This study compared two groups of patients admitted to SUD and psychiatry wards: those admitted involuntarily (IA group) and those admitted voluntarily (VA group). Patients in the IA group were recruited from three publicly funded treatment centres in the south-eastern part of Norway. These centres are located in Kristiansand, Tønsberg, and Oslo, and they have four, four, and three beds, respectively, for patients admitted involuntarily. All patients in the VA group were from a single ward in the Kristiansand centre. The three wards are organized quite similarly. They all treat patients of both genders, but most patients were males. The patients may spend time in communal areas, but the exterior doors are locked. Most patients are allowed to leave the ward, when accompanied by a representative from the staff. Many patients received visits from friends and family. Both as a routine procedure and due to suspicion, the patients are required to undergo a urine test for drug-screenings. All wards were multidisciplinary (psychiatrists, psychologists, social workers, occupational therapists, specialized nurses, and other trained staff) and had specialized units that offered treatment for patients with primary SUD combined with mental disorders, a combination which is often observed. Treatment included assessments of somatic and mental health; diagnoses, based on a structured interview and examination, consistent with the International Classification of Diseases and Related Health Problems, 10th Revision (ICD-10); pharmacotherapy; cognitive milieu therapy; and individual motivation enhancement. The patient population was recruited mainly from urban and suburban areas.
Recruitment for the study continued consecutively from 1 January 2009 to 17 December 2011. The criteria for inclusion were: substance abuse or dependence, age ≥18 years, good understanding/speech in Norwegian language, and at least 3 weeks of hospital residence after admission. Approximately 150 decisions are made yearly in Norway concerning the involuntary admission of patients with SUD into institutions, pursuant to the Public Health Act .
Before inclusion, patients in both the IA and VA groups were in a detoxified state, verified with negative urine tests for alcohol, opioids, central stimulants (amphetamines, methamphetamines, and cocaine), benzodiazepines, and cannabis. Patients with positive urine tests spent a minimum of 14 days in detoxification to establish baseline values that were not influenced by withdrawal symptoms. Patients were excluded when they exhibited mental retardation (IQ < 70) that prevented them from understanding the questionnaires. Pregnant patients with SUD were treated in specialized wards, and were not included in this study.
We identified 103 consecutive patients that were admitted involuntarily. Among these, 15 did not meet the inclusion criteria (12 patients stayed for an insufficient time period, and 3 patients had insufficient mental capacity); 11 patients were not asked to participate, due to logistical issues. Of the 77 patients eligible for inclusion, 12 patients refused to participate. Therefore, the rate of consent to participate was 84% (65/77 patients). Due to missing scores on the Perceived Coercion Questionnaire (PCQ), two patients were not included in the final analyses. The 63 patients included in the IA group were distributed among three treatment centres: 39 in Kristiansand, 16 in Tønsberg, and 8 in Oslo. We identified 223 patients that were admitted voluntarily; 72 were excluded (69 patients stayed for insufficient time periods, and 3 patients lacked sufficient mental capacity). Of the remaining 151 eligible patients, 14 patients refused to participate. Therefore, the rate of consent in the VA group was 91% (137/151 patients). However, due to missing PCQ scores, eight patients were not included in the final analyses.
The study was approved by The Regional Committee for Research Ethics in Norway (REK 08/206d, 2008/2900, 09/2413) and by the Privacy Issues Unit, Norwegian Social Science Data Services (NSD no. 18782). Written informed consent was obtained from all study participants.
Instruments and measures
The ICD-10 was used to diagnose current SUDs, the current type and severity of psychiatric problems, and the level of functioning . All patients were interviewed with a clinical psychiatric examination, supported by the Mini International Neuropsychiatric Interview (MINI) version 2005. The MINI is a short psychiatric interview for the assessment of psychiatric disorders, which is in accordance with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition and ICD-10 classification systems . This interview has high acceptance and validity [17, 18]. Interviews were conducted by senior psychiatrists and psychologists with several years of clinical and research experience in the psychiatric assessment of patients with physical disorders. Severe SUD was indicated by the injection of illicit drugs within 6 months before admission and a high lifetime frequency of overdoses.
