s):  
Atrial Fibrillation ◽  
Lower Risk ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Oral Anticoagulants ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Hazards Model ◽  
Hazard Ratios ◽  
Prescription Date

To compare the risk of hospitalization among non-valvular atrial fibrillation (NVAF) patients newly initiated with an oral anticoagulant (OAC): apixaban, dabigatran, rivaroxaban, or warfarin. Retrospective cohort study using Humana Medicare Advantage data from 7/1/2009 - 9/30/2014. NVAF patients ≥18 years receiving one OAC on the index date with 6 months continuous enrollment prior to index prescription date and 3 months post-index were eligible. Hospitalizations were identified by standard codes for inpatient admission. Bleeding-related hospitalizations required an additional code for major/clinically relevant non-major (CRNM) bleeding. A cox proportional hazards model was used to estimate the hazard ratios (HR) of hospitalizations adjusted for age, sex, region, comorbidities and comedications. Adherence for each OAC was also calculated using a proportion of days covered approach to understand medication taking behaviors. Among the 53,168 patients initiated on an OAC, 2,028 (3.8%) apixaban, 5,644 (10.6%) dabigatran, 7,667 (14.4%) rivaroxaban and 37,829 (71.1%) warfarin. Patients in apixaban cohort were older (mean 75.5 years, P <0.05) with higher mean CHA 2 DS 2- VASc score (P <0.05). Abixaban patients had a higher mean HAS-BLED score vs. dabigatran (P <0.0001), lower mean score vs. warfarin (P <0.0001) and did not differ significantly vs. rivaroxaban (P =0.46). Patients receiving apixaban had a significantly lower risk for all-cause hospitalization across cohorts, and a sig. lower risk for bleeding-related hospitalization vs. patients receiving rivaroxaban or warfarin (Table). Adherence ranged from 87.8% to 90.4% across cohorts. In a real-world setting, initiation with apixaban was associated with a significantly lower risk for all-cause hospitalization, and a significantly lower risk of bleeding-related hospitalization compared to rivaroxaban or warfarin. Table: Adjusted Hazard Ratios of All-cause and Bleeding-related Hospitalizations

scholarly journals Risk factors associated with major adverse cardiac and cerebrovascular events following percutaneous coronary intervention: a 10-year follow-up comparing random survival forest and Cox proportional-hazards model

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Maryam Farhadian ◽  
Sahar Dehdar Karsidani ◽  
Azadeh Mozayanimonfared ◽  
Hossein Mahjub
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Coronary Intervention ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Hazards Model ◽  
Cerebrovascular Events ◽  
Long Term Follow Up ◽  
Stent Length

Abstract Background Due to the limited number of studies with long term follow-up of patients undergoing Percutaneous Coronary Intervention (PCI), we investigated the occurrence of Major Adverse Cardiac and Cerebrovascular Events (MACCE) during 10 years of follow-up after coronary angioplasty using Random Survival Forest (RSF) and Cox proportional hazards models. Methods The current retrospective cohort study was performed on 220 patients (69 women and 151 men) undergoing coronary angioplasty from March 2009 to March 2012 in Farchshian Medical Center in Hamadan city, Iran. Survival time (month) as the response variable was considered from the date of angioplasty to the main endpoint or the end of the follow-up period (September 2019). To identify the factors influencing the occurrence of MACCE, the performance of Cox and RSF models were investigated in terms of C index, Integrated Brier Score (IBS) and prediction error criteria. Results Ninety-six patients (43.7%) experienced MACCE by the end of the follow-up period, and the median survival time was estimated to be 98 months. Survival decreased from 99% during the first year to 39% at 10 years' follow-up. By applying the Cox model, the predictors were identified as follows: age (HR = 1.03, 95% CI 1.01–1.05), diabetes (HR = 2.17, 95% CI 1.29–3.66), smoking (HR = 2.41, 95% CI 1.46–3.98), and stent length (HR = 1.74, 95% CI 1.11–2.75). The predictive performance was slightly better by the RSF model (IBS of 0.124 vs. 0.135, C index of 0.648 vs. 0.626 and out-of-bag error rate of 0.352 vs. 0.374 for RSF). In addition to age, diabetes, smoking, and stent length, RSF also included coronary artery disease (acute or chronic) and hyperlipidemia as the most important variables. Conclusion Machine-learning prediction models such as RSF showed better performance than the Cox proportional hazards model for the prediction of MACCE during long-term follow-up after PCI.

scholarly journals Elevated plasma growth and differentiation factor 15 predicts incident anemia in older adults aged 60 years and older

2020 ◽  
Author(s):  
Yuko Yamaguchi ◽  
Marta Zampino ◽  
Toshiko Tanaka ◽  
Stefania Bandinelli ◽  
Yusuke Osawa ◽  
...  
Keyword(s):  
Older Adults ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Differentiation Factor ◽  
Hazards Model ◽  
Increased Risk ◽  
The Relationship

Abstract Background Anemia is common in older adults and associated with greater morbidity and mortality. The causes of anemia in older adults have not been completely characterized. Although elevated circulating growth and differentiation factor 15 (GDF-15) has been associated with anemia in older adults, it is not known whether elevated GDF-15 predicts the development of anemia. Methods We examined the relationship between plasma GDF-15 concentrations at baseline in 708 non-anemic adults, aged 60 years and older, with incident anemia during 15 years of follow-up among participants in the Invecchiare in Chianti (InCHIANTI) Study. Results During follow-up, 179 (25.3%) participants developed anemia. The proportion of participants who developed anemia from the lowest to highest quartile of plasma GDF-15 was 12.9%, 20.1%, 21.2%, and 45.8%, respectively. Adults in the highest quartile of plasma GDF-15 had an increased risk of developing anemia (Hazards Ratio 1.15, 95% Confidence Interval 1.09, 1.21, P&lt;.0001) compared to those in the lower three quartiles in a multivariable Cox proportional hazards model adjusting for age, sex, serum iron, soluble transferrin receptor, ferritin, vitamin B12, congestive heart failure, diabetes mellitus, and cancer. Conclusions Circulating GDF-15 is an independent predictor for the development of anemia in older adults.

