The Effectiveness of Screening and Brief Intervention on Reducing Driving While Intoxicated Citations

Abstract

The purpose of this study was to use retrospective data, including citations for driving while intoxicated (DWI), to assess the long-term effectiveness of a program consisting of Screening and Brief Intervention (SBI) for at-risk alcohol users and its impact on traffic safety. A second objective was to study ethnic differences in response to SBI. During the time period of 1998–1999, LCF Research, together with the Lovelace Health System, participated in the Cutting Back SBI study for at-risk drinkers. A total of 426 subjects exhibiting at-risk drinking behaviors from the New Mexico cohort were examined for the study, including 211 subjects who received a brief counseling intervention and 215 in the no intervention control group. This study examined DWI citations for all 426 subjects during the 5 years following the Cutting Back study. The brief interventions were shown to have had a significant impact on reducing DWI citations for at-risk drinkers, with the added benefit lasting for the 5-year duration of the study. The SBI was found to be most effective at reducing DWI citations for Hispanic at-risk drinkers. Evidence is presented to show that screening to identify at-risk drinkers followed by a brief intervention has a statistically significant lasting impact on improving traffic safety. (Population Health Management 2012;15:52–57)

Introduction

I ndividuals who drive while intoxicated with alcohol (DWI) pose a serious risk to society. Of the 30,797 crashes involving fatalities in the United States during 2009, a total of 9817 (31.9%) were alcohol related.¹ Alcohol misuse is the most common risk factor for trauma patients, affecting 25%–40% of those treated in major trauma centers. Alcohol misuse results in repeated episodes of trauma, drunk driving, and alcohol-related crashes. A prior study found that trauma patients with alcohol problems were more than twice as likely to be readmitted with injuries during the next 2 years as were patients without alcohol problems.²

Programs consisting of Screening and Brief Intervention (SBI) have been shown to be effective at reducing alcohol consumption for at-risk drinking in individuals.³ Fleming et al⁴ showed effectiveness in reducing DWI convictions up to 4 years for SBI with additional follow-up therapy. This report extends our understanding of the effectiveness of a single brief intervention without the necessity of additional hours of therapy.

Although the problem of alcohol-dependent individuals is well understood, there are many more “at-risk” drinkers who also pose a serious risk, even though they are not alcohol dependent (Fig. 1). The National Institute on Alcoholism and Alcohol Abuse (NIAAA)⁵ estimates that, although 5% of the adult US population are classified as dependent drinkers, 4 times that number (20%) are in the at-risk categories of “hazardous” and “harmful.”⁵ According to the NIAAA, an inappropriate drinking level is defined as having more than 14 drinks per week or more than 4 drinks per occasion for men 65 years of age or younger, and more than 7 drinks per week or more than 3 drinks per occasion for women and for men older than 65 years of age.⁵

FIG. 1.

NIAAA spectrum of alcohol use. NIAAA, National Institute on Alcohol Abuse and Alcoholism.

Screening and Brief Intervention (SBI)

SBI has been widely implemented in primary care, emergency and trauma department operations, as well as numerous other settings. The SBI process begins with a brief self-reported screening survey for substance abuse. Screening quickly assesses the presence of at-risk or dependent drinking; a positive screening score may be followed up with a more in-depth assessment, and then an appropriate intervention is provided. At-risk drinkers typically receive a 5–15-minute counseling intervention by a health care practitioner (brief intervention); dependent drinkers are referred to behavioral health.^6,7

The brief intervention uses motivational interviewing methods.⁸ Motivational interviewing is a client-centered, directive therapeutic style to enhance readiness for change by helping clients explore and resolve ambivalence.⁹ A meta-analysis of 32 randomized trials of SBIs enrolling a total of 5718 patients indicated that such interventions were effective at decreasing problem drinking and lowering subsequent health care utilization.¹⁰ A randomized controlled trial of trauma patients found that SBI reduced drinking by two thirds 12 months after the intervention and lowered recidivism for new injuries by 50%.^3,10 From a review of cost analyses in several studies, it appears that this low-cost investment could reap substantial benefits in savings in future health care costs, making it of interest to managed care organizations.^{4,5,11

