Does Regular Exercise Impact the Lung Function of Healthy Children and Adolescents? A Systematic Review and Meta-Analysis.

PURPOSE: To assess the quality of the available evidence on the effect of exercise for the improvement of lung function in healthy children and adolescents. METHOD: We performed a systematic review and meta-analysis of intervention studies examining the effects of regular exercise on spirometric parameters of healthy children and adolescents aged ≤18 years. RESULTS: Within the exercise groups, there were significant improvements in forced vital capacity (mean difference: 0.17 L; 95% confidence interval, 0.07 to 0.26; P < .05) and forced expiratory volume in the first second (mean difference: 0.14 L; 95% confidence interval, 0.06 to 0.22; P < .05). Results were consistent across different age groups and duration of interventions. In the between-group analysis, forced vital capacity, forced expiratory volume in the first second, and peak expiratory flow were higher in the exercise group compared with the nonexercise group, but the differences did not reach statistical relevance. There was significant statistical heterogeneity between studies. CONCLUSION: Regular exercise has the potential to improve lung function parameters in healthy children and adolescents; however, the small number of studies and the heterogeneity between them raise concern about the quality of the currently available evidence. These findings bring to attention the need for well-designed trials addressing this important public health issue.

Students' intentions to practice primary care are associated with their motives to become doctors: a longitudinal study.

BACKGROUND: Medical schools can contribute to the insufficient primary care physician workforce by influencing students' career preferences. Primary care career choice evolves between matriculation and graduation and is influenced by several individual and contextual factors. This study explored the longitudinal dynamics of primary care career intentions and the association of students' motives for becoming doctors with these intentions in a cohort of undergraduate medical students followed over a four-year period. METHODS: The sample consisted of medical students from two classes recruited into a cohort study during their first academic year, and who completed a yearly survey over a four-year period from their third (end of pre-clinical curriculum) to their sixth (before graduation) academic year. Main outcome measures were students' motives for becoming doctors (ten motives rated on a 6-point scale) and career intentions (categorized into primary care, non-primary care, and undecided). Population-level flows of career intentions were investigated descriptively. Changes in the rating of motives over time were analyzed using Wilcoxon tests. Two generalized linear mixed models were used to estimate which motives were associated with primary care career intentions. RESULTS: The sample included 217 students (60% females). Career intentions mainly evolved during clinical training, with smaller changes at the end of pre-clinical training. The proportion of students intending to practice primary care increased over time from 12.8% (year 3) to 24% (year 6). Caring for patients was the most highly rated motive for becoming a doctor. The importance of the motives cure diseases, saving lives, and vocation decreased over time. Primary care career intentions were positively associated with the motives altruism and private practice, and negatively associated with the motives prestige, academic interest and cure diseases. CONCLUSION: Our study indicates that career intentions are not fixed and change mainly during clinical training, supporting the influence of clinical experiences on career-related choices. The impact of students' motives on primary care career choice suggests strategies to increase the attractivity of this career, such as reinforcing students' altruistic values and increasing the academic recognition of primary care.

Development and Cross-National Validation of a French Version of the Jefferson Scale of Empathy for Students.

Empathy is a multifaceted personal ability combining emotional and cognitive features modulated by cultural specificities. It is widely recognized as a key clinical competence that should be valued during professional training. The Jefferson Scale of Empathy for medical students (JSE-S) has been developed for this purpose and validated in several languages, but not in French. The aims of this study were to gather validity evidence for a newly developed version of the JSE-S and compare it between two French-speaking contexts. In total, 1,433 undergraduate medical students from the universities of Lyon (UL), France and Geneva (UG), Switzerland participated in the study completing the JSE-S in French. Total and partial scores of the three subscales ("perspective taking," "compassionate care" and "walking in patient's shoes") were calculated for each site. Construct validity of the JSE-S was analyzed considering three sources of evidence: content, internal structure and relations to other variables. A first-order Confirmatory Factor Analysis using structural equation modeling examined the three latent variables of the JSE-S subscales. Cronbach's α coefficients were 0.75 (UG) and 0.81 (UL). The items' discrimination power ranged between 0.29 and 1.60 (median effect size of 1.24). The overall correlations between items and total or partial scores derived from the latent JSE-S subscales were consistently similar in both study sites. Findings of this study confirm the latent structure of the JSE-S in French and its cross-national reproducibility. The comparable underlying structure of the questionnaire tested in two distinct French-speaking contexts endorses the generalizability of its measure.

