Risk Factors for Self-reported Driving Under the Influence of Alcohol and/or Illicit Drugs Among Older Adults

Namkee G. Choi, PhD; Diana M. DiNitto, PhD; C. Nathan Marti, PhD

Disclosures

Gerontologist. 2016;56(2):282-291. 

In This Article

Results

Sample Characteristics by Past-Year Substance Use

Table 1 shows that 69.56% of the 50–64 age group and 52.19% of the 65+ age group used alcohol and/or illicit drugs in the preceding 12 months. In both age groups, more than 98% of users of any substance used alcohol, whereas 12.47% of the 50–64 age group and 3.30% of the 65+ age group used illicit drugs. For both age groups, compared with nonusers, substance users had higher proportions of men, non-Hispanic whites, married persons, college graduates, employed persons, and those with income at or above 200% of federal poverty guidelines. Substance users also reported better self-ratings of health and fewer chronic illnesses and included a smaller proportion of those who experienced SPD. For the 50–64 age group, substance users also included a smaller proportion of those with MDE. However, for the 65+ age group, there was no difference between users and nonusers in MDE rates.

Table 2 shows that 14.54% and 6.19% of substance users in the 50–64 age group and the 65+ age group, respectively, self-reported DUI in the preceding 12 months, but only a tiny proportion reported having been arrested/booked for DUI. As expected, a majority of those reporting DUI drove under the influence of alcohol rather than other drugs.

Sample Characteristics by Past-Year DUI Status Among Substance Users

Table 3 shows that for both age groups, those reporting DUI, compared with those who did not, were more likely to be men, college graduates, employed, had income at or above 200% of federal poverty guidelines, and reported better self-ratings of health and fewer chronic illnesses. In the 50–64 age group, DUI reporters were also more likely to be non-Hispanic white, but the racial/ethnic distribution in the 65+ age group did not differ significantly by DUI status. DUI reporters aged 65+ were also more likely to be married than those not reporting DUI, but DUI reporters aged 50–64 were less likely to be married.

As expected, those who reported DUI, compared with those who did not, used alcohol more frequently and in larger quantities. Of DUI reporters, 20.38% aged 50–64 and 34.78% aged 65+ reported consuming alcohol on 300+ days in the preceding 12 months. Nearly 20% of DUI reporters in both age groups reported heavy drinking in the preceding 30 days and 33.89% of DUI reporters aged 50–64 and 27.73% aged 65+ reported binge, although not heavy drinking, in the preceding 30 days. Nearly 25% of DUI reporters, compared with 3% of nonreporters, aged 50–64 and more than 21% of DUI reporters, compared with 2% of nonreporters, aged 65+ met DSM-IV diagnostic criteria for alcohol dependence or abuse.

Of DUI reporters, 28.95% in the 50–64 age group and 9.96% in the 65+ age group reported any illicit drug use, with 22.14% and 8.18%, respectively, reporting marijuana use. Nearly 4% of DUI reporters, compared with less than 1% of nonreporters, in the 50–64 age group, and approximately 1.5% of DUI reporters, compared with 0.17% of nonreporters, in the 65+ age group met DSM-IV diagnostic criteria for illicit drug dependence or abuse, but the abuse diagnosis alone was not statistically different between DUI reporters and nonreporters in the 65+ age group. Further analysis (not shown in Table 3) also found that higher proportions of DUI reporters than nonreporters in both age groups reported having received substance abuse treatment in their lifetime (12.52% vs. 4.52% in the 50–64 age group, χ2(1) = 4195.0, p < .001; 5.19% vs. 1.69% in the 65+ age group, χ2(1) = 1082.20, p < .001) or during the preceding 12 months (3.17% vs. 0.79% in the 50–64 age group, χ2(1) = 1785.30, p < .001; 0.93% vs. 0.27% in the 65+ age group, χ2(1) = 228.40, p = .039). Of DUI reporters, 25.36% aged 50–64 and 22.32% aged 65+ reported that they needed treatment but did not receive it during the preceding year.

As also shown in Table 3, a higher proportion of DUI reporters than nonreporters in both age groups experienced MDE. Although a higher proportion of DUI reporters than nonreporters in the 50–64 age group experienced SPD, the difference was not statistically significant in the 65+ age group. A significantly higher proportion of DUI reporters than nonreporters in both age groups had been arrested/booked for breaking the law in their lifetimes. Further analysis also found that a higher proportion of DUI reporters than nonreporters in both age groups reported that they received mental health treatment in the preceding 12 months (19.93% vs. 15.48% in the 50–64 age group, χ2(1) = 515.29, p < .001; 15.96% vs. 9.63% in the 65+ age group, χ2(1) = 730.84, p = .012).

DUI Risk Factors Among Substance Users: Multivariate Analysis Results

Table 4 shows that controlling for demographic and health status, both frequency and quantity of alcohol use were significant predictors of DUI in both age groups. For example, in both age groups, compared with those who consumed alcohol on fewer than 50 days, those who did so on 300 or more days had nearly fivefold greater odds of reporting DUI (odds ratio [OR] = 4.97, 95% confidence interval [95% CI] = 3.76–6.57, p < .001 for the 50–64 age group; OR = 4.72, 95% CI = 2.98–7.50, p < .001 for the 65+ age group). Compared with nonbinge drinkers, binge drinkers had significantly higher odds of DUI reports (OR = 2.52, 95% CI = 2.18–2.91, p < .001 for the 50–64 age group; OR = 3.22, 95% CI = 2.27–4.58, p < .001 for the 65+ age group). Marijuana use was also a significant predictor of DUI reports in both age groups (OR = 3.12, 95% CI = 2.54–3.820, p < .001 for the 50–64 age group; OR = 4.94, 95% CI = 2.12–11.52, p < .001 for the 65+ age group). Other illicit drug use was a significant predictor in the younger, but not the older, age group. MDE was a significant predictor for both age groups (OR = 2.05, 95% CI = 1.64–2.57, p < .001 for the 50–64 age group; OR = 4.20, 95% CI = 1.83–9.63, p = .001 for the 65+ age group). Lifetime arrest history did not predict DUI in the younger age group, but it did in the 65+ age group (OR = 2.32, 95% CI = 1.58–3.42, p < .001). Of the demographic variables, being male and having income at or above 200% of federal poverty guidelines significantly increased the odds of DUI reports for both age groups. In addition, higher education in the 65+ age group and being non-Hispanic white and being employed in the 50–64 age group increased the odds, whereas being married decreased the odds in the 50–64 age group. The health status variables significantly predicted DUI in the 50–64 age group only, with better health being associated with greater odds of DUI reports.

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