1. Alcohol Use & Misuse
10/18/12

2. Gmel & Rehm (2003) take-home messages: part I
correlation vs. causation ?
heavy drinking & workplace productivity
No clear effect of consumption on absenteeism
Some effect on work performance and coming late/leaving early
consider potential confounding variables. . .
Reverse causality: Work conditions lead to stress, poor productivity and drinking to cope
Developmental process: Under-education/training due to alcohol problems may lead to bad jobs which could lead to absenteeism and poor performance on the job
3rd variable explanation: psychopathology or poor achievement orientation may lead to BOTH drinking and poor work performance

3. Gmel & Rehm (2003) take-home messages: part II
correlation vs. causation ?
alcohol intoxication probably plays a causal role in many unintentional injuries
MVA, falls, drowning, burns, hypothermia
via cognitive and physical impairment due to BAC
Potential confounding variables?
3rd variable explanations? Impulsivity, disinhibition, poor judgment/cognitive impairment

4. Alcohol & Driving
1/3 of traffic fatalities are alcohol-related (MMWR, 2011)
1.8% of people who drank in last month admit to driving after drinking
4 million adults = 112,116,00 events
Significant impairment in driving simulators is seen at BACs > .02
Divided attention
Eye movement and visual perception
Reaction times
In 2009, about 10,839 persons died in alcohol-related traffic crashes, which constituted 39.5 percent of the total traffic crash fatalities.
The proportion of alcohol-related traffic fatalities varied across States, ranging from 25.5 percent (Utah) to 52.2 percent (Rhode Island).
Risks increase with BAC.

5. The risk of having a fatal crash rises sharply with higher BACs, relative to drivers who have not been drinking
Risks increase with BAC; measurable at .02, and rise steeply.
Age also makes a difference: risks increase even faster among drivers under 21.

6. Risk factors associated with alcohol-impaired driving
Men aged account for ___ % of alcohol- impaired driving events
85% of episodes were reported by ___________
the rate of alcohol-related driving events was 4x higher among _____________________
People living in the __________ drove under the influence more than people living in other regions
32%
Though they are only 11% of the population
BINGE DRINKERS
The 4.5% of adult population who binged 4+ in a month accounted for 55% of all alcohol-impaired driving episodes
PERSONS WHO DON’T ALWAYS USE SEATBELTS
This suggests a 3rd variable: what might be related to both drinking and driving and failure to use seatbelts?
MIDWEST
Midwest also associated with highest prevalence of binge drinking in US: 16.5%

7. Percentage distributions of BAC among alcohol-involved drivers, by age, United States, 2004.
From Yi, Chen, & Williams (2006) NIAAA publication
Young drivers ages 21 to 24 continued to have the highest proportion (39.1 percent) of alcohol involvement among drivers in all age groups.
But NOTE that drivers under 21 tended to be involved in crashes at lower BACs.
Perhaps a combination of inexperience with driving, inexperience with drinking, or incomplete brain development,
but this is a major reason for the MLDA being raised to >
So , you might ask, is this an effective way to reduce alcohol-involved traffic accidents among youth??

8. Percent change in alcohol-related motor vehicle accidents with changes in MLDA
YES
From Shults et al (2001, AJPM) meta-analyses:
This summarizes a bunch of studies and puts them on the same metric: how much accidents changed from before to after the change in MLDA; this line (at 0) represents no change - increase - decrease
TOP: In 1975, last US state reduced MLDA from (after Vietnam era) ==> increase in alcohol related crashes of 10%
BOTTOM: After 1984, when Uniform Drinking Age Act was passed, drinking ages were effectively lifted in all 50 states to 21 ==> decrease of 16%
But that was then, society and young adults have changed since then. . .
We happen to have a recent example of what might happen -- on this one dimension -- if MLDA were to be brought down.

9. “Lowering the minimum purchase age for alcohol increased traffic crash injuries among year olds in NZ” (Kypri et al., 2005)
Journal of the American Public Health Association
In 1999, NZ dropped the drinking age from
This gives us a recent test of what might happen if the US drinking age was lowered.
For male and females, newly legal (18-19) youth, traffic crashes due to alcohol intoxication went up significantly.
Trickle down effect: crashes also went up in the age bracket just below them (15-17)
Keep in mind that traffic crashes account for HALF of all deaths in the age range.

10. Are MLDA laws effective ?
States with more laws on the books restricting alcohol use have lower youth drinking rates
Enforcement of underage drinking laws predicts lower drinking rates
Enforcement of the Legal Minimum Drinking Age in the United States
Alexander C. Wagenaar, Mark Wolfson
Journal of Public Health Policy, Vol. 15, No. 1 (Spring, 1994), pp
rates of enforcement of the legal drinking age are very low;
actions against outlets or adults providing alcohol to youth are particularly rare;
penalties appear too lenient to deter providers of alcohol; and
levels of enforcement of the drinking age vary significantly across states.

11. Framework for reducing alcohol-impaired driving
Shults et al. (2001)