Predictors of Readmission Following Outpatient Treatment for Alcohol Use Disorder

Emmanuel Mangkornkaew Hansen; Anna Mejldal; Anette Søgaard Nielsen


Alcohol Alcohol. 2020;55(3):291-298. 

In This Article

Abstract and Introduction


Aims: To identify predictors of readmission to outpatient treatment for alcohol use disorder (AUD) with a view to identifying underlying mechanisms for preventing relapse.

Methods: A consecutive clinical cohort of 2130 AUD outpatients treated between 1 January 2006 and 1 June 2016 was studied. Data were collected by means of the Addiction Severity Index upon treatment entry and at discharge. Outcome measures were readmission to outpatient treatment and time to readmission. Potential predictors were tested for significance using Cox Proportional Hazards multivariate analysis.

Results: A total of 22% were readmitted during the follow-up time. Patients readmitted within 1 year of treatment conclusion differed significantly from those not readmitted on age, cohabitation status and completion status of index treatment. Significant predictors of readmission during follow-up time were younger age (hazard ratio (HR) = 0.99, 95% confidence interval (CI), 0.98–1.00), history of psychiatric illness (HR = 1.24, 95% CI, 1.02–1.50), drop-out from index treatment (HR = 1.41, 95% CI, 1.15–1.72) and length of index treatment (HR = 1.02, 95% CI, 1.00–1.04).

Conclusion: Premature drop-out from treatment, a history of psychiatric illness, younger age and longer treatment episodes appear to be the most important predictors of readmission.


Most patients with alcohol use disorder (AUD) are treated in outpatient clinics (National Institute of Health and Care Excellence (NICE), 2011) but high relapse rates are a significant challenge. This has led to the suggestion that remission from AUD should not be regarded as a binary state of being either drinking or abstaining (Witkiewitz and Marlatt, 2007). It has been reported that only 24% of patients remain abstinent a year after completing formal treatment (Miller et al., 2001). Predictors of relapse have been found to be female gender, having a history of prior treatment for AUD, having a history of prior psychiatric treatment (Soyka and Schmidt, 2009), shorter education, as well as a higher frequency of mood disorders and medical conditions (Durazzo and Meyerhoff, 2017), when relapse is defined as not having achieved total abstinence following outpatient treatment for AUD. The majority of patients with AUD thus experience a chronic relapsing–remitting course (Witkiewitz and Marlatt, 2007), if successful treatment outcome is defined as complete abstinence. If relapse is defined as problem drinking following outpatient treatment for AUD, the predictors for relapse have been found to be higher educational level, problem drinking at treatment initiation, a treatment goal of controlled drinking (when compared to a goal of abstinence) and having a history of prior AUD treatment (Haug and Schaub, 2016).

Individual definitions of treatment goal can complicate an unambiguous definition of relapse, since the treatment goal of patients seeking AUD treatment in outpatient clinics can vary from total abstinence to controlled drinking (Haug and Schaub, 2016). Therefore, when evaluating the efficiency of outpatient AUD treatment programs, the use of total abstinence as an outcome measure is problematic since varying treatment goals are present. Instead outcome measures such as days with heavy drinking, defined as consumption of certain levels of alcohol in a 30-day period, have been used to define relapse (Soyka and Schmidt, 2009; Manning et al., 2013; Mellentin et al., 2018), yet the definition of controlled drinking as a successful treatment goal may vary between patients and misestimations of alcohol quantities among study participants have been shown to result in overestimations of treatment efficiency and underestimation of relapse (Kirouac et al., 2019).

An alternative way of defining relapse is to define it as readmission to treatment. Independently of treatment goal and definition of relapse as exceeding some specific amount of alcohol, readmission to treatment may be seen as an indicator that the patient has (again) reached a point, where he or she can no longer control alcohol intake or fears losing control. As an outcome measure, it has the advantage of not being reliant on self-reported data.

Furthermore, readmission as an outcome measure of treatment efficiency is highly relevant from an institutional and financial perspective, as recurrent patients add to the workload of the outpatient institutions offering treatment for AUD.

Readmission is often used as an outcome measure of detoxification treatment efficiency (Siegel et al., 1984; Ponzer et al., 2002; Running Bear et al., 2014; Yedlapati and Stewart, 2018), of inpatient care (Ahacic et al., 2011; Müller et al., 2016), and a very few studies have examined readmission rates following outpatient substance abuse treatment (Luchansky et al., 2000). To our knowledge, however, none have studied a population consisting exclusively of patients seeking outpatient treatment for AUD.

In studies of readmission to inpatient alcohol detoxification, predictors for readmission were having a history of prior treatment (Siegel et al., 1984; Ponzer et al., 2002), being female, having psychiatric comorbidity, treatment discharge against medical advice (Yedlapati and Stewart, 2018), having more severe alcohol problems (Ponzer et al., 2002), lower overall levels of social, psychological and occupational functioning (Running Bear et al., 2014) and shorter treatment duration (Siegel et al., 1984).

Detoxification is, however, not sufficient treatment for AUD, and typically only serves as the first step in long-term treatment (NICE, 2011). Patients entering post-detoxification aftercare services have been shown to have lower rates of readmission to detoxification (Siegel et al., 1984). This suggests that different factors may be associated with readmission to long-term outpatient AUD treatment compared to detoxification treatment.

Identifying predictors of readmission to AUD outpatient treatment is an important step in identifying underlying mechanisms and preventing relapse leading to these readmissions. Knowing at treatment start which patients are at increased risk of being readmitted may also aid clinicians in ensuring that patients receive treatment that matches their needs.

Therefore, this study aimed to identify predictors of readmission to outpatient AUD treatment in an outpatient alcohol treatment clinic.