Survey design and analysis considerations when utilizing misclassified sampling strata

Abstract Background A large multi-center survey was conducted to understand patients’ perspectives on biobank study participation with particular focus on racial and ethnic minorities. In order to enrich the study sample with racial and ethnic minorities, disproportionate stratified sampling was implemented with strata defined by electronic health records (EHR) that are known to be inaccurate. We investigate the effect of sampling strata misclassification in complex survey design. Methods Under non-differential and differential misclassification in the sampling strata, we compare the validity and precision of three simple and common analysis approaches for settings in which the primary exposure is used to define the sampling strata. We also compare the precision gains/losses observed from using a disproportionate stratified sampling scheme compared to using a simple random sample under varying degrees of strata misclassification. Results Disproportionate stratified sampling can result in more efficient parameter estimates of the rare subgroups (race/ethnic minorities) in the sampling strata compared to simple random sampling. When sampling strata misclassification is non-differential with respect to the outcome, a design-agnostic analysis was preferred over model-based and design-based analyses. All methods yielded unbiased parameter estimates but standard error estimates were lowest from the design-agnostic analysis. However, when misclassification is differential, only the design-based method produced valid parameter estimates of the variables included in the sampling strata. Conclusions In complex survey design, when the interest is in making inference on rare subgroups, we recommend implementing disproportionate stratified sampling over simple random sampling even if the sampling strata are misclassified. If the misclassification is non-differential, we recommend a design-agnostic analysis. However, if the misclassification is differential, we recommend using design-based analyses

Association between Hypothyroidism Onset and Alzheimer Disease Onset in Adults with Down Syndrome

Adults with Down syndrome (DS) have an exceptionally high frequency of Alzheimer disease (AD) with a wide variability in onset, from 40 to 70 years of age. Equally prevalent in DS is hypothyroidism. In this study, we sought to quantify the relationship between the two. A total of 232 adults with DS and AD were stratified into three AD onset age groups: early (<47 years), typical (48–59), and late (>59). Among patients with available data, differences in the distributions of demographics, hypothyroidism variables (presence, age of onset), thyroid function tests, thyroid autoantibodies, and APOE genotypes were assessed (e.g., chi-squared, Mann–Whitney tests). Spearman and partial Spearman correlations and ordinal logistic regression models were constructed to quantify the association between ages of AD and hypothyroidism onset with and without covariate adjustments. We observed a positive association between the ages of AD and hypothyroidism onset after accounting for APOE-Ɛ4 (correlation: 0.44, 0.24, 0.60; odds ratio: 1.09, 1.05–1.14). However, an early age of hypothyroidism onset and the presence of the APOE-Ɛ4 allele were independently associated with the early age of AD onset. Similar findings were observed when accounting for other factors. Our study provides evidence for the importance of hypothyroidism and associated pathological mechanisms for risk of AD in DS

A simulation-based curriculum to introduce key teamwork principles to entering medical students

Abstract Background Failures of teamwork and interpersonal communication have been cited as a major patient safety issue. Although healthcare is increasingly being provided in interdisciplinary teams, medical school curricula have traditionally not explicitly included the specific knowledge, skills, attitudes, and behaviors required to function effectively as part of such teams. Methods As part of a new “Foundations” core course for beginning medical students that provided a two-week introduction to the most important themes in modern healthcare, a multidisciplinary team, in collaboration with the Center for Experiential Learning and Assessment, was asked to create an experiential introduction to teamwork and interpersonal communication. We designed and implemented a novel, all-day course to teach second-week medical students basic teamwork and interpersonal principles and skills using immersive simulation methods. Students’ anonymous comprehensive course evaluations were collected at the end of the day. Through four years of iterative refinement based on students’ course evaluations, faculty reflection, and debriefing, the course changed and matured. Results Four hundred twenty evaluations were collected. Course evaluations were positive with almost all questions having means and medians greater than 5 out of 7 across all 4 years. Sequential year comparisons were of greatest interest for examining the effects of year-to-year curricular improvements. Differences were not detected among any of the course evaluation questions between 2007 and 2008 except that more students in 2008 felt that the course further developed their “Decision Making Abilities” (OR 1.69, 95% CI 1.07–2.67). With extensive changes to the syllabus and debriefer selection/assignment, concomitant improvements were observed in these aspects between 2008 and 2009 (OR = 2.11, 95% CI: 1.28–3.50). Substantive improvements in specific exercises also yielded significant improvements in the evaluations of those exercises. Conclusions This curriculum could be valuable to other medical schools seeking to inculcate teamwork foundations in their medical school’s preclinical curricula. Moreover, this curriculum can be used to facilitate teamwork principles important to inter-disciplinary, as well as uni-disciplinary, collaboration