Sociodemographic variables were measured with the European Addiction Severity Index. This personal, structured interview was designed for both clinical and research purposes. It focuses on seven areas: medical status, employment and support status, drug and alcohol use, legal status, family history, family and social relationships, and psychiatric status . Trained and certified staff performed all European Addiction Severity Index-based interviews.
The Symptom Checklist-90-R instrument was used to evaluate the range of psychological problems and symptoms of psychopathology. This test contains 90 items, which measures nine primary symptom dimensions, and it provides an overview of a patient’s symptoms and symptom intensity. Each of the 90 items is rated on a five-point Likert-type scale, ranging from ‘not at all’ (0 points) to ‘extremely’ (4 points); higher values indicate greater symptom severity during the past week. The Global Symptom Index score was used to assess the level of general psychological distress .
The PCQ was developed specifically for patients undergoing addiction treatment. The PCQ includes six subscales (Self, Family, Legal, Finance, Health, and Work). Five out of the six subscales measure external coercion to participate in a substance-abuse treatment programme. The sixth subscale, Self, measures an internal form of perceived coercion or pressure. For example, item #1 is, ‘I feel pressure to participate in this drug/alcohol treatment programme…because I know that I’m an addict/alcoholic and that I need rehab to get off drugs/alcohol,’ and #3 is ‘I feel pressure to participate in this drug/alcohol treatment programme…because I feel horrified and ashamed of the person I have turned into’. The PCQ instrument contains 30 items that are presented in the form of statements (see Additional file 1). Respondents rate each statement with a 5-point scale (1, strongly disagree; 2, somewhat disagree; 3, neither agree nor disagree; 4, somewhat agree; 5, strongly agree). A higher score implies a greater degree of coercion perceived by the respondent . Klag et al. (2006) reported that the PCQ has acceptable divergent validity. The validity was demonstrated by a negligible relationship between the PCQ and a presumably unrelated measure (i.e., a measure of spirituality), where the overall r was 0.04 and r values for PCQ subscales were 0.03–0.10) . A previous analysis of PCQ reliability indicated that the subscales showed adequate internal consistency (Cronbach’s alpha: 0.66–0.87) and good total internal consistency (Cronbach’s alpha: 0.87) . To validate the PCQ in the new setting, we undertook an exploratory factor analysis. First, three items were removed from the PCQ, based on a pre-test of the scale and the notion that these items seemed irrelevant in a Norwegian setting (see Additional file 1). We proceeded to examine whether the remaining items yielded a factor structure similar to that of the original version and whether each item had sufficient factor loadings on its respective subscales. The analysis included principal axis and oblique rotation methods (promax). Kaiser’s eigenvalue-greater-than-one rule was used to determine the number of factors . To ensure internal validity for the present study and to obtain the most parsimonious model, problematic items were removed when they had low factor loadings (<0.4)  or did not work as intended. As a result of this analysis, we removed two items in the health subscale. One item was removed, because it represented an extra (seventh) subscale, which constituted a single item only (probably an overfactoring issue: this scale barely exceeded the eigenvalue-of-one criteria). The other item was removed, because it had a low factor loading (see Additional file 1). After these amendments, the scale factors were similar to those in the original scale, and all items had factor loadings > 0.4 on their respective subscales. Based on the PCQ scale results, we divided the patients into two groups: patients that did not perceive any form of coercion and patients that perceived some form of coercion (agreed or strongly agreed) on one or more of the subscales.
Analysis and statistical methods
Continuous variables are reported as the mean and standard deviation. Categorical variables are reported as the frequency. Independent sample t-tests, the chi-squared test, and Fisher’s exact test were used to detect statistically significant differences between groups. The threshold for statistical significance was p < 0.05. Linear regression was performed to identify factors that were associated with the PCQ score. Results are presented as β-values with 95% confidence intervals (95% CI) . Analyses were performed with SPSS 22.0 software (SPSS Inc., Chicago, IL, USA).