Background: Contraceptive methods are one of the most important health interventions of the twent... more Background: Contraceptive methods are one of the most important health interventions of the twenty-first century, and they are critical in slowing population growth and improving women's and family health. Contraceptive methods are now a global issue in general, and in developing countries in particular. Method: This study sought to identify the factors associated with the timing of the use of modern contraceptive methods among Ethiopian women. The study's data were based on EDHS (2016) obtained from CSA. To identify the risk factors associated with when to use modern contraceptive methods, a parametric survival model with frailty was used and compared using AIC and log-likelihood ratio test. Result: The study found that out of a total of 7,890 women, approximately 1,061 (13.45 percent) used modern contraceptive methods, while 6829 (86.55 percent) did not. Conclusion: The Weibull regression survival model with Gamma frailty model was an appropriate fit of time to use modern ...
Background:Coronavirus is a zoonotic disease caused by coronavirus 2 (severe acute respiratory sy... more Background:Coronavirus is a zoonotic disease caused by coronavirus 2 (severe acute respiratory syndrome) which was discovered on December 31, 2019, in Wuhan, Hubei Province, China. Methodology: The study population was the patients of COVID-19 treated at Eka Kottebe General Hospital from March 2020 to December 2020. Descriptive statistics, chi-square test, and stereotype ordinal logistic regression model were used to analyze our data. Result: Out of the total (454) patients considered in the study, about 240 (52.86%), 60 (13.22%), 106 (23.35%), and 48 (10.57%) patients were in mild, moderate, severe, and critical stage, respectively. Independent variables like sex, presence of a symptom, fever, headache, chest pain, and shortness of breath, general weakness, cough, co-morbid, diabetes mullets, and hypertension had a significant association with the severity of illness at a 5% level of significance. The stereotype ordinal logistic regression result shows that sex, age, presence of sy...
Background: Contraceptive methods are one of the most important health interventions of the twent... more Background: Contraceptive methods are one of the most important health interventions of the twenty-first century, and they are critical in slowing population growth and improving women's and family health. Contraceptive methods are now a global issue in general, and in developing countries in particular. Method: This study sought to identify the factors associated with the timing of the use of modern contraceptive methods among Ethiopian women. The study's data were based on EDHS (2016) obtained from CSA. To identify the risk factors associated with when to use modern contraceptive methods, a parametric survival model with frailty was used and compared using AIC and log-likelihood ratio test. Result: The study found that out of a total of 7,890 women, approximately 1,061 (13.45 percent) used modern contraceptive methods, while 6829 (86.55 percent) did not. Conclusion: The Weibull regression survival model with Gamma frailty model was an appropriate fit of time to use modern ...
Background: Contraceptive methods are one of the most important health interventions of the twent... more Background: Contraceptive methods are one of the most important health interventions of the twenty-first century, and they are critical in slowing population growth and improving women's and family health. Contraceptive methods are now a global issue in general, and in developing countries in particular. Method: This study sought to identify the factors associated with the timing of the use of modern contraceptive methods among Ethiopian women. The study's data were based on EDHS (2016) obtained from CSA. To identify the risk factors associated with when to use modern contraceptive methods, a parametric survival model with frailty was used and compared using AIC and log-likelihood ratio test. Result: The study found that out of a total of 7,890 women, approximately 1,061 (13.45 percent) used modern contraceptive methods, while 6829 (86.55 percent) did not. Conclusion: The Weibull regression survival model with Gamma frailty model was an appropriate fit of time to use modern ...
The measurement of the CD4+ count is the predictor of evolution to AIDS, in ART. Studying the way... more The measurement of the CD4+ count is the predictor of evolution to AIDS, in ART. Studying the way of the CD4+ count over time provides an insight to the disease evolution. The main objective of this study was to apply statistical analysis on longitudinally measured CD4+ Cell counts of HIV-positive patients under ART. The study population consists of 647 HIV+ patients who were 16 years old or older and who were under ART follow up from 2012 to 2017 in Debre Berhan Referral Hospital, Debre Berhan, Ethiopia. The data were from the patients' chart. All patients who have initiated to ART and measured their CD4+ cell counts at least two times, including the baseline and those who started the first line ART regimen class was included in the study population. Data were explored using basic descriptive statistics and individual and mean profile plots. The methods of LMM and GLMM were used. The mean profile of CD4+ count revealed that there is an improvement in the duration of treatment in a linear pattern. From the GLMM covariates duration of treatment, sex, BMI, baseline CD4, regimen class, duration by age, duration by baseline CD4 and duration by regimen class significantly determines the change in CD4+ count overtime at 5% level of significance. There is the duration of treatment effect on the current CD4+ count. The study result suggests that HIV+ patients attending in ART improve their CD4+ count.
