Recent substance intake and drug influence among patients admitted to acute psychiatric wards : A cross-sectional study of toxicological findings, physician assessment and patient self-report in two Norwegian hospitals

Abstract

Background: Patients presenting for emergency psychiatric evaluation have a high prevalence of combined medical and psychiatric illness and psychoactive substance use. This comorbidity causes differential diagnostic challenges and deserves careful attention. Detection of recent substance intake, which may be required for appropriate diagnosis and intervention, can be based upon clinical assessment, patients’ self-report or toxicological analyses. There is, however, no consensus on how this assessment should be performed, and the utility of laboratory analyses has not been widely evaluated. Also, estimates of psychoactive substance use among acutely admitted psychiatric patients vary among studies, and few have used comprehensive laboratory methods.<br><br>

Objectives: The first main objective was to identify the rates of psychoactive substance use and drug influence among patients admitted to acute psychiatric wards, by using chromatography-based analyses of blood and urine. The second objective was to investigate associations between substance use and various clinical variables, and the third was to compare physician assessment and on-site urine testing with the results of comprehensive toxicological analyses.<br><br>

Methods: A cross-sectional and laboratory-based pilot study was conducted in 2003 in Oslo, Norway. The study sample comprised 100 acute psychiatric admissions (86% of all consecutive admissions in the project period). Blood and urine samples were collected as soon as possible after admission and extensively analyzed for alcohol, medicinal and illegal drugs, and drug influence at the time of admission was estimated on the basis of blood drug concentrations. The main study was conducted in 2006/2007, in two psychiatric departments situated in Oslo and Arendal, Norway. The study sample comprised 309 consecutive admissions in Oslo (88% of all) and 47 (42%) in Arendal. Blood and urine samples were collected and analyzed for alcohol, medicinal and illegal drugs, and a routine on-site urine screening test was performed in 92 of the cases. At admission, the physician on call performed an overall judgment of recent drug intake and of current drug influence. Psychotic symptoms were assessed with the positive subscale of the Positive and Negative Syndrome Scale. Patient self-report questionnaires included the Alcohol and Drug Use Disorder Identification Tests. Both patients and physicians were asked if they thought that the admission was related to substance use, and patients were also asked if they needed professional help for substance use. Sociodemographic variables, clinical characteristics and medication history were obtained through the review of medical records.<br><br>

Results: In the pilot study, psychoactive substances were detected in 63% of the 100 admissions, medicinal drugs in 47%, alcohol in 8% and illegal drugs in 36%. On the basis of blood drug concentrations, drug influence was estimated in 26% of the patients. In the main study, similar rates were found: Substances were detected in 63% of the 298 admissions, medicinal drugs in 46%, alcohol in 12% and illegal drugs in 28%. A total of 20 different substances were identified, with up to 10 in a single patient. Nonprescribed use of medicinal drugs was found for 36% of patients. Patients using alcohol had a high suicidal risk score at admission and the shortest length of stay (median one day). Use of illegal drugs was associated with psychotic symptoms and readmission. Self-report questionnaires indicated harmful use of alcohol for half of the patients and of other substances for one-third. A need for professional help for substance use was reported by one-third of patients. When comparing clinical and laboratory data, our findings indicated clinical under-detection of recent substance intake. On-site urine testing identified substance use that was not recognized by the physician’s initial assessment, although specificity for cannabis and benzodiazepines was low. Finally, patients were judged by the physician as being under the influence of drugs and/or alcohol in 28% of the cases. The clinical assessment of drug influence showed a moderate positive relationship with the blood drug concentration scores, and also to symptoms of hyperactivity/agitation and to the detection of alcohol, cannabis and amphetamines.<br><br>

Conclusion: Our findings demonstrate the major impact of both recent and long-term substance use. Given the high rates of substance use and the important clinical associations, drug screening seems warranted in acute psychiatric settings. Chromatographic urine analyses should be considered for routine screening, and clinical staff using on-site urine screening tests should be aware of their inaccuracy. Also, interventions designed for substance-using patients should be developed and integrated.