Five or more days of heavy drinking within 3 months linked with later severe alcohol use disorder
Five or more days of heavy drinking in a 3-month period predicts an increased likelihood that a person will develop a severe alcohol use disorder, according to new research from Kaiser Permanente.
The study, published in the journal Addiction, examined the self-reported drinking habits of 138,765 adult patients of Kaiser Permanente Northern California (KPNC) to determine a threshold for the number of such days that might be related to a later diagnosed drinking problem.
The resulting 5-day threshold could assist primary care physicians in identifying patients at risk, said study senior author Stacy Sterling, DrPH, MSW, co-director of the Center for Addiction and Mental Health Research at the Kaiser Permanente Division of Research.
“This study is an important scientific contribution but more importantly, it can be integrated as a tool for clinicians,” Sterling said. “Busy primary care clinicians need to differentiate between somebody who may be appropriate for brief advice about alcohol use with watchful waiting, versus somebody who might be headed for a more serious problem.”
The analysis used the definition of “heavy drinking day” recommended by the National Institute on Alcohol Abuse and Alcoholism: at least 5 drinks for healthy men up to 65 years old, or at least 4 drinks for adult women and healthy men over 65.
The researchers examined records for adults who were screened for alcohol use in KPNC primary care between 2014 and 2017 and reported at least 1 heavy drinking day in the previous 3 months. The authors then looked in those patients’ records for a new diagnosis of severe alcohol use disorder in the following year.
The analysis identified 5 or more heavy drinking days as a reliable predictive threshold for the whole group studied. The authors also identified thresholds specific to certain patient subgroups:
- For younger men and women aged 18-24, 5 or more heavy drinking days was predictive of a later problem, possibly reflecting patterns of binge drinking more common among young adults, said study lead author Verena Metz, PhD, a staff scientist with the Division of Research.
- For men aged 25-64, the threshold for a problem was 6 or more days, and for older men 7 or more days; the researchers believe the latter result may relate to older men not reducing their drinking at 65 even though the recommended number of drinks drops at that age.
- For adult women of all ages, the threshold was 4 or more heavy drinking days in 3 months.
The results are consistent with other research and clinical observations that suggest in general, women can develop an alcohol use disorder at lower consumption levels than men, Sterling said. “Men and women metabolize alcohol differently based on body composition, so it’s not surprising that the threshold for a problem is lower for women,” she said.
The threshold numbers can be useful for physicians who are evaluating patients and identifying those at risk of an alcohol use disorder, said Joseph Elson, MD, a primary care physician and assistant chief of medicine with The Permanente Medical Group (TPMG) in San Francisco. “This is one more validated tool that can be used to identify those at highest risk of progressing from unhealthy drinking habits to actual substance abuse disorder, which has a lot more potential for illness and mortality,” he said.
Tracking heavy drinking days can also be helpful for patients who want to know whether their alcohol use is heading into problem territory, said Caroline Corriveau, MD, an addiction medicine specialist with TPMG. “It can be easy for a patient to think, ‘I may have drunk more heavily this week, but I usually don’t go beyond the recommended daily or weekly limits,’” she said. “Looking back over a 3-month period for multiple heavy drinking days might help identify patterns of concern.”
Corriveau cautioned that patients should not see the 5-day threshold as suggesting fewer days are automatically safe; there could still be risk of both a use disorder and other health problems.
Predicting risk vs. diagnosing disorder
The risk threshold is separate from the criteria doctors use to diagnose a patient with alcohol use disorder, which can be mild, moderate, or severe. These criteria include several symptoms relating to how drinking impacts the patient’s ability to function in daily life, such as being unable to reduce or stop drinking, or having alcohol use interfere with work, school, or family.
The study builds on previous research by other investigators that suggested a threshold of 8 heavy drinking days over a year is predictive of a problem. Sterling noted that a shorter 3-month period would be helpful to both doctors and patients who may not precisely recall their drinking behavior from many months before.
The authors carried out a statistical analysis to test various numbers of heavy drinking days as predictive of a future severe alcohol use disorder; the optimal thresholds were selected to maximize accuracy – based on several test performance measures including sensitivity (ability to detect true positives) and specificity (ability to detect true negatives). They also wanted to design a tool that would not overburden primary care doctors with patients not truly at risk.
The results should be validated by other researchers so that the straightforward findings can be easily integrated into provider education, clinical workflows, and decision support tools, said lead author Metz. “Thresholds can efficiently help primary care physicians identify patients most in need of further assessment, referral to specialty treatment, and treatment planning for alcohol problems and associated medical conditions,” she said.
The study was funded by the National Institute on Alcohol Abuse and Alcoholism.
Additional co-authors were Vanessa Palzes, MPH, Andrea H. Kline-Simon, MA, Felicia W. Chi, MPH, and Constance Weisner, DrPH, MSW, all of the Division of Research.
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About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 600-plus staff is working on more than 450 epidemiological and health services research projects. For more information, visit divisionofresearch.kaiserpermanente.org or follow us @KPDOR.