Background In many countries, deferring first births and increasing the interval between births h... more Background In many countries, deferring first births and increasing the interval between births has played an important role in lowering fertility rates. Any country's fertility rate is a key demographic indicator, and it has always been important to closely monitor changes in the pattern of births to determine how many children are being conceived. Any country's fertility rate is a key demographic indicator, and it has always been important to closely monitor changes in the pattern of births to determine how many children are being conceived. The primary goal of this study is to apply zero-truncated regression models to estimate the number of children ever born per mother in Ethiopia from the MiniDHS 2019. Mothods The data collection was carried out by the Ethiopian Public Health Institute (EPHI) in collaboration with the Central Statistical Agency (CSA) and the Federal Ministry of Health. Zero truncated count regression models were used to identify the determinant of the n...
In this study we focus on a negative binomial (NB) regression model to take account of regression... more In this study we focus on a negative binomial (NB) regression model to take account of regression coefficients in Poisson counts. An algorithm for estimating parameters was obtained and score test versus its alternative tests were presented for testing the significance of regression coefficients in Poisson regression model against NB regression model. The power of the score test is compared with their Likelihood ratio test (LRT) and Wald test via Monte Carlo simulation. The simulation result indicated that the Wald test is superior over the LRT and Score test in terms of its power. An Ethiopian under five children death rate data is used to illustrate the tests.
Road traffic accident is the major phenomena of the world as well as our country, Ethiopia which ... more Road traffic accident is the major phenomena of the world as well as our country, Ethiopia which is from the low-income countries. Statistical modeling for count response variables is a primary interest in, insurance, and other areas. The main objective of this study is used to identify the most appropriate count regression model to fit the number of human deaths per road traffic accident (RTAs). The data for this study get from Addis Ababa Traffic Control, and Investigation Department (AATCID), daily basis recorded from July 30, 2013 to July 29, 2014. The difficultyassumption of Poisson regression model shifts to look for extended models like the negative binomial model, zero inflatedPoisson, and zero-Inflated Negative binomial regression models. Specifically, traffic accidents generate count response variables with an invalid assumption of Poisson distribution such thatthe variance and mean of human death per road traffic accident are (0.58) and (0.36), and the overdispersion para...
The aim of this study is to identify factors affecting academic achievement of second year regula... more The aim of this study is to identify factors affecting academic achievement of second year regular students of Addis Ababa University, School of Commerce. Data were obtained from primary and secondary sources. A cross-sectional survey was conducted on a total of 79 students from six different departments using multistage stratified sampling techniques. A designed questionnaire was used to obtain data on background information, student level, department level and school level. The secondary data were obtained from the registrar office of School of Commerce, Addis Ababa University. Multiple linear regression and multilevel linear regression were used to analyze the data. From the study, it was found out that multilevel regression model is much better than the classical regression model in fitting the data and in explaining the variations of the academic achievement at different levels. The results of this study showed that the mean academic achievements of commerce second year regular...
The measurement of the CD4+ count is the predictor of evolution to AIDS, in ART. Studying the way... more The measurement of the CD4+ count is the predictor of evolution to AIDS, in ART. Studying the way of the CD4+ count over time provides an insight to the disease evolution. The main objective of this study was to apply statistical analysis on longitudinally measured CD4+ Cell counts of HIV-positive patients under ART. The study population consists of 647 HIV+ patients who were 16 years old or older and who were under ART follow up from 2012 to 2017 in Debre Berhan Referral Hospital, Debre Berhan, Ethiopia. The data were from the patients' chart. All patients who have initiated to ART and measured their CD4+ cell counts at least two times, including the baseline and those who started the first line ART regimen class was included in the study population. Data were explored using basic descriptive statistics and individual and mean profile plots. The methods of LMM and GLMM were used. The mean profile of CD4+ count revealed that there is an improvement in the duration of treatment in a linear pattern. From the GLMM covariates duration of treatment, sex, BMI, baseline CD4, regimen class, duration by age, duration by baseline CD4 and duration by regimen class significantly determines the change in CD4+ count overtime at 5% level of significance. There is the duration of treatment effect on the current CD4+ count. The study result suggests that HIV+ patients attending in ART improve their CD4+ count.
In this paper we focus on a negative binomial (NB) regression model to take account of overdisper... more In this paper we focus on a negative binomial (NB) regression model to take account of overdispersion in Poisson counts. Moreover, we present the power of score test for testing the overdispersion parameter in the negative binomial regression model. The power of the proposed score test was compared with the LRT and Wald test via Monte Carlo simulation technique using SAS 9.2 software. The application of the test was shown using two real datasets such as using numerical illustration and real datasets.
