scholarly journals Extension of Cox Proportional Hazard Model for Estimation of Interrelated Age-period-Cohort Effects on Cancer Survival

2011 ◽  
Vol 10 ◽  
pp. CIN.S6770 ◽  
Author(s):  
Tengiz Mdzinarishvili ◽  
Michael X. Gleason ◽  
Leo Kinarsky ◽  
Simon Sherman
Keyword(s):  
Birth Cohort ◽  
Survival Data ◽  
Hazard Function ◽  
Cohort Effect ◽  
Age At Diagnosis ◽  
Cohort Effects ◽  
Proportional Hazard ◽  
Cox Proportional Hazard ◽  
Time Period ◽  
Birth Cohort Effect

In the frame of the Cox proportional hazard (PH) model, a novel two-step procedure for estimating age-period-cohort (APC) effects on the hazard function of death from cancer was developed. In the first step, the procedure estimates the influence of joint APC effects on the hazard function, using Cox PH regression procedures from a standard software package. In the second step, the coefficients for age at diagnosis, time period and birth cohort effects are estimated. To solve the identifiability problem that arises in estimating these coefficients, an assumption that neighboring birth cohorts almost equally affect the hazard function was utilized. Using an anchoring technique, simple procedures for obtaining estimates of interrelated age at diagnosis, time period and birth cohort effect coefficients were developed. As a proof-of-concept these procedures were used to analyze survival data, collected in the SEER database, on white men and women diagnosed with LC in 1975–1999 and the age at diagnosis, time period and birth cohort effect coefficients were estimated. The PH assumption was evaluated by a graphical approach using log-log plots. Analysis of trends of these coefficients suggests that the hazard of death from LC for a given time from cancer diagnosis: (i) decreases between 1975 and 1999; (ii) increases with increasing the age at diagnosis; and (iii) depends upon birth cohort effects. The proposed computing procedure can be used for estimating joint APC effects, as well as interrelated age at diagnosis, time period and birth cohort effects in survival analysis of different types of cancer.

scholarly journals Influence of birth cohort on age of onset cluster analysis in bipolar I disorder

2015 ◽  
Vol 30 (1) ◽  
pp. 99-105 ◽  
Author(s):  
M. Bauer ◽  
T. Glenn ◽  
M. Alda ◽  
O.A. Andreassen ◽  
E. Angelopoulos ◽  
...  
Keyword(s):  
Family History ◽  
Birth Cohort ◽  
Age Of Onset ◽  
Cohort Analysis ◽  
Cohort Effect ◽  
First Episode ◽  
Mixture Analysis ◽  
Bipolar I Disorder ◽  
Model Based Clustering ◽  
Birth Cohort Effect

AbstractPurpose:Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset, using a large, international database.Methods:The database includes 4037 patients with a diagnosis of bipolar I disorder, previously collected at 36 collection sites in 23 countries. Generalized estimating equations (GEE) were used to adjust the data for country median age, and in some models, birth cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared.Results:There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After adjusting for the birth cohort or when considering only those born after 1959, two subgroups were found. With results of either two or three subgroups, the youngest subgroup was more likely to have a family history of mood disorders and a first episode with depressed polarity. However, without adjusting for birth cohort (three subgroups), family history and polarity of the first episode could not be distinguished between the middle and oldest subgroups.Conclusion:These results using international data confirm prior findings using single country data, that there are subgroups of bipolar I disorder based on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more useful for research.

Gastric Cancer Mortality Trends in Tuscany, Italy, 1971–2004

2008 ◽  
Vol 94 (6) ◽  
pp. 787-792 ◽  
Author(s):  
Giuseppe Gorini ◽  
Lucia Giovannetti ◽  
Giovanna Masala ◽  
Elisabetta Chellini ◽  
Andrea Martini ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
High Risk ◽  
Birth Cohort ◽  
Cancer Mortality ◽  
Cohort Effect ◽  
Low Risk ◽  
Period Effect ◽  
Mortality Trends ◽  
Risk Areas ◽  
Birth Cohort Effect

