Faculty Bibliography

Classically derived estimates of heritability from twin models have been plagued by the possibility of genetic-environmental covariance. Survey questions that attempt to measure directly the extent to which more genetically similar kin (such as monozygotic twins) also share more similar environmental conditions represent poor attempts to gauge a complex underlying phenomenon of GE-covariance. The present study exploits a natural experiment to address this issue: Self-misperception of twin zygosity in the National Longitudinal Survey of Adolescent Health (Add Health). Such twins were reared under one "environmental regime of similarity" while genetically belonging to another group, reversing the typical GE-covariance and allowing bounded estimates of heritability for a range of outcomes. In addition, we examine twins who were initially misclassified by survey assignment--a stricter standard--in three datasets: Add Health, the Minnesota Twin Family Study and the Child and Adolescent Twin Study in Sweden. Results are similar across approaches and datasets and largely support the validity of the equal environments assumption.

[...]a third of all people who experience heart attacks have no chest symptoms

We evaluated the prevalence of chronotropic incompetence (CI), a marker of autonomic dysfunction, and its prognostic value in patients with chronic obstructive pulmonary disease (COPD). We performed a retrospective analysis of 449 patients with severe COPD who underwent a cardiopulmonary exercise test, after excluding patients with lung volume reduction surgery, left ventricular dysfunction and those not in sinus rhythm. CI was defined as percent predicted heart rate reserve (%HRR). Events were defined as death or lung transplant during a median follow-up of 68 months. Median age was 61 years; median percent predicted forced expiratory volume in one second (%FEV1) of 25% and median %HRR of 33%. The hazard ratio for an event in the lowest quartile of %HRR, taking the highest quartile as reference, was of 3.2 (95% confidence interval: 2.1-4.8; p<0.001). In a multivariate regression model, %HRR was an independent predictor of events. In conclusion, CI was an independent and powerful outcome predictor in patients with severe COPD.

If it's an academic institution, a bevy of medical students, interns and residents accompany an attending physician from room to room, checking up on the patient, doing a daily physical exam, reviewing the latest test results and highlighting the relevant teaching points. [...]computers handily beat out patients:

PURPOSE: To update the 2009 American Society of Clinical Oncology guideline on pharmacologic interventions for breast cancer (BC) risk reduction. METHODS: A systematic review of randomized controlled trials and meta-analyses published from June 2007 through June 2012 was completed using MEDLINE and Cochrane Collaboration Library. Primary outcome of interest was BC incidence (invasive and noninvasive). Secondary outcomes included BC mortality, adverse events, and net health benefits. Guideline recommendations were revised based on an Update Committee's review of the literature. RESULTS: Nineteen articles met the selection criteria. Six chemoprevention agents were identified: tamoxifen, raloxifene, arzoxifene, lasofoxifene, exemestane, and anastrozole. RECOMMENDATIONS: In women at increased risk of BC age >/= 35 years, tamoxifen (20 mg per day for 5 years) should be discussed as an option to reduce the risk of estrogen receptor (ER) -positive BC. In postmenopausal women, raloxifene (60 mg per day for 5 years) and exemestane (25 mg per day for 5 years) should also be discussed as options for BC risk reduction. Those at increased BC risk are defined as individuals with a 5-year projected absolute risk of BC >/= 1.66% (based on the National Cancer Institute BC Risk Assessment Tool or an equivalent measure) or women diagnosed with lobular carcinoma in situ. Use of other selective ER modulators or other aromatase inhibitors to lower BC risk is not recommended outside of a clinical trial. Health care providers are encouraged to discuss the option of chemoprevention among women at increased BC risk. The discussion should include the specific risks and benefits associated with each chemopreventive agent.

Participant attrition may be a significant threat to the generalizability of the results of educational research studies if participants who do not persist in a study differ from those who do in ways that can affect the experimental outcomes. A multi-center trial of the efficacy of different computer-based instructional strategies gave us the opportunity to observe institutional and student factors linked to attrition from a study and the ways in which they altered the participation profile. The data is from a randomized controlled trial conducted at seven US medical schools investigating the educational impact of different instructional designs for computer-based learning modules for surgical clerks. All students undertaking their surgical clerkships at the participating schools were invited participate and those that consented were asked to complete five study measures during their surgery clerkship. Variations in study attrition rates were explored by institution and by participants' self-regulation, self-efficacy, perception of task value, and mastery goal orientation measured on entry to the study. Of the 1,363 invited participants 995 (73 %) consented to participate and provided baseline data. There was a significant drop in the rate of participation at each of the five study milestones with 902 (94 %) completing at least one of two module post-test, 799 (61 %) both module post-tests, 539 (36 %) the mid-rotation evaluation and 252 (25 %) the final evaluation. Attrition varied between institutions on survival analysis (p < 0.001). Small but statistically significant differences in self-regulation (p = 0.01), self-efficacy (p = 0.02) and task value (p = 0.04) were observed but not in mastery or performance goal orientation measures (p = NS). Study attrition was correlated with lower achievement on the National Board of Medical Examiners subject exam. The results of education trials should be interpreted with the understanding that students who persist may be somewhat more self-regulated, self-efficacious and higher achievers than their peers who drop out and as such do not represent the class as a whole.

BACKGROUND: This study employed the risk perception attitude (RPA) framework to determine whether health care personnel (HCP) influenza-related risk perceptions and efficacy beliefs could be used to segment individuals into meaningful groups related to vaccination uptake, absenteeism, and patient safety beliefs. METHODS: After pilot interviews, a questionnaire was administered to 318 hospital-based HCP (80%) and nonclinical support staff (20%) in Lexington, KY, in 2011. Follow-up interviews were conducted with 29 respondents. RESULTS: Cluster analysis was used to create 4 groups that correspond to the RPA framework: responsive (high risk, strong efficacy), avoidance (high risk, weak efficacy), proactive (low risk, strong efficacy), and indifference (low risk, weak efficacy). A significant association was found between membership in 1 or more of the 4 RPA groups and the 3 study variables of interest: influenza vaccination uptake (F7,299 = 2.51, P < .05), influenza-related absenteeism (F7,269 = 3.6, P < .001), and perceptions of patient safety climate (F7,304 = 6.21, P < .001). A subset of respondents indicated the principal reasons for not getting vaccinated were "had one before and got sick anyway," "concerned about vaccine safety," and "no convenient time." In follow-up interviews, HCP indicated that employee vaccinations were altruistic, increased herd immunity, and important for patient safety. CONCLUSION: The RPA framework is a valid health promotion tool for improving patient safety, targeting specific groups for interventions, and improving HCP influenza vaccination rates.