Background: Contraceptive methods are one of the most important health interventions of the twent... more Background: Contraceptive methods are one of the most important health interventions of the twenty-first century, and they are critical in slowing population growth and improving women's and family health. Contraceptive methods are now a global issue in general, and in developing countries in particular. Method: This study sought to identify the factors associated with the timing of the use of modern contraceptive methods among Ethiopian women. The study's data were based on EDHS (2016) obtained from CSA. To identify the risk factors associated with when to use modern contraceptive methods, a parametric survival model with frailty was used and compared using AIC and log-likelihood ratio test. Result: The study found that out of a total of 7,890 women, approximately 1,061 (13.45 percent) used modern contraceptive methods, while 6829 (86.55 percent) did not. Conclusion: The Weibull regression survival model with Gamma frailty model was an appropriate fit of time to use modern ...
Background:Coronavirus is a zoonotic disease caused by coronavirus 2 (severe acute respiratory sy... more Background:Coronavirus is a zoonotic disease caused by coronavirus 2 (severe acute respiratory syndrome) which was discovered on December 31, 2019, in Wuhan, Hubei Province, China. Methodology: The study population was the patients of COVID-19 treated at Eka Kottebe General Hospital from March 2020 to December 2020. Descriptive statistics, chi-square test, and stereotype ordinal logistic regression model were used to analyze our data. Result: Out of the total (454) patients considered in the study, about 240 (52.86%), 60 (13.22%), 106 (23.35%), and 48 (10.57%) patients were in mild, moderate, severe, and critical stage, respectively. Independent variables like sex, presence of a symptom, fever, headache, chest pain, and shortness of breath, general weakness, cough, co-morbid, diabetes mullets, and hypertension had a significant association with the severity of illness at a 5% level of significance. The stereotype ordinal logistic regression result shows that sex, age, presence of sy...
Background: Contraceptive methods are one of the most important health interventions of the twent... more Background: Contraceptive methods are one of the most important health interventions of the twenty-first century, and they are critical in slowing population growth and improving women's and family health. Contraceptive methods are now a global issue in general, and in developing countries in particular. Method: This study sought to identify the factors associated with the timing of the use of modern contraceptive methods among Ethiopian women. The study's data were based on EDHS (2016) obtained from CSA. To identify the risk factors associated with when to use modern contraceptive methods, a parametric survival model with frailty was used and compared using AIC and log-likelihood ratio test. Result: The study found that out of a total of 7,890 women, approximately 1,061 (13.45 percent) used modern contraceptive methods, while 6829 (86.55 percent) did not. Conclusion: The Weibull regression survival model with Gamma frailty model was an appropriate fit of time to use modern ...
Background: Contraceptive methods are one of the most important health interventions of the twent... more Background: Contraceptive methods are one of the most important health interventions of the twenty-first century, and they are critical in slowing population growth and improving women's and family health. Contraceptive methods are now a global issue in general, and in developing countries in particular. Method: This study sought to identify the factors associated with the timing of the use of modern contraceptive methods among Ethiopian women. The study's data were based on EDHS (2016) obtained from CSA. To identify the risk factors associated with when to use modern contraceptive methods, a parametric survival model with frailty was used and compared using AIC and log-likelihood ratio test. Result: The study found that out of a total of 7,890 women, approximately 1,061 (13.45 percent) used modern contraceptive methods, while 6829 (86.55 percent) did not. Conclusion: The Weibull regression survival model with Gamma frailty model was an appropriate fit of time to use modern ...
The measurement of the CD4+ count is the predictor of evolution to AIDS, in ART. Studying the way... more The measurement of the CD4+ count is the predictor of evolution to AIDS, in ART. Studying the way of the CD4+ count over time provides an insight to the disease evolution. The main objective of this study was to apply statistical analysis on longitudinally measured CD4+ Cell counts of HIV-positive patients under ART. The study population consists of 647 HIV+ patients who were 16 years old or older and who were under ART follow up from 2012 to 2017 in Debre Berhan Referral Hospital, Debre Berhan, Ethiopia. The data were from the patients' chart. All patients who have initiated to ART and measured their CD4+ cell counts at least two times, including the baseline and those who started the first line ART regimen class was included in the study population. Data were explored using basic descriptive statistics and individual and mean profile plots. The methods of LMM and GLMM were used. The mean profile of CD4+ count revealed that there is an improvement in the duration of treatment in a linear pattern. From the GLMM covariates duration of treatment, sex, BMI, baseline CD4, regimen class, duration by age, duration by baseline CD4 and duration by regimen class significantly determines the change in CD4+ count overtime at 5% level of significance. There is the duration of treatment effect on the current CD4+ count. The study result suggests that HIV+ patients attending in ART improve their CD4+ count.
