Hazardous Drinkers and Drug Users in HMO Primary Care: Prevalence, Medical Conditions, and Costs Jennifer R. Mertens, Constance Weisner, G. Thomas Ray, Bruce Fireman, and Kevin Walsh Background: There exists substantial evidence that individuals with alcohol and drug disorders have heightened comorbidities and health care costs. However, little is known about the larger population of “hazardous” drinkers (those whose consumption increases their “risk of physical and psychological harm”) and drug users. Methods: A sample of 1,419 patients from HMO primary care clinics was screened for hazardous drinking and drug use. Health plan databases were used to examine medical conditions and health care costs of hazardous drinkers and drug users in the year prior to screening, in comparison to 13,347 patients from the same clinics, excluding those screened. Results: We found a prevalence of 7.5% for hazardous drinking and 3.2% for drug use in primary care (10% had at least one of the two problems). Hazardous drinkers and drug users had heightened prevalences for eight medical conditions, including costly conditions such as injury and hypertension, and psychiatric conditions. Medical costs for the year examined were not higher, except for those who also had psychiatric conditions. Conclusions: The prevalence of hazardous drinking and drug use was similar to hypertension and diabetes. Hazardous drinkers and drug users’ heightened medical conditions, especially those related to alcohol and drug abuse, indicate that screening and brief intervention at this lower threshold of hazardous drinking and drug use will detect individuals with health risks sooner. Optimal treatment and prevention of some medical disorders may require identification and intervention of underlying hazardous alcohol or drug use. Key Words: Hazardous Drinkers, Screening, Medical Comorbidities, Primary Care. M EDICINE IS INCREASINGLY focusing on “haz- ardous” drinking— defined by WHO as “alcohol consumption which confers the risk of physical and/or psy- chological harm” (Saunders et al., 1993). The U.S. Preven- tive Services Task force recommends screening and inter- vention to reduce “risky/hazardous” drinking in primary care (PC) settings (U.S. Preventive Services Task Force, 2004). Similarly, a DHHS consensus panel recommended periodic screening for drug use in PC (Levin et al., 1998). Compared to individuals meeting dependence criteria, haz- ardous drinkers and drug users (HDDUs) are less likely to be identified in family, work, or legal settings. Screening provides an opportunity to intervene, prevent worsening of problems, and improve overall health (Edmunds et al., 1997; Institute of Medicine, 1990). Other studies have found screening and intervention of hazardous drinking to be cost-effective because it reduces medical costs (Fleming et al., 2002). Little is known about the comorbidities of individuals with less severe alcohol and drug problems. Alcohol and drug abuse are associated with medical and psychiatric morbidity, including traumatic injuries, hypertension, HIV, coronary artery disease, hepatitis, and psychiatric disorders (Chou et al., 1996; Mertens et al., 2003; National Institute on Alcohol Abuse and Alcoholism, 2000; Piette et al., 1998; Sikkink and Fleming, 1992; Stein, 1999), but research has focused on populations with severe disorders. Chemical dependency patients have higher medical costs (Blose and Holder, 1991; Holder and Blose, 1986; Holder and Blose, 1991; Parthasarathy et al., 2001), partly because they use more inpatient and emergency room (ER) services (Parthasarathy et al., 2003; Parthasarathy et al., 2001). However, many costs occur in the few months before treat- ment, perhaps representing medical crises which galvanize patients to enter treatment (Parthasarathy et al., 2003; Parthasarathy et al., 2001). One study compared medical costs of hazardous drinkers to other drinkers and found higher costs for male hazardous drinkers-only (Polen et al., 2001). In another study, hazardous drinkers were at greater Division of Research, Kaiser Permanente Medical Care Program (JM, CW, GTR, BF), Oakland, CA; Department of Psychiatry and Mental Health (JM), University of Cape Town, South Africa; University of California, San Fran- cisco, Department of Psychiatry (CW), San Francisco, CA; The Permanente Medical Group (KW), Sacramento, CA Received for publication December 9, 2004; accepted March 28, 2005. Supported by the Robert Wood Johnson Foundation and the National Institute on Drug Abuse (R01 DA10572). Reprint requests: Jennifer Mertens, MA, Kaiser Permanente Division of Research, 2000 Broadway, 3 rd Floor, Oakland, CA 94612; Fax: 510 – 891– 3606, E-mail: Jennifer.Mertens@kp.org. Copyright © 2005 by the Research Society on Alcoholism. DOI: 10.1097/01.ALC.0000167958.68586.3D 0145-6008/05/2906-0989$03.00/0 ALCOHOLISM:CLINICAL AND EXPERIMENTAL RESEARCH Vol. 29, No. 6 June 2005 Alcohol Clin Exp Res, Vol 29, No 6, 2005: pp 989–998 989