Relationship between self-reported cognitive and behavioural empathy among medical students.

OBJECTIVE: The aim of this study was to explore the relationship between cognitive and behavioural empathy in medical students. METHODS: Fourteen 4th year medical students recruited on the basis of their scores on the self-reported Jefferson Scale of Empathy (JSE-S) were divided into two groups: low JSE-S scorers (n = 8) (M = 96.75, SD = 10.3) and high JSE-S scorers (n = 6) (M = 121.3, SD = 2.94). They were discreetly videotaped while taking history with an incognito standardized patient. Students' behavioural empathy was measured using the Verona Coding System (VR-CoDES-P) and rating of non-verbal behaviour. RESULTS: Patients expressed the same number of concerns per encounter in both groups but gave more cues to high-scorers (p = 0.029). However, students of both groups demonstrated the same amount of verbal empathy (high: 16% vs low: 15% p = 1.00). High JSE-S scorers' non-verbal communication tended to be rated slightly higher than low JSE-S-scorers with a higher use of facial expression (p = 0.008). CONCLUSION: This study did not reveal any differences of students' verbal empathy to patients' cues and concerns between low and high JSE_S scorers. PRACTICE IMPLICATIONS: The VR-CoDES_P is a useful tool to assess medical students and physicians empathic behaviour, allowing to disentangle the different components of empathy.

Trajectories of learning approaches during a full medical curriculum: impact on clinical learning outcomes.

BACKGROUND: No consensus exists on whether medical students develop towards more deep (DA) or surface learning approaches (SA) during medical training and how this impacts learning outcomes. We investigated whether subgroups with different trajectories of learning approaches in a medical students' population show different long-term learning outcomes. METHODS: Person-oriented growth curve analyses on a prospective cohort of 269 medical students (Mage=21years, 59 % females) traced subgroups according to their longitudinal DA/SA profile across academic years 1, 2, 3 and 5. Post-hoc analyses tested differences in academic performance between subgroups throughout the 6-year curriculum until the national high-stakes licensing exam certifying the undergraduate medical training. RESULTS: Two longitudinal trajectories emerged: surface-oriented (n = 157; 58 %), with higher and increasing levels of SA and lower and decreasing levels of DA; and deep-oriented (n = 112; 42 %), with lower and stable levels of SA and higher but slightly decreasing levels of DA. Post hoc analyses showed that from the beginning of clinical training, deep-oriented students diverged towards better learning outcomes in comparison with surface-oriented students. CONCLUSIONS: Medical students follow different trajectories of learning approaches during a 6-year medical curriculum. Deep-oriented students are likely to achieve better clinical learning outcomes than surface-oriented students.

Patterns of Change in Approaches to Learning and Their Impact on Academic Performance Among Medical Students: Longitudinal Analysis.

THEORY: Several medical education studies suggest that deep approaches to learning (DA) are associated with better academic performance, whereas surface approaches (SA) are associated with worse academic performance. However, no study has assessed how these approaches change at the individual level during undergraduate medical training and how these trajectories contribute to academic performance. We assessed individual patterns of change in learning approaches throughout five years of medical training to determine whether and how DA and SA evolve during the curriculum and whether initial levels and rates of change predict performance in Year 5. Hypotheses: We hypothesized that (1) medical students have a higher preference for DA in comparison with SA; (2) these preferences change along the medical curriculum; and (3) DA predicts better academic performance. Method: Participants were 268 Geneva medical students (59% female) who completed the revised two-factor study process questionnaire in Years 1, 2, 3, and 5 of their 6-year curriculum. Student academic performance was registered in Year 5. Multivariate latent growth modeling was used to assess individual trajectories in learning approaches and test their associations with performance in Year 5. Results: Medical students were inclined to use DA rather than SA. Nevertheless, from Year 2 onward their use of DA decreased while their use of SA increased. Students with higher initial levels of DA tended to have lower initial levels of SA. Moreover, increases in SA were significantly associated with decreases in DA. However, only initial levels of DA and non-repeater status in Year 1 were positive and significant predictors of academic performance in Year 5. Conclusions: Although students tended to use DA rather than SA when entering medical school, their preferences for DA tended to decline throughout medical training while increasing for SA. Learning approaches during early study years, characterized by engagement and meaningful learning, predicted later academic performance. DA should be promoted during the early years of medical studies to foster student learning and to improve academic performance.

