Higher Hazard Rate Research Articles

How Morphology Shapes Survival in Invasive Squamous Cell Carcinoma of the Lung.

Squamous cell carcinoma (SQCC) represents a significant proportion of human malignancies affecting various anatomical sites, including the lung. Understanding the prognostic factors is crucial for establishing effective risk stratification in these patients, as multiple critical aspects significantly impact overall survival. A retrospective study was conducted on 99 patients with operable lung SQCC treated at a tertiary center. The exclusion criteria included patients under 18, those with in situ or metastatic SQCC, and those who received neoadjuvant therapy. The surgical specimens were re-analyzed, and data were collected on multiple variables, including pTNM staging, tumor characteristics, and overall survival (OS). The Kaplan-Meier survival analysis and Cox regression models were used to identify significant prognostic factors. The Kaplan-Meier analysis showed a median survival of 36 months with a 65.65% mortality rate. Significant factors influencing survival included keratinization, histological grading, tumor size and stage, pleural invasion, tumor cell arrangement, tumor budding, spread through air space (STAS), and mitotic index. A multiple Cox regression highlighted the nonkeratinizing tumors, advanced pT stages, single-cell invasion, and high mitotic index as key predictors of poorer outcomes. The nonkeratinizing tumors showed higher mortality and shorter median survival rates compared to keratinizing tumors. The tumor staging, cell arrangement, and tumor budding significantly impacted the survival curves. The study underscores the importance of detailed histopathological evaluations in lung SQCC. The nonkeratinizing tumors, advanced pT stage, single-cell invasion, and high mitotic index were associated with higher hazard rates, emphasizing the need for a comprehensive grading system incorporating these factors to improve prognostic accuracy and guide treatment strategies.

Confronting Inequalities and Bridging the Divide: A Retrospective Study Assessment of Country-Level COVID-19 Vaccine Equality with a Cox Regression Model.

COVID-19 vaccination is vital in reducing illness, hospitalization, and mortality in the face of this global pandemic. However, COVID-19 vaccination rates worldwide remain below WHO public health targets, and persistent structural inequities reduce vaccine uptake likelihood among populations of low socioeconomic status. We conducted a cross-sectional study based on publicly available data from the Our World in Data project. We included all 124 countries with available open epidemic data and a population of more than 5 million. We used a Cox Regression Model, with population, population density, median age, human development index, GDP per capita, gender inequality index, healthcare access and quality index, hospital beds per thousand people, completion rate of primary education, infection cases of COVID-19 by the end of 2022, and death rate due to COVID-19 by the end of 2022 as predictors for model hazard rates of completion of 50% population vaccination. According to our study, countries with higher populations, higher population density, higher human development index, lower gender inequality index, and lower hospital beds per 1000 people had a higher hazard rate, which means they were more likely to achieve 50% population vaccination faster. By utilizing the time to achieve vaccination rate goals as our primary endpoint, we evaluated inequity from a dual perspective, considering both the differences in vaccination rates and the duration required to attain them. Consequently, this study employed survival analysis approaches to gain a comprehensive understanding of vaccine drivers and population-level trends nationally and inform all communities from a statistical perspective to prepare for health emergencies. Development-level standing modified the effects of equal access to COVID-19 vaccination on cumulative cases and mortality, for which countries of low or medium human development tended to fare worse in outcomes than high human development countries. As COVID-19 vaccination efforts evolve, healthcare professionals, scholars, and policymakers need to identify the structural impediments to equitable vaccination awareness, access, and uptake so that future vaccination campaigns are not impeded by these barriers to immunization. Recognizing the complex nature of this significant barrier, it is evident that no single statistical analysis method can comprehensively address all intricacies.

Age-related subtypes of late life depression and mortality: Aprospective clinical cohort study.

