Browsing by Subject "Group size"

Now showing 1 - 2 of 2
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    A randomized trial comparing weight loss treatment delivered in large versus small groups
    (Springer Nature, 2014-09-24) Dutton, Gareth R.; Nackers, Lisa M.; Dubyak, Pamela J.; Rushing, Nicole C.; Huynh, Tuong-Vi T.; Tan, Fei; Anton, Stephen D.; Perri, Michael G.; Mathematical Sciences, School of Science
    Background: Behavioral interventions for obesity are commonly delivered in groups, although the effect of group size on weight loss has not been empirically evaluated. This behavioral weight loss trial compared the 6- and 12-month weight changes associated with interventions delivered in a large group (LG) or small groups (SG). Methods: Obese adults (N = 66; mean age = 50 years; mean BMI = 36.5 kg/m2; 47% African American; 86% women) recruited from a health maintenance organization were randomly assigned to: (1) LG treatment (30 members/group), or (2) SG treatment (12 members/group). Conditions were comparable in frequency and duration of treatment, which included 24 weekly group sessions (months 1-6) followed by six monthly extended care contacts (months 7-12). A mixed effects model with unstructured covariance matrix was applied to analyze the primary outcome of weight change while accounting for baseline weight and dependence among participants' measurements over time. Results: SG participants lost significantly more weight than LG participants at Month 6 (-6.5 vs. -3.2 kg; p = 0.03) and Month 12 (-7.0 vs. -1.7 kg; p < 0.002). SG participants reported better treatment engagement and self-monitoring adherence at Months 6 and 12, ps < 0.04, with adherence fully mediating the relationship between group size and weight loss. Conclusions: Receiving obesity treatment in smaller groups may promote greater weight loss and weight loss maintenance. This effect may be due to improved adherence facilitated by SG interactions. These novel findings suggest that the perceived efficiency of delivering behavioral weight loss treatment to LGs should be balanced against the potentially better outcomes achieved by a SG approach.
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    Size Matters: Towards a Contingency Theory of Diversity Effects on Performance
    (Taylor & Francis, 2020) Park, Sanghee
    This study examines the diversity-performance link by focusing on two types of diversity—gender and functional—in the context of governing boards of 24 quasi-government agencies in Korea over 16 years (2000-2015). Although public management scholarship contains evidence regarding the importance of diversity in public organizations, there is little consensus on what constitutes diversity and how it affects public sector performance. This study expands the scope of dialogues by highlighting multi-dimensional characteristics of diversity and the contingent nature of diversity effects. Multiplicative interaction models confirm that there are distinctive effects of different types of diversity on performance, and the relationship is moderated by the size of the group to which minorities belong. While the effect of board gender diversity is limited in our data, the effect of having a female chief executive is positively significant with decreasing marginal effect as the number of board members increases. On the other hand, the relationship of functional diversity in the boardroom to agency performance is negative, while the negative marginal effect decreases and becomes positive when board size rises above a critical number.