scholarly journals Survival Analysis of Cholera Patients a Parametric and Non-parametric Approach

2019 ◽  
pp. 1-18
Author(s):  
Umar M. Hassan ◽  
A. A. Abiodun
Keyword(s):  
Risk Factors ◽  
Survival Analysis ◽  
Survival Probability ◽  
Failure Time ◽  
Parametric Method ◽  
Significant Risk ◽  
Rank Test ◽  
Parametric Approach ◽  
Survival Times ◽  
Non Parametric

Aims: The aim of this study is to investigate survival probability of cholera patients who were under follow-up and identify significant risk factors for mortality. Methodology: In this research, we present the basic concepts, nonparametric methods (the Kaplan-Meier method and the log-rank test) and parametric method. Parametric AFT models (Exponential, Weibull, Lognormal and Log logistic) were compared using Akaike’s Information Criterion (AIC). Results: Recorded data of 513 patients were obtained from UNICEF Cholera Hospital for Internally Displaced Persons Camps within Maiduguri, Borno State. Non-Parametric and Parametric approach were used to estimate the survival probability of the patients and examine the association between the survival times with different risk factors. The analysis shows that some factors significantly contribute to longer survival time of cholera patients. These factors include being a female, age less than twenty, being vaccinated before the infection and mild degree of dehydration. Conclusion: The vaccination, age, sex and degree of dehydration of a cholera patient affects its survival hence, much attention should be given to older patients, degree of dehydration and vaccine (killed oral 01 with whole-cell with Bsubunit) should be administered whenever there is outbreak. When carrying out survival analysis of this kind, a Weibull model is Recommended for used while if dealing with Accelerated Failure Time models.

scholarly journals The impact of socio-demographic factors on the survival of cancer patients in Zimbabwe

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Idika E. Okorie ◽  
Ricardo Moyo ◽  
Saralees Nadarajah
Keyword(s):  
Risk Factors ◽  
Survival Analysis ◽  
Marital Status ◽  
Cancer Patients ◽  
Hazard Rate ◽  
Significant Risk ◽  
Demographic Factors ◽  
Female Cancer Patients ◽  
Socio Demographic Factors ◽  
The Impact

AbstractWe provide a survival analysis of cancer patients in Zimbabwe. Our results show that young cancer patients have lower but not significant hazard rate compared to old cancer patients. Male cancer patients have lower but not significant hazard rate compared to female cancer patients. Race and marital status are significant risk factors for cancer patients in Zimbabwe.

scholarly journals Patterns and patient factors associated with loss to follow-up in the Muhimbili sickle cell cohort, Tanzania

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Upendo Masamu ◽  
Raphael Z. Sangeda ◽  
Daniel Kandonga ◽  
Jesca Ondengo ◽  
Flora Ndobho ◽  
...  
Keyword(s):  
Survival Analysis ◽  
Sickle Cell ◽  
Retention Rate ◽  
Clinical Care ◽  
Parametric Method ◽  
Comprehensive Care ◽  
Rank Test ◽  
Mean Cell Volume ◽  
Loss To Follow Up

Abstract Background Monitoring patient’s clinical attendance is a crucial means of improving retention in care and treatment programmes. Sickle cell patients’ outcomes are improved by participation in comprehensive care programmes, but these benefits cannot be achieved when patients are lost from clinical care. In this study, patients are defined as loss to follow-up when they did not attend clinic for more than 9 months. Precise information on the retention rate and characteristics of those who are not following their clinic appointments is needed to enable the implementation of interventions that will be effective in increasing the retention to care. Method This was a retrospective study involving sickle cell patients registered in the Muhimbili Sickle Cohort in Tanzania. Descriptive and survival analysis techniques both non-parametric methods (Kaplan-Meier estimator and Log-rank test) and semi-parametric method (Cox’s proportional hazard model), were used. A p-value of 0.05 was considered significant to make an inference from the analysis. Results A total of 5476 patients were registered in the cohort from 2004 to 2016. Of these, 3350 (58.13%) were actively participating in clinics, while 2126 (41.87%) were inactive, of which 1927 (35.19%) were loss to follow-up. We used data from 2004 to 2014 because between 2015 and 2016, patients were referred to other government hospitals. From the survival analysis results, pediatric (HR: 14.29,95% CI: 11.0071–18.5768, p <  0.001) and children between 5 and 17 years [HR:2.61,95% CI:2.2324–3.0705, p <  0.001] patients were more likely to be loss to follow-up than the adult (18 and above years) patients. It was found that patients with above averages for hematocrit (HR: 2.38, 95% CI: 1.0076–1.0404, p = 0.0039) or mean cell volume (HR: 4.28, (95% CI: 1.0260–1.0598, p < 0.001) were more likely to be loss to follow-up than their counterparts. Conclusion Loss to follow-up is evident in the cohort of patients in long term comprehensive care. It is, therefore, necessary to design interventions that improve patients’ retention. Suggested solutions include refresher training for health care workers and those responsible for patient follow-up on techniques for retaining patients and comprehensive transition programs to prepare patients who are moving from pediatric to adult clinics.

