Thomas C. Harford

Age at onset of alcohol use and DSM-IV alcohol abuse and dependence: a 12-year follow-up

PURPOSEnThe purpose of this study was to examine the relationship between age at drinking onset and the development of DSM-IV alcohol abuse and dependence in a 12-year prospective study of youth in the United States.nnnMETHODSnLogistic regression analyses were used to quantify the relationship between age at drinking onset and the development of alcohol abuse and dependence controlling for sociodemographic factors and problem indicators.nnnRESULTSnThe odds of alcohol dependence decreased by 5% in 1989 and 9.0% in 1994 for each year drinking onset was delayed. In 1994, the odds of alcohol abuse increased by 7.0% with each decreasing year of age at drinking onset, while age at drinking onset was not related to alcohol abuse in 1989. Several other risk factors were found to be strong and consistent predictors of abuse and dependence in 1989 and 1994, including being male, divorced, separated or never married, younger, and having an early history antisocial behaviors and marijuana use.nnnIMPLICATIONSnImplications of the results of this study are discussed in terms of other factors that may impact on the onset-abuse and onset-dependence relationship and the need to focus future prevention efforts.

The changing profile of disability in the U.S. Army: 1981-2005.

BACKGROUNDnwe sought to provide a profile of U.S. Army soldiers discharged with a permanent disability and to clarify whether underlying demographic changes explain increasing risks.nnnMETHODSnfrequency distributions and logistic regression analyses describe active-duty Army soldiers discharged with a disability (January 1981 through December 2005; N = 108,119). Time-series analysis describes temporal changes in demographic factors associated with disability.nnnRESULTSndisability risk has increased 7-fold over the past 25 years. In 2005, there were 1,262 disability discharges per 100,000 active-duty soldiers. Risk factors include female gender, lower rank, married or formerly married, high school education or less, and age 40 or younger. Army population demographics changed during this time; the average age and tenure of soldiers increased, and the proportion of soldiers who were officers, women, and college educated grew. Adjusting for these demographic changes did not explain the rapidly increasing risk of disability. Time-series models revealed that disability among women is increasing independently of the increasing number of women in the Army; disability is also increasing at a faster pace for younger, lower-ranked, enlisted, and shorter-tenured soldiers.nnnCONCLUSIONndisability is costly and growing in the Army. Temporal changes in underlying Army population demographics do not explain overall disability increases. Disability is increasing most rapidly among female, junior enlisted, and younger soldiers.

The 5-year course of alcohol abuse among young adults.

PURPOSEnThis study describes the course of alcohol abuse among a nationally representative sample of young adults over a 5-year time period for the purpose of examining the validity of the DSM-IV alcohol abuse category.nnnMETHODSnDSM-IV diagnoses of alcohol abuse at baseline and follow-up were examined using logistic regression analyses.nnnRESULTSnAlcohol abuse and dependence were shown to have different courses. Very few abusers at Time 1 became dependent at Time 2, suggesting that abuse is not merely prodromal to dependence. Females, Blacks, and high school dropouts were less likely to receive an abuse diagnosis at baseline. Marital status, family history, earlier onset of drinking, and heavy drinking were also related to abuse at baseline. Alcohol abuse at baseline, in addition to gender, marital status, family history, early onset drinking, and heavy drinking, predicted abuse at follow-up. Exclusion of the hazardous criterion item driving after drinking too much from the abuse diagnosis yielded similar results.nnnDISCUSSIONnThe DSM-IV alcohol abuse category was shown to have some diagnostic utility.

Drinking and Spouse Abuse Among U.S. Army Soldiers

BACKGROUNDnThis study examines the relationship between typical weekly drinking and perpetration of spouse abuse as well as the relationship between the perpetrators typical weekly drinking and alcohol use during the abuse event among U.S. Army male soldiers.nnnMETHODSnCases include all active duty, male, enlisted Army spouse abusers identified in the Armys Central Registry who had also completed an Army Health Risk Appraisal Survey (HRA) between 1991 and 1998 (N = 9534). Cases were matched on sex, rank, and marital status with 21,786 control subjects who had also completed an HRA.nnnRESULTSnIn multivariate logistic regression models, heavy drinkers (22 or more drinks per week) were 66% more likely to be spouse abusers than were abstainers (odds ratio 1.66; 95% confidence interval 1.40-1.96). In addition, self-reported moderate and heavy drinkers were three times as likely and light drinkers (1-7 drinks per week) were twice as likely as nondrinkers to be drinking during the time of the abuse event.nnnCONCLUSIONnSelf-reported heavy drinking is an independent risk factor for perpetration of spouse abuse among male, enlisted Army soldiers. Even 5 years or more after ascertainment of typical drinking habits, there is a significant association between self-reported heavy drinking and alcohol involvement at the time of the spouse abuse event. Personnel who work with perpetrators and victims of spouse abuse should be trained carefully to query about current and typical drinking patterns.