–15}

Cutting Back Research Project

Although there have been many studies of SBI in a controlled setting, the Cutting Back SBI study, a multisite research project coordinated by the University of Connecticut Health Center with funding from the Robert Wood Johnson Foundation, was the first to test SBI in a real-world setting.¹² The study was conducted in 5 integrated delivery systems in the United States from 1998 through 2002. LCF Research, in cooperation with the Lovelace Health System in New Mexico, participated as one of the research sites. The goals of the project focused on: (1) assessment of how best to implement and sustain SBI in this setting, (2) estimation of the effectiveness of SBI in primary care, and (3) evaluation of the costs and benefits of SBI. This SBI approach utilized a standardized self-report screening questionnaire to identify potential at-risk and dependent drinkers. If the individual received a positive screening score for at-risk drinking, his or her screening was followed by a 3–5 minute brief counseling intervention delivered by either a physician, a mid-level provider, or a nurse specialist using motivational interviewing as described. Dependent drinkers were referred to behavioral health.

The Cutting Back study was a cluster randomized trial in which 2 of the New Mexico clinics received a brief intervention and 1 clinic received usual care. Patients who presented for care in all 3 clinics were asked to complete a Health Appraisal Survey (HAS), a 10-item survey with 3 alcohol screening questions embedded from the Alcohol Use Disorders Identification Test (AUDIT), later identified as the AUDIT-C.¹³ These questions represent frequency, quantity, and intensity of consumption. Specifically, the questions were:

1. How often do you drink anything containing alcohol?

2. How many drinks do you have on a typical day when you are drinking?

3. How often do you have more than 4 drinks on one occasion?

Results of the Cutting Back study showed significant reductions in patient self-reported alcohol consumption for the intervention clinics compared to the control clinics. It further showed no significant difference between the interventions given by health care providers vs. those provided by the nurse specialist. Several articles based on data collected across all 5 participating study sites have been published using the Cutting Back results.^11

–16 A recent separate analysis of the Cutting Back study data collected at Lovelace during 1998–1999 confirms these findings for the New Mexico site.

Ethnicity and At-Risk Drinking

Drinking patterns, their consequences, and the relationship of patterns and consequences are influenced by the individual's culture. Rehm et al¹⁴ explored the effects of culture on different drinking patterns (episodic drinking [where the purpose is to become intoxicated], high-volume and high-frequency consumption, and variable patterns of frequency and volume) and reported that relationships between acute consequences (eg, injuries) and drinking measures of volume and frequency vary by culture. Acculturation, or adaptation to prevailing norms in the surrounding population, has been shown to have an impact on both alcohol consumption patterns and related consequences. Alaniz et al¹⁵ described a telephone survey conducted in 3 northern California cities and reported that acculturation had a direct effect on self-reported drinking for women. In particular, less acculturated women of Mexican descent tended to be abstainers; however, more acculturated women were more likely to be heavy drinkers. This does not appear to be true for men of Mexican descent. Borges et al¹⁶ reported that the relative risk of injury 1 hour after alcohol consumption varied from greater than 3:1 for Hispanics, whose acculturation was assessed as low to medium, to less than 1:1 for Hispanics with high acculturation, when compared to non-Hispanic whites.

Approximately 40% of New Mexico's population characterize themselves as Hispanic.¹⁷ This large ethnic group allows the opportunity to explore the issues of drinking and ethnicity in the New Mexico cohort, and the implications for interventional strategies in this cohort.

Methods

This study is based on the collection and analysis of DWI citations received by the Cutting Back participants during the 5-year period following the date of each individual's completion of the HAS questionnaire. The New Mexico Department of Transportation maintains a database of all DWI citations in New Mexico at the University of New Mexico's Division of Government Research (DGR). DWI citations were used instead of DWI convictions to obtain the sample size necessary for the analysis. The study was approved by the LCF Institutional Review Board and the Lovelace Health Plan Privacy Board, and all protected health information was encoded and kept on password-protected computers in locked facilities.