scholarly journals Adherence patterns among patients receiving  healthcare services in the Muhimbili Sickle Cell Cohort, Tanzania

2020 ◽  
Author(s):  
Upendo Masamu ◽  
Raphael Zozimus Sangeda ◽  
Daniel Kandoga ◽  
Jesca Ondego ◽  
Florah Ndobho ◽  
...  
Keyword(s):  
Survival Analysis ◽  
Sickle Cell ◽  
Parametric Method ◽  
Healthcare Services ◽  
Rank Test ◽  
P Value ◽  
Mean Cell Volume ◽  
Loss To Follow Up ◽  
Lost To Follow Up

Abstract Background: Monitoring of patient’s clinical attendance is one of the crucial means that is used to improve adherence to care and treatment among the Sickle Cell Disease (SCD) patients. Adherence to care has been shown to improve health outcomes in SCD patients. However, these benefits cannot be achieved when patients are lost to follow-up to care. Method : We analyzed data on loss to follow up to determine the patterns among sickle cell patients registered at Muhimbili Sickle Cell Cohort (MSC), in Dar es Salaam, Tanzania. Data was aggregated and analysed using R software and Microsoft Excel Spreadsheet. Survival analysis techniques, both non-parametric methods (Kaplan-Meier estimator and Log-rank test) and semi-parametric method (Cox’s proportional hazard model), were used. A p-value of 0.05 was considered significant to make a strong inference of the analysis. Results: 5476 SCD patients were registered at MSC from 2004 to 2016, 3350 (58.13%) were actively participating in clinics while, 2126 (41.87%) were inactive, out of which 35.19% were lost to follow-up. From the survival analysis results, patients who were between 5 to 17 years were more likely to be lost to follow-up than the rest with a hazard ratio of 2.65 times more than those who were above 18 years. Patients with mean cell volume above 77.73 fL and white blood cell above 15.73(10ˆ3/uL) were more likely to be loss to follow-up than those below average. Conclusion: Loss to follow-up is evident in a cohort of patients in long term comprehensive care follow-up. It is, therefore, necessary to design interventions that minimize its impacts. Suggested solutions might include training of the health care workers, more emphasis on newborn screening and advocacy to patients regarding the effect of loss to follow-up.

scholarly journals A Non-Parametric Approach for Survival Analysis of Component-Based Software

2020 ◽  
Vol 5 (2) ◽  
pp. 309-318
Author(s):  
Sandeep Chopra ◽  
Lata Nautiyal ◽  
Preeti Malik ◽  
Mangey Ram ◽  
Mahesh K. Sharma
Keyword(s):  
Survival Analysis ◽  
Failure Rate ◽  
Growth Models ◽  
Reliability Estimation ◽  
Parametric Models ◽  
Model Parameters ◽  
Parametric Approach ◽  
Estimation Model ◽  
Failure Data ◽  
Non Parametric

Reliability of a software or system is the probability of system to perform its functions adequately for the stated time period under specific environment conditions. In case of component-based software development reliability estimation is a crucial factor. Existing reliability estimation model falls into two broad categories parametric and non-parametric models. Parametric models approximate the model parameters based on the assumptions of fundamental distributions. Non-parametric models enable parameter estimation of the software reliability growth models without any assumptions. We have proposed a novel non-parametric approach for survival analysis of components. Failure data is collected based on which we have calculated failure rate and reliability of the software. Failure rate increases with the time whereas reliability decreases with the time.

Risk factors for 6-month continuation of S-1 adjuvant chemotherapy for resected pancreatic cancer.

