P-Value, a true test of statistical significance? a cautionary note

While it’s not the intention of the founders of significance testing and hypothesis testing to have the two ideas intertwined as if they are complementary, the inconvenient marriage of the two practices into one coherent, convenient, incontrovertible and misinterpreted practice has dotted our standard statistics textbooks and medical journals. This paper examine factors contributing to this practice, traced the historical evolution ofthe Fisherian and Neyman-Pearsonian schools of hypothesis testing, exposed the fallacies and the uncommon ground and common grounds approach to the problem. Finally, it offers recommendations on what is to be done to remedy the situation

Clustering of cardiovascular disease risk‑factors in semi‑urban population in Northern Nigeria

Introduction: Non‑communicable diseases (NCDs) are major causes of morbidity and mortality particularly for developing countries. Large proportion of all NCDs deaths are occurring in low‑ and ‑middle‑income countries are estimated to occur in people under 70‑years‑old. These low‑ and middle‑income are undergoing epidemiological transition which allows the concomitant occurrence of both communicable and NCDs due to adoption of western life‑style that predisposes them to development of these diseases. It is also known that there are risk‑factors that tend to cluster in individuals and make them more susceptible to NCDs especially cardiovascular diseases (CVDs). Among NCDs, CVDs constitute the largest share responsible for 48% of all deaths due to NCDs. To determine extend of clustering of these risk‑factors in a semi‑urban community in northern Nigeria, a population‑based study was carried out.Materials and Methods: This study was conducted in Dakace, a semi‑urban settlement near Zaria. A simple random sampling of 199 eligible respondents out of 424 was adopted to select study participants. An interviewer‑administered questionnaire was used to collect socio‑demographic information, smoking habits, alcohol consumption as well as level of physical activity. The following measurements were carried out on these respondents: Blood pressure (BP), fasting blood glucose, serum lipids, weight, and height to calculate body mass index (BMI).Results: There were of 199 participants: 94 males (47.2%) and 105 females (52.8%) with an overall mean age of 39.9 ± 15.6 years. About 20% had no risk factor; more females than males had risk‑factors. Proportion of subjects with risk‑factors increase with increasing BMI, particularly high BP; physical activity does not protect subjects from developing risk‑factors.Conclusion: This study clearly shows that CVD risk‑factors are prevalent even in segment of the population that hitherto may be considered free and the prevalence of these risk‑factors are high compared to some obtained from other part of Nigeria.Keywords: Cardiovascular, clustering, Dakace, Northern Nigeria, risk‑factorsNigerian Journal of Clinical Practice • Oct-Dec 2013 • Vol 16 • Issue

Determinants of antenatal care, institutional delivery and postnatal care services utilization in Nigeria

Introduction: Utilization of antenatal care, institutional delivery and postnatal care services in Nigeria are poor even by african average. Methods: We analysed the 2013 Nigeria DHS to determine factors associated with utilization of these health MCH indicators by employing both bivariate and multivariate logistic regressions. Results: Overall, 54% of women had at least four ANC visits, 37% delivered in health facility and 29% of new born had postnatal care within two of births. Factors that consistently predict the utilization of the three MCH services are maternal and husband's level education, place of residence, wealth level and parity. Antenatal care strongly predicts both health facility delivery (OR=2.16, 95%CI: 1.99-2.34) and postnatal care utilization (OR=4.67, 95%CI: 3.95-5.54); while health facility delivery equally predicting postnatal care (OR=2.84, 95%CI: 2.20-2.80). Conclusion: Improving utilization of these three MCH indicators will require targeting women in the rural areas and those with low level of education as well as creating demand for health facility delivery. Improving ANC use by making it available and accessible will have a multiplier effect of improving facility delivery which will lead to improved postnatal care utilization

Optimal sizing and techno-economic analysis of grid-connected nanogrid for tropical climates of the savannah

Reliability and costs are mainly considered in performance analysis of renewable energy-based distributed grids. Hybrid Optimization of Multiple Energy Renewables was used in techno-economic analysis of renewable energy systems involving photovoltaics, wind, diesel and storage in tropical regions of Amazon, Central Asia and Mediterranean. In a study for a Guinea Savannah region, 70% of renewable energy fraction was achieved. However, levelized cost of energy of 0.689 $/kWh was higher than tariff rate of 0.6$/kWh. This paper considers Hybrid Optimization of Multiple Energy Renewables to achieve lower levelized cost of energy and net present costs of a nanogrid for increased reliability and low per capita energy consumption of 150 kWh in a Sudan Savannah region of Nigeria. The proposed grid connected nanogrid aims to serve daily residential demand of 355 kWh. A range of 0.0110 $/kWh to 0.0095$/kWh and $366,210 to$288,680 as negative values of levelized cost of energy and net present cost respectively were realized, implying potentials for a large grid export. The renewable energy fraction of up to 98% was also achieved in addition to low greenhouse gas emission of 2,328 tons/year. The results may further be consolidated with strategies for power dispatch and load scheduling