Aims, Background, and Methods In Tuscany, Italy, gastric cancer mortality has been decreasing since 1950, although with relevant geographical variability across the region. In Eastern Tuscan areas close to the mountains (high risk areas), gastric cancer mortality has been and is still significantly higher than that recorded in Western coastal areas and in the city of Florence (low risk areas). High-risk areas also showed higher Helicobacter pylori seroprevalence. Aim of this paper is to study gastric cancer mortality trends in high and low-risk areas, during the period 1971–2004, using age-period-cohort models. Results In high-risk areas, gastric cancer mortality rates declined from 61.4 per 100,000 in 1971–74 to 19.8 in 2000–2004 and in low-risk areas from 34.9 to 9.8. Mortality decline in high-risk areas was mainly attributable to a birth cohort effect, whereas in low-risk areas it was due either to a birth cohort effect or a period effect. In low- and high-risk areas, birth-cohort risks of dying decreased over subsequent generations, except for the birth cohorts born around the second world war. Conclusions Gastric cancer mortality in areas with higher H. pylori seroprevalence in Tuscany (high-risk areas) showed a predominant decline by birth cohort, in particular for younger generations, possibly due to the decrease of the infection for improvement of living conditions.

Is there a birth cohort effect for Crohn's disease?

2000 ◽  
Vol 118 (4) ◽  
pp. A1359
Author(s):  
Danielle L. Morris ◽  
David A. Leon ◽  
James Kyle ◽  
Scott M. Montgomery ◽  
Roy E. Pounder ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Birth Cohort ◽  
Cohort Effect ◽  
Birth Cohort Effect

scholarly journals High EVI1 Expression Predict Adverse Outcome in Children with Acute Myeloid Leukemia: A Multicenter, Nonrandomized Clinical Study in China

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 37-38
Author(s):  
Yongzhi Zheng ◽  
Jian Li ◽  
Xiaoqin Feng ◽  
Chunfu Li ◽  
Mincui Zheng ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
Hazard Function ◽  
Adverse Outcome ◽  
Proportional Hazard ◽  
Newly Diagnosed ◽  
Blood Cell Count ◽  
Chi Square ◽  
Cox Proportional Hazard ◽  
Chi Square Test ◽  
Pediatric Aml

Backgroud and purpose In clinical studies in adult acute myeloid leukemia (AML), high ecotropic virus integration-1 (EVI1) gene expression has shown to be an independent prognostic factor. However, the predictive value of high EVI1 expression (EVI1+) in children with AML is little known. The purpose of this study was to investigate frequency and prognostic significance of high EVI1 expression in children with AML. Patients and methods Total of 403 newly diagnosed childhood AML patients from 7 centers of south of China from November 2014 to May 2020 were included in the study. A diagnostic assay detecting multiple EVI1 splice variants was developed to determine the relative EVI1 expression by single real-time quantitative polymerase chain reaction in the 403 newly diagnosed pediatirc patients with AML younger than 14 years. Patients were treated with C-HUANAN-AML15 protocol. In the C-HUANAN-AML15 protocol, tandem 2 courses of FLAG-IDA regimen, or sequential DAE(3+5+10) and DAE(3+5+8) were applied as induction chemotherapy. One course of Homoharringtonine (substitution of Amsacrine in MRC-AML 15 protocol)/ Cytarabine/ Etoposide and one course of Mitoxantrone/ Cytarabine in consolidation chemotherapy were uniform in both groups. 75 patients selected hematopoietic stem cell transplantation (HSCT) in first CR. The median follow-up period was 20 (0.8 to 67.7) months up to July 2020. The similarity of clinical data was analyzed by the chi square test and COX proportional hazard function model. Complete remission (CR) rates, event-free survival (EFS) and overall survival (OS) were compared by Log-Rank chi square test. Results EVI1+ was found in 36/403 (8.9%) of children with de novo AML. The clinical features of the patients with EVI1+(n=36) compared with EVI1-(n=367) AML were summarized in Table 1. No significant differences in sex, white blood cell count, and age were noted between EVI1+and EVI1- AML. When studying the relationship between EVI1+ and conventional classification criteria such as morphology (FAB classification) and cytogenetic data, EVI1+ was predominantly found in FAB M7, t(9;11) and other t(v;11q23), as well as complex karyotype, but mutually exclusive with t(8;21), inv(16)/t(16;16), CEBPA, NPM1 or C-KIT mutations. Furthermore, EVI1+ was significantly associated with unfavoralbe cytogenetic risk. Twenty-five patients (22 cases in the EVI1-group and 3 cases in the EVI1+ group) who gave up treatment or transferred to other hospital when treatment was not completed were excluded, and the remaining 378 AML children with standard treatment were included in the survival analysis. Univariate analysis showed that initial white blood cell count (≥50×109/L), RUNX1-RUNX1T1 fusion gene, FLT3-ITD mutation and EVI1+ affected 5-year EFS (P=0.000, 0.001, 0.016, 0.011). Multivariate prognostic analysis with COX proportional hazard function model for EFS identified EVI1+ as an independent prognosis factor (HR0.531, 95%CI 0.298-0.945, P=0.032). Patients with EVI1+ AML (n=12) who received HSCT in first CR had better 5-year EFS, but the difference was not statistically significant (46.103% vs. 56.250%, P=0.33). Conclusion It could be concluded that EVI1+ can be found in ~10% of pediatric AML in China. It is predominantly found in intermediate to unfavorable cytogenetic subtypes and predicts adverse outcome. EVI1 screening at diagnosis should be included in risk stratification of pediatric AML. Whether pediatric patients with EVI1+ AML can benefit from HSCT in first CR needs further reasearch. Disclosures No relevant conflicts of interest to declare.