Late Life Depression (LLD) is associated with increased mortality rates, but it remains unclear which depressed patients are at increased risk. This study examined the mortality risk of previously identified subgroups of depressed older patients based on age-related clinical features (the presence of physical and cognitive frailty). A six-year follow-up of a clinical cohort study including 375 depressed older patients and 132 non-depressed persons (NESDO). Depressed patients were diagnosed with the Composite International Diagnostic Interview (CIDI) according to DSM-IV criteria and classified by latent profile analysis on depressive symptom severity, cognitive domains and physical frailty. We estimated the hazard rate of mortality for the four depressed subgroups compared to non-depressed persons by applying Cox-regression analyses. Models were adjusted for age, sex and education as confounders and for explanatory variables per pathway in separate models: somatic burden, lifestyle characteristics, vascular burden or inflammation markers. A total of 61/375 (16.3%) depressed patients and 8/132 (6.1%) non-depressed persons died during the 6-year follow-up. Two of the four subgroups (n=186/375 (50%) of the depressed sample) had a higher hazard rate (HR) for mortality compared to non-depressed participants, that is, frail-depressed patients (HR=5.25, [95%-CI: 2.13-13.0]) and pure mild depressed patients (HR=3.32 [95%-CI: 1.46-7.58]) adjusted for confounders. Adding possible underlying pathways did not explain these associations. Age-related features (the presence of physical and cognitive frailty) contribute to the increased mortality risk in late-life depression. Future studies in depressed older patients should study the additional value of a clinical geriatric assessment and integrated treatment aimed to at reduce frailty and ameliorate their mortality risk.

Increasing the Retirement Age: Policy Effects and Underlying Mechanisms

We study the effects of increasing the statutory retirement age (SRA) in the Netherlands, using regression discontinuity design and administrative data on the universe of the population. We find clear and large employment effects of the reform. A simple model in which individuals stay longer in their pre-SRA labor market state predicts the treatment effects well. The employment level before the SRA and the retirement hazard at the SRA are the key determinants of the effects of the policy change. Exploring potential explanations for the high hazard rate observed in the Netherlands, our results point to an important role for employers’ effects. (JEL H55, J14, J26, J32)

Risk of gastric adenoma and adenocarcinoma in patients with familial adenomatous polyposis in Japan: a nationwide multicenter study

BackgroundPatients with familial adenomatous polyposis (FAP) have an increased risk of developing gastric neoplasms. However, the clinical course of FAP with these gastric lesions has not yet been fully clarified. The present study aimed to clarify the changes in the incidence risk of developing gastric adenoma or gastric cancer during the lifespan of patients with FAP.MethodsFour hundred forty-three patients with data regarding gastric adenoma and gastric cancer retrospectively registered in a nationwide Japanese multicenter study were enrolled. The cumulative incidences and hazard rates (HRs) of gastric neoplasms were evaluated.ResultsThe cumulative incidence rates in 50-year-old patients with FAP were 22.8% for gastric adenoma and 7.6% for gastric cancer, respectively. No significant association was found between gastric neoplasms and the colonic phenotype. The peak age for the HR of gastric adenoma was 65 years, with the highest HR (0.043). Regarding the incidence of gastric cancer, the HR increased moderately up to the age of 40 years, but the increase accelerated from the age of 50 years (HR = 0.0067).ConclusionCareful surveillance of the upper gastrointestinal tract in elderly patients with FAP, such as shortening the interval of follow-up according to age, may be helpful for early diagnosis of gastric cancer.

Recurrence Patterns and Risk Factors after Curative Resection for Colorectal Cancer: Insights for Postoperative Surveillance Strategies.

This study aimed to assess recurrence patterns and related risk factors following curative resection of colorectal cancer (CRC). This retrospective observational study was conducted at a tertiary care center, including 2622 patients with stage I-III CRC who underwent curative resection between 2008 and 2018. Hazard rates of recurrence were calculated using a hazard function. The primary outcome was the peak recurrence time after curative resection and secondary outcomes were prognostic factors associated with recurrence. Over a median follow-up period of 53 months, the overall, locoregional and systemic recurrence rates were 8.9%, 0.7%, and 8.5%, respectively. Recurrence rates were significantly higher for rectal cancer (14.9% overall, 4.4% locoregionally, and 12.3% systemically) than for colon cancer (all p < 0.001). The peak recurrence time was 11 months, with variations in hazard rates and curves depending on the tumor location, stage, and risk factors. Patients with AL or CRM involvement exhibited a distinct pattern, with a high hazard rate in the early postoperative period. Understanding these recurrence patterns and risk factors is crucial for establishing effective postoperative surveillance strategies. Our findings suggested that short-interval surveillance should be considered during the first 2 years post-surgery, particularly for high-risk patients who should receive early attention.

