This document summarizes research analyzing factors associated with the clinical characteristic of "dominance" in patients with cocaine dependence. The researchers explored correlations between dominance and scores on measures of depression, personality traits, and alcohol use. They found that dominance was most strongly correlated with scores of vindictiveness, intrusiveness, and alcohol use. The researchers then categorized these scores into high and low groups and explored interactions between the groupings. Statistical modeling found that dominance was best explained by interactions between the vindictiveness, intrusiveness, and alcohol use groupings. Longitudinal modeling across six months yielded similar results, supporting the persistence of these correlations over time.
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1. Factors associated with the clinical characteristic Dominance published in Psychosocial Treatments for Cocaine Dependence [Arch Gen Psychiatry 56: June 1999] Tim Hare STA531 Fall 2009
2. Cross-sectional (Month = 6) modeling of DOMI (Dominance) as a primary outcome The outcome measure under consideration is the clinical attribute/behavior dominance. Preliminary hypothesis directed the search somewhat: Is Dominance correlated with depression scores and psychological characteristics scores? A focus on scores for personality traits as well as assessed alcohol use yielded a subset of candidate predictors with strong correlation. VIND = vindictive ALC_SUB = ASI Alcohol composite INTR = intrusive COLD Exploratory analysis of these to develop the hypothesis?
3. Correlation data for raw score VIND vs. DOMI Binned by score trend of the 95% CIs suggests possible significance of categorical based on binning 1.00000 0.80637 <.0001 VIND 0.80637 <.0001 1.00000 DOMI VIND DOMI PearsonCorrelationCoefficients,N=456 Prob>|r|underH0:Rho=0
4. Correlation data for raw score INTR vs DOMI Again, trend in the 95% CIs 1.00000 0.79210 <.0001 INTR 0.79210 <.0001 1.00000 DOMI INTR DOMI PearsonCorrelationCoefficients,N=456 Prob>|r|underH0:Rho=0
5. Correlation data for raw score COLD vs DOMI Again, trend in the 95% CIs 1.00000 457 0.73152 <.0001 456 COLD 0.73152 <.0001 456 1.00000 456 DOMI COLD DOMI PearsonCorrelationCoefficients Prob>|r|underH0:Rho=0 NumberofObservations
6. Cross-sectional (Month = 6) modeling of DOMI (Dominance) as a primary outcome The outcome measure under consideration is the clinical attribute/behavior dominance. A number of potential factors were evaluated, however a focus on related psychological scores as well as assessed alcohol use yielded a subset of relatively strong predictors. VIND = vindictive ALC_SUB = ASI Alcohol composite INTR = intrusive COLD Based upon the preliminary exploration , the above patient scores were transformed to create a new set of 2-LEVEL categorical variables codified by assignment according to whether they were above or below their mean (e.g. high low) VINDGROUP ALC_SUBGRUOP INTRGROUP COLDGROUP Additional crossed 2- and 3-way group variables were created based upon the ABOVE GROUP variables (e.g. combinations of high and low levels). VA = vindictive + ASI Alcohol composite VI = vindictive + intrusive VAI = vindictive + ASI Alcohol composite + intrusive Before we get started, what about any MODELING ASSUMPTIONS?
7. OUTCOME MEASURE = DOMI Raw score NORMAL PROBABILITY PLOT 1.00000 0.94328 <.0001 zdomi Rank for Variable DOMI 0.94328 <.0001 1.00000 DOMI zdomi DOMI PearsonCorrelationCoefficients,N=456 Prob>|r|underH0:Rho=0
8. Potential 2-way & 3-way CROSS FACTOR GROUP VIEWS VINDGROUP-INTRGROUP VINDGROUP-ALC_SUBGROUP VINDGROUP-ALC_SUBGROUP-INTRGROUP 1) Evidence for non-homogeneous variance. 2) As well, groups are unbalanced (dissimilar counts) USE PROC MIXED
9. Any hypothesis suggest itself? Lets take a look at the new CATEGORICAL VARIABLES we created, graphically Lets also take a look at the new observational CROSS FACTOR data groups... Lets also look for any confounding 2-way or 3-way INTERACTIONS between the variables Will a story emerge?
10. NEW CATEGORICAL VARIABLES (NOT RAW DATA) MEAN DOMI SCORE by LEVEL ALC_SUBGROUP INTRGROUP VINDGROUP Some good evidence that our 2-LEVEL categorization correlates with our OUTCOME measure. What about combinations of the above CATEGORIES by LEVEL?
11. 2-way- & 3-way CROSS FACTOR GROUPS MEAN DOMI SCORES (VIND*INTR) (VIND*ALC_SUB) VIND*ALC_SUB*INTR Good story to explore What about interaction???
