Meta-Analysis With Complex Research Designs

Scammacca, Nancy; Roberts, Gregory J; Stuebing, Karla K.

doi:10.3102/0034654313500826

Cited by 223 publications

(93 citation statements)

References 34 publications

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“…There were 223 total effect sizes (i.e., total k =223). The number of effect sizes per study that we obtained is relatively common in social science research (Scammacca et al, 2014) and is similar to the number of effect sizes per study seen in similar meta-analyses (Shields et al, 2015). Stress effects on working memory were examined in 34 studies ( k =164) with 1,353 participants.…”

Section: Resultssupporting

confidence: 76%

“…Multiple outcomes are a problem for conventional meta-analytic methods, as averaging effect sizes within studies without accounting for their correlations can alter or obscure true effect size estimates (Borenstein et al, 2009; Scammacca et al, 2014). Thus, we employed the meta-analytic technique of robust variance estimation, a random-effects meta-regression that can account for dependence between effect size estimates (Hedges et al, 2010; Tanner-Smith and Tipton, 2014).…”

Section: Methodsmentioning

confidence: 99%

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The effects of acute stress on core executive functions: A meta-analysis and comparison with cortisol

Shields

Sazma

Yonelinas

2016

Neuroscience & Biobehavioral Reviews

565

473

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Core executive functions such as working memory, inhibition, and cognitive flexibility are integral to daily life. A growing body of research has suggested that acute stress may impair core executive functions. However, there are a number of inconsistencies in the literature, leading to uncertainty about how or even if acute stress influences core executive functions. We addressed this by conducting a meta-analysis of acute stress effects on working memory, inhibition, and cognitive flexibility. We found that stress impaired working memory and cognitive flexibility, whereas it had nuanced effects on inhibition. Many of these effects were moderated by other variables, such as sex. In addition, we compared effects of acute stress on core executive functions to effects of cortisol administration and found some striking differences. Our findings indicate that stress works through mechanisms aside from or in addition to cortisol to produce a state characterized by more reactive processing of salient stimuli but greater control over actions. We conclude by highlighting some important future directions for stress and executive function research.

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Section: Resultssupporting

confidence: 76%

Section: Methodsmentioning

confidence: 99%

The effects of acute stress on core executive functions: A meta-analysis and comparison with cortisol

Shields

Sazma

Yonelinas

2016

Neuroscience & Biobehavioral Reviews

565

473

View full text Add to dashboard Cite

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“…The present study applied a systematic and rigorous meta-analytic method and examined high quality longitudinal studies of varying duration. In an attempt to more precisely synthesize and quantify the association of peer behavior with smoking initiation and continuation, we also employed the robust variance estimation approach (RVE) with small-sample corrections, a mathematically sound and well-validated method for modeling within-study dependence among effect sizes (Hedges et al, 2010; Samson et al, 2012; Scammacca, Roberts, & Stuebing, 2014; Tanner-Smith & Tipton, 2014; Tipton, 2015). Finally, examining potential moderators of the effect allows us to advance theories of social influence on risk taking during adolescence.…”

Section: Discussionmentioning

confidence: 99%

The influence of peer behavior as a function of social and cultural closeness: A meta-analysis of normative influence on adolescent smoking initiation and continuation.

Liu¹,

Zhao²,

Chen

et al. 2017

Psychological Bulletin

120

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Although the influence of peers on adolescent smoking should vary depending on social dynamics, there is a lack of understanding of which elements are most crucial and how this dynamic unfolds for smoking initiation and continuation across areas of the world. The present meta-analysis included 75 studies yielding 237 effect sizes that examined associations between peers’ smoking and adolescent smoking initiation and continuation with longitudinal designs across 16 countries. Mixed-effects models with robust variance estimates were used to calculate weighted-mean odds ratios. This work showed that having peers who smoke is associated with about twice the odds of adolescents beginning ( trueOR¯ = 1.96, 95% CI [1.76, 2.19]) and continuing to smoke ( trueOR¯ = 1.78, 95% CI [1.55, 2.05]). Moderator analyses revealed that (a) smoking initiation was more positively correlated with peers’ smoking when the interpersonal closeness between adolescents and their peers was higher (versus lower); and (b) both smoking initiation and continuation were more positively correlated with peers’ smoking when samples were from collectivistic (versus individualistic) cultures. Thus, both individual as well as population level dynamics play a critical role in the strength of peer influence. Accounting for cultural variables may be especially important given effects on both initiation and continuation. Implications for theory, research, and anti-smoking intervention strategies are discussed.

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“…Multiple outcomes are a problem for conventional meta-analytic methods, as averaging effect sizes within studies without accounting for their correlations can alter or obscure true effect size estimates (Borenstein, Hedges, Higgins, & Rothstein, 2009; Scammacca, Roberts, & Stuebing, 2014). Thus, we employed the meta-analytic technique of robust variance estimation, a random-effects meta-regression that can account for dependence between effect size estimates (Hedges, Tipton, & Johnson, 2010; Tanner-Smith & Tipton, 2014).…”

Section: Methodsmentioning

confidence: 99%

The effects of acute stress on episodic memory: A meta-analysis and integrative review.

Shields¹,

Sazma²,

McCullough³

et al. 2017

Psychological Bulletin

354

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A growing body of research has indicated that acute stress can critically impact memory. However, there are a number of inconsistencies in the literature, and important questions remain regarding the conditions under which stress effects emerge as well as basic questions about how stress impacts different phases of memory. In this meta-analysis, we examined 113 independent studies in humans with 6,216 participants that explored effects of stress on encoding, post-encoding, retrieval, or post-reactivation phases of episodic memory. The results indicated that when stress occurred prior to or during encoding it impaired memory, unless both the delay between the stressor and encoding was very short and the study materials were directly related to the stressor, in which case stress improved encoding. In contrast, post-encoding stress improved memory unless the stressor occurred in a different physical context than the study materials. When stress occurred just prior to or during retrieval, memory was impaired, and these effects were larger for emotionally valenced materials than neutral materials. Although stress consistently increased cortisol, the magnitude of the cortisol response was not related to the effects of stress on memory. Nonetheless, the effects of stress on memory were generally reduced in magnitude for women taking hormonal contraceptives. These analyses indicate that stress disrupts some episodic memory processes while enhancing others, and that the effects of stress are modulated by a number of critical factors. These results provide important constraints on current theories of stress and memory, and point to new questions for future research.

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Meta-Analysis With Complex Research Designs

Cited by 223 publications

References 34 publications

The effects of acute stress on core executive functions: A meta-analysis and comparison with cortisol

The effects of acute stress on core executive functions: A meta-analysis and comparison with cortisol

The influence of peer behavior as a function of social and cultural closeness: A meta-analysis of normative influence on adolescent smoking initiation and continuation.

The effects of acute stress on episodic memory: A meta-analysis and integrative review.

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