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

What factors influence training opportunities for older workers? Three factorial surveys exploring the attitudes of HR professionals

The core research questions addressed in this paper are: what factors influence HR professionals in deciding whether to approve training proposals for older workers? What kind of training are they more likely to recommend for older employees and in which organizational contexts? We administered three factorial surveys to 66 HR professionals in Italy. Participants made specific training decisions based on profiles of hypothetical older workers. Multilevel analyses indicated that access to training decreases strongly with age, while highly-skilled older employees with low absenteeism rates are more likely to enjoy training opportunities. In addition, older workers displaying positive performance are more likely to receive training than older workers who perform poorly, suggesting that training late in working life may serve as a reward for good performance rather than as a means of enhancing productivity. The older the HR professional evaluating training proposals, the higher the probability that older workers will be recommended for training. keywords: training; older workers; HR professionals; factorial survey; multilevel model

Impact of age norms and stereotypes on managers' hiring decisions of retirees

Purpose -Our study investigates the role of managers in the re-employment of early retirees and asks what the effect is of managers’ age norms and stereotypes on managers’ employment decisions. Design/methodology/approach- A combination of a factorial study and a survey was conducted. First, information on the age norms and stereotypes was collected. Secondly, profiles of hypothetical retired job applicants were presented to the employers, who were asked to make a specific hiring decision. The information collected during both studies was combined in the analysis and multilevel models were estimated. Findings -The results indicate that higher age norms result in a higher propensity to hire an early retiree. Stereotypes, by contrast, do not influence managers’ decisions. Early retirees’ chances for re-employment are also related to their own circumstances (physical appearance and relevant experience) and organisational forces, as they are hired when organisations face labour force shortages. Research limitation / implications – with the use of vignettes study we deal with hypothetical hiring situation. Originality value- Although the effect of age norms and age stereotypes has been often suggested, not much empirical evidence was presented to support this notion. Our study estimates the effect of age norms and stereotypes on hiring decision. key words: bridge employment; early retirees; age norms; age stereotypes; multilevel models.

Burden of domestic violence amongst infertile women attending infertility clinics in Nigeria

No Abstract Nigerian Journal of Medicine Vol. 16 (4) 2007: pp. 375-37