scholarly journals Improved Cognitive Function in the Tromsø Study in Norway From 2001 to 2016

2021 ◽  
pp. 10.1212/CPJ.0000000000001115
Author(s):  
Bente Johnsen ◽  
Bjørn Heine Strand ◽  
Ieva Martinaityte ◽  
Ellisiv B. Mathiesen ◽  
Henrik Schirmer
Keyword(s):  
Physical Activity ◽  
Birth Cohort ◽  
Age Groups ◽  
Cohort Effect ◽  
Cognitive Test ◽  
Birth Cohorts ◽  
Cohort Differences ◽  
Level Increase ◽  
Drinking Frequency ◽  
Birth Cohort Effect

AbstractObjective:Physical capacity and cardiovascular risk profiles seem to be improving in the population. Cognition have been improving due to a birth cohort effect, but evidence is conflicting on whether this improvement remains in the latest decades, and what is causing the changes in our population over 60 years old. We aimed to investigate birth cohort differences in cognition.Method:The study comprised 9514 participants from the Tromsø study, an ongoing longitudinal cohort study. Participants were in the ages 60–87 years, born between 1914 and 1956. They did four cognitive tests in three waves during 2001-2016. Linear regression was applied, and adjusted for age, education, blood pressure, smoking, hypercholesterolemia, stroke, heart attack, depression, diabetes, physical activity, alcohol use, BMI and height.Results:Cognitive test scores were better in later-born birth cohorts for all age groups, and in both sexes, compared with earlier born cohorts. Increased education, physical activity, alcohol intake, decreasing smoking prevalence and increasing height was associated with one third of this improvement across birth cohorts in women and one half of the improvement in men.Conclusion:Cognitive results were better in more recent born birth cohorts compared with earlier born, assessed at the same age. The improvement was present in all cognitive domains, suggesting an overall improvement in cognitive performance. The 80-year-olds assessed in 2015-16 performed like 60-year-olds assessed in 2001. The improved scores were associated with increased education level, increase in modest drinking frequency, increased physical activity and for men, smoking cessation and increased height.

Persistence of the Decline in the Diagnosis of Schizophrenia Among First Admissions to Scottish Hospitals from 1969 to 1988

1993 ◽  
Vol 163 (5) ◽  
pp. 620-626 ◽  
Author(s):  
John R. Geddes ◽  
Roger J. Black ◽  
Lawrence J. Whalley ◽  
John M. Eagles
Keyword(s):  
Birth Cohort ◽  
Age Groups ◽  
Admission Rate ◽  
Cohort Effect ◽  
Affective Psychoses ◽  
Admission Rates ◽  
Younger Age ◽  
Birth Cohort Effect ◽  
First Admission

Age-standardised rates were calculated for first admissions to hospital in Scotland with ICD-9 diagnoses of schizophrenia, affective psychoses, paranoid psychoses, reactive psychoses and depressive neuroses (ICD-9 295, 296, 297, 298 and 300.4) for the period 1969–88. First-admission rates for schizophrenia declined by an average of 3.3% per year in males and 4.4% per year in females over the period. The first-admission rate in males in 1988 was 8.4/100 000 (57% of 1969 rate) and in females was 4.8/100 000 (43% of 1969 rate). Rates for depressive neuroses, affective psychoses, reactive psychoses and combined psychoses also fell. Rates for mania rose, as did those for paranoid states in males. The decrease in first-admission rates is likely to reflect a true decrease in the incidence of schizophrenia over the period. The decline was unlikely to be accounted for by diagnostic change because there was no reciprocal increase in any other diagnosis sufficient to account for the change, and the rates for combined psychoses also decreased. There was evidence that rates for schizophrenia declined to a greater extent in younger age groups, especially in females. This could imply the presence of a birth cohort effect.

