22 research outputs found

    Lifetime body size and reproductive factors: comparisons of data recorded prospectively with self reports in middle age

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    <p>Abstract</p> <p>Background</p> <p>Data on lifetime exposures are often self-reported in epidemiologic studies, sometimes many years after the relevant age. Validity of self-reported data is usually inferred from their agreement with measured values, but few studies directly quantify the likely effects of reporting errors in body size and reproductive history variables on estimates of disease-exposure associations.</p> <p>Methods</p> <p>The MRC National Survey of Health and Development (NSHD) and the Million Women Study (MWS) are UK population-based prospective cohorts. The NSHD recruited participants at birth in 1946 and has followed them at regular intervals since then, whereas the MWS recruited women in middle age. For 541 women who were participants in both studies, we used statistical measures of association and agreement to compare self-reported MWS data on body size throughout life and reproductive history, obtained in middle age, to NSHD data measured or reported close to the relevant ages. Likely attenuation of estimates of linear disease-exposure associations due to the combined effects of random and systematic errors was quantified using regression dilution ratios (RDRs).</p> <p>Results</p> <p>Data from the two studies were very strongly correlated for current height, weight and body mass index, and age at menopause (Pearson r = 0.91-0.95), strongly correlated for birth weight, parental heights, current waist and hip circumferences and waist-to-height ratio (r = 0.67-0.80), and moderately correlated for age at menarche and waist-to-hip ratio (r = 0.52-0.57). Self-reported categorical body size and clothes size data for various ages were moderately to strongly associated with anthropometry collected at the relevant times (Spearman correlations 0.51-0.79). Overall agreement between the studies was also good for most quantitative variables, although all exhibited both random and systematic reporting error. RDRs ranged from 0.66 to 0.86 for most variables (slight to moderate attenuation), except weight and body mass index (1.02 and 1.04, respectively; little or no attenuation), and age at menarche, birth weight and waist-to-hip ratio (0.44, 0.59 and 0.50, respectively; substantial attenuation).</p> <p>Conclusions</p> <p>This study provides some evidence that self-reported data on certain anthropometric and reproductive factors may be adequate for describing disease-exposure associations in large epidemiological studies, provided that the effects of reporting errors are quantified and the results are interpreted with caution.</p

    Inquiry-Based Chemistry Education in a High-Context Culture: a Qatari Case Study

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    This research took place within the context of ongoing educational reforms to promote inquiry-based science instruction and a desire to draw evidence to inform adoptions of western pedagogical practices in a high-context culture like Qatar. We report on the outcomes from Process Oriented Guided Inquiry Learning (POGIL) in a foundation chemistry course based on students’ achievement, their perceived learning gains, and their self-efficacy. The study utilized quantitative data obtained from normalized content tests and instruments to measure perceived learning gains and attitudes and experience. Qualitative data from open-ended student questionnaires were analyzed to cross-validate findings from the study. Positive effects of POGIL during fall (semester 1) and spring (semester 2) semesters were evidenced by (a) improved mean scores and medium to large effect sizes for content test results, perceived learning gains, and self-efficacy levels and (b) a positive correlation between the measures of perceived learning gains and self-efficacy. Students self-reported increased self-efficacy, interest, and better understanding of concepts using the POGIL method. Comparing fall and spring semesters, student reluctance and negative perceptions of the POGIL approach gradually diminished. Students were able to adapt easily to POGIL—a method of teaching that they had not experienced before but which was compatible with the high-context culture in which they live. In addition, this study reflects the current condition of science learning in Qatar, where the emerging outcomes of educational reforms play an important role in preparing local students to transition into higher education
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