scholarly journals Dementia Adjudication Triggers Associated With Increased Mortality for Older Australians: Evidence From ASPREE

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 161-161
Author(s):  
Jane Banaszak-Holl ◽  
Xiaoping Lin ◽  
Jing Xie ◽  
Stephanie Ward ◽  
Henry Brodaty ◽  
...  
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
The Elderly ◽  
Cox Proportional Hazards ◽  
Service Planning ◽  
Cox Proportional Hazards Model ◽  
Cognitive Test ◽  
Risk Of Death ◽  
Hazards Model ◽  
Using Data

Abstract Research Aims: This study seeks to understand whether those with dementia experience higher risk of death, using data from the ASPREE (ASPirin in Reducing Events in the Elderly) clinical trial study. Methods: ASPREE was a primary intervention trial of low-dose aspirin among healthy older people. The Australian cohort included 16,703 dementia-free participants aged 70 years and over at enrolment. Participants were triggered for dementia adjudication if cognitive test results were poorer than expected, self-reporting dementia diagnosis or memory problems, or dementia medications were detected. Incidental dementia was adjudicated by an international adjudication committee using the Diagnostic and Statistical Manual for Mental Disorders (DSM-IV) criteria and results of a neuropsychological battery and functional measures with medical record substantiation. Statistical analyses used a cox proportional hazards model. Results: As previously reported, 1052 participants (5.5%) died during a median of 4.7 years of follow-up and 964 participants had a dementia trigger, of whom, 575 (60%) were adjucated as having dementia. Preliminary analyses has shown that the mortality rate was higher among participants with a dementia trigger, regardless of dementia adjudication outcome, than those without (15% vs 5%, Χ2 = 205, p &lt;.001). Conclusion: This study will provide important analyses of differences in the hazard ratio for mortality and causes of death among people with and without cognitive impairment and has important implications on service planning.

scholarly journals Evaluation of Changes on World Stock Exchanges in Connection with the SARS-CoV-2 Pandemic. Survival Analysis Methods

Risks ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 121
Author(s):  
Beata Bieszk-Stolorz ◽  
Krzysztof Dmytrów
Keyword(s):  
Survival Analysis ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Stock Exchange ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Stock Exchanges ◽  
Analysis Methods ◽  
Hazards Model ◽  
Kaplan Meier

The aim of our research was to compare the intensity of decline and then increase in the value of basic stock indices during the SARS-CoV-2 coronavirus pandemic in 2020. The survival analysis methods used to assess the risk of decline and chance of rise of the indices were: Kaplan–Meier estimator, logit model, and the Cox proportional hazards model. We observed the highest intensity of decline in the European stock exchanges, followed by the American and Asian plus Australian ones (after the fourth and eighth week since the peak). The highest risk of decline was in America, then in Europe, followed by Asia and Australia. The lowest risk was in Africa. The intensity of increase was the highest in the fourth and eleventh week since the minimal value had been reached. The highest odds of increase were in the American stock exchanges, followed by the European and Asian (including Australia and Oceania), and the lowest in the African ones. The odds and intensity of increase in the stock exchange indices varied from continent to continent. The increase was faster than the initial decline.

scholarly journals Association between milk and yogurt intake and mortality: a community-based cohort study (Yamagata study)

BMC Nutrition ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Akiko Nakanishi ◽  
Erika Homma ◽  
Tsukasa Osaki ◽  
Ri Sho ◽  
Masayoshi Souri ◽  
...  
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Hazard Analysis ◽  
Total Mortality ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Milk Intake ◽  
Community Based ◽  
Hazards Model ◽  
Kaplan Meier

Abstract Background Dairy products are known as health-promoting foods. This study prospectively examined the association between milk and yogurt intake and mortality in a community-based population. Methods The study population comprised of 14,264 subjects aged 40–74 years who participated in an annual health checkup. The frequency of yogurt and milk intake was categorized as none (< 1/month), low (< 1/week), moderate (1–6/week), and high (> 1/day) intake. The association between yogurt and milk intake and total, cardiovascular, and cancer-related mortalities was determined using the Cox proportional hazards model. Results During the follow-up period, there were 265 total deaths, 40 cardiovascular deaths and 90 cancer-related deaths. Kaplan–Meier analysis showed that the total mortality in high/moderate/low yogurt intake and moderate/low milk intake groups was lower than that in none group (log-rank, P < 0.01). In the multivariate Cox proportional hazard analysis adjusted for possible confounders, the hazard ratio (HR) for total mortality significantly decreased in high/moderate yogurt intake group (HR: 0.62, 95% confidence interval [CI]: 0.42–0.91 for high intake, HR: 0.70, 95%CI: 0.49–0.99 for moderate intake) and moderate milk intake group (HR: 0.67, 95% CI: 0.46–0.97) compared with the none yogurt and milk intake groups. A similar association was observed for cancer-related mortality, but not for cardiovascular mortality. Conclusions Our study showed that yogurt and milk intake was independently associated with a decrease in total and cancer-related mortalities in the Japanese population.

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