An encoded file containing the patient-identifying information for all of the Cutting Back participants was transferred by secure FTP site to the DGR. The information included subject name, social security number, date of birth, and sex. DGR used the Link Plus software program¹⁸ to match the Cutting Back subjects to the New Mexico driver's license registry.

The data analysis was restricted to the 886 excessive drinkers (at-risk or dependent) identified by the initial screen. Age, sex, ethnicity, and family income for the 2 study groups are shown in Table 1. Ethnicity for the at-risk drinkers was self-reported during the 3-month follow-up survey. An estimate of mean income was derived from the patient's address and the 2000 census tract information. The low percentage of Hispanic males who were classified as at-risk drinkers appears to reflect differences between the sexes in the clinic population because Hispanic males are less likely to visit a primary care clinic than are Hispanic females. In fact, the Hispanic males who completed the HAS were 3 times as likely as their female Hispanic counterparts to be classified as at-risk drinkers.

Table 1.

Age, Sex, Ethnicity, and Family Income of Excessive Drinking Subjects

All Excessive Drinking Subjects						Hispanic Subjects
Group	#	Mean Age	% Male	% Hispanic	Mean Family Income	#	Mean Age	% Male	Mean Family Income
Intervention	538	39.3 years	50.2%	24.4%	$42,858	278	39.4 years	21.8%	$34,556
Control	348	44.1 years	56.9%	34.1%	$43,072	83	40.3 years	44.4%	$39,337
Total	886					361

Some of the 886 subjects identified as drinking excessively had to be excluded from the study. A total of 56 were determined to be dependent, and were excluded because the analysis focused only on the at-risk population. Some at-risk drinkers in the intervention clinics were identified in the database as not having received a brief intervention. These 229 (24.0%) subjects were excluded from the analysis as well. Anecdotal information indicated that, for some subjects, the report of the intervention was placed in the patient's chart rather than submitted to the University of Connecticut, thus preventing the intervention from being recorded in the database. Other logistical issues also could account for some of those without evidence of an intervention (eg, a breakdown in communication, the provider was too busy). A total of 601 subjects of the original 886 were eligible for inclusion in the study. Of these, 426 were successfully linked to the New Mexico drivers license database by DGR.

Three covariates were included in the regression analysis: age, sex, and smoking. These variables were selected because they affect drinking behaviors.^19,20 The inclusion of these variables in the model removes any influence on the analysis of treatment and ethnicity resulting from an imbalance produced by the cluster randomization; the variables are of interest on their own as well (Table 2).

Table 2.

Eligible Subjects for the DWI Citation Study

Treatment	Total At-risk	Audit-C<14	Intervention	Totals	Linked	# Citations
Intervention	548	509	280	280	211	8 (3.8%)
Control	338	321	0	321	215	14 (6.5%)
Total	886	830	280	601	426

AUDIT-C, Alcohol Use Disorders Identification Test; DWI, driving while intoxicated.

Results

An analysis addressing the time to first DWI citation is presented. Two approaches have been taken in the analysis. First, Kaplan-Meier survival curves were calculated to obtain a visual picture of the effectiveness and sustainability of the brief intervention.²¹ However, the Kaplan-Meier curves do not indicate the influence of age, sex, and smoking. A more detailed analysis using Cox proportional hazards regression allowed the inclusion of the covariates of age, sex, and smoking as well as the testing of the effectiveness of the intervention for statistical significance.

Kaplan-Meier survival curves

Kaplan-Meier survival curves show the probability of not receiving a DWI citation (survival) as a function of time. The survival curves for the brief intervention and control groups are presented in Figure 2. It can be seen that there is a lasting effect from the brief intervention even up to 5 years after the intervention, as shown by the higher survival probability (or greater likelihood of not receiving a DWI citation) for the brief intervention group at 5 years compared to the control group.

