331 research outputs found

    Comparison of machine learning clustering algorithms for detecting heterogeneity of treatment effect in acute respiratory distress syndrome: A secondary analysis of three randomised controlled trials

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    BACKGROUND: Heterogeneity in Acute Respiratory Distress Syndrome (ARDS), as a consequence of its non-specific definition, has led to a multitude of negative randomised controlled trials (RCTs). Investigators have sought to identify heterogeneity of treatment effect (HTE) in RCTs using clustering algorithms. We evaluated the proficiency of several commonly-used machine-learning algorithms to identify clusters where HTE may be detected. METHODS: Five unsupervised: Latent class analysis (LCA), K-means, partition around medoids, hierarchical, and spectral clustering; and four supervised algorithms: model-based recursive partitioning, Causal Forest (CF), and X-learner with Random Forest (XL-RF) and Bayesian Additive Regression Trees were individually applied to three prior ARDS RCTs. Clinical data and research protein biomarkers were used as partitioning variables, with the latter excluded for secondary analyses. For a clustering schema, HTE was evaluated based on the interaction term of treatment group and cluster with day-90 mortality as the dependent variable. FINDINGS: No single algorithm identified clusters with significant HTE in all three trials. LCA, XL-RF, and CF identified HTE most frequently (2/3 RCTs). Important partitioning variables in the unsupervised approaches were consistent across algorithms and RCTs. In supervised models, important partitioning variables varied between algorithms and across RCTs. In algorithms where clusters demonstrated HTE in the same trial, patients frequently interchanged clusters from treatment-benefit to treatment-harm clusters across algorithms. LCA aside, results from all other algorithms were subject to significant alteration in cluster composition and HTE with random seed change. Removing research biomarkers as partitioning variables greatly reduced the chances of detecting HTE across all algorithms. INTERPRETATION: Machine-learning algorithms were inconsistent in their abilities to identify clusters with significant HTE. Protein biomarkers were essential in identifying clusters with HTE. Investigations using machine-learning approaches to identify clusters to seek HTE require cautious interpretation. FUNDING: NIGMS R35 GM142992 (PS), NHLBI R35 HL140026 (CSC); NIGMS R01 GM123193, Department of Defense W81XWH-21-1-0009, NIA R21 AG068720, NIDA R01 DA051464 (MMC)

    A test of the DSM-5 severity specifier for bulimia nervosa in adolescents: Can we anticipate clinical treatment outcomes?

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    OBJECTIVE:This study tested clinical utility of the DSM-5 severity specifier for bulimia nervosa (BN) in predicting treatment response among adolescents (N = 110) within a randomized clinical trial of two psychosocial treatments. METHOD:Analyses grouped individuals meeting criteria for BN diagnosis by baseline severity, per DSM-5. Associations among baseline severity classification and BN behavior (i.e., binge eating and compensatory behavior) and eating disorder examination (EDE) Global scores at end-of-treatment (EOT), 6- and 12-month follow-up were examined. RESULTS:Associations between severity categories with BN symptoms were not significant at EOT, or follow-up. Test for linear trend in BN behavior was significant at EOT, F = 5.23, p = 0.02, without demonstrating a linear pattern. Relation between severity categories with EDE Global scores was significant at 6-month follow-up, F = 3.76, p = 0.01. Tests for linear trend in EDE Global scores were significant at EOT, F = 5.40, p = 0.02, and at 6 months, F = 10.73, p = 0.002, with the expected linear pattern. DISCUSSION:Findings suggest the DSM-5 BN severity specifier holds questionable utility in anticipating outpatient treatment response in adolescents with BN. The specifier may have improved ability to predict attitudinal rather than behavioral treatment outcomes