Empathy trajectories throughout medical school: relationships with personality and motives for studying medicine.

Empathy remains a widely discussed topic within medical education research. Studies on empathy changes among medical students are not univocal: empathy may decline, remain stable or increase. A largely unexplored research question regards inter-individual variability in empathy change, namely if different longitudinal trajectories of empathy exist. Evidence on the association of empathy trajectories with personality and motives for studying medicine is also scarce. Here, latent growth modeling examined empathy (measured with the Jefferson Scale of Empathy) among 201 medical students (Mage = 20.74, 57% females) across three assessments: at entry year (Year 1) and during the first two clinical years (Years 4 and 5). Associations between empathy trajectories, personality in Year 1 and motives for studying medicine in Years 4 and 5 were tested. We identified two empathy trajectory groups: lower and decreasing (n = 59; 29%) and higher and stable (n = 142; 71%). Regression analyses indicated that higher openness in Year 1 was associated with an increased probability of higher and stable group membership (controlling for motives in Year 1). The effect of openness disappeared controlling for motives in Years 4 and 5 while caring for patients (in Years 4 and 5) and altruism (in Year 4) were positively associated with an increased probability of higher and stable group membership. In sum, we observed that empathy remains stable in most medical students and declines in fewer; openness and patients-oriented motives for studying medicine are associated with higher and stable empathy. Encouraging medical students' patients-oriented motives from preclinical throughout clinical years may prevent empathy decline.

Associations between motivational factors for studying medicine, learning approaches and empathy among medical school candidates.

Previous research highlighted associations between students' motivation for medical studies and their learning approaches on the one hand and empathy on the other. Internal motivational factors for studying medicine (e.g., care for patients, save lives) coupled with a deep approach to learning have been positively related to empathy in contrast to external motivational factors (e.g., future earning potential, prestige) and surface learning. However, assessments of these assumptions among medical school candidates are scarce. This study examined the relationship between different motivational factors and empathy among students enrolled in a selection year in medicine by testing the mediating role of learning approaches. A sample of 572 candidates for medical studies answered a self-reported questionnaire half way through their selection year. Measures included internal and external motivational factors for studying medicine, deep and surface learning approaches and empathy. Path-analysis tested the mediation effects of deep and surface approaches to learning on the relationship of internal and external motivational factors with empathy. The deep learning approach partially mediated the significant positive association between internal motivational factors and empathy, while the surface learning approach fully mediated the significant negative association between external motivational factors and empathy. These results suggest that learning approaches could be a pathway by which internal and external motives for studying medicine are related to empathy among medical school candidates. Pedagogical strategies and educational environments accounting for individual differences in motivation and learning may contribute to training students to become professional and caring doctors in the future.

Integrated problem-based learning versus lectures: a path analysis modelling of the relationships between educational context and learning approaches.

Students' approaches to learning are central to the process of learning. Previous research has revealed that influencing students' approaches towards deep learning is a complex process and seems much more difficult than expected, even in student-activating learning environments. There is evidence that learning approaches are impacted not only by the learning environment, but also by how students perceive it. However the nature of the links between the environment itself, the way in which it is perceived by students and students' learning approaches is poorly understood. This study aimed at investigating the relationships between students' perception of their educational context and learning approaches in three learning environments differing by their teaching formats (lecture or problem-based-learning PBL) and integration level of the curriculum (traditional or integrated). We tested the hypothesis that a PBL format and an integrated curriculum are associated to deeper approaches to learning and that this is mediated by student perception. The study sample was constituted of 1394 medical students trained respectively in a traditional lecture-based (n = 295), in an integrated lecture-based (n = 612) and in an integrated PBL-based (n = 487) curricula. They completed a survey including the Dundee-Ready-Educational-Environment-Measure (students' perceptions of the educational environment) and the Revised-Study-Process-Questionnaire (learning approaches). Data were analysed by path analysis. The model showed that the learning environment was related to students' learning approaches by two paths, one direct and one mediated via students' perception of their educational context. In the lecture-based curricula students' used deeper approaches when it was integrated and both paths were cumulative. In the PBL-based curriculum students' did not use deeper approaches than with lectures, due to opposite effects of both paths. This study suggested that an integrated lecture-based curriculum was as effective as a PBL curriculum in promoting students' deep learning approaches, reinforcing the importance of integrating the curriculum before choosing the teaching format.

