Table 1. Moderator Articles Authors Year Journal Topic 1 Manikam et al RIDD Dual Diagnosis

Transcription

1 Moderators and Mediators 41 Table 1. Moderator Articles Authors Year Journal Topic 1 Manikam et al RIDD Dual Diagnosis 2 Frison, Wallander, & Browne 1998 AJMR QOL/Adolescents 3 Hodapp, Fidler, & Smith 1998 JIDR QOL/Families 4 Hastings & Johnson 2001 JADD QOL/Families 5 Rimmerman, & Muraver 2001 JIDR QOL/Mothers 6 Hastings & Brown 2002 AJMR QOL/Parents 7 Hastings 2003 JADD QOL/Siblings 8 Baker, Blacher, & Olsson 2005 JIDR QOL/Parents 9 Benson 2006 JADD QOL/Parents 10 Eisenhower & Blacher 2006 JIDR QOL/Mothers 11 Kersh et al JIDR QOL/Parents 12 Singer 2006 AJMR QOL/Mothers 13 Blacher & Baker 2007 AJMR QOL/Families 14 Feldman et al JIDR QOL/Parents 15 Paczkowski, & Baker 2007 JIDR Parenting 16 Plant, K. & Sanders, M JIDR QOL/Families 17 Matson et al RIDD Autism Symptoms 18 Devereux et al RIDD QOL/Support Staff 19 Felce, Kerr, & Hastings 2009 JIDR Challenging Behavior 20 Gibson, Grey, & Hastings 2009 JADD QOL/Support Staff 21 Orsmond & Seltzer 2009 JADD QOL/Siblings

2 Moderators and Mediators van Nieuwenhuijzen et al JIDR Challenging Behavior 23 Adamson, Deckner, & Ballerman 2010 JADD Early Interests 24 Pollmann, Finkenauer, & Begeer 2010 JADD QOL/Parents 25 Seltzer et al JADD Maternal Cortisol AJMR = American Journal of Mental Retardation (now American Journal of Intellectual and Developmental Disability), JADD = Journal on Autism and Developmental Disorders, JIDR = Journal on Intellectual Disability Research, RIDD = Research in Developmental Disabilities, QOL = quality of life. Studies included in the literature review are listed by year and by author. Article topics are listed as general category.

3 Moderators and Mediators 43 Table 2. Mediator Articles Authors Year Journal Topic 1 Heller, Bond, & Braddock 1988 AJMR Institutional Closure 2 Baxter 1992 JIDR QOL/Parents 3 Baker & Bramston 1997 JIDR Challenging Behavior 4 Pruchno & Patrick 1999 AJMR QOL/Mothers 5 Yurmiya et al JADD Theory of Mind 6 Yoder & Warren 2001 AJMR Maternal Communication 7 Egli et al RIDD Community Involvement 8 Hastings & Brown 2002 AJMR QOL/Parents 9 Hastings & Symes 2002 RIDD QOL/Mothers 10 Hastings 2003 JADD QOL/Siblings 11 Baker, Blacher, & Olsson 2005 JIDR QOL/Parents 12 Hassall, Rose, & McDonald 2005 JIDR QOL/Mothers 13 Nachshen & Minnes 2005 JIDR QOL/Parents 14 Benson 2006 JADD QOL/Parents 15 Eisenhower & Blacher 2006 JIDR QOL/Mothers 16 Esbensen & Benson 2006 AJMR Dual Diagnosis/ adults 17 Magana et al AJMR QOL/Parents 18 McCarthy et al RIDD QOL/Parents 19 Skok, Harvey, & Reddihough 2006 JIDR QOL/Parents 20 van Nieuwenhuijzen et al JIDR Challenging Behavior 21 Baker et al AJMR Social Skills

4 Moderators and Mediators Feldman et al JIDR QOL/Parents 23 Paczkowski & Baker 2007 JIDR QOL/Parents 24 Plant, K. & Sanders, M JIDR QOL/Families 25 Hartley, Lickel, & MacLean 2008 JIDR Dual Diagnosis/Adults 26 Stel, van den Heuvel, & Smeets 2008 JADD Facial Feedback 27 Weiss 2008 AJMR QOL/Mothers 28 Willner & Smith 2008 JIDR Staff Behavior 29 Benson & Karlof 2009 JADD QOL/Parents 30 Deveraux et al RIDD QOL/Caregivers 31 Dichter et al JADD ASD Symptoms 32 Gibson, Grey, & Hastings 2009 JADD QOL/Support Staff 33 Hill & Rose 2009 JIDR QOL/Parents 34 Peeters et al RIDD Reading Development 35 van Nieuwenhuijzen et al JIDR Challenging Behavior 36 Hartman et al JIDR Motor Performance 37 Mann et al JADD Predictors ASD 38 Pollmann, Finkenauer, & Begeer 2010 JADD QOL/Parents AJMR = American Journal of Mental Retardation (now American Journal of Intellectual and Developmental Disability), JADD = Journal on Autism and Developmental Disorders, JIDR = Journal on Intellectual Disability Research, RIDD = Research in Developmental Disabilities, QOL = quality of life. Studies included in the literature review are listed by year and by author. Article topics are listed as general category.