Application of Hazard Function to Investigate Recurrence of Intrahepatic Cholangiocarcinoma After Curative-Intent Liver Resection: A Novel Approach to Characterize Recurrence.

To investigate recurrence patterns after surgery for intrahepatic cholangiocarcinoma (ICC) relative to lymph node status, tumor extension, tumor burden score (TBS), and adjuvant chemotherapy. Patients who underwent curative-intent resection for ICC from 1990 to 2020 were enrolled from a multi-institutional database. The hazard function was applied to plot the hazard rates over time, with further stratification by T and N AJCC 8th edition categories, TBS, and adjuvant chemotherapy. A total of 1192 patients underwent curative-intent resection for ICC and 59.9% experienced recurrence. Overall, the peak of recurrence occurred at 6.6 months. Among patients with negative lymph nodes, the T4-category had a higher peak rate of recurrence (0.1199 at 10.2 months) compared with other T-categories, while high TBS had an earlier peak of recurrence (4.2 months) compared with lower TBS. Among patients with N1 disease, T2-T4 categories had multipeak patterns of recurrence with higher hazard rates during the first 3 years after surgery in comparison with T1-category, while patients with high TBS had an earlier (4.0 months) and higher hazard peak rate compared with lower TBS groups. The administration of adjuvant chemotherapy was associated with delayed hazard rates of recurrence for N1 (4 months) and NX (6 months) categories. The novel application of the hazard function to assess hazard rates and timing patterns of recurrence following resection for ICC demonstrated that recurrence varied based on T- and N-categories, as well as TBS. Hazard function-based recurrence data may be helpful to tailor counseling, surveillance, and adjuvant therapy recommendations.

Risk of Malocclusion Among Patients Undergoing Single-Stage Versus Two-Stage Cleft Palate Repair.

Evaluate impact of single-stage versus staged palate repair on the risk of developing malocclusion among patients with cleft palate (CP). Retrospective cohort study 2000-2016. Academic, tertiary children's hospital. Patients undergoing CP repair between 1999-2015. CP repair, categorized as either single-stage or staged. Time to development of Class III malocclusion. 967 patients were included; 60.1% had a two-stage CP repair, and 39.9% had single-stage. Malocclusion was diagnosed in 28.2% of patients. In the model examining all patients at ≤5 years (n = 659), patients who were not white had a higher risk of malocclusion (HR 2.46, p = 0.004) and staged repair was not protective against malocclusion (HR 0.98, p = 0.91). In all patients >5 years (n = 411), higher Veau classification and more recent year of birth were significantly associated with higher hazard rates (p < 0.05). Two-staged repair was not protective against developing malocclusion (HR 0.86, p = 0.60). In the model examining patients with staged repair ≤5 years old (n = 414), higher age at hard palate closure was associated with reduced malocclusion risk (HR 0.67, p < 0.001) and patients who were not white had increased risk (HR 2.56, p = 0.01). In patients with staged repair >5 years old, more recent birth year may be associated with a higher risk of malocclusion (HR 1.06, p = 0.06) while syndrome may be associated with lower risk of malocclusion diagnosis (HR 0.46, p = 0.07). Our data suggests that staged CP repair is not protective against developing Class III malocclusion.

Long-term Clinical Outcomes and Prognostic Factors After Endovascular Treatment in Patients With Chronic Limb Threatening Ischemia.

