118 research outputs found
Adverse birth outcome: a comparative analysis between cesarean section and vaginal delivery at Felegehiwot Referral Hospital, Northwest Ethiopia: a retrospective record review [Corrigendum]
No full textAbebe Eyowas F, Negasi AK, Aynalem GE, Worku AG. Pediatric Health, Medicine and Therapeutics. 2016;7:65–70On page 65 Abel Fekadu Dadi should have been listed as an author. The incorrect author list was:Fantu Abebe Eyowas1Ashebir Kidane Negasi1Gizachew Eyassu Aynalem1Abebaw Gebeyehu Worku2The correct author list should have been:Fantu Abebe Eyowas1Ashebir Kidane Negasi1Gizachew Eyassu Aynalem1Abebaw Gebeyehu Worku2Abel Fekadu Dadi2Read the original articl
Flexible two-piece distributions for right censored survival data
No full textAn important complexity in censored data is that only partial information on the variables of interest is observed. In recent years, a large family of asymmetric distributions and maximum likelihood estimation for the parameters in that family has been studied, in the complete data case. In this paper, we exploit the appealing family of quantile-based asymmetric distributions to obtain flexible distributions for modelling right censored survival data. The flexible distributions can be generated using a variety of symmetric distributions and monotonic link functions. The interesting feature of this family is that the location parameter coincides with an index-parameter quantile of the distribution. This family is also suitable to characterize different shapes of the hazard function (constant, increasing, decreasing, bathtub and upside-down bathtub or unimodal shapes). Statistical inference is done for the whole family of distributions. The parameter estimation is carried out by optimizing a non-differentiable likelihood function. The asymptotic properties of the estimators are established. The finite-sample performance of the proposed method and the impact of censorship are investigated via simulations. Finally, the methodology is illustrated on two real data examples (times to weaning in breast-fed data and German Breast Cancer data).sponsorship: The authors are grateful to the editor, and associate editor and reviewers for their valuable comments that led to an improvement of the manuscript. The second author gratefully acknowledge support from Research Grant FWO G0D6619N of the Flemish Science Foundation, and from the C16/20/002 project of the Research Fund KU Leuven. (Flemish Science Foundation|FWO G0D6619N, Research Fund KU Leuven|C16/20/002)status: Published onlin
A hybrid hazard-based model using two-piece distributions
No full textCox proportional hazards model is widely used to study the relationship between the survival time of an event and covariates. Its primary objective is parameter estimation assuming a constant relative hazard throughout the entire follow-up time. The baseline hazard is thus treated as a nuisance parameter. However, if the interest is to predict possible outcomes like specific quantiles of the distribution (e.g. median survival time), survival and hazard functions, it may be more convenient to use a parametric baseline distribution. Such a parametric model should however be flexible enough to allow for various shapes of e.g. the hazard function. In this paper we propose flexible hazard-based models for right censored data using a large class of two-piece asymmetric baseline distributions. The effect of covariates is characterized through timescale changes on hazard progression and on the relative hazard ratio; and can take three possible functional forms: parametric, semi-parametric (partly linear) and non-parametric. In the first case, the usual full likelihood estimation method is applied. In the semi-parametric and non-parametric settings a general profile (local) likelihood estimation approach is proposed. An extensive simulation study investigates the finite-sample performances of the proposed method. Its use in data analysis is illustrated in real data examples.The authors thank the reviewers for their valuable comments that led to an improvement
of the manuscript. The second author gratefully acknowledges support from Research Grant C16/20/002
project of the Research Fund KU Leuven
Two-piece distribution based semi-parametric quantile regression for right censored data