5 Moderators and Mediators 45 Table 3. Moderator Results Study Statistical Method Criteria for Moderation Explicit Criteria Did X and Mod Correlate? Precedence of Mod addressed? Pluralism 1 MR X*Mod N Y N Y 2 MR X*Mod N NR Y N 3 SR ME of Mod N NR N N 4 MR X*Mod Y NR Y N 5 ANOVA Unclear N NR N N 6 HR X*Mod Y N N Y 7 HR X*Mod Y NR Y Y 8 ANOVA X*Mod N Y N Y 9 MR X*Mod Y NR Y N 10 HR X*Mod N NR Y N 11 HR X*Mod Y Y Y N 12 ANOVA Effect Size Y N/A Y N 13 HR X*Mod N NR Y N 14 HR X*Mod Y Y N Y 15 ANCOVA X*Mod N NR N Y 16 HR X*Mod Y N Y N 17 MANOVA X*Mod N NR N N 18 HR X*Mod N NR Y Y 19 MR X*Mod N NR Y N 20 MR X*Mod Y N N Y 21 HR X*Mod Y NR N N

6 Moderators and Mediators HR X*Mod Y Y Y N 23 MR X*Mod N Y N N 24 HR X*Mod N Y N N 25 HR X*Mod N NR N N Criteria Satisfied: 100% 92% 44% 16% 40% 68% HR = Hierarchical Regression, MR = Multiple Regression, ANOVA = Analysis of Variance, SR = Stepwise Regression, ANCOVA = Analysis of Covariance, MANOVA = Multivariate Analysis of Variance, X*Mod = Interaction between the IV and the moderator, ME = Main effect, N = No, Y = Yes, NR = Not Reported, N/A = Not Applicable. Studies were coded with respect to statistical approach ( Statistical Method ), the criteria used to classify a moderator ( Criteria for Moderation ), whether or not those criteria were explicitly stated by the authors ( Explicit Criteria ), whether or not data were presented regarding the causal relationship between the independent variable and the putative moderator ( Did X and Mod correlate? ), whether or not the precedence of the moderator variable to the independent variable was addressed ( Precedence of Mod addressed? ), and whether or not a single variable was analyzed as both a moderator and mediator ( Pluralism ). Bolded entries did not satisfy the criterion.

7 Moderators and Mediators 47 Table 4. Mediator Results Study Statistical Method Direct Test of Effect Criteria for Mediation Explicit Criteria Precedence of IV addressed? Pluralism 1 HR N ME of Med N N N 2 MR N Unclear N N Y 3 SR a*b CS N Y N 4 SEM N CS N N N 5 MR N CS 1 N N N 6 MR N CS Y Y N 7 MR a*b CS N N N 8 HR N CS Y Y Y 9 HR N CS Y Y N 10 HR N CS Y Y Y 11 MR N CS Y N Y 12 CORR N CS 1 N N N 13 SEM N CS N N N 14 MR Sobel CS Y Y N 15 HR Sobel CS N N N 16 HR N/A CS Y Y N 17 SEM MacKinnon a*b Y Y N Asymptotic Distribution Significant 18 HR N/A CS N Y N 19 MR Sobel CS Y N N 20 SEM N CS N Y N

8 Moderators and Mediators HR Sobel CS Y Y N 22 HR N CS 1 N N Y 23 HR Sobel CS N N Y 24 HR N CS Y Y N 25 MR Sobel CS Y Y N 26 MR Sobel CS Y N N 27 MR Sobel CS Y Y N 28 SR N CS Y Y N 29 HR Sobel CS Y Y N (Bootstrap) 30 HR Preacher & CS Y Y Y Hayes Bootstrap 31 CORR N/A CS Y N N 32 MR N CS 1 Y N Y 33 MR Sobel CS 1 Y Y N 34 MR N CS Y N N 35 HR Sobel CS Y N N 36 MR Sobel CS Y Y N 37 MR Sobel CS Y Y N 38 Preacher Preacher & a*b 0 Y Y N & Hayes Bootstrap Hayes Bootstrap Criteria Satisfied: 100% 55% 82% 66% 58% 21% HR = Hierarchical Regression, SEM = Structural Equation Modeling, MR = Multiple Regression, SR = Stepwise Regression, CORR = Correlations, N/A = Not Applicable, N = No,

9 Moderators and Mediators 49 a*b = Product of paths a and b from Figure 3, CS = Causal steps criteria, ME = Main effect, Y = Yes. 1 Indicates that the authors used a subset of the causal steps criteria. Studies were coded with respect to statistical approach ( Statistical Method ), if and how the authors attempted to quantify the mediated effect ( Quantification ), the criteria used to classify a mediator ( Criteria for Mediation ), whether or not those criteria were explicitly stated by the authors ( Explicit Criteria ), whether or not the temporal relationship between the mediator and independent variable was defended ( Precedence of IV addressed? ), and whether or not a single variable was analyzed as both a moderator and mediator ( Pluralism ). Bolded entries did not satisfy the criterion.

10 Moderators and Mediators 50 Figure Captions Figure 1. A diagram of the relationship between the independent variable (IV) and the dependent variable (DV). Path c represents the regression coefficient in an equation where X predicts Y. Figure 2. A diagram of the effect of a moderator (Mod) on the relationship between the independent variable (X) and the dependent variable (Y). Paths c, b, and d represent the regression coefficient of the respective variable in predicting Y. Mod is a moderator if the interaction X*Mod significantly predicts outcome (path d), indicating that the relationship between X and Y differs depending on the level of Mod. Figure 3. A diagram of a mediator (Med) of the relationship between an independent variable (X) and a dependent variable (Y). Path a represents the regression of Med on X, path b the regression of Y on Med, and c the regression of Y on X. According to the Baron and Kenny (1986) guidelines, Med is a mediator if paths a and b are significant, and if path c is weaker than path c from Figure 1. The MacArthur guidelines add that a significant interaction between X and Med is also a possible condition for mediation.