Endovascular therapy (EVT) first strategy has been widely adopted for the treatment of chronic limb threatening ischemia (CLTI) patients in real-world practice. This study aimed to investigate long-term outcomes of CLTI patients who underwent EVT and identify prognostic factors. From the retrospective cohorts of a Korean multicenter endovascular therapy registry, 1,036 patients with CLTI (792 men, 68.8 ± 9.5 years) were included. The primary endpoint was amputation-free survival (AFS) defined as the absence of major amputation or death. Secondary endpoints were major adverse limb events (MALE; a composite of major amputation, minor amputation, and reintervention). Five-year AFS and freedom from MALE were 69.8% and 61%, respectively. After multivariate analysis, age (hazard ratio [HR], 1.476; p<0.001), end-stage renal disease (ESRD; HR, 2.340; p<0.001), Rutherford category (RC) 6 (HR, 1.456; p=0.036), and suboptimal EVT (HR, 1.798; p=0.005) were identified as predictors of major amputation or death, whereas smoking (HR, 0.594; p=0.007) was protective. Low body mass index (HR, 1.505; p=0.046), ESRD (HR, 1.648; p=0.001), femoropopliteal lesion (HR, 1.877; p=0.004), RC-6 (HR, 1.471; p=0.008), and suboptimal EVT (HR, 1.847; p=0.001) were predictors of MALE. The highest hazard rates were observed during the first 6 months for both major amputation or death and MALE. After that, the hazard rate decreased and rose again after 3-4 years. In CLTI patients, long-term outcomes of EVT were acceptable. ESRD, RC-6, and suboptimal EVT were common predictors for poor clinical outcomes. ClinicalTrials.gov Identifier: NCT02748226.

Effect of postmastectomy radiotherapy on pT1-2N1 breast cancer patients with different molecular subtypes

ObjectiveTo clarify the effect of postmastectomy radiotherapy (PMRT) on pT1-2N1 breast cancer patients with different molecular subtypes. MethodsWe retrospectively analyzed the data of 5442 patients with pT1-2N1 breast cancer treated using modified radical mastectomy in 11 hospitals in China. Univariate, multivariate, and propensity score matching (PSM) analyses were used to evaluate the effect of PMRT on locoregional recurrence (LRR). ResultsWith a median follow-up duration of 63.8 months, the 5-year LRR rates were 4.0% and 7.7% among patients treated with and without PMRT, respectively (p < 0.001). PMRT was independently associated with reduced LRR after adjustments for confounders (p < 0.001). After grouping the patients according to the molecular subtype of cancer and conducting PSM, we found that the 5-year LRR rates among patients treated with and without PMRT (in that order) were as follows: luminal HER2-negative cancer, 1.9% and 6.5% (p < 0.001); luminal HER2-positive cancer, 3.8% and 13.7% (p = 0.041); HER2-overexpressing cancer, 10.2% and 15.5% (p = 0.236); and triple-negative cancer, 4.6% and 15.9% (p = 0.002). Among patients with HER2-overexpressing and triple-negative cancers, the LRR hazard rate displayed a dominant early peak, and was extremely low after 5 years. However, patients with luminal cancer continued to have a long-lasting high annual LRR hazard rate during follow-up. ConclusionPMRT significantly reduced the LRR risk in patients with pT1-2N1 luminal and triple-negative breast cancers, but had no effect on the LRR risk in patients with HER2-overexpressing cancer. Patients with different molecular subtypes displayed different annual LRR patterns, and the late recurrence of the luminal subtype suggests the necessity of long-term follow-up to evaluate the efficacy of PMRT.

