They then applied ranking selection without specifying a significance threshold and conducted a follow-up study of 21 promising SNPs, representing 18 independent loci, in 5,048 cases and 5,051 controls and found supporting evidence for association at 10 loci.
But we have tried to see if and how risk prediction depends on the threshold, so the key issue was to have measurements in effect at different thresholds (and of course conducted blind to case-control status) and then use OPERA, log likelihoods and AUC to assess the relative goodness of fits.
The exclusion of the impact supplement from the survey pack may have reduced the reliability of the screening thresholds for conduct and emotional disorders as defined by the respective SDQ subscales.
No differences were found between individuals scoring below the callous unemotional and conduct problems threshold, or above the threshold for callous unemotional traits without conduct problems, suggesting the IQ relationship is with conduct problems.
Table 1 gives the descriptive characteristics for three groups; those below callous unemotional (CU) and conduct problems (CP) threshold, (CU− CP− group, n = 41), those above callous unemotional but not conduct problems threshold (CU+ CP− group, n = 38) and those above threshold for both callous unemotional and conduct problems (CU+ CP+, n = 8).
Robustness checks with different thresholds and alternative definitions are also conducted.
Whilst higher externalising symptom factor scores were associated with obesity, the risk of exceeding the screening thresholds for Conduct Disorder were only weakly increased, once adjusted for the influence of potentially confounding variables.
TD controls all scored below the clinical threshold for conduct problems and below 45 on the ICU.
Therefore, we also performed comparisons of RMIP values for joint-family analysis conducted with P=0.01 threshold and single-family analysis conducted with P=0.0001, since it was the threshold evaluated closest to the Bonferroni-corrected P-value of 0.01/25.
However, using the screening cut-off for the conduct problems subscale, it was observed that the association between obesity and exceeding the screening threshold for conduct problems was only of borderline statistical significance once the effects of income and gender were controlled for (OR 1.58, 95% CI 1.00 to 2.50)(see Table 3).
