Changes in substance use during outpatient treatment for substance use disorders: a prospective Norwegian cohort study from 2016 to 2020

Abstract

Background Continuous use of amphetamines, alcohol, benzodiazepines, cannabis, cocaine, or opioids contributes to health impairments, increased morbidity, and overdose deaths among patients with substance use disorders (SUDs). This study evaluates the impact of inpatient detoxification, injecting substance use, age, and gender on substance use over time among patients undergoing outpatient SUD treatment. Methods We used data from a cohort of SUD patients in Norway obtained from health assessments of self-reported substance use and sociodemographic and clinical factors. A total of 881 substance use measurements, including substances and frequency of use, were assessed for 708 SUD patients in 2016–2020. Of those, 171 patients provided two or more substance use measurements. The total substance use was calculated, creating a substance use severity index (SUSI), ranging from zero (no use) to one (daily use of all substances). We defined baseline as the first substance use measurement when the measurements were listed chronologically. Time was defined as years from baseline. We used a linear mixed model to analyze the SUSI at baseline and over time, and its associations with inpatient detoxification, injecting substance use, gender, and age, presented with coefficients and 95% confidence intervals (CI). Results No longitudinal changes in the SUSI were found compared with baseline (change in SUSI (cSUSI): 0.04, 95% CI: − 0.05;0.13, p = 0.397). Likewise, “inpatient detoxification” was not associated with changes in the SUSI compared with “no inpatient detoxification” (cSUSI: 0.00, 95% CI: − 0.04;0.04, p = 0.952). However, injecting substances were associated with a higher SUSI than not injecting substances at baseline (difference in SUSI: 0.19, 95% CI: 0.16;0.21, p = < 0.001), and starting to inject substances was associated with increasing SUSI over time compared with not starting to inject substances (cSUSI: 0.11, 95% CI: 0.07;0.15, p = < 0.001). Gender was not significantly associated with changes in the SUSI (cSUSI: − 0.04, 95% CI: − 0.07;0.00, p = 0.052), while patients over 60 years of age had a lower SUSI than those under the age of 30 at baseline (difference in SUSI: − 0.08, 95% CI: − 0.14;− 0.01, p = 0.018), with no change over time (cSUSI: − 0.05, 95% CI: − 0.16;0.05, p = 0.297). Conclusion The present study demonstrates that inpatient detoxification was not associated with substance use changes over time for patients undergoing outpatient SUD treatment. Otherwise, injecting substance use was a particular risk factor for a high level of substance use. Future research needs to evaluate the impact of other treatment approaches on substance use, ideally in randomized controlled trials.

Liver stiffness and associated risk factors among people with a history of injecting drugs: a prospective cohort study

“…We did not adjust HDL cholesterol or HbA1c values for the use of lipid-lowering drugs or antidiabetic drugs, as this information was not provided by the participants. Except for HCV infection status, due to relatively stable exposure variable values over time [ 40 ], all these variables including age group were kept constant at the baseline level in predicting the level and changes in the outcome variable. Interactions between these variables and time were added to the model to investigate whether exposure variables predicted changes in outcome.…”

Vitamin B12 Levels, Substance Use Patterns and Clinical Characteristics among People with Severe Substance Use Disorders: A Cohort Study from Western Norway

“…Generalized additive models and plots were generated to visualize the nonlinear associations of substance use severity with serum vitamin B12 concentration, adjusted for gender and age. To do this, a substance use severity index was generated based on the type, frequency and number of substances used (for details see Supplementary Table S1) [23]. A linear mixed model regression was performed in order to estimate associations of clinical and sociodemographic factors with serum vitamin B12 concentration at baseline, as well as the time interactions of these associations.…”

Prevalence and correlates of suicide attempts in high-risk populations: a cross-sectional study among patients receiving opioid agonist therapy in Norway

“…Patients receiving OAT usually have a history of hard injecting opioid use, often initiated in adolescence or early adulthood [23]. Additionally, polysubstance use, including substances used alongside OAT opioids, is common among OAT patients, with a prevalence of up to 70 % in this population [24,25]. While OAT may protect against suicide [9,10], polysubstance use is often a substantial contributor to reduced quality of life, homelessness, greater psychological distress, poorer social functioning, and mental disorder comorbidities -such as major depressive symptoms and borderline personality disorder [24,[26][27][28][29][30][31].…”