Hypertension, diabetes and lifestyle in the long-term - Results from a Swiss population-based cohort.

Healthy lifestyles are integral in preventing and treating common cardiovascular and metabolic diseases. The aim of this study was to observe smoking habits, alcohol intake, physical activity and body mass index over a 10-year period in a population-based cohort, particularly focusing on participants with hypertension and type 2 diabetes mellitus. Included were 4155 participants from the first (2001-2003) and second (2010-2011) follow-ups of the Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults (SAPALDIA). Information was collected via health questionnaire; height and weight were measured. In a healthy lifestyle score one point was attributed per criterion; non-smoking, low risk alcohol consumption, BMI<25kg/m2, and regular physical activity. Overall in 2010-2011, 16.4% were smokers, 7.7% had at risk alcohol consumption, 25.5% were physically inactive and 57.8% were overweight or obese. Both those with hypertension and diabetes had lower mean healthy lifestyle scores than those without disease. Women with incident hypertension from 2001 to 2011 had lower odds of improving their healthy lifestyle score during this time period compared to those without this disease. In contrast, women with incident diabetes had higher odds of lifestyle score improvement. In men, neither hypertension nor diabetes was associated with change in lifestyle score. Our findings suggest that, irrespective of disease status, preventative attention is needed, particularly in regards to physical activity and bodyweight. These needs could be met by population-based interventions, a necessary and suitable option in both preventing and treating the non-communicable disease epidemic which currently faces countries worldwide.

High blood pressure: prevalence and adherence to guidelines in a population-based cohort.

QUESTIONS UNDER STUDY: High blood pressure, the single leading health risk factor worldwide, contributes greatly to morbidity and mortality. This study aimed to add to the understanding of diagnosed and undiagnosed high blood pressure in Switzerland and to evaluate adherence to hypertension guidelines. METHODS: Included were 3962 participants from the first (2001-2003) and second (2010-2011) follow-ups of the population-based Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults. High blood pressure was defined as blood pressure ≥140/90 mm Hg and the prevalence of doctor-diagnosed hypertension was based on questionnaire information. RESULTS: High blood pressure was found in 34.9% of subjects, 49.1% of whom were unaware of this condition; 30.0% had doctor-diagnosed hypertension and, although 82.1% of these received drug treatments, in only 40.8% was blood pressure controlled (<140/90 mm Hg). Substantial first-line beta-blocker use and nonadherence to comorbidity-specific prescription guidelines were observed and remained mostly unexplained. Age-adjusted rates of unawareness and uncontrolled hypertension were more than 20% higher than in the USA. CONCLUSIONS: There is room for improvement in managing hypertension in Switzerland. Population-based observational studies are essential for identifying and evaluating unmet needs in healthcare; however, to pinpoint the underlying causes it is imperative to facilitate linkage of cohort data to medical records.

Air pollution and diabetes association: Modification by type 2 diabetes genetic risk score.

Exposure to ambient air pollution (AP) exposure has been linked to type 2 diabetes (T2D) risk. Evidence on the impact of T2D genetic variants on AP susceptibility is lacking. Compared to single variants, joint genetic variants contribute substantially to disease risk. We investigated the modification of AP and diabetes association by a genetic risk score (GRS) covering 63 T2D genes in 1524 first follow-up participants of the Swiss cohort study on air pollution and lung and heart diseases in adults. Genome-wide data and covariates were available from a nested asthma case-control study design. AP was estimated as 10-year mean residential particulate matter <10µm (PM10). We computed count-GRS and weighted-GRS, and applied PM10 interaction terms in mixed logistic regressions, on odds of diabetes. Analyses were stratified by pathways of diabetes pathology and by asthma status. Diabetes prevalence was 4.6% and mean exposure to PM10 was 22µg/m(3). Odds of diabetes increased by 8% (95% confidence interval: 2, 14%) per T2D risk allele and by 35% (-8, 97%) per 10µg/m(3) exposure to PM10. We observed a positive interaction between PM10 and count-GRS on diabetes [ORinteraction=1.10 (1.01, 1.20)], associations being strongest among participants at the highest quartile of count-GRS [OR: 1.97 (1.00, 3.87)]. Stronger interactions were observed with variants of the GRS involved in insulin resistance [(ORinteraction=1.22 (1.00, 1.50)] than with variants related to beta-cell function. Interactions with count-GRS were stronger among asthma cases. We observed similar results with weighted-GRS. Five single variants near GRB14, UBE2E2, PTPRD, VPS26A and KCNQ1 showed nominally significant interactions with PM10 (P<0.05). Our results suggest that genetic risk for T2D may modify susceptibility to air pollution through alterations in insulin sensitivity. These results need confirmation in diabetes cohort consortia.