1414Hormone replacement therapy, oral contraceptives and stroke risk

Abstract Background Millions of women use exogenous hormones as hormone replacement therapy (HRT) or oral contraceptives (OC). Still, time-dependent and long-term consequences of exogenous hormones on cerebrovascular health remains unclear. Methods We examined the effects of HRT and OC usage on stroke risk in 256,661 women from UK Biobank, born between 1939 and 1970. Outcomes included any type of stroke, ischemic stroke (IS), intracerebral hemorrhage (IH), and subarachnoid hemorrhage (SH). Exposures were analyzed as time-dependent variables in Cox regression models. Results are expressed as hazard ratios (HR) with 95% confidence intervals. Results During first year of exposure, HRT usage was associated with higher hazard rates of any stroke (HR = 2.12[1.66-2.70]), IS (HR = 1.93[1.04-3.56]) and SH (HR = 2.14[1.23-3.72]) compared to non-usage, which remained significant only for any stroke during remaining years of exposure. Similarly, we observed an increased hazard of any stroke during first year of OC exposure (HR = 2.29[1.34-3.92]), while the hazards were found to be comparable during remaining years of use (HR = 1.03[0.92-1.17]). Conversely, women who previously had been exposed to OC, had a lower hazard rate of any stroke later in life, (HR = 0.88[0.82-0.94]). Conclusions Our findings suggest that HRT and OC use cause immediate changes in hemostatic balance, therefore increasing the short-term stroke risk. However, long-term effects of OC use during reproductive years might improve cerebrovascular health and prevent stroke events later in life. Key messages HRT usage increase the risk of stroke, both short-term and with longer use, while the increased stroke risk might be limited to the first year of OC use.

Abstract P645: Sex Differences in the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) Trial

Introduction: Sex differences have been noted in stroke and estrogen is associated with decreased platelet aggregation. The purpose of this study was to assess sex differences in the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) study. Methods: We performed a secondary analysis of the POINT study. Patients were analyzed by intention to treat group: 1) Males, standard (n=1351) aspirin; 2) Males, intervention (n=1335) clopidogrel+aspirin; 3) Females; standard (n=1098) aspirin; and 4) Females, intervention (n=1097) clopidogrel+aspirin. Groups were compared for baseline demographics via ANOVA followed by Mann Whitney U. A Cox Proportional Hazards Model was used to assess the primary safety and efficacy outcomes. Results: Baseline characteristics were significantly different only for race (p&lt;.001) with white race being most represented. The primary outcome occurred in 6.4% of standard males, 6.7% of standard females, 5.1% of intervention males, and 4.8% of intervention females (p=0.12). Cox models suggest that male intervention participants had lower hazard rate compared to male standard participants (HR=0.79, CI:0.58-1.09) and female intervention participants had a lower hazard compared to male standard (HR=0.76, CI: 0.54-1.07) but this was not statistically significant. Major hemorrhage occurred in 0.4% of standard males, 0.5% of standard females, 0.8% of intervention males, and 1.1% of intervention females (p=0.11). Female intervention subjects had a significantly higher hazard rate of major hemorrhage compared to standard males (HR=2.99, CI:1.06-8.52) with no other between group differences. Conclusion: This study found that there were no significant sex differences in the reduction of recurrent vascular events in the POINT trial. The rate of major hemorrhage was higher in female intervention compared to male standard subjects, but there was no difference in rates between the female groups or the male intervention group. Future studies must provide a sample size with enough power to assess for sex differences to optimize care. Both males and females benefit from combination therapy but the risk of major hemorrhage must be considered.

Reliability-Aware Cost-Efficient Scientific Workflows Scheduling Strategy on Multi-Cloud Systems

Nowadays, more and more computation-intensive scientific applications with diverse needs are migrating to cloud computing systems. However, the cloud systems alone cannot meet applications’ requirements at all times with the increasing demands from users. Therefore, the multi-cloud systems that can provide scalable storage and computing resources become a good solution. The main challenges for such systems are multiple billing mechanisms, virtual resources heterogeneity, and systems reliability. In response to these challenges, we first build a multi-cloud systems fault-tolerant workflow scheduling framework, which tries to improve the scientific applications execution reliability and reduce their execution cost. Then, we use Weibull distribution to analyze task execution reliability and hazard rate, which is used to duplicate task with high execution hazard rate. Third, we integrate different multi-cloud providers’ billing mechanism into the proposed scheduling framework, and this workflow scheduling problem is mathematically formulated as an optimization problem. Fourth, we define the DAG tasks cost-efficient bottom level, and propose a fault-tolerant cost-efficient workflow scheduling algorithm (FCWS) that minimizes application execution cost, time while ensuring their reliability. Simulation experiments for performance evaluation were conducted based on two real-world applications: Epigenomics and LIGO. The results clearly demonstrate that our proposed FCWS algorithm outperforms existing FR-MOS, CWS in terms of cost and reliability, and FCWS is also better than CWS and inferior to FR-MOS in term of makespan.