Effect of availability of oral iron chelation therapy (ICT) on initiation, duration, and dose adequacy in patients with myelodysplastic syndromes (MDS) and transfusional iron overload (TIO).

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e17584-e17584
Author(s):  
Steven Gore ◽  
Amy J. Davidoff ◽  
Franklin Hendrick ◽  
Vu Duong ◽  
Bruce C. Stuart ◽  
...  
Keyword(s):  
Chelation Therapy ◽  
Iron Chelation ◽  
Oral Formulation ◽  
Proportional Hazard ◽  
Medicare Beneficiaries ◽  
Ict Use ◽  
Adequate Dose ◽  
Cox Proportional Hazard ◽  
Time Period ◽  
Cox Proportional Hazard Models

e17584 Background: Most patients with MDS do not receive ICT despite evidence of TIO. Till 2005, the only approved ICT was Deferoxamine (DFO), a drug which requires daily prolonged parenteral administration. In addition to therapeutic equipoise of its efficacy, the logistics of administration of DFO may limit ICT use in MDS. We sought to assess whether the approval of an oral ICT (Deferasirox, DFX) in November 2005 has changed ICT use rates, dose adequacy and adherence in MDS patients with TIO. Methods: Using 100% Medicare enrollment and claims data from 2005-2008, we selected beneficiaries with MDS who were enrolled in Medicare Parts A, B, and D and were ICT-eligible based on RBC transfusions ≥ 20 units. Cox proportional hazard models examined the effect of time period relative to DFX market entry on the probability of ICT initiation and the effect of DFX vs. DFO use on duration and dose adequacy. Results: Of 3,843 ICT-eligible patients, 13.8% received ICT, with 81.6% of those receiving DFX, and 29.5% receiving DFO. Relative to the latter half of 2005, the probability of ICT initiation increased beginning in 2007, with a hazard ratio of 1.793 (CI,1.13-2.84; P=0.012) associated with cohort entry in the latter half of 2008. Treatment duration was longer for beneficiaries using DFX (mean 29.7, median 22 weeks) compared to DFO (mean 19.43, median 9 weeks). Only 7.1% of DFO-users received an adequate dose, compared to 72.8% of DFX-users. Conclusions: Use of oral ICT (DFX), following its approval, was associated with increased use, duration and dose adequacy of ICT, compared to DFO, among Medicare beneficiaries with MDS and TIO. The dramatic increase in use associated with availability of an oral formulation may have implications for other new oral chemotherapy and supportive care drugs.

Multiplicative Piecewise Gamma in Survival Data Analysis

2014 ◽  
Vol 70 (1) ◽  
Author(s):  
Noraslinda Mohamed Ismail ◽  
Zarina Mohd Khalid ◽  
Norhaiza Ahmad
Keyword(s):  
Survival Data ◽  
Hazard Function ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Bayesian Estimator ◽  
Proportional Hazard ◽  
Proportional Hazard Model ◽  
Hazards Model ◽  
Proposed Model ◽  
Leukemia Data

The proportional hazard model is the most general of the regression models since it is not based on any assumptions concerning the nature or shape of the underlying survival distribution. The model assumes that the underlying hazard rate is a function of the covariates (independent variables) and there are no assumptions about the nature or shape of the hazard function. Proportional hazards model in survival analysis is used to estimate the effects of different covariates which was influenced by the survival data. This paper proposes the new multiplicative piecewise gamma in the hazard function using OpenBugs Statistical Packages. The proposed model is a flexible survival model for any types of non-informative censored data in estimating the parameters using Bayesian approach and also an alternative model to the existing model. We used the Markov Chain Monte Carlo method in computing the Bayesian estimator on leukemia data. The results obtained show that the proposed model can be an alternative to the existing multiplicative model since it can estimate the parameters using any types of survival data compared to the existing model that can only be used for leukemia data.  

Sign in / Sign up

Export Citation Format

Share Document