15. Graphical analysis to examine potential 3-WAY interaction VINDGROUP*INTRGROUP*ALC_SUBGROUP( LOW/HIGH ) ALC_SUBGROUP = LOW ALC_SUBGROUP = HIGH
16. PREVIEW for longitudinal modeling: Correlation noted in CROSS SECTIONAL (Month=6) data seems to persist across time Therefore suspect repeated measures (longitudinal modeling) may model well from the same variables
17. Exploration leads to Hypothesis Incidence of the clinical characteristic Dominance can likely be explained by modeling with the categorical variables (VINDGROUP, INTRGROUP, ALC_SUBGROUP, COLD) derived from the raw scores. Interaction terms (VINDGROUP*ALC_SUBGROUP, VINDGROUP*INTRGROUP, INTRGROUP*ALC_SUBGROUP) will likely play a role in the modeling process given the preliminary 2-/3-way interaction plots ( COLDGROUP*<other> not compelling, data not shown ). Finally, there are some compelling graphs that suggest that interaction can be explained and may be significant in many cases ( well explore these further with contrasts later ).
20. If youre Vindictive=Low, Intrusive=Low you probably dont have to worry about being overly Dominant after drinking At 95% conf. Level: not significant <.0001 5.55 447 0.3445 1.9119 LHL <.0001 4.53 447 0.2747 1.2440 LLL Pr > |t| tValue DF Standard Error Estimate Label Estimates 0.0938 2.82 447 1 LHL-LLL Pr>F F Value Den DF Num DF Label Contrasts
21. Does intrusiveness trump alcohol in low vindictives? VL AL/H IL VL AL/H IH <.0001 9.04 447 0.45 4.08 AVG(LHH,LLH) <.0001 6.58 447 0.24 1.58 AVG(LLL,LHL) 0.0001 3.92 447 0.66 2.57 LLH <.0001 9.00 447 0.62 5.59 LHH <.0001 5.55 447 0.34 1.91 LHL <.0001 4.53 447 0.27 1.24 LLL Pr > |t| tValue DF Standard Error Estimate Label Estimates <.0001 24.87 447 1 AVG(LHH,LLH)-AVG(LLL,LHL) 0.0009 11.21 447 1 LHH-LLH 0.093 2.82 447 1 LHL-LLL Pr>F F Value Den DF Num DF Label Contrasts
23. Repeated Measures Analysis of the entire Month1-Month6 data set The original cross sectional model was evaluated for COV / VAR structure (e.g. adjust for possible correlation in longitudinal data) by comparison CS, UN, AR(1) TOEP, CSH, ARH(1) COV / VAR type UN was retained as smallest -2ResLogLikelihood, significantly smaller than all the rest, adjusting for DF. ALC_SUBGROUP was retained due to participation in higher order terms of significance. 0.0012 7.16 102 2 VINDGR*ALC_SU*INTRGR 0.0098 6.93 102 1 VINDGROUP*ALC_SUBGRO <.0001 39.29 102 1 VINDGROUP*INTRGROUP <.0001 125.09 102 1 INTRGROUP 0.8081 0.06 102 1 ALC_SUBGROUP <.0001 132.23 102 1 VINDGROUP <.0001 22.20 102 1 COLDGROUP Pr>F F Value Den DF Num DF Effect Type 3 Tests of Fixed Effects
26. What about our cross sectional contrast of alcohol being trumped by intrusiveness in low vindictives? Does it still hold in the longitudinal analysis? Still significant At 95% CI <.0001 8.44 102 0.4247 3.5832 AVG(LHH,LLH) <.0001 6.74 102 0.2790 1.8806 AVG(LLL,LHL) <.0001 5.34 102 0.5583 2.9805 LLH <.0001 7.36 102 0.5689 4.1859 LHH <.0001 6.04 102 0.3452 2.0854 LHL <.0001 5.59 102 0.2996 1.6757 LLL Pr > |t| tValue DF Standard Error Estimate Label Estimates 0.0002 15.41 102 1 AVG(LHH,LLH)-AVG(LLL,LHL) 0.1069 2.65 102 1 LHH-LLH 0.2124 1.57 102 1 LHL-LLL Pr>F F Value Den DF Num DF Label Contrasts
27. Conclusions The interrelationship between the clinical attribute dominance and the related attributes intrusive vindictiveness, cold, along with the ASI Alcohol Composite score, combine to model the incidence of dominance in the clinical data. Both longitudinal modeling (using the entire data set) and cross sectional modeling (Month=6) support the same conclusions. We can use CONTRASTS to profitably to validate the BARCHARTS showing possible differences in relationship between the interactions of 3 key variables (VINDGROUP, INTRGROUP, and ALC_SUBGROUP) types that correlated with DOMINANCE, but have complex INTERACTIONS.