FIG. 2.

Survival curve—all cohorts.

The survival curves also were developed for the Hispanic cohort (Fig. 3). The probability of survival (not getting a citation) at 5 years was 96% for the brief intervention group compared to 77% for the control group. The probability of intervention group Hispanics not getting a DWI citation is consistent with the probability of not getting a citation for the total intervention group (96%; Fig. 2).

FIG. 3.

Survival curve—Hispanic cohort.

Cox proportional hazards regression

A Cox proportional hazards regression²² was used to compare time to a first DWI citation for the intervention vs. control groups, and also for the Hispanic vs. non-Hispanic white cohorts. The hazard function statistically tests the probability of a citation as a function of time. Hazard functions frequently are used to determine the effectiveness of various factors on electronic and mechanical components that have “wear-out.” The corollary in this study is to determine the sustainability of the SBI by comparing the intervention subjects to those in the control group across a period of time, in this case, 5 years. The hazards regression analysis also allowed the inclusion of the 3 covariates (age, sex, and smoking) in addition to the study variables.

Two analyses of the data were conducted using Cox regression. The first was to test the assumption of proportional hazards, and the second was to fit a proportional hazards regression model. The test for proportional hazards had a P value of 0.19, so the assumption of proportional hazards was not rejected, supporting the use of the Cox proportional hazards regression analysis.

The result of the proportional hazards regression analysis is presented in Table 3. We modeled the probability of subsequent citation=1. The 5-year sustained effectiveness of the intervention as seen in Figure 2 is clearly supported because the brief intervention group had a significantly smaller hazard function, with the hazard ratio indicating that the usual care (control) group is 3.38 times more likely to receive a DWI citation than the intervention group. Also, as seen for the Hispanic cohort in Figure 3, Hispanics have a hazards ratio of 5.04 (ie, a 5-fold increase in the risk of a DWI citation) compared to non-Hispanic whites. Age is a significant variable with the risk of receiving a DWI citation decreasing by a factor of 0.5 for each decade. Likewise, smoking is a significant variable, with smokers being twice as likely to receive a DWI citation. Sex, however, was not a significant explanatory variable.

Table 3.

Hazard Ratios (HR) for Subsequent Citation

Variable	P	HR	95% CI
SBI	–	1.00	-ref-
Usual care	0.0079	3.38	1.38–8.32
Hispanic vs. NHW	0.0008	5.04	1.96–12.95
Age	0.0012	0.51	0.34–0.77
Male vs. remale	0.095	2.17	0.87–5.26
Tobacco: Users vs. non	0.023	1.99	1.10–3.61

CI, confidence interval; NHW, non-Hispanic white; SBI, screening and brief intervention.

Discussion and Conclusion

A total of 426 subjects from the New Mexico cohort of the Cutting Back study who exhibited at-risk drinking behaviors were followed for 5 years after completing the HAS to ascertain the effectiveness of SBI on reducing DWI citations. Of this New Mexico cohort, 211 subjects received a brochure and a brief intervention from either a nurse specialist, a mid-level provider, or a physician and 215 in the control group received usual care during the original study conducted in 1998–1999. The purpose of the follow-up study reported herein was to examine whether the intervention's initial positive impact on drinking patterns was sustained over the following 5 years, as reflected in the rate of DWI citations.

Two different analyses were performed: a Kaplan-Meier survival curve analysis and a Cox proportional hazards regression. In both analyses, the effectiveness of the brief intervention was seen to be sustained for the 5-year period of study. The Cox regression showed that the effect of the intervention was to reduce the risk of a DWI citation by 3.38 (P<0.0079); that is, the no intervention population had a 3.38 times higher risk of experiencing a DWI citation in the 5 years following the original survey than the brief intervention population. In addition, Hispanics had a 5 times higher risk than did non-Hispanic whites (5.04, P=0.0008); the risk decreases by a factor of 0.51 for each decade of advancing age (P=0.0012) and smokers had twice the risk compared to nonsmokers (1.99, P=0.0095). Although sex was not statistically significant, males were estimated to have an increased risk (2.17, P=0.095). In addition, although the entire Hispanic cohort had a 5 times elevated risk of receiving a DWI citation, the Hispanic intervention group had a DWI risk much lower than their Hispanic control group counterparts, and this reduced risk was, in fact, comparable to that of the non-Hispanic white intervention group. This dramatic and long-lasting reduction in risk for the Hispanic population associated with SBI shows a major positive potential to redress the disparities in at-risk drinking and its negative consequences for those of Hispanic ethnicity.

