Cronbach’s α was .98 for GEC, .97 for the Metacognition Index, and .96 for the Behavioral Regulation Index (corresponding values for the paper and pencil version were .97, .96, and .94, see Supplementary Figure 1
for further details). Furthermore, only one respondent met the criteria for inconsistent responding (0.3%). As the Metacognition Index has been shown previously to differentiate ADHD+ and ADHD− children (McCandless & O’Laughlin, 2007
), this pattern was evaluated and verified with online BRIEF administration, ADHD− = 54.8 ± 0.8, ADHD+ = 69.5 ± 1.6, t
(271) = 7.91, p
< .0005. Overall, these three internal checks for the reliability and validity of online BRIEF administration all indicated very satisfactory psychometric properties.
Demographics, substance use patterns, and academic performance are depicted in . Women that did (NIC+) and did not (NIC−) use cigarettes during pregnancy did not differ in ethnicity, frequency of ADHD, or alcohol use. However, NIC+ women were younger and had lower income (both during pregnancy and currently), less education, were more likely to also use marijuana, cocaine, and methamphetamine during pregnancy and specifically in the third trimester. The NIC− and NIC+ children did not differ based on age or sex, but NIC+ were more likely to be diagnosed with ADHD and to be behind their peers in math and reading.
Further analysis of the NIC+ group divided into low (1–9 cigarettes/day) versus high (10–30 cigarettes/day during pregnancy) revealed that maternal age and income were significantly different in the both the low and high groups relative to NIC−. Notably, these groups did not differ from each other. Relative to unexposed children, reading difficulties were present in the low-NIC group (OR = 2.05, 95% CI = 1.02–4.14), but math difficulties (OR = 4.80, 95% CI = 2.19–10.52) and ADHD (OR = 2.64, 95% CI = 1.22–5.71) showed significant elevations only among high NIC.
The GEC was significantly elevated by 0.5 of a SD in NIC+ (63.1± 1.5) relative to NIC− (57.8 ± 0.8) children, F(1,356) = 9.76, p < .005. This difference was retained with maternal education, age at pregnancy, pregnancy income, child ADHD diagnosis, maternal ADHD diagnosis, prenatal marijuana, cocaine, methamphetamine, or alcohol exposure, prematurity, or current income entered as covariates. Additional analyses noted some evidence for exposed boys exhibiting a more pronounced profile than girls. For example, the Behavioral Regulation Index was increased by eight points in males, NIC− = 57.9 ± 1.3, NIC+ = 65.9 ± 2.6, t(173) = 2.85, p ≤ .005, but only three points in females, NIC− = 55.7 ± 1.2, NIC+ = 58.6 ± 1.8, t(181) = 1.32, p = 0.19. In contrast, younger (<9.5) and older (>9.5) children were similarly affected (data not shown).
shows a comparison of each NIC group. Both the low (p < .05) and high (p < .01) exposed children differed from the unexposed on the GEC. Similarly, the low- and high-NIC groups were elevated on the Behavioral Regulation Index. The low-, but not high-, NIC children exhibited increases on the Inhibit scale with the reverse pattern noted for Emotional Control. The low (p < .05) and high (p < .01) groups had difficulties with Metacognition. There was partial evidence for dose-dependent exposure effect with significant (p < .01) increases for the Initiate, Plan/Organize, and Monitor scales for only the high-NIC children. On the other hand, there were no significant differences between low- and high-NIC groups.
Figure 1. Standardized (T50) scores of maternal rating of executive function in children aged 5–18 years exposed to nicotine during pregnancy (low: 1–9 cigarettes/day and high: ≥10 cigarettes/day). GEC = Global Executive Composite, BRI = (more ...)
shows the likelihood of having a clinically significant problem (T50 ≥ 65) on the BRIEF, having an ADHD diagnosis or being behind peers academically based on maternal education, income, or nicotine use during pregnancy. The prevalence of all these outcomes was uniformly increased in the offspring of women with no post-secondary education (note that ADHD did not fulfill the statistical cutoff with p = .053). Similarly, women with lower incomes during pregnancy generally showed a less generalized pattern of difficulties on these domains. Maternal nicotine use was associated with a more focused profile on the BRIEF including on the Inhibit, Emotional Control, Organization, and Monitor scales. Importantly, only math showed a nicotine effect, which was retained when the variance attributable to education as well as income was removed.
Table 2. Odds Ratio (OR) and 95% CI for Clinically Significant Concerns on the Behavioral Rating Inventory of Executive Function (BRIEF), Diagnosis of Attention Deficit Hyperactivity Disorder (ADHD), and Performing Below Peers on Standardized Tests in Math and (more ...)