Papers by Afeez M Babalola
American Journal of Mathematics and Statistics, 2018
Count Data Models allow for regression-type analyses when the dependent variable of interest is a... more Count Data Models allow for regression-type analyses when the dependent variable of interest is a numerical count. They can be used to estimate the effect of a policy intervention either on the average rate or on the probability of no event, a single event, or multiple events. The mostly used distribution for modeling count data is the Poisson distribution (Horim and Levy; 1981) which assume equidispersion (Variance is equal to the mean). Since observed count data often exhibit over or under dispersion, the Poisson model becomes less ideal for modeling. To deal with a wide range of dispersion levels, Negative Binomial Regression, Generalized Poisson Regression, Poisson Regression, and lately Conway-Maxwell-Poisson (COM-Poisson) Regression can be used as alternative regression models. We compared the Generalized Poisson regression to all other regression models and also stated their advantages and usefulness. Data were analyzed using these four methods, the results from the four meth...
American Journal of Mathematics and Statistics, 2019
Malaria is an urgent public health priority. Malaria and the costs of treatment trap families in ... more Malaria is an urgent public health priority. Malaria and the costs of treatment trap families in a cycle of illness, suffering and poverty. Today, half of the world population is at risk. The study intended mainly to model and forecast the malaria mortality rate for the coming years. The Box-Jenkins Autoregressive Integrated Moving Average (ARIMA) was employed, parameters were estimated and several diagnostic tests were performed. Series of tentative models were developed to forecast the mortality rate based on minimum AIC and BIC values. Results: ARIMA (0,1,0) model was proved to be the best model for forecasting after satisfying the model assumptions. The forecasted results revealed a decreasing pattern of malaria mortality rate 2016 to 2022. Malaria Mortality was found to be on a decrease in the forecasted period. However, in order to zero mortality due to malaria from our society, government and health experts still need to put hands together to sanitize the system in terms of d...
American Journal of Mathematics and Statistics, 2018
This study is a retrospective analysis of the reproductive history data collected from the Nigeri... more This study is a retrospective analysis of the reproductive history data collected from the Nigeria Demographic and Health Surveys (NDHS) for 2013 to study some factors that are likely to be responsible for infant mortality. The essential aim of this study is to estimate the survival rates of infant’s mortality in Nigeria with the objectives of estimating and interpreting survivor/hazard function from survival data, describing and estimating the survival experience of different groups, selecting the best hazard model from the data. The Kaplan- Meier curve was plotted to describe the rate of survival of some of the factors responsible for infant mortality. The log- rank test which is a non-parametric test was used to test the hypothesis to compare the survival distributions of the samples. The log rank test was obtained for the region, type of resident, sex of the child, religion, gender, highest educational level of mother, wealth index, Age at death, age at birth. The Cox-Proportion...
Worldwide, Over 600,000 maternal deaths are recorded annually. Many women die due to pregnancy as... more Worldwide, Over 600,000 maternal deaths are recorded annually. Many women die due to pregnancy associated complications in Nigeria. Thus, this paper seeks to explore the application of poisson models in the study of incidence of pregnancy related death in Oyo state, Nigeria. The paper explores the application of poisson models in the study of maternal deaths. Understanding the incidence of maternal deaths may provide useful information to policy makers for the development of actionable plan to improve maternal health policies and its implementations. The analysis was based on data sourced from the records unit of the hospital for the period of 20092018. Within the 10 year period, a total of 1121 maternal death was observed, with the years 2016 and 2017 recording the highest deaths of 136 and 148 respectively. Also, the mean incidence of maternal deaths remained approximately the same over the period. Based on the result from our Mini-review Article Maxwell et al.; AJPCB, 2(2): 1-5, ...
American Journal of Mathematics and Statistics, 2019
The world mortality rate has declined 45% since 1990, but still 800 women die every day from preg... more The world mortality rate has declined 45% since 1990, but still 800 women die every day from pregnancy or childbirth related causes. According to the United Nations Population Fund (UNFPA) this is equivalent to about one woman every two minutes and for every woman who dies, 20 or 30 encounter complications with serious or long-lasting consequences. Young mothers face higher risks of complications and death during pregnancy than older mothers, especially adolescents aged 15 years or younger. Adolescents have higher risks for postpartum hemorrhage, thus, an increased risk of death during pregnancy or childbirth compared with older women. The study is therefore focused on addressing the issue of good statistical estimators, is born out of the weaknesses of the estimators in use, and the apparent lack of research into the application of other methods. Survival analysis technique was employed, once the survival function has been developed, various tests and the modeling of Maternal Morta...
