Aim: To compare the bias magnitude between logistic regression and Bayesian structural equation modeling (SEM) in a small sample with strong unmeasured confounding from two correlated latent variables.
Study Design: Statistical analysis of artificial data.
Methodology: Artificial binary data with above characteristics were generated and analyzed by logistic regression and Bayesian SEM over a plausible range of model parameters deduced by comparing the parameter bounds for two extreme scenarios of no versus maximum confounding.
Results: Bayesian SEM with flat priors achieved almost fourfold absolute bias reduction for the effects of observed independent variables on binary outcome in the presence of two correlated unmeasured confounders in comparison with standard logistic regression which ignored the confounding. The reduction was achieved despite a relatively small sample (N=100) and large bias and variance of the factor loadings for the latent confounding variables. However, the magnitude of residual confounding was still high.
Conclusion: Logistic regression bias due to unmeasured confounding may be considerably reduced with Bayesian SEM even in small samples with multiple confounders. The assumptions for Bayesian SEM are far less restrictive than those for the instrumental variable method aimed at correcting the effect size bias due to unmeasured confounders.
Introduction: Appropriate medical care-seeking could prevent a significant number of child deaths and complications due to ill health.
Objectives: The purpose of our study was to assess care-seeking behaviour of mothers during childhood illnesses and its influencing factors.
Methods: A cross-sectional household survey was conducted in June-July 2012. 600 mothers of children 0-23 months old were selected randomly using a two-stage 30-cluster sampling technique in the three districts of the Diber region. Data collected generated information on 2-week child morbidity and care-seeking practices for acute respiratory infections (ARI) and diarrhoea. Descriptive, bivariate and multivariate logistic regression analyses were used to show frequency distributions and associations.
Results: The prevalence of ARI and diarrhoea were 11.2% and 11.5 %, respectively. Eighty-seven (64%) children were taken to a health facility for advice or treatment. For most of the children (59.6%) care-seeking started on the second and subsequent days of perceived onset of illness. Paediatricians at public hospitals were the most frequently consulted providers, visited by 58 (66.7%) mothers. Mothers’ urban residence (OR=6.09, 95% CI: 1.14-41.72), having a male child (OR=6.02, 95% CI: 1.77-20.4), third and above wealth index (OR=6.02, 95% CI: 1.77-20.4), and knowledge of four or more child danger signs (OR=2.01, 95% CI: 1.04-7.22) increased the odds of ‘prompt’ care seeking.
Conclusions: The prevalence of appropriate healthcare-seeking behaviour in Diber is not adequate. Reinforcement of community based Integrated Management of Childhood Illnesses program may improve mothers’ ability to recognize danger signs of childhood illness and care-seeking behaviour.
Aim: Despite well established validity and reliability of Pap test, a significant proportion of false negative test results still remains and is partially due to the lack of agreement between observers. Visual inspection tests (VIT) share this difficulty but their results are immediately available, thus making it easier to reduce disagreement between observers if these are well trained. The objective of this paper was to verify the agreement on a typical squamous cells of undetermined significance (ASC-US) or higher grade lesions between different examiners with Pap smear and visual inspection tests (VIT) in screening for cervical cancer. It is part of a wider study to evaluate the screening performance of Pap test and VIT in Brazil.
Study Design: A cross-sectional study was conducted among consenting clients attending cervical cancer screening services at a non-governmental medical facility in southern Brazil.
Place and Duration of Study: “Rede Feminina de Combate ao Câncer”, a female cancer prevention center in Florianópolis, southern Brazil, between June 2010 and July 2012.
Methodology: Two observers evaluated 353 Pap smear test specimen and 284 visual inspection tests (VIT) of the women screened for cervical cancer in female cancer prevention center in southern Brazil . VIT started with naked eye examination after visual inspection by applying acetic acid (VIA) and Lugol’s iodine (VILI) to cervix, followed by additional examination with 2x magnifying glass for both modalities .
Results: Concordance between the first and the second observer regarding Pap test was reasonably good (kappa=0.67) but was even better regarding all VIT modalities (kappa range 0.76-0.83 ). Magnifying glass did not significantly improve the agreement.
Conclusion: VIT showed very good agreement between observers . Adding VIT to Pap smear test may improve diagnostic accuracy in cervical cancer screening .
The efficacy of Garcinia kola seed ethanolic extract on selected haematological parameters of male Wistar rats was investigated. Thirty (30) male Wistar rats weighing 150.42±3.98 g were divided into three groups (I, II and III) comprising ten animals each. Animals in group I (control) received 0.5 ml of distilled water while those in groups II and III were administered 100 and 200 mg/kg body weight of the extract respectively once daily for 21 days. After 21 days of extract administration, 5 rats from each group were sacrificed. Same was done after 42 days. Preliminary phytochemical screening of ethanolic extract of Garcinia kola seed revealed the presence of alkaloids, saponins, tannins, carbohydrates, steroids and flavonoids. The lethal dose (LD50) of the extract was found to be safe up to 5000 mg/kg body weight. The extract significantly (p<0.05) increased the red blood cell (RBC) count, packed cell volume (PCV), hemoglobin (Hb) concentration, white blood cell (WBC) count, platelet count and mean cell hemoglobin concentration (MCHC) in the plasma of the animals. The extract significantly (p<0.05) decreased the mean cell volume (MCV) and mean cell hemoglobin (MCH) in the plasma of the animals. Therefore, the ethanolic extract of Garcinia kola seed through its antioxidant property showed hematopoietic, stimulating and enhancing effects.
Background: The effect of crude extract of Erythrophleum suaveolens was studied on isolated tissues of the Rat’s phrenic nerve-diaphragm muscles. Study aimed to investigate the relaxant effect of crude extract of E. suaveolens on the skeletal muscle using isolated rat phrenic nerve-diaphragm preparation in comparison with selected test drugs activity.
Methods: Reference drugs (Hexamethonium, Pancuronium and Suxamethonium) were used on the isolated tissues. Crude extract blocked the effect of Acetylcholine-induced contractions, thus a relaxing effect.
Results: The relaxing effect of cold water stem-bark extract of E. suaveolens is evident on skeletal muscle of rat phrenic nerve-diaphragm. The observed relaxation-pattern is closely related with that of Hexamethonium.
Conclusions: Cold water stem-bark extract of Erythrophleum suaveolens is therefore a potent muscle relaxant as claimed by traditional healers, hence could be explored as a muscle relaxant.