Rewarding progress: Effective learning strategies through a variable ratio incentive-based approach in medical education

Medical students are faced with many unprecedented challenges, one of which is the large amount of material they are required to learn and retain. While effective learning strategies have been thoroughly researched, stress levels amongst medical students remain very high due to perceived failure to retain material, suggesting that novel methods of implementing such existing strategies are required. Aside from stress levels, additional challenges in medical education include the incorporation of inconsistent testing methods and the challenge of accommodating different learning styles and preferences. A more evidence-based approach that aims to cover many learning styles at once may be desirable. The aim of this commentary is to present some of the current learning and teaching strategies utilized within medical education across the world and to promote a novel supplementary approach to medical education involving a variable ratio incentive-based system of active recall and spaced repetition. This system aims to reward small achievements throughout the semester and complements formal structured examinations in order to motivate students. While this model has yet to be tested, we hope to motivate medical faculty to pilot a program with these evidence-based strategies in mind.

Rewarding progress: Effective learning strategies through a variable ratio incentive-based approach in medical education

Medical students are faced with many unprecedented challenges, one of which is the large amount of material they are required to learn and retain. While effective learning strategies have been thoroughly researched, stress levels amongst medical students remain very high due to perceived failure to retain material, suggesting that novel methods of implementing such existing strategies are required. Aside from stress levels, additional challenges in medical education include the incorporation of inconsistent testing methods and the challenge of accommodating different learning styles and preferences. A more evidence-based approach that aims to cover many learning styles at once may be desirable. The aim of this commentary is to present some of the current learning and teaching strategies utilized within medical education across the world and to promote a novel supplementary approach to medical education involving a variable ratio incentive-based system of active recall and spaced repetition. This system aims to reward small achievements throughout the semester and complements formal structured examinations in order to motivate students. While this model has yet to be tested, we hope to motivate medical faculty to pilot a program with these evidence-based strategies in mind.

Adverse events associated with sodium glucose co-transporter 2 inhibitors: an overview of quantitative systematic reviews

Background:

Multiple published quantitative systematic reviews have reported on adverse events associated with the use of sodium glucose co-transporter 2 (SGLT-2) inhibitors in patients with type 2 diabetes mellitus.

Aims:

To summarize and appraise the quality of evidence from quantitative systematic reviews assessing adverse events of SGLT-2 inhibitors.

Methods:

We searched PubMed, EMBASE and the Cochrane Library for quantitative systematic reviews assessing SGLT-2 inhibitor safety. Two reviewers extracted data and assessed methodological quality using the Assessment of Multiple Systematic Reviews 2 (AMSTAR 2) tool. Main outcomes included pooled and single study point estimaates (in the absence of pooled estimates) with corresponding 95% confidence intervals (CIs) of SGLT-2 inhibitors versus placebo or active comparators for genitourinary infections, volume depletion, acute kidney injury, bone fractures, diabetic ketoacidosis, lower limb amputations, cancers, and other notable adverse events.

Results:

Out of 1289 citations screened, 47 reviews assessed SGLT-2 inhibitor safety, of which 35 were of low quality. Canagliflozin, dapagliflozin and empagliflozin were consistently associated with an increased risk of genital tract infections versus placebo (point estimates ranged from 2.5 to 9.8) and other antihyperglycemic agents (point estimates ranged from 2.7 to 12.0). Canagliflozin and dapagliflozin were associated with an increased risk of diabetic ketoacidosis. Canagliflozin was the only agent associated with an increased amputation risk; however, this was driven by results from a single trial program. Dapagliflozin was the only agent that exhibited a statistically significant increased risk of urinary tract infections. Empagliflozin was associated with a statistically significant increased risk of bladder cancer; however, this finding was susceptible to detection bias. None of the agents were associated with a statistically significant increased risk of acute kidney injury, or bone fractures compared to placebo or mixed (active or placebo) comparators. Upper 95% CI limits do not rule out clinically meaningful outcomes.

Conclusion:

The majority of quantitative systematic reviews reporting on adverse events of SGLT-2 inhibitors were of low methodological quality. Despite almost 50 quantitative systematic reviews published on the safety of SGLT-2 inhibitors, clinicians are still left uncertain of the risks of important adverse effects.

Plain Language Summary

SGLT-2 iInhibitor side effects: overview of reviews

Many published systematic reviews have reported on side effects associated with the use of sodium glucose co-transporter 2 (SGLT-2) inhibitors in patients with type 2 diabetes. We aimed to summarize and appraise the quality of evidence from quantitative systematic reviews assessing side effects of SGLT-2 inhibitors. Using the Assessment of Multiple Systematic Reviews 2 (AMSTAR 2) tool, two authors extracted data and assessed the methods of included reviews. Main outcomes included reported pooled and single study point estimates for several SGLT-2 inhibitor side effects such as genital infections, bone fractures, lower limb amputations, increased blood acidity, among others. Of the reviews included in our study, 35 of the 47 reviews assessed were of low quality. Canagliflozin and dapagliflozin were associated with an increased risk of blood acidity in a 2020 review. Canagliflozin was the only agent associated with an increased amputation risk; however, this was driven by results from a single trial program. Dapagliflozin was the only agent that exhibited a significantly increased risk of urinary tract infections. Empagliflozin was associated with an increased risk of bladder cancer; however, this finding was susceptible to bias. None of the agents were associated with an increased risk of kidney injury or bone fractures.