Personal profile of medical students selected through a knowledge-based exam only: are we missing suitable students?

INTRODUCTION: A consistent body of literature highlights the importance of a broader approach to select medical school candidates both assessing cognitive capacity and individual characteristics. However, selection in a great number of medical schools worldwide is still based on knowledge exams, a procedure that might neglect students with needed personal characteristics for future medical practice. We investigated whether the personal profile of students selected through a knowledge-based exam differed from those not selected. METHODS: Students applying for medical school (N=311) completed questionnaires assessing motivations for becoming a doctor, learning approaches, personality traits, empathy, and coping styles. Selection was based on the results of MCQ tests. Principal component analysis was used to draw a profile of the students. Differences between selected and non-selected students were examined by Multivariate ANOVAs, and their impact on selection by logistic regression analysis. RESULTS: Students demonstrating a profile of diligence with higher conscientiousness, deep learning approach, and task-focused coping were more frequently selected (p=0.01). Other personal characteristics such as motivation, sociability, and empathy did not significantly differ, comparing selected and non-selected students. CONCLUSION: Selection through a knowledge-based exam privileged diligent students. It did neither advantage nor preclude candidates with a more humane profile.

Common SIRT1 variants modify the effect of abdominal adipose tissue on aging-related lung function decline.

Lung function is an independent predictor of mortality and serves as an aging marker in never smokers. The protein sirtuin-1 of gene SIRT1 has profound anti-inflammatory effects and regulates metabolic pathways. Its suggested longevity effects on lower organisms remain poorly studied in humans. In 1132 never smokers of the population-based SAPALDIA cohort, we investigated associations between single nucleotide polymorphisms (SNPs; rs730821, rs10997868, rs10823116) of SIRT1 and aging-related lung function decline over 11 years in terms of change in forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced expiratory flow between 25 and 75 % of FVC (FEF25-75) using multiple linear regression models. Interactions between the SIRT1 SNPs and adiposity parameters (body mass index (BMI), its change and weight gain) were tested by including multiplicative interaction terms into the models. SIRT1 polymorphisms exhibited no main effects, but modified the association between obesity measures and FEV1/FVC and FEF25-75 decline (p = 0.009-0.046). Per risk allele, FEV1/FVC decline was accelerated up to -0.5 % (95 % CI -1.0 to 0 %) and -0.7 % (-1.3 to -0.2 %) over interquartile range increases in BMI (2.4 kg/m(2)) or weight (6.5 kg), respectively. For FEF25-75 decline, corresponding estimates were -57 mL/s (-117 to 4 mL/s) and -76 mL/s (-1429 to -9 mL/s). Interactions were not present in participants with genetically lowered C-reactive protein concentrations. Genetic variation in SIRT1 might therefore affect lung function and human longevity by modifying subclinical inflammation arising from abdominal adipose tissue.

A common functional variant on the pro-inflammatory Interleukin-6 gene may modify the association between long-term PM10 exposure and diabetes.

