Bedside teaching: an invaluable tool in undergraduate medical education

AimsBedside teaching is one of the most important modalities in medical education. Sir William Osler stated, “Medicine is learned by the bedside and not in the classroom”. Despite this, the use of bedside teaching in the undergraduate curriculum has been declining, potentially due to changes in course design, increasing clinical workloads and reducing inpatient numbers. In my role as a Clinical Teaching Fellow (CTF), I have aimed to maximise bedside teaching and promote it as the primary approach for student learning.MethodAs a CTF, I deliver teaching to students from the Universities of Glasgow and Edinburgh during their placements in NHS Lanarkshire. Weekly teaching is provided to groups of 2-4 students, with around 50% of sessions delivered ‘at the bedside’.Within psychiatry, there is a vast range of potential bedside teaching topics. Given the length of time required to conduct a full psychiatric history and mental state examination (MSE), teaching sessions instead focus on one specific component of the patient interview, for example, assessing perceptual abnormalities or delusions, conducting a substance use history or exploring social circumstances and the functional impact of illness. This approach allows for more focussed feedback and teaching. Session structure is based upon Cox's model of bedside teaching, which I have modified slightly for the psychiatry setting.Student feedback has been collected via an anonymous electronic end-of-block questionnaire.ResultQualitative feedback reveals that students in NHS Lanarkshire value bedside teaching, with one student describing it as “informative, comprehensive and relevant for upcoming exams and clinical practice”.There are a number of potential barriers to consider when delivering bedside teaching in psychiatry. These include issues identifying suitable patients who can provide informed consent to participate and the ethical concerns regarding exploring difficult subjects such as suicide risk assessment with patients for purely educational purposes.These issues can be overcome; in inpatient units, there is usually a small cohort of patients who are able to consent and engage in student teaching, and difficult subjects can alternatively be addressed during role-play or simulation sessions.ConclusionDespite its challenges, bedside teaching can be an enjoyable and rewarding approach in undergraduate medical education, with feedback revealing it is positively received in NHS Lanarkshire. By utilising Cox's model and focussing on specific aspects of MSE and history-taking, bedside teaching is more accessible and an invaluable tool for psychiatric teaching. Clinicians and educators are encouraged to keep the patient at the centre of student learning.

Long-Term Tacrolimus Blood Trough Level and Patient Survival in Adult Liver Transplantation

Tacrolimus is the most widely used immunosuppressant in liver transplant (LT) patients. However, the ideal long-term target level for these patients is unknown. This retrospective study aimed to investigate the impact of tacrolimus blood concentration five years after LT on long-term patient survival outcomes in adult LT recipients. Patients who underwent LT between January 2004 and July 2014 at a tertiary medical center were included in this study (n = 189). The mean tacrolimus blood concentrations of each patient during the fifth year after LT were recorded and the overall survival rate was determined. A multivariate analysis of factors associated with long-term survival was conducted using a Cox’s model. The median follow-up period was 9.63 years, and 144 patients (76.2%) underwent live donor LT. Sixteen patients died within 5 years of LT. In the Cox’s model, patients with a mean tacrolimus blood trough level of 4.6–10.2 ng/mL had significantly better long-term survival than those with a mean tacrolimus blood trough level outside this range (estimated hazard ratio = 4.76; 95% confidence interval: 1.34–16.9, p = 0.016). Therefore, a tacrolimus level no lower than 4.6 ng/mL would be recommended in adult LT patients.

The Adjustment of Covariates in Cox’s Model under Case-Cohort Design

Case-cohort design is a biased sampling method. Due to its cost-effective and theoretical significance, this design has extensive application value in many large cohort studies. The case-cohort data includes a subcohort sampled randomly from the entire cohort and all the failed subjects outside the subcohort. In this paper, the adjustment for the distorted covariates is considered to case-cohort data in Cox’s model. According to the existing adjustable methods of distorted covariates for linear and nonlinear models, we propose estimating the distorting functions by nonparametrically regressing the distorted covariates on the distorting factors; then, the estimators for the parameters are obtained using the estimated covariates. The proof of consistency and being asymptotically normal is completed. For calculating the maximum likelihood estimates of the regression coefficients subject in Cox’s model, a minorization-maximization (MM) algorithm is developed. Simulation studies are performed to compare the estimations with the covariates undistorted, distorted, and adjusted to illustrate the proposed methods.

Tumor microenvironment and breast cancer survival: combined effects of breast fat, M2 macrophages and hyaluronan create a dismal prognosis

Purpose Tumor microenvironment, including inflammatory cells, adipocytes and extracellular matrix constituents such as hyaluronan (HA), impacts on cancer progression. Systemic metabolism also influences tumor growth e.g. obesity and type 2 diabetes (T2D) are risk factors for breast cancer. Here, in 262 breast cancer cases, we explored the combined impacts on survival of M2-like tumor associated macrophages (TAMs), the abundance of breast fat visualized as low density in mammograms, and tumor HA, and their associations with T2D. Methods Mammographic densities were assessed visually from the diagnostic images and dichotomized into very low density (VLD, density ≤ 10%, “fatty breast”) and mixed density (MID, density > 10%). The amounts of TAMs (CD163+ and CD68+) and tumor HA were determined by immunohistochemistry. The data of T2D was collected from the patient records. Statistical differences between the parameters were calculated with Chi square or Mann–Whitney test and survival analyses with Cox’s model. Results A combination of fatty breasts (VLD), abundance of M2-like TAMs (CD163+) and tumor HA associated with poor survival, as survival was 88–89% in the absence of these factors but only 40–47% when all three factors were present (p < 0.001). Also, an association between T2D and fatty breasts was found (p < 0.01). Furthermore, tumors in fatty breasts contained more frequently high levels of M2-like TAMs than tumors in MID breasts (p = 0.01). Conclusions Our results demonstrate a dramatic effect of the tumor microenvironment on breast cancer progression. We hypothesize that T2D as well as obesity increase the fat content of the breasts, subsequently enhancing local pro-tumoral inflammation.

Factors affecting time until myocardial infarction in hypertension patients using truncated Cox regression

Background and aims: Hypertension is one of the most common and important risk factors of cardiovascular diseases. This phenomenon, if not cured, causes lots of problems in vital organs of the body like kidneys, brain, eyes, and heart. The aim of the current study was to identify factors which affect the time until myocardial infarction (MI) in hypertension patients using truncated Cox regression. Methods: This study was a population retrospective cohort and its statistical population included patients with hypertension symptoms, who had MI for the first time in Sari. A decision was made based on continuing the study as a nested case and control study because the number of MI incidents was low (7%) in the studied sample. In addition, the Cox’s model and truncated Cox were used for determining the factors affecting the patients’ survival. Results: The median and mean survival times in this sample were equal to 57 and 66.44 months, respectively. Considering time truncation, family history (HR=1.70) and the age at diagnosis (HR=0.99) were statistically significant in the Cox’s model (P< 0.05). Conclusion: Overall, using the Akaike criterion for comparing the survival time without the effect of truncation, the Cox’s model demonstrated better fitness by controlling the truncation effect. These results show the importance of controlling the truncation in those diseases in which it is impossible to distinguish the time of the appearance from the symptoms.