    Prospective Study of Violence Risk Reduction by a Mental Health Court

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    Although many mental health courts (MHCs) have been established to reduce criminal justice involvement of persons with mental disorders, research has not kept pace with the widespread implementation of these courts. Whereas early MHCs were restricted to persons charged with nonviolent misdemeanors, many MHCs now accept persons with more serious charges for whom ameliorating risk of violence is a greater concern. This study evaluated the relationship between MHC participation and risk of violence by using a prospective design. It was hypothesized that MHC participation would decrease the risk of violence during a one year follow-up compared with a matched comparison group.The sample included 169 jail detainees with a mental disorder who either entered an MHC (N=88) or received treatment as usual (N=81). Seventy-two percent had been charged with felonies. Participants were interviewed at baseline and during a one-year follow up, and their arrest records were reviewed. Propensity-adjusted logistic regression evaluated the relationship between MHC participation and risk of violence, controlling for potential confounders such as history of violence, demographic characteristics, baseline treatment motivation, and time at risk in the community.MHC participation was associated with reduction in risk of violence (odds ratio=.39). During follow-up, 25% of the MHC group perpetrated violence, compared with 42% of the treatment-as-usual group.MHC participation can reduce the risk of violence among justice-involved persons with mental disorders. The findings support the conclusion that the MHC model can be extended beyond persons charged with nonviolent misdemeanors in a way that enhances public safety

    An International Systematic Review of Smoking Prevalence in Addiction Treatment

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    Aims: Smoking prevalence is higher among people enrolled in addiction treatment compared with the general population, and very high rates of smoking are associated with opiate drug use and receipt of opiate replacement therapy (ORT). We assessed whether these findings are observed internationally. Methods: PubMed, PsycINFO and the Alcohol and Alcohol Problems Science Database were searched for papers reporting smoking prevalence among addiction treatment samples, published in English, from 1987 to 2013. Search terms included tobacco use, cessation and substance use disorders using and/or Boolean connectors. For 4549 papers identified, abstracts were reviewed by multiple raters; 239 abstracts met inclusion criteria and these full papers were reviewed for exclusion. Fifty-four studies, collectively comprising 37364 participants, were included. For each paper we extracted country, author, year, sample size and gender, treatment modality, primary drug treated and smoking prevalence. Results: The random-effect pooled estimate of smoking across people in addiction treatment was 84% [confidence interval (CI)=79, 88%], while the pooled estimate of smoking prevalence across matched population samples was 31% (CI=29, 33%). The difference in the pooled estimates was 52% (CI=48%, 57%, P<.0001). Smoking rates were higher in programs treating opiate use compared with alcohol use [odds ratio (OR)=2.52, CI=2.00, 3.17], and higher in ORT compared to out-patient programs (OR=1.42, CI=1.19, 1.68). Conclusions: Smoking rates among people in addiction treatment are more than double those of people with similar demographic characteristics. Smoking rates are also higher in people being treated for opiate dependence compared with people being treated for alcohol use disorder

    Expectancies regarding the interaction between smoking and substance use in alcohol-dependent smokers in early recovery.

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    The purpose of this study was to investigate expectancies regarding the interaction between cigarette smoking and use of alcohol among alcohol-dependent smokers in early recovery, using the Nicotine and Other Substances Interaction Expectancies Questionnaire (NOSIE). Participants were 162 veterans, 97% male, with a mean age of 50 years, enrolled in a clinical trial aimed at determining the efficacy of an intensive smoking cessation intervention versus usual care. At baseline, participants were assessed on measures of smoking behavior, abstinence thoughts about alcohol and tobacco use, symptoms of depression, and smoking-substance use interaction expectancies. In addition, biologically verified abstinence from tobacco and alcohol was assessed at 26 weeks. Participants reported that they expected smoking to have less of an impact on substance use than substance use has on smoking (p &lt; .001). Severity of depressive symptoms was significantly associated with the expectancy that smoking provides a way of coping with the urge to use other substances (p &lt; .01). The expectation that smoking increases substance urges/use was predictive of prospectively measured and biologically verified abstinence from smoking at 26 weeks (p &lt; .03). The results add to our knowledge of smoking-substance use interaction expectancies among alcohol-dependent smokers in early recovery and will inform the development of more effective counseling interventions for concurrent alcohol and tobacco use disorders
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