Prevalence of Drinking Within Low-Risk Guidelines During the First 2 Years After Inpatient Rehabilitation for Moderate or Severe Traumatic Brain Injury

The Study

The purpose of this study is to determine the typical level of alcohol drinking reported by individuals with TBI. National Institute on Alcohol Abuse and Alcoholism (NIAAA) guidelines define “low-risk drinking” as no more than 4 drinks per day (and limit of 14 drinks per week) for men or 3 drinks per day (and limit of 7 drinks per week) for women. Many studies have found that heavy drinking after severe TBI puts individuals at increased risk for suicide, seizures, and early death. However, research has been limited or unclear about the safety or harm for low-risk drinking. This lack of information may result in patients and families getting inconsistent information from providers, and they may then form their own conclusions as to how much alcohol is safe or too much. The sample of participants in this study included 6348 adults (18 years or older) with moderate or severe TBI (injured October 2006-May 2016) who received inpatient rehabilitation at a civilian TBI Model Systems center. Participants were asked questions about how much alcohol they drank before injury and at 1 and 2 years after injury. Based on their answers, each person was placed into one of the NIAAA alcohol use risk groups: non-drinker (0 drinks); low-risk drinking (4 drinks per day and 14 drinks per week for men, 3 drinks per day and 7 drinks per week for women); at-risk (drinking more than daily or weekly limits, but not both); or high-risk (drinking more than both daily and weekly limits).

More than one-third of persons with TBI were drinking one year after injury and 43% were drinking at two years after injury. About half of those drinking prior to injury reported no drinking of alcohol at year 1 following injury. However, drinking increased with time. Regardless of drinking level before injury, if people drank alcohol at 1 or 2 years following injury, they were likely to consume alcohol at levels that are considered low risk in healthy people. The findings highlight the importance of future research to determine if lower levels of drinking present unique risks for persons with TBI.

Who may be affected by these findings? Individuals with TBI, family members, caregivers.

Caveats: This study used self-report data and this may limit the results and interpretations. The TBIMS did not begin assessing binge drinking using NIAAA-recommended sex-specific cut-points until 2017. The authors noted that some women in this study may be coded as low-risk when they may have met the updated definition for female-specific binge drinking (moving them into a higher risk level).

Bottom Line: This study found that individuals with TBI mostly reported drinking alcohol within the low-risk category and increased their drinking over time. Additional studies are needed to assess if “low-risk” or limited drinking will translate to low risk for harmful outcomes following TBI.