Hazard function analysis of metastatic recurrence after colorectal cancer surgery-A nationwide retrospective study.

An optimal postoperative surveillance protocol for colorectal cancer (CRC) is dependent on understanding the time line of recurrence. By hazard function analysis, this study aimed at evaluating the time of occurrence of metastasis. A total of 21,671 Stage I-III colon cancer patients were retrospectively included from the Japanese study group for postoperative follow-up of colorectal cancer database. The 5-year incidence by metastasized organ was 6.3% for liver (right:left = 5.5%:7.0%, p = .0067), 6.0% for lung (right:left:rectum = 3.7%:4.4%:8.8%, p = 7.05E-45), and 2.0% for peritoneal (right:left:rectum = 3.1%:2.0%:1.2%, p = 1.29E-12). The peak of liver metastasis hazard rate (HR) (0.67 years) was earlier and higher than those of other metastases. The peak HR tended to be delayed in early stage CRCs (0.91, 0.76, and 0.52 years; for Stages I, II, and III, respectively). When analyzed as per the primary tumor location (right-sided, left-sided, and rectum), the peak HR for lung metastasis was twice as high for rectal cancer than for colon cancer, and peritoneal metastasis had a high HR in right-sided colon cancers. The time course for the risk of recurrence in various metastatic organs based on the primary tumor site was clearly visualized in this study. This will aid in individualizing postoperative surveillance schedules.

Statistical Joint Modeling for Predicting the Association of CD4 Measurement and Time to Death of People Living with HIV Who Enrolled in ART, Southwest Ethiopia.

BackgroundIn much epidemiological HIV research, patients are often followed over a period of time to predict their survival on the basis of repeatedly measured CD4 status. To predict survival, statistical models of the association between mortality and longitudinal CD4 measurement have been conducted widely using time-varying Cox models. However, in the presence of repeated measure, this approach leads to biased estimates. In view of the limitation of time-varying Cox models, in the present study, we considered joint modeling to predict the association of longitudinal CD4 measurement and time to death among patients initiated on ART.MethodsA retrospective cohort study was employed for five years from 2009 to 2014 on a randomly selected 358 samples. Data were collected from patients’ ART and pre-ART follow-up registration book, database and other clinical records. Data were analyzed using joint latent class modeling of repeated CD4 measurement and time-to-event (HIV death).ResultsWe have studied a total of 358 HIV-positive patients. The median and interquartile ranges of the age of patients were 30.31 years and 13.82, respectively. Males constitute the larger proportion, 51.68%. The square root of CD4 count has declined on average over time. This has been indicated with the negative sign of the coefficient for the time effect. The deterioration of health of individuals is severe in class 1, it has been observed with a worse decline in CD4 cell counts over time in this class than other classes (β= −0.488). Women had a larger risk rate than men (β=−2.475, p-value=0.013). Besides, the CD4 counts measurement of patients has been revealed to decrease as age increases (β= −0.016, p=0.008).ConclusionThe finding indicated that the square root CD4 cell measurement dropped over time in the three classes. This clearly suggested deterioration in the health of individuals. Women were found to have a higher hazard rate than men.

