Alaa Althubaiti

Information bias in health research: definition, pitfalls, and adjustment methods

As with other fields, medical sciences are subject to different sources of bias. While understanding sources of bias is a key element for drawing valid conclusions, bias in health research continues to be a very sensitive issue that can affect the focus and outcome of investigations. Information bias, otherwise known as misclassification, is one of the most common sources of bias that affects the validity of health research. It originates from the approach that is utilized to obtain or confirm study measurements. This paper seeks to raise awareness of information bias in observational and experimental research study designs as well as to enrich discussions concerning bias problems. Specifying the types of bias can be essential to limit its effects and, the use of adjustment methods might serve to improve clinical evaluation and health care practice.

Non-Gaussian Berkson errors in bioassay

The experimental design plays an important role in every experimental study. However, if errors in the settings of the studied factors cannot be avoided, i.e. Berkson errors occur, the estimates of the model parameters may be biased and the variability in the study increased. Correction methods for the effect of Berkson errors are compared. The emphasis is on the study of correlated Berkson errors which follow non-Gaussian distribution as this appears to have been a neglected, yet important, area. It is shown that the regression calibration approach bias correction methods are useful when the Berkson errors are independent. However, when these errors are dependent, the newly proposed method B-SIMEX clearly outperforms the other methods.

Severe Vitamin D Deficiency A Significant Predictor of Early Hypocalcemia after Total Thyroidectomy

Objective To assess the role of preoperative serum 25 hydroxyvitamin D as predictor of hypocalcemia after total thyroidectomy. Study Design Retrospective cohort study. Setting University teaching hospital. Subjects and Methods All consecutively performed total and completion thyroidectomies from February 2007 to December 2013 were reviewed through a hospital database and patient charts. The relationship between postthyroidectomy laboratory hypocalcemia (serum calcium ≤2 mmol/L), clinical hypocalcemia, and preoperative serum 25 hydroxyvitamin D level was evaluated. Results Two hundred thirteen patients were analyzed. The incidence of postoperative laboratory and clinical hypocalcemia was 19.7% and 17.8%, respectively. The incidence of laboratory and clinical hypocalcemia among severely deficient (<25 nmol/L), deficient (<50 nmol/L), insufficient (<75 nmol/L), and sufficient (≥75 nmol/L) serum 25 hydroxyvitamin D levels was 54% versus 33.9%, 10% versus 18%, 2.9% versus 11.6%, and 3.1% versus 0%, respectively. Multiple logistic regression analysis revealed preoperative severe vitamin D deficiency as a significant independent predictor of postoperative hypocalcemia (odds ratio [OR], 7.3; 95% confidence interval [CI], 2.3-22.9; P = .001). Parathyroid hormone level was also found to be an independent predictor of postoperative hypocalcemia (OR, 0.6; 95% CI, 0.5-0.8; P = .002). Conclusion Postoperative clinical and laboratory hypocalcemia is significantly associated with low levels of serum 25 hydroxyvitamin D. Our findings identify severe vitamin D deficiency (<25 nmol/L) as an independent predictor of postoperative laboratory hypocalcemia. Early identification and management of patients at risk may reduce morbidity and costs.

Sources of Stress and Coping Strategies among Undergraduate Medical Students Enrolled in a Problem-Based Learning Curriculum

Background. Medical education is rated as one of the most difficult trainings to endure. Throughout their undergraduate years, medical students face numerous stressors. Coping with these stressors requires access to a variety of resources, varying from personal strengths to social support. We aimed to explore the perceived stress, stressors, and coping strategies employed by medical students studying in a problem-based learning curriculum. Methodology. This is a cross-sectional study of randomly selected medical students that explored demographics, perceived stress scale, sources of stress, and coping strategies. Results. Of the 378 medical students that participated in the study, males were 59.3% and females 40.7%. Nearly 53% of the students often felt stressed, and a third felt that they could not cope with stress. Over 82% found studying stressful and 64.3% were not sleeping well. Half of the students reported low self-esteem. Perceived stress scores were statistically significantly high for specific stressors of studying in general, worrying about future, interpersonal conflict, and having low self-esteem. Coping strategies that were statistically significantly applied more often were blaming oneself and being self-critical, seeking advice and help from others, and finding comfort in religion. Female students were more stressed than males but they employ more coping strategies as well. Conclusions. Stress is very common among medical students. Most of the stressors are from coursework and interpersonal relationships. Low self-esteem coupled with self-blame and self-criticism is quite common.