BACKGROUND: Air pollutants have been linked to type 2 diabetes (T2D), hypothesized to act through inflammatory pathways and may induce interleukin-6 gene (IL6) in the airway epithelium. The cytokine interleukin-6 may impact on glucose homeostasis. Recent meta-analyses showed the common polymorphisms, IL6 -572G > C and IL6 -174G > C to be associated with T2D risk. These IL6 variants also influence circulatory interleukin-6 levels. We hypothesize that these common functional variants may modify the association between air pollutants and T2D. METHODS: We cross-sectionally studied 4410 first follow-up participants of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases (SAPALDIA), aged 29 to 73 years who had complete data on genotypes, diabetes status and covariates. We defined diabetes as self-reported physician-diagnosed, or use of diabetes medication or non-fasting glucose >11.1 mmol/L or HbA1c > 0.065. Air pollution exposure was 10-year mean particulate matter <10 µm in diameter (PM10) assigned to participants' residences using a combination of dispersion modelling, annual trends at monitoring stations and residential history. We derived interaction terms between PM10 and genotypes, and applied mixed logistic models to explore genetic interactions by IL6 polymorphisms on the odds of diabetes. RESULTS: There were 252 diabetes cases. Respective minor allele frequencies of IL6 -572G > C and IL6 -174G > C were 7 and 39 %. Mean exposure to PM10 was 22 µg/m(3). Both variants were not associated with diabetes in our study. We observed a significant positive association between PM10 and diabetes among homozygous carriers of the pro-inflammatory major G-allele of IL6 -572G > C [Odds ratio: 1.53; 95 % confidence interval (1.22, 1.92); P interaction (additive) = 0.003 and P interaction (recessive) = 0.006]. Carriers of the major G-allele of IL6 -174G > C also had significantly increased odds of diabetes, but interactions were statistically non-significant. CONCLUSIONS: Our results on the interaction of PM10 with functionally well described polymorphisms in an important pro-inflammatory candidate gene are consistent with the hypothesis that air pollutants impact on T2D through inflammatory pathways. Our findings, if confirmed, are of high public health relevance considering the ubiquity of the major G allele, which puts a substantial proportion of the population at risk for the development of diabetes as a result of long-term exposure to air pollution.

Rhinitis in Swiss adults is associated with asthma and early life factors, but not second hand tobacco smoke or obesity.

BACKGROUND: Second hand tobacco smoke (SHS) and overweight/obesity are risk factors for asthma and lower airway respiratory symptoms. We investigated whether SHS or overweight/obesity were also associated with allergic or non-allergic rhinitis. METHODS: Cross-sectional data were obtained during the second SAPALDIA Study. Interviewer administered questionnaires were completed by 8047 participants from 8 communities in Switzerland. Blood was collected from 5841 participants and tested for allergen specific IgE. Allergic rhinitis was defined as nasal symptoms with detectable IgE. Data were analysed by multinomial logistic regression with four outcome categories defined according to the presence or absence of rhinitis and/or atopy. RESULTS: The prevalence of allergic rhinitis was 885 (15.2%) and non-allergic rhinitis 323 (5.5%). The risk of allergic rhinitis was increased in subjects with physician diagnosed asthma (Relative Risk Ratio 6.81; 95%CI 5.39, 8.6), maternal atopy (1.56; 1.27, 1.92) and paternal atopy (1.41; 1.11, 1.79). Older subjects were at lower risk (0.96; 0.95,0.97 per year), as were those raised on a farm (0.64; 0.49,0.84), with older siblings (0.92; 0.86,0.97 per sib) or from rural areas. The risk of non-allergic rhinitis was also increased in subjects with physician diagnosed asthma (4.02; 2.86, 5.67), reduced in males (0.59; 0.46, 0.77), but not associated with upbringing on a farm or older siblings. There were no significant associations of SHS or overweight/obesity with either form of rhinitis. CONCLUSIONS: Allergic and non-allergic rhinitis have different risk factors apart from asthma. There are significant regional variations within Switzerland, which are not explained by the factors examined.

How Many Responses Do We Need? Using Generalizability Analysis to Estimate Minimum Necessary Response Rates for Online Student Evaluations.