The association of sodium-glucose cotransporter 2 inhibitors with cancer: An overview of quantitative systematic reviews

AIMS

To summarize reported cancer events associated with SGLT-2 inhibitors used in patients with type 2 diabetes mellitus, as well as assess the quality of included reviews.

MATERIALS AND METHODS

In May 2019, we searched PubMed, Embase and the Cochrane Library for quantitative systematic reviews assessing the safety of SGLT-2 inhibitors. Data were abstracted using a standardized form, and methodological quality was assessed using the AMSTAR 2 tool. Main outcome measures included total cancer events and specific cancers such as breast cancer, bladder cancer, gastrointestinal cancer, prostate cancer, respiratory cancer, renal cancer and skin cancer. Pooled treatment effects from included reviews were summarized for SGLT-2 inhibitors as a class and for individual SGLT-2 inhibitors commonly used worldwide (canagliflozin, dapagliflozin and empagliflozin).

RESULTS

We screened 1248 unique citations, of which eight quantitative systematic reviews meta-analysed results from studies reporting the association between an SGLT-2 inhibitor and any cancer. Only one review was rated as high quality according to AMSTAR 2 assessment. In total, data from 170 cancer-related point estimates (PE) were reported. As a class, SGLT-2 inhibitors were not associated with an increased risk of any cancer event versus placebo and active comparators. Most point estimates (7/143) were nonsignificant for individual cancers except for two associations. Empagliflozin was associated with an increased risk of bladder cancer versus placebo and active comparators in two reviews, while canagliflozin appeared protective for gastrointestinal cancer versus placebo and active comparators in one review.

CONCLUSIONS

It appears that SGLT-2 inhibitors are not associated with an increased risk of total cancer or specific cancers in patients with type 2 diabetes. However, higher quality evidence is needed to derive confident conclusions.

Morphological analysis of circulating tumour cells in patients undergoing surgery for non-small cell lung carcinoma using the isolation by size of epithelial tumour cell (ISET) method

BACKGROUND AND OBJECTIVE

Recurrence rates after surgery for non-small cell lung cancer (NSCLC) range from 25 to 50% and 5-year survival is only 60-70%. Because no biomarkers are predictive of recurrence or the onset of metastasis, pathological TNM (pTNM) staging is currently the best prognostic factor. Consequently, the preoperative detection of circulating tumour cells (CTCs) might be useful in tailoring therapy. The aim of this study was to characterize morphologically any circulating non-haematological cells (CNHCs) in patients undergoing surgery for NSCLC using the isolation by size of epithelial tumour cell (ISET) method.

METHODS

Of 299 blood samples tested, 250 were from patients with resectable NSCLC and 59 from healthy controls. The presence of CNHCs was assessed blindly and independently by 10 cytopathologists on May-Grünwald-Giemsa stained filters and the cells classified into three groups: (i) malignant cells, (ii) uncertain malignant cells, and (iii) benign cells. We assessed interobserver agreement using Kappa (κ) analysis as the measure of agreement.

RESULTS

A total of 123 out of 250 (49%) patients showed CNHCs corresponding to malignant, uncertain malignant and benign cells, in 102/250 (41%), 15/250 (6%) and 6/250 (2%) cases, respectively. No CNHCs were detected in the blood of healthy subjects. Interobserver diagnostic variability was absent for CNHCs, low for malignant cells and limited for uncertain malignant and benign cells.

CONCLUSION

Identification of CTCs in resectable NSCLC patients, using ISET technology and according to cytopathological criteria of malignancy, appears to be a new and promising field of cytopathology with potential relevance to lung oncology.

Cyclosporine lymphocyte maximum level monitoring in de novo kidney transplant patients: a prospective study

OBJECTIVES

To determine prospectively the temporal variations of cyclosporine-A lymphocyte maximum level, whole blood maximum concentration, and total lymphocyte count in patients with de novo kidney transplantation.

MATERIALS AND METHODS

Lymphocyte maximum level, whole blood maximum concentration, and total lymphocyte count were prospectively measured in 35 patients at 1, 2, and 3 months after kidney transplantation. Two groups--a biopsy-proven acute rejection group (REJ+) and a rejection-free group (REJ-)--were compared.