2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 471-471
Author(s):  
Yusuke Katayama ◽  
Toru Aoyama ◽  
Masahiro Asari ◽  
Masaaki Murakawa ◽  
Koichiro Yamaoku ◽  
...  
Keyword(s):  
Risk Factors ◽  
Pancreatic Cancer ◽  
Adjuvant Chemotherapy ◽  
Serum Creatinine ◽  
Serum Creatinine Level ◽  
Creatinine Level ◽  
Significant Risk ◽  
Rank Test ◽  
Independent Predictive Factor ◽  
Significant Difference

471 Background: The factors which affect the six-month continuation of adjuvant chemotherapy with S-1 have not been fully evaluated in pancreatic cancer. The objective of this retrospective study was to clarify the risk factors for the discontinuation of S-1 adjuvant chemotherapy after six months of treatment. Methods: The study included patients who underwent curative surgery for pancreatic cancer, were diagnosed with stage II or III disease, had a serum creatinine level < 1.2 mg/dl and received adjuvant S-1 between June 2007 and March 2014. Results: Forty patients were eligible for the present study. A comparison of the six-month continuation stratified by each clinical factor using the log-rank test revealed a significant difference in the creatinine clearance (CCr) between the patients who continued and discontinued the treatment. A CCr of 60 ml/min was regarded as a critical point. The uni- and multivariate Cox’s proportional hazard analyses demonstrated that the CCr was the only significant independent predictive factor. The six-month continuation rate was 70.8% in the patients with a CCr > 60 ml/min, and was 25.0% in patients with a CCr < 60 ml/min (P=0.008). The patients with a CCr < 60 ml/min developed adverse events more frequently and earlier than those with a CCr > 60 ml/min. Conclusions: A CCr < 60 ml/min was a significant risk factor for the six-month discontinuation of S-1 adjuvant chemotherapy in pancreatic cancer patients, even though the renal function was judged to be normal based on the serum creatinine level. Careful attention is therefore required to improve the S-1 continuation in patients with a CCr < 60 ml/min.

scholarly journals REGIONAL CONVERGENCE IN NORTH AFRICA REGIONS : PARAMETRIC AND NON PARAMETRIC APPROACHES

2021 ◽  
pp. 13-19
Author(s):  
Mohamed HAZEM
Keyword(s):  
Spatial Interaction ◽  
Parametric Method ◽  
Spillover Effects ◽  
Policy Implications ◽  
Parametric Approach ◽  
Spatial Associations ◽  
Long Run ◽  
Convergence Process ◽  
Conditional Beta ◽  
Non Parametric

Attention to issues of inequality and convergence has become a topic of considerable interest in both developing and developed economies. The purpose of this paper is to study empirically the evolution of the disparities between more than 360 Maghreb regions considering spatial dependence and to explore a non-parametric approach for characterizing convergence of GDP per capita. This study utilizes growth theory as the theoretical foundation to explore the convergence hypothesis. The methodology consists of identifying the shape of the long-run spatial associations through the use of Markov chains which make it possible to derive a unique stationary distribution related to the transition matrix. The results of the analysis indicate the persistence of regional disparities and the importance of geography to explain the global convergence process with positive spatial spillover effects. The proportion of high-income regions surrounded by similar regions has significantly increased detrimentally to the other spatial associations. This non-parametric approach complements the standard parametric method (absolute and conditional beta-convergence) which shows that the slow convergence process can be accelerated by beneficial spatial interaction effects. These results have strong policy implications with regard to national and territorial policies in these countries.

scholarly journals Survival Analysis for Pancreatic Cancer Patients using Cox-Proportional Hazard (CPH) Model

2021 ◽  
pp. 29-46
Author(s):  
Aditya Chakraborty ◽  
Chris P. Tsokos
Keyword(s):  
Risk Factors ◽  
Pancreatic Cancer ◽  
Cancer Patients ◽  
Significant Risk ◽  
The United States ◽  
Hazard Ratio ◽  
Proportional Hazard ◽  
Survival Times ◽  
Prognostic Effect ◽  
Cox Proportional Hazard