UNLABELLED: CONSTRUCT: The study compares paper and online ratings of instructional units and analyses, with the G-study using the symmetry principle, the response rates needed to ensure acceptable precision of the measure when compliance is low. BACKGROUND: Students' ratings of teaching contribute to the quality of medical training programs. To date, many schools have replaced pen-and-paper questionnaires with electronic forms, despite the lower response rates consistently reported with the latter. Few available studies have examined the effects of low response rates on the reliability and precision of the evaluation measure. Moreover, the minimum number of raters to target when response rates are low remains unclear. APPROACH: Descriptive data were derived from 799 students' paper and online ratings of 11 preclinical instructional units (PIUs). Reliability was assessed by Cronbach's alpha coefficients. The generalizability method applying the symmetry principle approach was used to analyze the precision of the measure with a reference standard error of mean (SEM) set at 0.10; optimization models were built to estimate minimum response rates. RESULTS: Overall, response rates were 74% and 30% (p < .001) and PIUs ratings were 3.8 ± 0.5 and 3.6 ± 0.5 (p = .02), respectively in paper and online questionnaires. Higher SEM levels and significantly larger 95% confidence intervals of PIUs rating scores were observed with online evaluations. To keep the SEM within preset limits of precision, a minimum of 48% response rate was estimated for online formats. CONCLUSIONS: The proposed generalizability analysis allowed estimating the minimum response needed to maintain acceptable precision in online evaluations. The effects of response rates on accuracy are discussed.

Long-Term Exposure to Ambient Air Pollution and Metabolic Syndrome in Adults.

Air pollutants (AP) play a role in subclinical inflammation, and are associated with cardiovascular morbidity and mortality. Metabolic syndrome (MetS) is inflammatory and precedes cardiovascular morbidity and type 2 diabetes. Thus, a positive association between AP and MetS may be hypothesized. We explored this association, (taking into account, pathway-specific MetS definitions), and its potential modifiers in Swiss adults. We studied 3769 participants of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults, reporting at least four-hour fasting time before venepuncture. AP exposures were 10-year mean residential PM10 (particulate matter <10µm in diameter) and NO2 (nitrogen dioxide). Outcomes included MetS defined by World Health Organization (MetS-W), International Diabetes Federation (MetS-I) and Adult Treatment Panel-III (MetS-A) using four- and eight-hour fasting time limits. We also explored associations with individual components of MetS. We applied mixed logistic regression models to explore these associations. The prevalence of MetS-W, MetS-I and MetS-A were 10%, 22% and 18% respectively. Odds of MetS-W, MetS-I and MetS-A increased by 72% (51-102%), 31% (11-54%) and 18% (4-34%) per 10µg/m3 increase in 10-year mean PM10. We observed weaker associations with NO2. Associations were stronger among physically-active, ever-smokers and non-diabetic participants especially with PM10 (p<0.05). Associations remained robust across various sensitivity analyses including ten imputations of missing observations and exclusion of diabetes cases. The observed associations between AP exposure and MetS were sensitive to MetS definitions. Regarding the MetS components, we observed strongest associations with impaired fasting glycemia, and positive but weaker associations with hypertension and waist-circumference-based obesity. Cardio-metabolic effects of AP may be majorly driven by impairment of glucose homeostasis, and to a less-strong extent, visceral adiposity. Well-designed prospective studies are needed to confirm these findings.

Spirometer Replacement and Serial Lung Function Measurements in Population Studies: Results From the SAPALDIA Study.

The Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults (SAPALDIA), a population cohort study, used heated-wire spirometers in 1991 and 2002 and then ultrasonic spirometers in 2010 revealing measurement bias in healthy never smokers. To provide a practical method to control for measurement bias given the replacement of spirometer in long-term population studies, we built spirometer-specific reference equations from healthy never smokers participating in 1991, 2002, and 2010 to derive individualized corrections terms. We compared yearly lung function decline without corrections terms with fixed terms that were obtained from a quasi-experimental study and individualized terms. Compared with baseline reference equations, spirometer-specific reference equations predicted lower lung function. The mean measurement bias increased with age and height. The decline in forced expiratory volume in 1 second during the reference period of 1991-2002 was 31.5 (standard deviation (SD), 28.7) mL/year while, after spirometer replacement, uncorrected, corrected by fixed term, and individualized term, the declines were 47.0 (SD, 30.1), 40.4 (SD, 30.1), and 30.4 (SD, 29.9) mL/year, respectively. In healthy never smokers, ultrasonic spirometers record lower lung function values than heated-wire spirometers. This measurement bias is sizeable enough to be relevant for researchers and clinicians. Future reference equations should account for not only anthropometric variables but also spirometer type. We provide a novel method to address spirometer replacement in cohort studies.