ACT research report: The validity over time of college freshman grade prediction equations

Author(s):  
Richard Sawyer ◽  
E. James Maxey
Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
James E Peterman ◽  
Matthew Harber ◽  
Mary Imboden ◽  
Mitchell Whaley ◽  
bradley fleenor ◽  
...  

Introduction: Mortality risk predictions are improved with routine assessment of cardiorespiratory fitness (CRF). Accordingly, an American Heart Association Scientific Statement suggests routine clinical assessment of CRF in apparently healthy adults minimally using non-exercise prediction equations, which can be calculated from common health metrics. However, no study has assessed the ability of non-exercise CRF prediction equations to accurately detect longitudinal changes. Hypothesis: Changes in estimated CRF (eCRF) would be related to directly-measured changes, yet appreciable misclassification would occur at the individual level. Methods: The sample included 987 apparently healthy adults (324 females; mean±SD age 43.1±10.4 years) who completed 2 cardiopulmonary exercise tests (CPX) at least 3 months apart (3.2±5.4 years follow-up). The change in eCRF from 27 distinct non-exercise prediction equations was compared to the change in directly-measured CRF determined from CPX. A change of ≥5% was used to classify participants as having a directional increase or decrease in CRF. Analysis included Pearson product moment correlations, standard error of estimate (SEE) values, the Benjamini-Hochberg procedure to compare eCRF with directly-measured CRF, and chi-squared tests to examine the impact of follow-up time on the percentage of participants correctly identified as having a directional increase or decrease in CRF. Results: The change in eCRF from each equation was correlated to the change in directly-measured CRF ( P <0.001) with R 2 values ranging from 0.06-0.43 and SEE values ranging from 0.9-5.9 ml·kg -1 ·min -1 . For 16 of the 27 equations, the change in eCRF was significantly different from the change in directly-measured CRF. When classifying directional changes, the prediction equations correctly categorized an average of 54% of individuals as having increased, decreased, or no change in CRF. When examining the influence of follow-up time, the average percentage of individuals correctly classified as having a directional increase in CRF was greater when the time between tests was ≤8months (54%) compared to ≥2years (28%). In contrast, the average percentage correctly classified as having a directional decrease in CRF was lower with tests ≤8months apart (8%) compared to ≥2years (73%). Conclusions: As hypothesized, discernible variability was found in the accuracy between non-exercise prediction equations and the ability of equations to accurately assess changes in directly-measured CRF over time. Considering the appreciable error that prediction equations had with detecting even directional changes in CRF, these results suggest eCRF may have limited clinical utility.


2020 ◽  
Vol 20 (1) ◽  
pp. 45-61
Author(s):  
Leah C. Butler ◽  
Bonnie S. Fisher ◽  
Rachael Schilling ◽  
Nicole V. Lasky ◽  
Suzanne C. Swan

2011 ◽  
Vol 31 (5) ◽  
pp. 782-802 ◽  
Author(s):  
HEIDRUN MOLLENKOPF ◽  
ANNETTE HIEBER ◽  
HANS-WERNER WAHL

ABSTRACTThis research report starts from the assumption that a solely geriatric and transport-related view of out-of-home mobility needs to be extended to incorporate other aspects of perceived and experienced mobility. In particular, our goal is to understand better the stability and change in people's perceptions of out-of-home mobility over ten years. We concentrate on: (a) the subjective meaning of mobility over time, including perceived changes in mobility and perceived reasons for change; (b) trends in satisfaction with various mobility domains; and (c) a case-oriented exploration of inter-individual variation over time. A qualitative–quantitative data-analytic approach was applied to data collected from 82 participants on three occasions over ten years in 1995, 2000 and 2005. The mean age of the sample in 2005 was 75.2 years. The results indicate overall stability in the meaning attached to mobility between 1995 and 2005, while the perceived changes point to major losses in the array of mobility experiences and decreasing satisfaction with mobility opportunities, out-of-home leisure activities and travelling, but in contrast satisfaction with public transport increased. Case studies exemplified the reasons for the pronounced variation in satisfaction with mobility dynamics over time. In conclusion, the findings confirm that out-of-home mobility remains of utmost importance when people move from late midlife into old age.


Author(s):  
Ioannis Tarnanas ◽  
Vassilios Kikis

That portion of the Internet known as the World Wide Web has been riding an exponential growth curve since 1994 (Network Wizards, 1999; Rutkowski, 1998), coinciding with the introduction of NCSA’s graphically based software interface Mosaic for “browsing” the World Wide Web (Hoffman, Novak, & Chatterjee 1995). Currently, over 43 million hosts are connected to the Internet worldwide (Network Wizards, 1999). In terms of individual users, somewhere between 40 to 80 million adults (eStats, 1999) in the United States alone have access to around 800 million unique pages of content (Lawrence & Giles, 1999), globally distributed on arguably one of the most important communication innovations in history. Yet even as the Internet races ambitiously toward critical mass, some social scientists have begun to examine carefully the policy implications of current demographic patterns of Internet access and usage (Hoffman & Novak, 1998; Hoffman, Kalsbeek, & Novak, 1996; Hoffman, Novak, & Venkatesh, 1997; Katz & Aspden, 1997; Wilhelm, 1998). Looming large is the concern that the Internet may not scale economically (Keller, 1996), leading to what Lloyd Morrisett, the former president of the Markle Foundation, has called a “digital divide” between the information “haves” and “have-nots.” For example, although almost 70% of the schools in this country have at least one computer connected to the Internet, less than 15% of classrooms have Internet access (Harmon, 1997). Not surprisingly, access is not distributed randomly, but correlated strongly with income and education (Coley, Cradler, & Engel 1997). A recent study of Internet use among college freshman (Sax, Astin, Korn, & Mahoney 1998) found that nearly 83% of all new college students report using the Internet for school work, and almost two-thirds use e-mail to communicate. Yet, closer examination suggests a disturbing disparity in access. While 90.2% of private college freshman use the Internet for research, only 77.6% of students entering public black colleges report doing so. Similarly, although 80.1% of private college freshman use e-mail regularly, only 41.4% of students attending black public colleges do. Further, although numerous studies (e.g., CyberAtlas, 1999; Maraganore & Morrisette, 1998) suggest that the gender gap in Internet use appears to be closing over time and that Internet users are increasingly coming from the ranks of those with lower education and income (Pew Research Center, 1998), the perception persists that the gap for race is not decreasing (Abrams, 1997). We now raise a series of points for further discussion. We believe these issues represent the most pressing unanswered questions concerning access and the impact of the digital divide on the emerging digital economy. This article is intended to stimulate discussion among scholars and policymakers interested in how differences in Internet access and use among different segments in our society affect their ability to participate and reap the rewards of that participation in the emerging digital economy. In summary, we have reviewed the most recent research investigating the relationship of race to Internet access and usage over time. Our objective is twofold: (1) to stimulate an informed discussion among scholars and policymakers interested in the issue of diversity on the Internet, and 2) to propose a research agenda that can address the many questions raised by this and related research.


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