Current Trends on Biostatistics and Biometrics, 2019
Background: The study is mainly focused on visualization technique that gives a 3D impression of ... more Background: The study is mainly focused on visualization technique that gives a 3D impression of the whole data set without segmentation. The underlying model is based on the emission and absorption of light that pertains to every voxel of the view volume. The algorithm simulates the casting of light rays through the volume from preset sources. It determines how much light reaches each voxel on the ray and is emitted or absorbed by the voxel. Then it computes what can be seen from the current viewing point as implied by the current placement of the volume relative to the viewing plane, simulating the casting of sight rays through the volume from the viewing point.
Current Trends on Biostatistics and Biometrics, 2019
Background: This study examined contraceptive use patterns and method selection among women of re... more Background: This study examined contraceptive use patterns and method selection among women of reproductive age in Nigeria, with a particular focus on the extent to which demographic and socioeconomic characteristics influenced contraceptive use practice. The Logistic models shows that women who know at least one method are more likely to use any contraceptive method than their non-method-knowing counterparts. Moreover, those women with more children ever born are more likely than their counterparts with fewer children ever born to use modern contraceptive methods. The probable reason for this may be that women with fewer children may still want more children and have the fear of side effects attributed to modern contraceptives.
American Journal of Mathematics and Statistics, 2018
The goal of this study is to investigate the best goodness-of-fit test among five selected normal... more The goal of this study is to investigate the best goodness-of-fit test among five selected normality tests under various continuous non-normal distributions using power as criteria. The tests were compared when the normal parameters are unknown and sample sizes are 10, 30, 50, 100, 300, 500 and 1000 were iterated 1000 times each with 0.01, 0.05, and 0.10 level of significance, using the Monte Carlo technique. We study the procedures based on five well-known normality tests: the Anderson–Darling, Cramer–von Mises, Shapiro–Wilk, Jarque–Bera and Chi-Square. Evidence from the simulation study reveals that the performance of the five normality test statistics varies with the level of significance, sample size and alternative distributions.
Asian Journal of Pregnancy and Childbirth, 2019
Worldwide, Over 600,000 maternal deaths are recorded annually. Many women die due to pregnancy as... more Worldwide, Over 600,000 maternal deaths are recorded annually. Many women die due to pregnancy associated complications in Nigeria. Thus, this paper seeks to explore the application of poisson models in the study of incidence of pregnancy related death in Oyo state, Nigeria. The paper explores the application of poisson models in the study of maternal deaths. Understanding the incidence of maternal deaths may provide useful information to policy makers for the development of actionable plan to improve maternal health policies and its implementations. The analysis was based on data sourced from the records unit of the hospital for the period of 2009-2018. Within the 10 year period, a total of 1121 maternal death was observed, with the years 2016 and 2017 recording the highest deaths of 136 and 148 respectively. Also, the mean incidence of maternal deaths remained approximately the same over the period. Based on the result from our Mini-review Article Maxwell et al.; AJPCB, 2(2): 1-5, 2019; Article no.AJPCB.47716 2 analysis, we recommend that management and government reevaluate all existing intervention programs for reducing maternal deaths since they seem not to have yielded the expected results over the past ten years (2009-2018) reference to this general hospital.
Current Trends on Biostatistics & Biometrics, 2019
Background: The study is mainly focused on visualization technique that gives a 3D impression of ... more Background: The study is mainly focused on visualization technique that gives a 3D impression of the whole data set without segmentation. The underlying model is based on the emission and absorption of light that pertains to every voxel of the view volume. The algorithm simulates the casting of light rays through the volume from preset sources. It determines how much light reaches each voxel on the ray and is emitted or absorbed by the voxel. Then it computes what can be seen from the current viewing point as implied by the current placement of the volume relative to the viewing plane, simulating the casting of sight rays through the volume from the viewing point.
Current Trends on Biostatistics & Biometrics, 2019
Background: This study examined contraceptive use patterns and method selection among women of re... more Background: This study examined contraceptive use patterns and method selection among women of reproductive age in Nigeria, with a particular focus on the extent to which demographic and socioeconomic characteristics influenced contraceptive use practice. The Logistic models shows that women who know at least one method are more likely to use any contraceptive method than their non-method-knowing counterparts. Moreover, those women with more children ever born are more likely than their counterparts with fewer children ever born to use modern contraceptive methods. The probable reason for this may be that women with fewer children may still want more children and have the fear of side effects attributed to modern contraceptives.