Serum Sclerostin Levels in Patients with Human Immunodeficiency Virus Infection and Their Association with Bone Turnover Markers and Bone Mineral Densitometry.

Background The aim of the study was to compare serum sclerostin levels in human im-munodeficiency virus (HIV)-infected patients and healthy controls, and to evaluate their relationship with bone turnover markers (BTM) and bone mineral density (BMD). Methods We prospectively studied 33 HIV treatment-naive patients and 63 healthy individuals; matched for age and sex. Serum sclerostin levels, BTM, BMD were measured. Viral load and cluster of differentiation 4 (CD4) levels were also assessed in HIV-infected patients. Results The mean±standard deviation (SD) age of sample was 37.6±10.3 years (range, 19 to 59 years). Of the 96 subjects, 58 (60.4%) were male and 38 (39.6%) were female. Infection with HIV is associated with significant reduction in serum sclerostin levels (HIV-infected: 39.4±28.3 vs. non HIV: 76.6±15.7 pmol/L; P<0.001) and a decrease in BMD at femoral neck and lumbar spine compared to healthy controls. Sclerostin however was not correlated with BMD and was not related to age, generally a strong correlation. There were no significant correlations between sclerostin and BTM (P>0.05). Conclusions These findings suggest that untreated HIV and the resulting immune deficiency and/or systemic inflammation could be an important regulator of serum sclerostin in this population.

Class attendance and cardiology examination performance: a study in problem-based medical curriculum

Background and aims Information on the effect of students’ class attendance on examination performance in a problem-based learning medical curriculum is limited. This study investigates the impact of different educational activities on students’ academic performance in a problem-based learning curriculum. Methods This is a retrospective cohort study conducted on the cardiology block at the College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia. All students who undertook the cardiology block during the academic year 2011–2012 were included. The students’ attendance was measured using their overall attendance percentage. This percentage is a product of their attendance of many activities throughout the block. The students’ performance was assessed by the final mark obtained, which is a product of many assessment elements. Statistical correlation between students’ attendance and performance was established. Results A total of 127 students were included. The average lecture attendance rate for the medical students in this study was found to be 86%. A significant positive correlation was noted between the overall attendance and the accumulated students’ block mark (r=0.52; P<0.001). Students’ attendance to different education activities was correlated to their final mark. Lecture attendance was the most significant predictor (P<0.001), that is, 1.0% increase in lecture attendance has predicted a 0.27 increase in students’ final block mark. Conclusion Class attendance has a positive effect on students’ academic performance with stronger effect for lecture attendance compared to attendance in other teaching modalities. This suggests that lecture attendance is critical for learning even when a problem-based learning medical curriculum is applied.

Undergraduate Medical Research Programme: A Cross-Sectional Study of Students" Satisfactions, Perceived Challenges, and Attitudes