No full textWidely used methods such as Cox proportional hazards, accelerated failure time, and Bennet proportional odds models do not model the quantiles directly, but rather allow to assess the influence of the covariates only on the location of the distribution. Quantile regression allows to assess the effects of covariates, not only on a location parameter (such as a mean or median) but also on specific percentiles of the conditional distribution. In recent years, a large family of flexible two-piece asymmetric distributions where the location parameter coincides with a specific quantile of the distribution has been studied. In a conditional (regression) setting the use of such a family of two-piece asymmetric distributions has only been investigated in the complete data case in the literature. In this paper, we propose a semi-parametric procedure to estimate the conditional quantile curves of two-piece asymmetric distributions based on right censored survival data. We use a local likelihood estimation technique in a multi-parameter functional form, via which the effect of a covariate on the location, scale, and index of the conditional survival distribution can be assessed. The finite sample performance of the estimators is investigated via simulations, and the methodology is illustrated on real data examples.The authors are grateful to an Associate Editor and two reviewers for their comments which led to an improvement of the manuscript. We thank the authors of Christou and Akritas (2019) to provide us with the R code to calculate their estimator in the SIQR model. The second author gratefully acknowledges support from Research Grant FWO G0D6619N of the Flemish Science Foundation, and from the C16/20/002 project of the Research Fund KU Leuven. The resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation - Flanders (FWO) and the Flemish Government
Drug-Resistant tuberculosis in Ethiopia: Characteristics of cases in a referral hospital and the implications
No full textBackground: Tuberculosis (TB) programs should design intervention strategies based on the sound knowledge of the existing local epidemiology and sociodemographic characteristics of drug-resistant-TB (DR-TB) cases. The aim of the study was to characterize the pulmonary multidrug-resistant (MDR) and rifampicin-resistant (RR) TB cases enrolled in a referral hospital at Addis Ababa, Ethiopia, called All Africa Leprosy, Tuberculosis, Rehabilitation and Training (ALERT) Hospital. Methods: We conducted a descriptive study based on retrospective review of medical records of 340 pulmonary MDR/RR-TB cases enrolled in ALERT Hospital from November 2011 to December 2016. To characterize the cases, we described the distribution of demographic and clinical characteristics. To compare the distribution of demographic and clinical characteristics between male and female cases, we used Pearson's Chi-squared test. Results: Males accounted for 52.9% of the 340 cases. Nine out of ten cases were in the age group of 15–44 years. Sputum acid-fast bacilli smear-positive and human immunodeficiency virus-coinfected cases constituted 63.7% and 18.1% of cases, respectively. The proportion of new cases increased through the years from nil in 2011 to 21.4% in 2016. Adult males above 24 years constituted more than three quarters (77.2%) of the total male cases, while adult females in this age group constituted 56.9%. The age distribution between male and female cases showed significant differences (P < 0.001). Conclusion: There is age disparity between male and female cases with high impact of MDR/RR-TB on productive adult male population. The transmission potential for DR-TB is also high in the community
Determinants of loans and advances of commercial banks in Ethiopia
No full textThe main objective of this study is to investigate the effect of core bank-specific and industryspecific determinants of commercial banks total loans and advances from the period 2002-2013.
The paper examined the impact level of volume of deposits, interest (lending) rate, stipulated
cash reserve requirements ratio and liquidity ratio on the Lending behavior of commercial
Banks currently operating in Ethiopia by taking eight commercial Banks and using OLS
estimation method to measure the effect of internal and external determinants on total loans and
advances, Secondary data obtained from the financial statements (Balance sheet and Profit/Loss
income statement) of commercial banks and data collected from NBE are analyzed. The findings
of the study reveal that volume of deposit, cash reserve requirement and liquidity ratio have a
positive and statistically significant relationship with the lending behavior of commercial banks'.