Marijuana use among adults. A longitudinal study of current and former users.

This study examines the pattern of marijuana use among respondents who have passed the age of risk of onset, as well as some of the correlates related to the initiation and current use of marijuana. The data for this study included 8885 respondents drawn from the National Longitudinal Survey of Labor Market Experience of Youth (NLSY). Based on cross-tabulations of lifetime marijuana use in 1984 and 1994, the following outcomes were examined: incidence of lifetime marijuana use, inconsistent reports of lifetime marijuana use, and current compared with former use. Controlling for the effects of all variables studied, significant and independent effects were noted for sociodemographic factors, former patterns of use, and the use of other substances.

Prior Health Care Utilization Patterns and Suicide among U.S. Army Soldiers.

Suicides among U.S. Army soldiers are increasing and, in January 2009, outpaced deaths due to combat. For this study, 1,873 army suicides identified through death, inpatient, and emergency room records were matched with 5,619 controls. In multivariate models, older, male, White, single, and enlisted soldiers with a prior injury (OR = 2.04, 95% CI = 1.64-2.54), alcohol (OR = 3.41, 95% CI = 2.32-4.99), or mental health hospitalization (OR = 6.62, 95% CI = 4.77-9.20) were at increased risk for suicide. Risk was greatest immediately following diagnoses, but remained elevated even after 5 or more years of follow-up. Most injury hospitalizations were unintentional but, nonetheless, significantly associated with suicide. Interactions indicate soldiers with both mental health and injury history are particularly vulnerable.

Deployment to a combat zone and other risk factors for mental health-related disability discharge from the U.S. Army: 1994–2007†

Combat exposure is associated with subsequent mental health symptoms, but progression to mental health disability is unclear. Army soldiers discharged with mental health disability (n = 4,457) were compared to two matched control groups: other disability discharge (n = 8,974) and routine discharge (n = 9,128). In multivariate logistic models, odds of mental health disability discharge versus other disability and routine discharge were significantly higher for soldiers deployed to combat zones; odds ratios increased with deployment time. Prior mental health hospitalization decreased these odds, though they remained significantly elevated. Mental health hospitalization with successful treatment may facilitate better coping during deployment. The frequency of disability after mental health hospitalization suggests remaining gaps in deployment-related mental health assessment and treatment.

Temporal changes in the nature of disability: U.S. Army soldiers discharged with disability, 1981-2005.

BACKGROUNDnWe sought to (1) document and describe the relative proportion of disabilities by major type over the study period, (2) describe the population at risk for different types of disability, and (3) document and describe the type of compensation (an indicator of severity) awarded for different types of disability and any temporal changes in these associations.nnnMETHODSnTime-series, logistic regression analyses, and direct standardization of rates were used to study 108,119 active-duty Army soldiers discharged with permanent disability between 1981 and 2005.nnnRESULTSnOf all disability, 91% is captured within the top five most prevalent types of disability: musculoskeletal (72%, n=77,418), neurological (6%, n=6,896), mental health (5%, n=5,075), cardiovascular system (4%, n=4,429), and respiratory (4%, n=4,202). Musculoskeletal disability rates are increasing rapidly (+2.5% per year); neurological and cardiovascular disability rates are decreasing (-1.3% and -10.0% annually, respectively), and respiratory and mental health disability rates did not change significantly. Demographic risk factors vary by disability type. At greatest risk for musculoskeletal disability were female soldiers, soldiers who were between the ages of 21 and 35 years, white, in lower- to mid-level enlisted ranks with relatively short service tenure, and soldiers without a college education. Compensation awards also varied by disability type: Overall, 77% (n=83,320) received separation with severance pay, 15% (n=16,107) received a permanent disability retirement, and 8% (n=8,692) received separation without benefits. Separation with severance pay was the largest and fastest growing disability disposition for all disabilities and for musculoskeletal disability specifically.nnnCONCLUSIONSnDemographic risk factors vary by type of disability and by compensation award. Musculoskeletal disability rates are rapidly increasing as is separation with severance pay-particularly among white, young, lower ranking female soldiers.

Prescription and non-prescription drug use: A longitudinal study

This study examines changes in the lifetime prevalence of prescription and non-prescription drug use in a national longitudinal sample of young adults. Cohort data used in this study are from the National Longitudinal Survey, Youth Cohort (NLSY) who responded to questions on use of prescription drugs for the years 1984 and 1992 (N = 8,771). Results reveal increases in the lifetime prevalence of prescription use of sedatives, transquilizers, and stimulants. Prescription use was higher among women while non-prescription use was higher among men. Non-prescription drug use in 1984 was significantly related to prescription use in 1992.