American Journal of Mathematics and Statistics, 2018
The goal of this study is to investigate the best goodness-of-fit test among five selected normal... more The goal of this study is to investigate the best goodness-of-fit test among five selected normality tests under various continuous non-normal distributions using power as criteria. The tests were compared when the normal parameters are unknown and sample sizes are 10, 30, 50, 100, 300, 500 and 1000 were iterated 1000 times each with 0.01, 0.05, and 0.10 level of significance, using the Monte Carlo technique. We study the procedures based on five well-known normality tests: the Anderson–Darling, Cramer–von Mises, Shapiro–Wilk, Jarque–Bera and Chi-Square. Evidence from the simulation study reveals that the performance of the five normality test statistics varies with the level of significance, sample size and alternative distributions.
American Journal of Mathematics and Statistics, 2018
This study is a retrospective analysis of the reproductive history data collected from the Nigeri... more This study is a retrospective analysis of the reproductive history data collected from the Nigeria Demographic and Health Surveys (NDHS) for 2013 to study some factors that are likely to be responsible for infant mortality. The essential aim of this study is to estimate the survival rates of infant’s mortality in Nigeria with the objectives of estimating and interpreting survivor/hazard function from survival data, describing and estimating the survival experience of different groups, selecting the best hazard model from the data. The Kaplan- Meier curve was plotted to describe the rate of survival of some of the factors responsible for infant mortality. The log- rank test which is a non-parametric test was used to test the hypothesis to compare the survival distributions of the samples. The log rank test was obtained for the region, type of resident, sex of the child, religion, gender, highest educational level of mother, wealth index, Age at death, age at birth. The Cox-Proportional Hazard Model was fitted to assess the importance of various covariates in the survival times of infant through the hazard ratio. The hazard ratio which was used to interpret the cox proportional model is compare on its closeness to 1. Also testing the significant of the covariate to the model using the p-value if less than 0.05 level of significant.
American Journal of Mathematics and Statistics, 2019
Malaria is an urgent public health priority. Malaria and the costs of treatment trap families in ... more Malaria is an urgent public health priority. Malaria and the costs of treatment trap families in a cycle of illness, suffering and poverty. Today, half of the world population is at risk. The study intended mainly to model and forecast the malaria mortality rate for the coming years. The Box-Jenkins Autoregressive Integrated Moving Average (ARIMA) was employed, parameters were estimated and several diagnostic tests were performed. Series of tentative models were developed to forecast the mortality rate based on minimum AIC and BIC values. Results: ARIMA (0,1,0) model was proved to be the best model for forecasting after satisfying the model assumptions. The forecasted results revealed a decreasing pattern of malaria mortality rate 2016 to 2022. Malaria Mortality was found to be on a decrease in the forecasted period. However, in order to zero mortality due to malaria from our society, government and health experts still need to put hands together to sanitize the system in terms of drugs manufacturing.
American Journal of Mathematics and Statistics, 2018
Common problems in multiple regression models are multicollinearity and non-normal errors, which ... more Common problems in multiple regression models are multicollinearity and non-normal errors, which produce undesirable effects on the Least Squares estimators. However, it would seem important to combine methods of estimation designed to deal with these problems. In this study, different estimation methods, namely the Ordinary Least Squares (OLS), Ridge Regression (R), Weighted Ridge (WR), Robust M-estimation (M) and Robust Ridge regression based on M-estimation (RM) were examined in the presence of multicollinearity and non-normal errors. From a simulation study, the results of comparisons shows that for the condition of collinearity, Robust Ridge (RM) estimates are more efficient than the other estimators considered. While for the condition of collinearity and non-normal error, M-estimator (M) produces estimates that were more efficient and precise.
American Journal of Mathematics and Statistics, 2019
The world mortality rate has declined 45% since 1990, but still 800 women die every day from preg... more The world mortality rate has declined 45% since 1990, but still 800 women die every day from pregnancy or childbirth related causes. According to the United Nations Population Fund (UNFPA) this is equivalent to about one woman every two minutes and for every woman who dies, 20 or 30 encounter complications with serious or long-lasting consequences. Young mothers face higher risks of complications and death during pregnancy than older mothers, especially adolescents aged 15 years or younger. Adolescents have higher risks for postpartum hemorrhage, thus, an increased risk of death during pregnancy or childbirth compared with older women. The study is therefore focused on addressing the issue of good statistical estimators, is born out of the weaknesses of the estimators in use, and the apparent lack of research into the application of other methods. Survival analysis technique was employed, once the survival function has been developed, various tests and the modeling of Maternal Mortality, as well as the determination of the appropriate distributions that best describes maternal mortality was done, using both the parametric and non-parametric methods. These include the identification of prognostic factors through regression analysis and the determination of an appropriate distribution for maternal survival. Results of its application to data from Oyo State, Nigeria showed that while about 90% of pregnant women made it alive to delivery, only 86% of them survived to the end of the postpartum period. There were significant differentials by location, and Maternal Age: The Weibull distribution described maternal survival well.
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Papers by Afeez M Babalola