Geographical Distribution of Publications in the African Journal of Reproductive Health: An Analysis of 2006 – 2010 papers

Scientific research has been recognized as one of the cornerstones of economic growth and development. Publication of research findings in biomedical journals has grown exponentially in the past few decades globally but the contribution of developing countries is still abysmally low. To evaluate the productivity of Nigerian biomedical community, this study was conducted using the African Journal of Reproductive Health (AJRH) as a benchmark. This was a retrospective review of all articles published in AJRH between 2006 and 2010. Using a proforma all relevant information in the journal were extracted. There were a total of 204 articles produced by 798 authors. In terms of geographical spread of authors within Nigeria Edo, Oyo and Kaduna states are the three leading states, while outside Nigeria, the US is the leading country. More than 81% of the authors are affiliated to either the University or Research Institutions. In six publications, funding came from within Nigeria while in 87 funding was from outside Nigeri

Prevalence of diabetes in a semi-urban community in northern Nigeria.

Background: Diabetes mellitus is a growing public health problem both in developing and developed nations. The prevalence of diabetes globally is projected to rise from 2.8% in 2000 to 4.4% in 2030.This study was conducted to assess the prevalence of diabetes in Dakace village, near Zaria Method: This study was part of a larger study to assess the prevalence of cardiovascular disease risk factors among adults in Dakace village, near Zaria. Out of a total of 492 eligible respondents for the study, a subsample of 199 persons was recruited using a systematic sampling technique had their fasting blood glucose levels determined. Body mass indices of the participants were also determined. Results: A total of 199 subjects (94 males and 105 females) participated in this segment of the study. Three subjects had fasting blood glucose (FBG) of more than 7.0mmol/L; one participant a previously known diabetic on medication had a good glycaemic control. The overall prevalence of diabetes was 2.0%.Five participants (2.5%) had impaired fasting glucose (IFG). Among the diabetics, one was overweight (BMI= 27.43Kg/m2) and one was obese (BMI=31.55Kg/m2), while among those with impaired fasting glucose two were overweight. Fortythree subjects (21.6%) were overweight and 15 (7.5%) were obese. Conclusion: The prevalence of diabetes mellitus in this semi-urban community is keeping with what had been reported earlier from across the country.Nigerian Journal of Medicine Vol. 17 (4) 2008: pp. 414-41

Mortality and cause of death in Abuth, Zaria: 1999-2005

Background: Accurate mortality statistics are needed for policy formulation,implementation and monitoring of health intervention that are aimed at improving the health status of the people. Mortality level is one of the indicators of the quality of life and status of health of a population. However, accurate collection, collation, analysis and interpretation of such data is poorly organised in developing nations, including Nigeria leading to a gap in health policy formulation, implementation and monitoring. Therefore, policies and strategies for disease prevention are based on empirical evidence rather than on data primarily collected to formulate disease specific interventions.Though, hospital data have inherent deficiency in its use to design prevention. However, when accurately generated and adequately managed would provide both qualitative and quantitative information on morbidity and mortality if not for the entire society at least for a segment of the population utilizing it. We implemented a system of death certification to determine causes and pattern of mortality in Ahmadu Bello University Teaching Hospital, Zaria Methods: From May 1999 to November 2005, all case folders of deceased patients were retrieved from the central library of health information management department of the hospital; case folders of deceased patients are required to have in them a completed IFMCCD(International Form of Medical Certification of Cause of Death). All case folders of deceased patients after relevant information were extracted by the staff of health management information department, were passed on to the staff of department of Community Medicine directly involved in this study. The completed cause of death certificates received in the department of Community Medicine (between May 1999 and November 2005), were examined. Coding rules were employed to select the appropriate code for those certificates that were incorrectly completed. The underlying cause of death as identified from the correctly completed IFMCCDS is coded according to ICD-10.Results: For the period under study, there were 4019 deaths: 2212 males and 1807 females. Total of 2914 (72.5%) deaths were certified, using the IFMCCD of which 1641 of them were males and 1273 females and formed the basis of this analysis. Coverage rates ranges from 56.2% in 2001 to 85% in 1999. The proportion of garbage codes ranges from 0% to 2.4% while the three leading causes of death are HIV infection, road traffic accident (RTA), and cardiovascular diseases among the ten. The time-trend of the leading causes of death show RTA maintaining steady upward climb while malaria, septicemia, PEM, sepsis in the neonatal period shows unsteady fluctuation. Conclusion: This study assessed the pattern of mortality and causes of death in ABU Teaching Hospital, Zaria; it also provided information on leading causes of death