RESULTS

Both groups had similar lymphocyte maximum levels, whole blood maximum concentrations, and total lymphocyte counts at the first month after transplantation. REJ+ patients had significantly lower lymphocyte maximum levels at 2 and 3 months (59+/-34 and 33+/-9 pg/Lc) and higher total lymphocyte counts (0.00204+/-0.00078x10(9)/L and 0.00203+/-0.00022x10(9)/L) when compared with their REJ- counterparts (87+/-56 and 63+/-30 pg/Lc, P<.05 and P<.007) and (0.00137+/-0.00074x10(9)/L and 0.0015+/-0.0006x10(9)/L, P<.02 and P<.003) respectively. Whole blood maximum concentrations were significantly higher in patients in the REJ+ group (2050+/-623 vs 1414+/-536 ng/mL, P<.02) at 2 months. At 3 months, the 2 groups were comparable (1158+/-340 vs 1365+/-525 ng/mL, P=NS).

CONCLUSIONS

These results suggest that acute rejection is associated with a relatively low cyclosporine- A lymphocyte maximum level and high total lymphocyte count in the early posttransplant period. Cyclosporine-A whole blood maximum concentration failed to correlate with clinical outcome. Cyclosporine-A lymphocyte maximum level seems to offer a more reliable alternative than does whole blood maximum concentration for cyclosporine-A monitoring in patients with kidney transplantation.

Mycophenolic acid plasma trough level: correlation with clinical outcome

OBJECTIVES

Assess the relationship between clinical diagnosis, state of immunosuppression, mycophenolic acid (MPA) plasma trough levels (MPACmin), and mycophenolate mofetil (MMF) dosage in renal transplant recipients.

MATERIALS AND METHODS

MPACmin were determined in 30 kidney transplant patients, of whom 7 exhibited biopsy-proven acute rejection. The remaining 23 had normal graft function. Graft outcome, defined by clinical diagnosis and serum creatinine level, was compared according to MPACmin, MMF dosage, and total lymphocyte count (LC).

RESULTS

Patients with acute rejection had similar MPACmin (2.4 +/- 1.7 microg/mL), MMF dosages (1.7 +/- 0.5 g), and LCs (0.001165 +/- 0.0040 x 10(9)/L) when compared with normal patients (2.2 +/- 0.7 microg/mL, 1.7 +/- 0.4 g and 0.001160 +/- 0.00527 x 10(9)/L) respectively. Rejection rates were comparable irrespective of MPACmin)ranges and higher in those receiving the 1-g dose (30%) when compared with those receiving 1.5-g and 2-g doses (12.5% and 11.7%). No relationship was observed between MPACmin and MMF doses, and neither parameter correlated with LC.

CONCLUSIONS

These results suggest that MPACmin is a poor correlate of clinical outcome and state of immunosuppression. Although the usually recommended dosage of MMF (2 g) may be associated with acute rejection, low-dose MMF (1 g) seems to constitute a higher risk.

The venous drainage of the pancreas

With the aim of clarifying certain contradictory aspects of the description of the venous drainage of the pancreas, a review of the literature and an anatomic study were carried out. Fifty duodeno-pancreatic blocks were studied by the injection-corrosion technique, of which 45 were available for study of the right pancreas and 37 for that of the left pancreas. The venous drainage of the duodeno-pancreas is effected via two territories: a posterosuperior and an anteroinferior, the former draining toward the portal v. and the second into the superior mesenteric v. The borderline between the two is represented by the inferior posterior pancreatico-duodenal (IPPD) v. Four veins ensure duodeno-pancreatic drainage: the superior anterior, inferior anterior, superior posterior and inferior posterior pancreatico-duodenal vv. (SAPD, IAPD, SPPD and IPPD). The major vein of the ventral aspect is the SAPD; that of the dorsal aspect is the SPPD. Two arches, anterior and posterior, were found in the majority of cases. The left pancreas drains into the splenic v. via several collateral branches. Other veins participate in the venous drainage of the isthmus, body and tail of the pancreas, including the inferior or transverse pancreatic v.

HLA-DR antigens and phenotypes in Dutch coeliac children and their families

In a study on the HLA-DR antigens and phenotypes in a series of Dutch coeliac children and their first-degree relatives, the B-cell antigens of 36 unrelated coeliac children, 110 first-degree relatives of 33 of them, and 201 controls were typed with the two-colour fluorescence test. The most frequent antigen was HLA-DR3 (69%), followed by DR7 (36%). The distribution of DR phenotypes showed that the most frequent was DR3/other DR (25%), followed by DR3/DR7 (17%), DR3/DR4 (14%), and DR3/DR3 (14%). However, due to the frequency of certain antigens in the controls, only phenotypes DR3/DR3 (relative risk = 6.2), DR3/DR7 (relative risk = 6.4), and DR3/DR4 (relative risk = 6.2) were significantly associated with CD. The family study confirmed the segregation of the disease with phenotypes DR3/DR3 and DR3/DR7. The present results show that the association between CD and phenotypes DR3/DR3 and DR3/DR7 is not an exclusive characteristic of Southern coeliac children.