Background In many countries, deferring first births and increasing the interval between births h... more Background In many countries, deferring first births and increasing the interval between births has played an important role in lowering fertility rates. Any country's fertility rate is a key demographic indicator, and it has always been important to closely monitor changes in the pattern of births to determine how many children are being conceived. Any country's fertility rate is a key demographic indicator, and it has always been important to closely monitor changes in the pattern of births to determine how many children are being conceived. The primary goal of this study is to apply zero-truncated regression models to estimate the number of children ever born per mother in Ethiopia from the MiniDHS 2019. Mothods The data collection was carried out by the Ethiopian Public Health Institute (EPHI) in collaboration with the Central Statistical Agency (CSA) and the Federal Ministry of Health. Zero truncated count regression models were used to identify the determinant of the n...
In this study we focus on a negative binomial (NB) regression model to take account of regression... more In this study we focus on a negative binomial (NB) regression model to take account of regression coefficients in Poisson counts. An algorithm for estimating parameters was obtained and score test versus its alternative tests were presented for testing the significance of regression coefficients in Poisson regression model against NB regression model. The power of the score test is compared with their Likelihood ratio test (LRT) and Wald test via Monte Carlo simulation. The simulation result indicated that the Wald test is superior over the LRT and Score test in terms of its power. An Ethiopian under five children death rate data is used to illustrate the tests.
Road traffic accident is the major phenomena of the world as well as our country, Ethiopia which ... more Road traffic accident is the major phenomena of the world as well as our country, Ethiopia which is from the low-income countries. Statistical modeling for count response variables is a primary interest in, insurance, and other areas. The main objective of this study is used to identify the most appropriate count regression model to fit the number of human deaths per road traffic accident (RTAs). The data for this study get from Addis Ababa Traffic Control, and Investigation Department (AATCID), daily basis recorded from July 30, 2013 to July 29, 2014. The difficultyassumption of Poisson regression model shifts to look for extended models like the negative binomial model, zero inflatedPoisson, and zero-Inflated Negative binomial regression models. Specifically, traffic accidents generate count response variables with an invalid assumption of Poisson distribution such thatthe variance and mean of human death per road traffic accident are (0.58) and (0.36), and the overdispersion para...
The aim of this study is to identify factors affecting academic achievement of second year regula... more The aim of this study is to identify factors affecting academic achievement of second year regular students of Addis Ababa University, School of Commerce. Data were obtained from primary and secondary sources. A cross-sectional survey was conducted on a total of 79 students from six different departments using multistage stratified sampling techniques. A designed questionnaire was used to obtain data on background information, student level, department level and school level. The secondary data were obtained from the registrar office of School of Commerce, Addis Ababa University. Multiple linear regression and multilevel linear regression were used to analyze the data. From the study, it was found out that multilevel regression model is much better than the classical regression model in fitting the data and in explaining the variations of the academic achievement at different levels. The results of this study showed that the mean academic achievements of commerce second year regular...
The measurement of the CD4+ count is the predictor of evolution to AIDS, in ART. Studying the way... more The measurement of the CD4+ count is the predictor of evolution to AIDS, in ART. Studying the way of the CD4+ count over time provides an insight to the disease evolution. The main objective of this study was to apply statistical analysis on longitudinally measured CD4+ Cell counts of HIV-positive patients under ART. The study population consists of 647 HIV+ patients who were 16 years old or older and who were under ART follow up from 2012 to 2017 in Debre Berhan Referral Hospital, Debre Berhan, Ethiopia. The data were from the patients' chart. All patients who have initiated to ART and measured their CD4+ cell counts at least two times, including the baseline and those who started the first line ART regimen class was included in the study population. Data were explored using basic descriptive statistics and individual and mean profile plots. The methods of LMM and GLMM were used. The mean profile of CD4+ count revealed that there is an improvement in the duration of treatment in a linear pattern. From the GLMM covariates duration of treatment, sex, BMI, baseline CD4, regimen class, duration by age, duration by baseline CD4 and duration by regimen class significantly determines the change in CD4+ count overtime at 5% level of significance. There is the duration of treatment effect on the current CD4+ count. The study result suggests that HIV+ patients attending in ART improve their CD4+ count.
In this paper we focus on a negative binomial (NB) regression model to take account of overdisper... more In this paper we focus on a negative binomial (NB) regression model to take account of overdispersion in Poisson counts. Moreover, we present the power of score test for testing the overdispersion parameter in the negative binomial regression model. The power of the proposed score test was compared with the LRT and Wald test via Monte Carlo simulation technique using SAS 9.2 software. The application of the test was shown using two real datasets such as using numerical illustration and real datasets.
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Papers by Dejen Tesfaw