Bayesian frailty modeling of correlated survival data with application to under-five mortality

BackgroundThere is high rate of under-five mortality in West Africa with little effort made to study determinants that significantly increase or decrease its risk across the West African sub-region. This is important since it will help in the design of effective intervention programs for each country or the entire region. The overall objective of this research evaluates the determinants of under-five mortality prior to the end of the 2015 Millennium Development Goals, to guide West African countries implement strategies that will aid them achieve the Sustainable Development Goal 3 by 2030.MethodThis study used the Demographic and Health Survey (DHS) data from twelve (12) out of the eighteen West African countries; Ghana, Benin, Cote d’ Ivoire, Guinea, Liberia, Mali, Niger, Nigeria, Sierra Leone, Burkina Faso, Gambia and Togo. Data were extracted from the children and women of reproductive age files as provided in the DHS report. The response or outcome variable of interest is under-five mortality rate. A Bayesian exponential, Weibull and Gompertz regression models via a gamma shared frailty model were used for the analysis. The deviance information criteria and Bayes factors were used to discriminate between models. These analyses were carried out using Stata version 15 software.ResultsThe study recorded 101 (95% CI: 98.6–103.5) deaths per 1000 live births occurring among the twelve countries. Burkina Faso (124.4), Cote D’lvoire (110.1), Guinea (116.4), Nigeria (120.6) and Niger (118.3) recorded the highest child under-5 mortality rate. Gambia (48.1), Ghana (60.1) and Benin (70.4) recorded the least unde-5 mortality rate per 1000 livebirths. Multiple birth children were about two times more likely to die compared to singleton birth, in all except Gambia, Nigeria and Sierra Leone. We observed significantly higher hazard rates for male compared to female children in the combined data analysis (HR: 1.14, 95% CI: [1.10–1.18]). The country specific analysis in Benin, Cote D’lvoire, Guinea, Liberia, Mali and Nigeria showed higher under-5 mortality hazard rates among male children compared to female children whilst Niger was the only country to report significantly lower hazard rate of males compared to females.ConclusionThere is still quite a substantial amount of work to be done in order to meet the Sustainable Development Goal 3 in 2030 in West Africa. There exist variant differences among some of the countries with respect to mortality rates and determinants which require different interventions and policy decisions.

Sink or Swim? A survival analysis of sport dropout in Australian youth swimmers.

To examine long-term participation and dropout rates in Australian youth swimming using survival analyses and to determine whether multiple individual, socio-demographic, and competition-related factors influenced dropout. Retrospective cohort study of registration and competitive performance data. Part 1-Registration data from N=17161 female (n=9400) and male (n=7761) New South Wales (NSW) swimmers aged 10-15years (inclusive). Part 2-Competition level involvement in a subsample of female (n=1011) and male (n=811) swimmers, aged 12-15years, was also examined. To determine dropout rates and influential factors, Kaplan-Meier survival analyses supplemented by Cox regression were used. (1) Kaplan-Meier analyses identified median sustained participation rates of four years (95% CI=3.93-4.06), with 15.9% maintaining participation over 10years. Cox regressions identified age-group was associated with dropout (P<.001), with a 184.9% higher Hazard Rate (HR) for 10- vs 15-year-olds. Residential proximity to major cities was associated with dropout (P<.001), with urban swimmers reporting a 24.8% higher HR rate than rural swimmers. Sex and relative age were not associated with dropout. (2) The subsample median sustained participation was five years (95% CI=4.79-5.20), with 25.3% maintaining participation for ten years. Level of competition was associated (P<.001), with an 86% higher HR when considering lower competition levels (ie, club/district v national). In a large representative sample of swimmers, survival analyses identified age-group, competition level, and city proximity were associated with increased swimming dropout rates.