The study findings are consistent with other studies. The sustainability of the intervention for 5 years is consistent with the Fleming et al⁴ study, which documented a reduction in DWI citations for up to 48 months. However, in the Fleming study the intervention involved 3 additional follow-up therapy sessions; in the current study the intervention involved a single, very brief SBI. The favorable impact of the intervention for the Hispanic cohort is also observed in Hittma et al⁹ and Arroyo et al.²³ The role of age and sex is previously noted in Andreasen et al²⁵ and Reed et al.²⁶

With approximately 10,000 DWI related fatal crashes per year in the United States,¹ the 3.38-fold reduction in DWI citations and the persistence of the intervention shown in this article demonstrated a significant benefit to society. However, the potential impact of SBI on traffic safety is far greater than this decrease in DWI citations alone. The risk of being in a fatal crash while alcohol impaired rises far faster than a level proportionate to the blood alcohol content (BAC). A driver with a BAC between 0.05 and 0.09 has a 9-fold increased risk of a fatal crash compared to a driver with a BAC of zero. This compares to a 300–600-fold increase for a driver with a BAC ≥0.15.²⁴ The purpose of SBI is not to make abstainers of at-risk drinkers, but rather to reduce their consumption to an “appropriate” level. Reducing at-risk drinking to a BAC of 0.08, which is the legal limit in most states, would represent a 30- to 60-fold reduction in fatal crashes. This level of reduction in the approximately 10,000 fatal crashes per year would represent a monumental savings in human lives, not to mention the major decrease in economic cost and human suffering resulting from the crashes. Given the reasonable time and cost of administering SBI, it is imperative that practitioners seriously evaluate implementing SBI with their staff. The present study reinforces this result and shows the sustainability of the intervention.

The results of this study could be interpreted that there is no wear-out over time for the effectiveness of SBI. Although the sustainability of SBI shown by this analysis is impressive, it is not the intent of this article to recommend that the standard SBI practice of annual “booster shots” be suspended. It is recommended that screening be conducted annually, especially with young subjects and subjects with high AUDIT scores.¹⁷

The present study extends our understanding of the sustainability of the impact of a specific version of SBI in which there was only 1 brief intervention without subsequent behavioral health therapy. The screening identifies patients likely to have an alcohol misuse problem, and the brief intervention is an inexpensive measure to mitigate that risk. The requirement of additional therapy would involve greater expense, and is likely to be limited by a lack of patient follow-through in attending the additional therapy sessions.

This study has several limitations. DWI citations involve all types of substance abuse, but this study focused on at-risk alcohol consumption. The HAS specifically focused on alcohol and subjects who scored positive on their HAS were classified as at-risk alcohol drinkers. Consequently, the findings of this report are limited to alcohol consumption and DWI citations. It is also possible that some patients may have had additional reinforcement of the brief intervention at subsequent visits with their providers.

Footnotes

Author Disclosure Statement

Drs. Davis, Beaton, and Gunter, Ms. Von Worley, and Mr. Parsons disclosed no conflicts of interest.

This research was supported by National Highway Traffic Safety Administration contract DTNH22-09-R-00300.

Acknowledgments

The authors would like to acknowledge the National Highway Traffic Safety Administration for its support of this research. The authors would like to acknowledge the assistance given by the University of New Mexico Division of Government Research, especially Keith Smith for his programming support.

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