Background: Implementing an undergraduate Medical Research Programme (MRP) in medical colleges may not only improve the subsequent career of medical students but also benefit the health system in general. If not designed effectively, however, such a programme could have the opposite impact. Therefore, the quality of a MRP should be evaluated continuously. This study aims to evaluate the MRP from medical students’ perspective. Methods: A cross-sectional survey study was conducted from March to April 2014 amongst undergraduate medical students at the College of Medicine, King Saud University for Health Sciences, Riyadh, Saudi Arabia. Satisfaction, perceived challenges, and attitudes towards the MRP were evaluated. Results: A total of 154 responses were collected from the students; 81(52.6%) were in the 2nd year and 73 (47.4%) were in the 3rd year of the MRP, 97(63%) were males. The mean ± SD age was 21.5 ± 0.82 years. Overall, most students were satisfied with the MRP (51.3%). The majority of students were of the opinion that there was a shortage of time to complete their work (57.6%) and a lack of motivation to do research (53.3%). Significant differences were found in the satisfaction levels and perceived challenges between students in the 2nd and 3rd year of the MRP (P≤ .013). Discussion: Assessment of medical students’ perspective towards the MRP is an important aspect of the educative process. We recommend more evaluation studies, because they ensure that programmes effectively meet their goals and continue to be improved. A solid MRP is essential and will increase the university’s profile.

The effect of epidural education on Primigravid Women’s decision to request epidural analgesia: a cross-sectional study

BackgroundEpidural analgesia represents one of the most effective pharmacological ways to relieve labour pain. Women’s awareness regarding the use of epidurals is increasing. As the decision to use epidural analgesia during labour is affected by many social, personal and medical factors, this study aimed to explore the factors contributing to a pregnant women’s decision to use epidurals and to understand the benefit of implementing a health education program regarding epidural analgesia.MethodsA cross-sectional study was conducted with primigravid women visiting the Obstetric Clinics for their routine antenatal care at King Abdul-Aziz Medical City in Riyadh from October 2014 to December 2016. The participating pregnant women were educated on the use of epidural analgesia during labour by a professional health educator utilizing specially designed educational materials. We assessed the relationship between the women’s decision to request epidural analgesia and their age, place of residence, occupation, income and education level using a questionnaire.ResultsA total of 81 primigravid women were included in the study. Employed pregnant women were more likely to request epidural analgesia than non-employed women (46.7% vs. 18.2%, P = 0.019). After education, significantly more pregnant women were planning to request epidurals (mean score for answers before education was 2.12 ± 0.578 vs. 2.27 ± 0.592 after education, P = 0.013). Other variables, such as age, level of education, income and place of residence were not significantly associated with the participants’ decision to request epidural analgesia.ConclusionHealth education on epidural analgesia is an important factor in increasing primigravid women’s desire to request epidural analgesia. Education on epidural analgesia during antenatal care is needed for better decision making regarding the use of epidural analgesia during labour.

Impact of birth characteristics, breast feeding and vital statistics on the eruption of primary teeth among healthy infants in Saudi Arabia: an observational study

Objectives This study aimed to explore the impact of gender, birth weight, maternal age, type of delivery, gestational age and feeding practices on the eruption of teeth in children with no underlying medical conditions or developmental defects in their first year of life. Design A cross-sectional observational study design was used. Setting A primary healthcare setting in Riyadh, Saudi Arabia. Participants All children in their first year of life attending a vaccination clinic (n=422) were included in the study. Infants with chronic childhood illnesses, those who were below the 5th percentile in height or weight, infants with congenital birth defects and chronic illnesses, infants who were born preterm and low birth weight infants were excluded from the study. Outcome measures The type of delivery, birth weight, age of mother, height and weight percentile for age (as plotted on the WHO growth chart for infants) and feeding practices were recorded by the examiner, and this was followed by a clinical examination to determine the presence or absence of each tooth. Regression models were developed to determine the effect of the different variables on the presence of primary teeth. Results There was a significant association between the weight percentile of the child (adjusted for age) and the number of erupted primary teeth, suggesting that heavier children have an earlier eruption of teeth. No association was observed between birth weight, height percentile for age or maternal age at the time of birth and the number of erupted primary teeth. Children who were exclusively breast fed were significantly more likely to have an erupted first primary tooth earlier than non-breastfed group. Conclusions Breast feeding and the weight of the child may have an influence on the eruption of primary teeth in the first year of life.