Pancreatic cancer is comparatively rare but extremely lethal. In the United States, pancreatic cancer is the 4thleading cause of cancer death, and in Europe, it is the 6th. Though Pancreatic cancer remains incurable if detected late, research into improving the therapeutic strategy has increased significantly in recent years. However, it is ambiguous if sustained improvements have been achieved by identifying the most prominent risk factors responsible for cancer. In this article, we studied the survival times of 677 pancreatic cancer patients with fifteen risk factors. The semi-parametric Cox proportional hazard (CPH) model was used to examine the covariate effect taking into account all of the statistically significant risk factors and their significant two way interactions. A careful and rigorous assessment of the risk factors based on the AIC of the stepwise selection technique revealed seven risk factors, and ten interaction terms are statistically significantly contributing to the survival times. The final Cox-PH model was well-validated and satisfied all the key assumptions. The identified risk factors and their interactions are ranked according to the prognostic effect on the survival time based on the hazard ratio. We found the most contributing risk factor is the combined effect of patients with emphysema and cancer stage regional with a hazard ratio (HR) = 8.84.

scholarly journals EFFICIENCY PERFORMANCE ANALYSIS OF PANIN DUBAI SYARIAH BANK IN COLLECTING AND DISTRIBUTING THIRD PARTY FUNDS BEFORE AND AFTER MERGER

2019 ◽  
Vol 5 (1) ◽  
pp. 46-56
Author(s):  
Supriyono Supriyono ◽  
Ahmad Rodoni ◽  
Yacop Suparno ◽  
Hermadi Hermadi ◽  
Hilyatun Nafisah
Keyword(s):  
Data Envelopment Analysis ◽  
Parametric Method ◽  
Third Party ◽  
Programming Approach ◽  
Data Envelopment ◽  
Linear Programs ◽  
Parametric Approach ◽  
Free Disposal Hull ◽  
Free Disposal ◽  
Non Parametric

In this study, the researcher would make Panin Dubai Syariah Bank was the object of research on Islamic banks that carry out mergers and acquisitions. This research by using quarterly financial reports to determine the level of efficiency of the Panin Dubai Syariah Bank to be analyzed using the Data Envelopment Analysis (DEA) method. The researcher was used the annual report to find out the extent the Panin Dubai Syariah Bank carries out its Shariah values and objectives to be analyzed based on the Maqashid Index Sharia. The frontier approach can be divided into parametric approaches and non-parametric approaches. The parametric  approach  takes  measurements  using  stochastic  econometrics  and  seeks  to  eliminate interference from the effects of inefficiency. While the non-parametric approach with linear programs ( non-parametric linear programming approach ) performs non-parametric measurements using an approach is not stochastic and tends to combine the interference into inefficiency. This is based on the discovery and observation of the population and evaluates efficiency relative to the units observed. In the non- parametric method, the approaches that can be used are Data Envelopment Analysis (DEA) and Free Disposal Hull (FDH). The results of the measurement of Bank Panin Dubai Syariah using DEA indicate that the decision to merge carried out by Panin Syariah Bank with Dubai Islamic Bank was the right decision because, with the merger, Panin Dubai Syariah Bank could produce almost perfect efficiency value of 99% in the year 2015. With doing the merger, Bank Panin Dubai Syariah can minimize the inefficiencies that occur in the input variable so that it can maximize the efficiency that occurs in the output variable

scholarly journals Biological Therapy Survivability in Children with Psoriasis: Cohort Study

2021 ◽  
Vol 20 (5) ◽  
pp. 451-458
Author(s):  
Roman A. Ivanov ◽  
Nikolay N. Murashkin
Keyword(s):  
Risk Factors ◽  
Biological Therapy ◽  
Practical Importance ◽  
Significant Risk ◽  
High Body Mass Index ◽  
Genetically Engineered ◽  
Rank Test ◽  
Old Patients ◽  
Adalimumab Therapy ◽  
Significant Difference