Older patients\u27 perceptions of medication importance and worth: an exploratory pilot study

BACKGROUND: Cost-related medication non-adherence may be influenced by patients\u27 perceived importance of their medications. OBJECTIVES: This exploratory pilot study addresses three related but distinct questions: Do patients perceive different levels of importance among their medications? What factors influence perceptions of medication importance? Is perceived importance associated with perceived worth of medications, and does expense impact on that association? METHODS: Study participants included individuals aged \u3eor=60 years who were taking three or more prescription drugs. Semi-structured, in-person interviews were conducted to measure how patients rated their medications in terms of importance, expense and worth. Factors that influenced medication importance were identified using qualitative analysis. Ordinal logistic regression analyses were employed to examine the association between perceived importance and perceived worth of medications, and the impact of expense on that association. RESULTS: For 143 prescription drugs reported by 20 participants, the weighted mean rating of medication importance was 8.2 (SD 1.04) on a scale from 0 (not important at all) to 10 (most important). Patients considered 38% of these medications to be expensive. The weighted mean rating of worth was 8.4 (SD 1.46) on a scale from 0 (not worth it at all) to 10 (most worth). Three major factors influenced medication importance: drug-related (characteristics, indications, effects and alternatives); patient-related (knowledge, attitudes and health); and external (the media, healthcare and family caregivers, and peers). Regression analyses showed an association between perceived importance and perceived worth for inexpensive medications (odds ratio [OR] 2.23; p = 0.002) and an even greater association between perceived importance and perceived worth for expensive medications (OR 4.29; p \u3c 0.001). DISCUSSION: This study provides preliminary evidence that elderly patients perceive different levels of importance for their medications based on factors beyond clinical efficacy. Their perception of importance influences how they perceive their medications\u27 worth, especially for medications of high costs. Understanding how patients perceive medication importance may help in the development of interventions to reduce cost-related non-adherence

Comparison of expected imaging findings following percutaneous microwave and cryoablation of pulmonary tumors: ablation zones and thoracic lymph nodes

Abstract Objective To compare temporal changes of ablation zones and lymph nodes following lung microwave ablation (MWA) and cryoablation. Methods This retrospective cohort study compared lung ablation zones and thoracic lymph nodes following MWA and cryoablation performed 2006–2020. In the ablation zone cohort, ablation zone volumes were measured on serial CT for 12 months. In the lymph node cohort, the sum of bidimensional products of lymph node diameters was measured before (baseline) and up to 6 months following ablation. Cumulative incidence curves estimated the time to 75% ablation zone reduction and linear mixed-effects regression models compared the temporal distribution of ablation zones and lymph node sizes between modalities. Results Ablation zones of 59 tumors treated in 45 sessions (16 MWA, 29 cryoablation) in 36 patients were evaluated. Differences in the time to 75% volume reduction between modalities were not detected. Following MWA, half of the ablation zones required an estimated time of 340 days to achieve a 75% volume reduction compared to 214 days following cryoablation (p = .30). Thoracic lymph node sizes after 33 sessions (13 MWA, 20 cryoablation) differed between modalities (baseline–32 days, p = .01; 32–123 days, p = .001). Following MWA, lymph nodes increased on average by 38 mm2 (95%CI, 5.0–70.7; p = .02) from baseline to 32 days, followed by an estimated decrease of 50 mm2 (32–123 days; p = .001). Following cryoablation, changes in lymph nodes were not detected (baseline–32 days, p = .33). Conclusion The rate of ablation zone volume reduction did not differ between MWA and cryoablation. Thoracic lymph nodes enlarged transiently after MWA but not after cryoablation. Key Points • Contrary to current belief, the rate of lung ablation zone volume reduction did not differ between microwave and cryoablation. • Transient enlargement of thoracic lymph nodes after microwave ablation was not associated with regional tumor spread and decreased within six months following ablation. • No significant thoracic lymph node enlargement was observed following cryoablation