Predicting the Survival of AIDS Patients Using Two Frameworks of Statistical Joint Modeling and Comparing Their Predictive Accuracy

The present study aimed to estimate the survival of HIV-positive patients and compare the accuracy of two commonly used models, Shared Random-Effect Model (SREM) and Joint Latent Class Model (JLCM) for the analysis of time to death among these patients. Data on a retrospective survey among HIV-positive patients diagnosed during 1989-2014 who referred to the Behavioral Diseases Consultation Center of Mashhad University of Medical Sciences was used in this study. Participants consisted of HIV-positive high-risk volunteers, referrals of new HIV cases from prisons, blood transfusion organization and hospitals. Subjects were followed from diagnosis until death or the end of study. SREM and JLCM were used to predict the survival of HIV/AIDS patients. In both models age, sex and addiction were included as covariates. To compare the accuracy of these alternative models, dynamic predictions were calculated at specific time points. The receiver operating characteristic (ROC) curve was used to select the more accurate model. Overall, 213 patients were eligible that met entry conditions for the present analysis. Based on BIC criteria, three heterogeneous sub-populations of patients were identified by JLCM and individuals were categorized in these classes ("High Risk", "Moderate Risk" and "Low Risk") according to their health status. JLCM had a better predictive accuracy than SREM. The average area under ROC curve for JLCM and SREM was 0.75 and 0.64 respectively. In both models CD4 count decreased with time. Based on the result of JLCM, men had higher hazard rate than women and the CD4 counts levels of patients decreased with increasing age. Predicting risk of death (or survival) is vital for patients care in most medical research. In a heterogeneous population, such as HIV-positive patients fitting JLCM can significantly improve the accuracy of the risk prediction. Therefore, this model is preferred for these populations.

Reliability modelling with redundancy—A case study of power generation engines in a wastewater treatment plant

AbstractPower generators are critical assets in wastewater treatment plants (WWTPs) in Australia and many countries. Better managing the lifetime, minimising failures, improving reliability and availability, and reducing operating and maintenance costs of the power generation assets are still challenging topics for water utilities. This case study aims to develop power generation system reliability and availability modelling considering redundancy to minimise operation and maintenance costs. The two‐parameter Weibull model was used to assess system reliability and availability to power generation engines in WWTPs. The Kaplan‐Meier method (a time‐driven estimation technique) and the log beta‐Weibull model (which is suitable for modelling censored and uncensored data) were used to analyse and validate the modelling results. Shape and scale parameters of the Weibull models were estimated by maximising the log‐likelihood function using non‐linear optimisation. Hazard and reliability functions were calculated using the Weibull model. Results using two‐parameter Weibull, Kaplan‐Meier, and log beta‐Weibull models display low reliability and high hazard rate over time, which was associated with spark plug failure due to a suboptimal start and stop operation strategy.

Two theoretical strands of social capital, and total, cardiovascular, cancer and other mortality: A population-based prospective cohort study

The aim is to prospectively investigate both the “cohesion” and “network” perspectives of social capital in relation to total, cardiovascular (CVD), cancer and all other causes mortality. The 2008 public health survey in Scania was a postal questionnaire with three letters of reminder, and it was answered in the Autumn by 28,198 respondents (55% participation) aged 18–80 from a stratified random sample of the population register. This baseline was connected with the national causes of death registry (Dödsorsaksregistret) with a more than five-year follow-up August 27- November 14 (depending on individual response) to December 31, 2013 (946 deaths). The analyses were performed in multiple adjusted survival (Cox-) regression models. Results show that low social participation, common to both theoretical perspectives, had consistently high hazard rate ratios (HRRs) of total, CVD, cancer and other morality, and that HRRs of total and CVD mortality remained statistically significant even after adjustments for all covariates including health behaviors, BMI, unmet healthcare needs and self-rated health, HRR 1.28 (1.08–1.52) and HRR 1.79 (1.28–2.50), respectively. In contrast, low social support, specific to the “network” perspective, showed no significant associations with mortality, except for low emotional and instrumental support and other causes mortality for which HRRs remained significant adjusted for demographics and socioeconomic status (SES). Generalized trust in other people, specific to the “cohesion” perspective, showed statistically significant HRRs for total and other causes mortality until adjustments for health-related behaviours and BMI, although not after complete adjustments, and significant HRRs for CVD and cancer mortality before adjustment for health behaviours. In conclusion, low social participation is consistently associated with all forms of mortality, and particularly total and CVD mortality. Social participation represents a strong core of social capital theory, and items should measure both variety of social contact surfaces and intensity.