Background. There is a need to study genetically engineered biological therapy (GEBT) survivability and identify any significant risk factors for its ineffectiveness due to the increasing prevalence of psoriasis among children and the spreading GEBT administration. Such information has practical importance, it can be used to predict treatment outcomes and to develop individual therapeutic approaches. Objective. Our aim was to study biological therapy survivability and to identify risk factors for its ineffectiveness in children with moderate and severe forms of psoriasis. Methods. The study included data from 4-17 years old patients with moderate and severe forms of psoriasis vulgaris. Groups were formed according to the biological medication used. Statistical analyses were performed via SPSS Statistics. Biologic therapy survivability was determined via Kaplan-Meier method with the assessment of differences significance using log-rank test. Significant factors affecting cumulative risk growth were determined by Cox multiple regression method. Results. The study analysed data from the medical records of 105 patients. The average survivability of ustekinumab was 28.7 months, etanercept — 23.1, and adalimumab — 18.4. In the group of bio-naive patients, the survivability was higher: 30.8 months for ustekinumab and 24.4 months for ethanercept, while in the group of patients administrated previously with biological medication the survivability was 24.2 and 8.3 months, respectively. No statistically significant difference was revealed for adalimumab therapy. Significant risk factors for therapy ineffectiveness were the following: high body mass index (BMI) at the time of GEBT onset, aggravated family history, and prior use of one or several subsequent GEBT lines. Conclusion. The therapy survivability is inevitably declining over time. The best results were noted in bio-naive patients treated with ustekinumab that allows us to recommend it as the first-line drug in children with severe and moderate forms of psoriasis.

Partial Meniscectomy for Degenerative Medial Meniscal Root Tears Shows Favorable Outcomes in Well-Aligned, Nonarthritic Knees

2019 ◽  
Vol 47 (3) ◽  
pp. 606-611 ◽  
Author(s):  
Bum-Sik Lee ◽  
Seong-Il Bin ◽  
Jong-Min Kim ◽  
Min-Ho Park ◽  
Sang-Min Lee ◽  
...  
Keyword(s):  
Risk Factors ◽  
Significant Risk ◽  
Lysholm Score ◽  
Rank Test ◽  
Varus Alignment ◽  
Level Of Evidence ◽  
Term Survival ◽  
Arthroscopic Meniscectomy ◽  
End Stage

Background: Arthroscopic meniscectomy has been commonly performed for persistent pain caused by degenerative medial meniscal posterior root tears (MMPRTs). However, risk factors that affect long-term outcomes and joint survivorship after meniscectomy are unclear. Purpose: To identify the risk factors associated with end-stage osteoarthritis after arthroscopic meniscectomy for degenerative MMPRT for middle-aged or elderly patients and to determine the joint survivorship according to the identified risk factors. Study Design: Case-control study; Level of evidence, 3. Methods: Data from 288 patients (24 male and 264 female), followed for at least 5 years after arthroscopic meniscectomy for degenerative MMPRTs performed between 1999 and 2010, were examined retrospectively. The modified Lysholm score was used for clinical evaluation. Cox proportional hazards regression analysis was used to assess factors that affect joint survivorship when conversion to total knee arthroplasty (TKA) was taken as the endpoint; these factors were age, sex, body mass index (BMI), preoperative tibiofemoral alignment (varus [<2° valgus] vs well-aligned [2°-10° valgus]), preoperative Kellgren-Lawrence grade (0 or 1 vs 2 or 3), and the modified Outerbridge grade of the medial compartment. Kaplan-Meier survival analysis and the log-rank test were used to compare overall survivorship with respect to each significant risk factor. Results: Mean age at the time of surgery was 58.9 years (range, 43-78 years). Sixty (20.8%) patients underwent TKA at 7.0 ± 3.6 years (range, 1.1-14.4 years) postoperatively. The mean follow-up time for those who did not undergo TKA was 8.9 ± 2.9 years (range, 4.5-16.5 years). The overall modified Lysholm score improved from 64.4 to 81.3 ( P < .001), but progression of radiographic arthritis was noted in 156 (61.9%) patients ( P < .001) at 2 years postoperatively. Age (hazard ratio [HR] = 1.049), BMI (HR = 1.092), varus alignment (HR = 2.283), and Kellgren-Lawrence grade 2 or higher (HR = 2.960) were significant risk factors for end-stage arthritis requiring TKA. Well-aligned nonarthritic knees (n = 131, 45.5%) survived significantly longer before requiring TKA than did knees with varus alignment or radiographic arthritis ( P < .05). The 5- and 10-year survival rates in these low-risk groups were 97.7% (95% CI, 95.2%-100.2%) and 89.1% (95% CI, 82.4%-95.8%), respectively. Conclusion: Arthroscopic meniscectomy is an effective treatment for degenerative MMPRTs, with favorable long-term survival in well-aligned nonarthritic knees. However, meniscectomy should be undertaken cautiously in patients with varus alignment and preoperative radiographic osteoarthritis.

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