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Comparing treatment policies with assistance from the structural nested mean model.

ABSTRACT: Treatment policies, also known as dynamic treatment regimes, are sequences of decision rules that link the observed patient history with treatment recommendations. Multiple, plausible, treatment policies are frequently constructed by researchers using expert opinion, theories, and reviews of the literature. Often these different policies represent competing approaches to managing an illness. Here, we develop an "assisted estimator" that can be used to compare the mean outcome of competing treatment policies. The term "assisted" refers to the fact estimators from the Structural Nested Mean Model, a parametric model for the causal effect of treatment at each time point, are used in the process of estimating the mean outcome. This work is motivated by our work on comparing the mean outcome of two competing treatment policies using data from the ExTENd study in alcohol dependence.

SUBMITTER: Lu X

PROVIDER: S-EPMC4789134 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature

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Comparing treatment policies with assistance from the structural nested mean model.

Lu Xi X Lynch Kevin G KG Oslin David W DW Murphy Susan S

Biometrics 20150913 1

Treatment policies, also known as dynamic treatment regimes, are sequences of decision rules that link the observed patient history with treatment recommendations. Multiple, plausible, treatment policies are frequently constructed by researchers using expert opinion, theories, and reviews of the literature. Often these different policies represent competing approaches to managing an illness. Here, we develop an "assisted estimator" that can be used to compare the mean outcome of competing treatm ...[more]

PMID: 26363892

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Project description:BackgroundInternet-based cognitive behavioural therapy (iCBT) for depression is effective when guided by a clinician, less so if unguided.QuestionWould guidance from a technician be as effective as guidance from a clinician?MethodRandomized controlled non-inferiority trial comparing three groups: Clinician-assisted vs. technician-assisted vs. delayed treatment. Community-based volunteers applied to the VirtualClinic (www.virtualclinic.org.au) research program, and 141 participants with major depressive disorder were randomized. Participants in the clinician- and technician-assisted groups received access to an iCBT program for depression comprising 6 online lessons, weekly homework assignments, and weekly supportive contact over a treatment period of 8 weeks. Participants in the clinician-assisted group also received access to a moderated online discussion forum. The main outcome measures were the Beck Depression Inventory (BDI-II) and the Patient Health QUESTIONnaire-9 Item (PHQ-9). Completion rates were high, and at post-treatment, both treatment groups reduced scores on the BDI-II (p<0.001) and PHQ-9 (p<0.001) compared to the delayed treatment group but did not differ from each other. Within group effect sizes on the BDI-II were 1.27 and 1.20 for the clinician- and technician-assisted groups respectively, and on the PHQ-9, were 1.54 and 1.60 respectively. At 4-month follow-up participants in the technician group had made further improvements and had significantly lower scores on the PHQ-9 than those in the clinician group. A total of approximately 60 minutes of clinician or technician time was required per participant during the 8-week treatment program.ConclusionsBoth clinician- and technician-assisted treatment resulted in large effect sizes and clinically significant improvements comparable to those associated with face-to-face treatment, while a delayed treatment control group did not improve. These results provide support for large scale trials to determine the clinical effectiveness and acceptability of technician-assisted iCBT programs for depression. This form of treatment has potential to increase the capacity of existing mental health services.Trial registrationAustralian New Zealand Clinical Trials Registry ACTRN12609000559213.

Project description:BackgroundInternet-based cognitive behavioural therapy (iCBT) for generalized anxiety disorder (GAD) has been shown to be effective when guided by a clinician. The present study sought to replicate this finding, and determine whether support from a technician is as effective as guidance from a clinician.MethodRandomized controlled non-inferiority trial comparing three groups: Clinician-assisted vs. technician-assisted vs. delayed treatment. Community-based volunteers applied to the VirtualClinic (www.virtualclinic.org.au) research program and 150 participants with GAD were randomized. Participants in the clinician- and technician-assisted groups received access to an iCBT program for GAD comprising six online lessons, weekly homework assignments, and weekly supportive contact over a treatment period of 10 weeks. Participants in the clinician-assisted group also received access to a moderated online discussion forum. The main outcome measures were the Penn State Worry Questionnaire (PSWQ) and the Generalized Anxiety Disorder-7 Item (GAD-7). Completion rates were high, and both treatment groups reduced scores on the PSWQ (p<0.001) and GAD-7 (p<0.001) compared to the delayed treatment group, but did not differ from each other. Within group effect sizes on the PSWQ were 1.16 and 1.07 for the clinician- and technician-assisted groups, respectively, and on the GAD-7 were 1.55 and 1.73, respectively. At 3 month follow-up participants in both treatment groups had sustained the gains made at post-treatment. Participants in the clinician-assisted group had made further gains on the PSWQ. Approximately 81 minutes of clinician time and 75 minutes of technician time were required per participant during the 10 week treatment program.ConclusionsBoth clinician- and technician-assisted treatment resulted in large effect sizes and clinically significant improvements comparable to those associated with face-to-face treatment, while a delayed treatment/control group did not improve. These results provide support for large scale trials to determine the clinical effectiveness and acceptability of technician-assisted iCBT programs for GAD. This form of treatment has potential to increase the capacity of existing mental health services.Trial registrationAustralian New Zealand Clinical Trials Registry ACTRN12609000563268.

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Comparing treatment policies with assistance from the structural nested mean model.

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Comparing treatment policies with assistance from the structural nested mean model.

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