Statistics in Medical Research: Misuse of Sampling and Sample Size Determination

One of the major issues in planning a research is the decision as to how large a sample and the method to be employed to select the estimated sample in order to meet the objective of the research. Sampling is an essential tool for research in medicine. A good number of the medical literature while reporting their sampling method go by stating that the sample was collected by random sampling and no further explanation as how the sample has been drawn as if the word random is generic to all the known sampling methods. The aim of this paper is to sensitise our researchers on the importance of proper sampling and sample size determination. Using a few examples we demonstrated that investigators adhere poorly to the statistical precondition of simple random sampling, have poor understanding of simple random technique, and quite a number of estimated sample sizes were bloated without appreciating the implications of that. Finally, we recommended, among others that investigators should consult biostatisticians at the design stages of their research work and a competent biostatistician should review any article containing even the most elementary statistical procedure.\u13d'un des questions principales d'un recherch\ue9 pour prendre un d\ue9cision, comment le grande \ue9chantillon et la m\ue9thode d'\ueatre employ\ue9 se s\ue9l\ue9ctionner un \ue9chantillon \ue9stim\ue9 afin d'atteindre le but d'un recherchre. \uc9chantillonnage est un utile essentiale \ue0 la recherche en m\ue9dicine. Le mieux nombre de la litterature de la m\ue9dicine alors que la reportage de leur \ue9chantillonnage m\ue9thode not\ue9 que l'\ue9chantillonnage avait collect\ue9 par l'\ue9chatillonnage al\ue9atoire et pas explication davantage comment l'\ue9chantillon \ue0 \ue9t\ue9 attirer si le mot al\ue9atoire est g\ue9n\ue9rique aux savoir d'al\ue9atoires \ue9chantillonnage. Le but de cette expos\ue9 est pour sensibilser notre rechercheur sur l'importance d'\ue9chantillonnage proper et d\ue9t\ue9rmin la sauter \u10fal\ue9atoire \ue9chatillonnage. Nous avons utiliser quelque examples prouve que les investigateurs mal obeir en la pr\ue9condition statistiques d'al\ue9atoire \ue9chatillonnage simple, ils ont mal comprend la technique \u10fal\ue9atoire simple, et un bon nombre d'\ue9stimer les sauters simple \ue9tait hypertrophi\ue9 sans appr\ue9ciation de l'implication. Finallement, nous avons reccomand\ue9 que entre autres investigateurs devraient consulter les biostatisciens \ue0 l'\ue9tage \u10f\ue9baucher leur travail et un comp\ue9tent biostatisticien devrais en revue l'article contienir m\ueame le plus proc\ue9dure \ue9l\ue9mentaire statistique

Mitigating Striga hermonthica parasitism and damage in maize using soybean rotation, nitrogen application, and Striga-resistant varieties in the Nigerian savannas

Open Access article; Published online: 14 Aug 2020Striga hermonthica infestation causes significant losses of maize yield in the Nigerian savannas and several technologies have been developed and promoted to control Striga in maize. However, since no single technology has been found to be effective against Striga, integrated management is needed to achieve satisfactory and sustainable Striga control. Both on-station and on-farm trials were undertaken from 2013 to 2015 in Bauchi and Kano States of Nigeria to evaluate the performance of integrated Striga control technologies. In the on-station trials, a soybean–maize rotation did not suppress Striga in maize in either location. However, nitrogen application suppressed and reduced Striga infection, except in Bauchi in 2014. The soybean–maize rotation accompanied by N application reduced Striga damage in both locations. On farmers’ fields, rotating soybean with maize significantly reduced Striga infection. At the same time, the use of maize varieties with a combined tolerance to drought and resistance to Striga parasitism also increased maize grain yield on farmers’ fields, probably due to three factors: a reduction in Striga infection, reduced effects of a mid-season moisture deficit, and increased uptake of nutrients from the soil. We concluded that the use of Striga-resistant maize varieties in combination with the application of N fertilizer and rotation with soybean could increase the productivity of maize in Striga-infested fields in the Nigerian savannas