A Net to Catch You Post-detox

There are a number of factors contributing to readmission within a year of completing detoxification, with engagement in follow-up care being a particularly important one.  Other factors include the network of referrals of the treatment center, prior treatment (vs being naive to treatment), heroin as the primary substance, and racial disparities.


There is not sufficient integration of detoxification (detox) treatment programs with outpatient or step-down substance use disorder treatment programs.  Only 23% of detox admissions result in transitions to substance use disorder treatment, which may in part underlie the finding that one third of patients received two or more detox treatments within a six-month period. The patient-level factors which result in more detox readmissions are the preferred substances of use, residential instability, older age, unemployment, being single and fee-for-service Medicaid plans. The program-level factors leading to more readmissions are larger program size, decreased proximity between detox and outpatient treatment facilities, and decreased discharge planning.  This study looks at a system-level factor, namely the role of inter-organizational networks in either decreasing or increasing the probability of readmission to a detox program within a year of discharge from such a program.


Authors analyzed data from the California Outcomes Measurement System (CalOMS). This data set, reported to the federal government, collects information on all admissions and discharges for all patients of publically-funded alcohol and other drug treatment services in California.


The information collected includes alcohol and drug use, criminal justice involvement, employment and education, family and social supports, physical and psychological health and includes two measures of substance use severity (10 items from the Addiction Services Index and the Drug Abuse Reporting Program).  The data was collected from 56 counties in California from July 2008 through June 2009.   The study focuses on the 18,278 patients who were admitted to one of the 57 residential detox programs (in 32 counties) during that year period and followed their readmissions for a further year.

The network analysis tracked all patient transfers (within 14 days of discharge) across all levels of substance use treatment (residential, outpatient, methadone programs, drug-free programs).  Transfers can flow in any direction between all program types.  Only the number of ties between different programs was analyzed, not the number of patients transferred.  The dependent variable was readmission to one or more detox programs (either residential or outpatient) within a year after discharge from the initial detox admission.  The independent variable is an efficiency score that calculates the non-redundant interconnectedness of the different treatment programs.

A higher efficiency score is attained when a center has transfers to a treatment program outside of the group of centers that already share transfers – indicative of a more robust network.  The hypothesis being tested in this study is that patients served by detox programs with greater network efficiency would have lower odds of readmission to detox.


1. Most patients leave detox without follow-up care:  Of the 18,000 patients who had inpatient detox, 50% were discharged with no entry into a different treatment setting within two weeks (24% were transferred to another detox, 17% to residential and 9% to outpatient treatment).

Patient transfers from Residential Detox

Distribution of patient transfers from Residential Detox Programs, CalOMS 2008–2009 (N = 18,278).
SOURCE: Spear, 2014


2. Patients have many treatment episodes in a given year:  Interestingly, the 150,955 patients who accessed detox or treatment services had a total of 440, 496 admissions (on average, 4 treatment admissions per patient per year at any level of substance use disorder treatment).

3. Having many connections to other treatment programs outside of one’s immediate treatment network results in lower rates of detox readmission: For every 10-point increase in efficiency (a measure on non-redundant interconnectedness with other treatment programs) they found the odds of detox readmission decreases by 18%.

4. Continuity of Care reduces detox admission: Transitioning from detox to another substance use treatment within 2 weeks had 56% lower odds of detox readmission.

5. Many individual factors predisposed patients to detox readmission:



In addition to providing further data on the characteristics predisposing individuals to repeat detox admissions within a single year, this study suggests that having higher levels of referrals outside of a facility’s immediate treatment network leads to decreased detox readmissions (a sign of treatment failure).  There are very few studies looking at inter-organizational networks in substance use disorder treatment.  Though this study focused on the effect of network efficiency of treatment centers on detox readmission, it also highlights the importance of having follow-up substance use treatment lined up within two weeks of discharge on reducing detox readmissions.

  1. Although the data is drawn from 150,000 patients, since this is limited to California, it only looks at 48 detox centers, thus the network efficiency results are weaker than the patient-level data analyzed (their analysis was done at two levels, the patient and the detox program).
  2. The effect of network efficiency after controlling for patient-level factors and continuity of care is small (odds ratio 95% confidence interval is 0.97-0.99)
  3. Given the large effect of setting up continuity of care at the time of detox discharge, and that continuity of care is related to the referral network, the effect of network efficiency on detox readmissions may be in fact mediated by continuity of care
  4. The data was drawn only from treatment centers that received some amount of public funding so does not represent the full network of substance use treatment services. In addition, transfers to mutual help organizations or charitable organizations that are not formal treatment centers would not be captured, thus overestimating the number of patients without follow-up care.


  • For individuals & families seeking recovery: Finding detox centers that have broad referral networks (outside of their immediate system of care) may result in lower detox readmissions.  Having continuity of care set up upon discharge from a detox facility significantly decreases the likelihood of having a detox readmission within that year.
  • For scientists: This study highlights the paucity of research being done on networks of care as predictors of substance use treatment success.  Network theory analysis was successfully applied to the California treatment centers
  • For policy makers: Given the number of Federal and State-sponsored initiatives for substance use treatment, increasing the richness of referral networks outside of the immediate system of care will likely improve outcomes.
  • For treatment professionals and treatment systems: Ensuring continuity of care upon detox discharge is one important factor with a large effect on preventing a detox readmission within the subsequent year.


Spear, S. E. (2014). Reducing readmissions to detoxification: An interorganizational network perspective. Drug & Alcohol Dependence137, 76-82.