However, average lending rate has negative and statistically significant relationship with the
lending behavior of commercial banks'. The study suggests that banks should mobilize more
deposit in order to develop their lending performance, they should watch their loan pricing
decisions and banks should cooperate with regulatory authorities
Effect of NP Fertilizer Rate and Bradyrhizobium Inoculation on Nodulaton, N-Uptake and Crude Protein Content of Soybean [Glycine Max (L.) Merrill], At Jinka, Southern Ethiopia
No full textA field experiment was conducted at Jinka Agricultural Research Center to determine the effect of NP fertilizers application rate and bradyrhizobium inoculation on nodulation, N-uptake and crude prtein content of soybean [Glycine max (L.) Merrill] at Jinka under rain fed conditions in 2008. The experiment was conducted with two levels of nitrogen in the form of urea (0 and 46 kg ha-1), two levels of bradyrhizobium (0 and Str-TAL-379) and four levels of phosphorous fertilizer in the form of TSP (0, 25, 50 and 75 kg ha-1). The experimental design was split-split plot with four replications where, N was arranged as main plot factor, bradyrhizobium and P were arranged as sub and sub-sub plot factors, respectively. Nodulation parameters, N-uptake and crude protein content of soybean were studied. Nitrogen application significantly affected N uptake by soybean except straw N uptake. Application of 46 kg N ha-1, inoculation or P fertilization of 25 kg P ha-1 resulted in higher net benefit and maximum MRR (%). Therefore, it can be concluded from this result that nitrogen application of 46 kg N ha-1, inoculation or phosphorous application at the rate of 25 kg P ha-1 is advisable and could be appropriate for soybean production in the test area even though further testing is required to put the recommendation on a strong basis. Key words: Inoculation, Nitrogen fertilizer, Phosphrous fertilizer and Soybe
Screening for ocular abnormalities and subnormal vision in school children of Butajira Town, southern Ethiopia
No full textScreening for ocular abnormalities and subnormal vision in school children of Butajira Town, southern Ethiopia
No full textAbstract
Background: As in most African countries there is no national preschool or school eye screening service in Ethiopia. The purpose of this study was to conduct school eye screening in Butajira town to identify the causes of ocular morbidity and subnormal vision in school children and suggest possible intervention strategies.
Methods: A cross-sectional study of 1846 students from Mekicho (1397) and Dobo-tuto (449) junior and elementary schools of Butajira Town selected by systematic random sampling of the sections of each grade was performed from Sep.13 to Nov.11, 1999. Visual acuity and detailed ophthalmologic examinations were done.
Results: One or more ocular abnormalities were found in 62.6% of the students. Trachoma was the leading cause (54%) of ocular morbidity, followed by refractive error (11.8%), strabismus (4.4%), non-trachomatous acute conjunctivitis (2.3%), corneal opacity (1.3%), Xerophthalmia (1.1%)and Vernal keratoconjunctivitis (0.7%). Refractive error was the leading cause of low vision.
Conclusion: Trachoma is a public health problem in the community, hence mass mobilization and the WHO comprehensive SAFE strategy has to be implemented. Concerned government bodies as well as NGO’s should take the initiative of providing those children with refractive error with low cost eyeglasses. Health education and yearly school eye screening by local health personnel will prevent common causes of blindness and visual impairment. [Ethiop.J.Health Dev. 2002;16(2):165-171
Family planning utilization and associated factors among postpartum women in Addis Ababa, Ethiopia, 2018.
No full textBackgroundPregnancies that occur in the first year after birth can result in adverse outcomes for the mothers and their babies. Postpartum family planning (PPFP) can save lives of many mothers and children. Only few data are available about the magnitude of PPFP use and its determinants in Addis Ababa, Ethiopia.ObjectiveTo assess PPFP utilization and associated factors in Addis Ababa, Ethiopia.MethodA facility-based cross-sectional study was conducted from April to June 2018. A total of 625 women were enrolled in the study. Statistical Package for the Social Sciences (SPSS) software was used to analyze the data. Binary logistic regression model with adjusted odd ratio (AOR) and 95% confidence interval (CI) was used to identify the factors associated with PPFP use. A p-value less than 0.05 was considered as significant.ResultThe magnitude of PPFP utilization in Addis Ababa was 71.8%. Previous family planning (FP) information (AOR = 13.2; 95% CI: (1.96, 88.07)), FP information from health facility visit (AOR = 2.23; 95% CI: (1.45, 3.43)), antenatal care (AOR = 4.96; 95% CI: (1.58, 15.64)), counseling on FP at postnatal care (AOR = 1.97; 95% CI: (1.27, 3.05)), menses resumption after birth (AOR = 1.75; 95% CI: (1.11, 2.76)), and commencing sexual activity after birth (AOR = 9.34; 95% CI: (5.39, 16.17)) were the factors associated with PPFP use.Conclusion and recommendationThough the magnitude of PPFP use is encouraging, still three out of the ten postpartum women did not use PPFP. The determinants of PPFP use were having FP information, having FP information from health facility visit, antenatal care, counseling about FP during postnatal care, menses resumption after birth, and commencing sexual activity after birth. The health system in the City and the healthcare providers should strive to reach every woman who is not accessing the PPFP services and antenatal care services, and improve counseling services on PPFP during delivery and postnatal care services
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