Use of Schoenfeld’s global test to test the proportional hazards assumption in the Cox proportional hazards model: an application to a clinical study

Abeysekera, Wwm; Sooriyarachchi, M. R.

doi:10.4038/jnsfsr.v37i1.456

Cited by 64 publications

(53 citation statements)

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“…Subsequently, multivariable proportional hazards models were conducted, adjusting for age, sex, race, education, marital status, family history of dementia, BIMC score, MADRC Dementia Severity Rating, duration of symptoms, speed of onset, disease course, Deyo‐Charlson Comorbidity Index and previous acute hospitalization. The Schoenfeld global test 24 was conducted to test the proportionality assumption, which was not violated in any of the models. The Gompertz model 25 was used to confirm the results of the Cox models.…”

Section: Methodsmentioning

confidence: 99%

Hospitalization in Community‐Dwelling Persons with Alzheimer's Disease: Frequency and Causes

Rudolph

Zanin

Jones

et al. 2010

J American Geriatrics Society

177

200

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Objectives-To examine the rates of and risk factors for acute hospitalization in a prospective cohort of older community-dwelling Alzheimer's disease (AD) patients Design-Longitudinal patient registry Setting-AD Research CenterParticipants-827 older persons with AD Measurements-Acute hospitalization after AD research center visit was determined from Medicare database. Risk factor variables included demographics, dementia-related, comorbidity and diagnoses were measured by interviews and Medicare data. Conclusion-In community-dwelling population with generally mild AD, hospitalization is frequent, occurring in two-thirds of participants over a median follow-up time of 3 years. With these results, clinicians may be able to identify dementia patients at high risk for hospitalization. Results-Of

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Section: Methodsmentioning

confidence: 99%

Hospitalization in Community‐Dwelling Persons with Alzheimer's Disease: Frequency and Causes

Rudolph

Zanin

Jones

et al. 2010

J American Geriatrics Society

177

200

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“…The proportional hazard assumption was controlled by computing and plotting the Schoenfeld residuals for each covariate using the survival and graphic packages in R statistics [1,13,33]. The cumulative survival and histogram graphs were created with the graphics package in R statistics.…”

Section: Methodsmentioning

confidence: 99%

Method of Fixation Does Not Influence the Overall Risk of Rerevision in First-time Cup Revisions

Mohaddes

Garellick

Kärrholm

2013

Clinical Orthopaedics &Amp; Related Research

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Background During the last two decades, uncemented fixation has been increasingly preferred worldwide during cup revision surgery. In Sweden, the number of uncemented cup revisions has been increasing during the last decade. However, it is unclear whether the risk of rerevision differs between cemented and uncemented cups. Question/purposes We determined (1) the risk of rerevision after cemented and uncemented fixation; (2) the influence of concomitant stem revision on the risk of rerevision of the cup; (3) the difference in risk of rerevision of an uncemented cup revision compared with liner revision only; and (4) whether the surgical incision influenced the risk of rerevision. Methods Between 1979 and 2010, 19,342 first-time cup revisions were reported to the Swedish Hip Arthroplasty Register. From these, 749 were excluded (hip resurfacing, cases with tumor diagnoses, and missing data) leaving 18,593 (73% cemented) for further analysis. We used a Cox regression model adjusted for age, sex, primary diagnosis, method of fixation, concomitant stem revision, and cemented/uncemented fixation to assess risk of rerevision. Results The relative risk for rerevision for any reason did not differ between cemented and uncemented fixation (relative risk [RR], 0.94). If the stem was not revised at index revision, the risk of further cup revision increased twofold (RR, 1.91). Liner revisions were associated with a 70%

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“…However, it is possible to check the assumptions in a non-parametric hazards model if one uses Schoenfeld residuals, test χ 2 and the Rho coefficient of rank correlation between residuals and time. Obtaining a horizontal regression line of residuals across the time axis confirms the proportionality of hazard (Abeysekera et al, 2009;Grambsch et al, 1994;Keele, 2010;Schoenfeld, 1982;Winett et al, 2001). Unfortunately, this important assumption has been checked and properly reported in very few scientific publications.…”

Section: Factors Influencing Long-term Prognosis In the Cox Proportiomentioning

confidence: 99%

“…In backward stepwise analysis, variables for which significance level p exceeded 0.05 were eliminated in order, from the highest to the lowest p value. The proportional hazard assumptions were verified using Schoenfeld residuals, χ 2 test and rank correlation coefficient Rho between residuals and time (Abeysekera et al, 2009;Schoenfeld, 1982). Results of Cox analysis were presented as hazard rate (HR) with a 95% confidence interval, z-statistic and corresponding p value.…”

Section: Methodsmentioning

confidence: 99%

“…For two units of defined values of covariates, the ratio of time-estimated hazard values should be constant. Failure to fulfill this assumption leads to a false model and to treating all hazard factors obtained in the model as essential and time-independent predictive factors (Abeysekera et al, 2009;Grambsch et al, 1994;Keele, 2010;Schoenfeld, 1982;Winett et al, 2001).…”

Section: Factors Influencing Long-term Prognosis In the Cox Proportiomentioning

confidence: 99%

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Limitations of Cox Proportional Hazards Analysis in Mortality Prediction of Patients with Acute Coronary Syndrome

Babińska

Chudek

Chełmecka

et al. 2015

Studies in Logic, Grammar and Rhetoric

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Abstract. The aim of this study was to evaluate the possibility of incorrect assessment of mortality risk factors in a group of patients affected by acute coronary syndrome, due to the lack of hazard proportionality in the Cox regression model. One hundred and fifty consecutive patients with acute coronary syndrome (ACS) and no age limit were enrolled. Univariable and multivariable Cox proportional hazard analyses were performed. The proportional hazard assumptions were verified using Schoenfeld residuals, χ2 test and rank correlation coefficient t between residuals and time. In the total group of 150 patients, 33 (22.0%) deaths from any cause were registered in the follow-up time period of 64 months. The non-survivors were significantly older and had increased prevalence of diabetes and erythrocyturia, longer history of coronary artery disease, higher concentrations of serum creatinine, cystatin C, uric acid, glucose, C-reactive protein (CRP), homocysteine and B-type natriuretic peptide (NT-proBNP), and lower concentrations of serum sodium. No significant differences in echocardiography parameters were observed between groups. The following factors were risk of death factors and fulfilled the proportional hazard assumption in the univariable model: smoking, occurrence of diabetes and anaemia, duration of coronary artery disease, and abnormal serum concentrations of uric acid, sodium, homocysteine, cystatin C and NT-proBNP, while in the multivariable model, the risk of death factors were: smoking and elevated concentrations of homocysteine and NT-proBNP. The study has demonstrated that violation of the proportional hazard assumption in the Cox regression model may lead to creating a false model that does not include only time-independent predictive factors.

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Use of Schoenfeld’s global test to test the proportional hazards assumption in the Cox proportional hazards model: an application to a clinical study

Cited by 64 publications

References 0 publications

Hospitalization in Community‐Dwelling Persons with Alzheimer's Disease: Frequency and Causes

Hospitalization in Community‐Dwelling Persons with Alzheimer's Disease: Frequency and Causes

Method of Fixation Does Not Influence the Overall Risk of Rerevision in First-time Cup Revisions

Limitations of Cox Proportional Hazards Analysis in Mortality Prediction of Patients with Acute Coronary Syndrome

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