A transdiagnostic group exercise intervention for mental health outpatients in Germany (ImPuls): results of a pragmatic, multisite, block-randomised, phase 3 controlled trial

BACKGROUND

Globally, mental health conditions pose a substantial burden of disease. Despite the availability of evidence-based pharmacological and psychological treatments, the symptoms of a substantial subgroup of patients do not respond to these interventions, and only a minority of patients have access to them. This study aimed to assess the efficacy of ImPuls, a 6-month transdiagnostic group exercise intervention, plus treatment-as-usual, compared with treatment-as-usual alone in outpatients with various mental disorders.

METHODS

In this pragmatic, two-arm, multisite, randomised controlled trial in Germany, ten outpatient rehabilitative and medical care facilities were involved as study sites. Participants were outpatients diagnosed according to ICD-10 with one or more of the following disorders based on structured clinical interviews: moderate or severe depression, primary insomnia, post-traumatic stress disorder (PTSD), panic disorder, or agoraphobia. Participants were required to be aged between 18 years and 65 years, insured by the health insurers Allgemeine Ortskrankenkasse Baden-Württemberg or Techniker Krankenkasse, fluent in German, and without medical contraindications for exercise. Blocks of six participants were randomly allocated to ImPuls plus treatment-as-usual or treatment-as-usual alone (allocation ratio: 1:1), stratified by study site. The randomisation sequence was generated by an external data manager. The team responsible for data collection and management was masked to the randomisation sequence. The ImPuls intervention comprised evidence-based outdoor exercises lasting 30 min, and aimed at achieving at least moderate intensity. It also incorporated behavioural change techniques targeting motivational and volitional determinants of exercise behaviour. Treatment-as-usual was representative of typical outpatient health care in Germany, allowing patients access to any standard treatments. The primary outcome was global symptom severity at 6 months after randomisation, measured using self-report on the Brief Symptom Inventory (BSI-18) and analysed in the intention-to-treat sample. No individuals with lived experience of mental illness were involved in conducting the study or writing the final publication. Safety was assessed in all participants. The trial was registered with the German Clinical Trials Register (DRKS00024152) with a completion date of June 30, 2024.

FINDINGS

600 patients provided informed consent, were recruited to the study, and underwent a diagnostic interview between Jan 1, 2021, and May 31, 2022. Following this, 199 were excluded on the basis of inclusion and exclusion criteria and one withdrew consent during the baseline assessment. Of the 400 eligible participants, 284 (71%) self-identified as female, 106 (27%) self-identified as male, and nine (2%) self-identified as other. The mean age was 42·20 years (SD 13·23; range 19-65). Ethnicity data were not assessed. 287 (72%) participants met the criteria for moderate or severe depression, 81 (20%) for primary insomnia, 37 (9%) for agoraphobia, 46 (12%) for panic disorder, and 72 (18%) for PTSD. 199 participants were allocated to the intervention group of ImPuls plus treatment-as-usual and 201 to the control group of treatment-as-usual alone. 38 (19%) participants did not receive the minimum ImPuls intervention dose. ImPuls plus treatment-as-usual demonstrated superior efficacy to treatment-as-usual alone in reducing global symptom severity, with an adjusted difference on BSI-18 of 4·11 (95% CI 1·74-6·48; d=0·35 [95% CI 0·14-0·56]; p=0·0007) at 6 months. There were no significant differences in the total number of adverse events or serious adverse events between the two groups. There was one serious adverse event (male, torn ligament) related to the intervention.

INTERPRETATION

ImPuls is an efficacious transdiagnostic adjunctive treatment in outpatient mental health care. Our findings suggest that exercise therapy should be implemented in outpatient mental health care as an adjunctive transdiagnostic treatment for mental disorders such as depression, insomnia, panic disorder, agoraphobia, and PTSD. Transdiagnostic group exercise interventions might ameliorate the existing disparity in care provision between the many individuals in need of evidence-based treatment and the few who are receiving it.

FUNDING

The German Innovation Fund of the Federal Joint Committee of Germany.

Concept and study protocol of the process evaluation of a pragmatic randomized controlled trial to promote physical activity in outpatients with heterogeneous mental disorders-the ImPuls study

BACKGROUND

Evidence suggests that patients suffering from different mental disorders benefit from exercise programs combined with behavior change techniques. Based on this evidence, we have developed an exercise program (ImPuls) specifically designed to provide an additional treatment option in the outpatient mental health care system. The implementation of such complex programs into the outpatient context requires research that goes beyond the evaluation of effectiveness, and includes process evaluation. So far, process evaluation related to exercise interventions has rarely been conducted. As part of a current pragmatic randomized controlled trial evaluating ImPuls treatment effects, we are therefore carrying out comprehensive process evaluation according to the Medical Research Council (MRC) framework. The central aim of our process evaluation is to support the findings of the ongoing randomized controlled trial.

METHODS

The process evaluation follows a mixed-methods approach. We collect quantitative data via online-questionnaires from patients, exercise therapists, referring healthcare professionals and managers of outpatient rehabilitative and medical care facilities before, during, and after the intervention. In addition, documentation data as well as data from the ImPuls smartphone application are collected. Quantitative data is complemented by qualitative interviews with exercise therapists as well as a focus-group interview with managers. Treatment fidelity will be assessed through the rating of video-recorded sessions. Quantitative data analysis includes descriptive as well as mediation and moderation analyses. Qualitative data will be analyzed via qualitative content analysis.

DISCUSSION

The results of our process evaluation will complement the evaluation of effectiveness and cost-effectiveness and will, for example, provide important information about mechanisms of impact, structural prerequisites, or provider qualification that may support the decision-making process of health policy stakeholders. It might contribute to paving the way for exercise programs like ImPuls to be made successively available for patients with heterogeneous mental disorders in the German outpatient mental health care system.

TRIAL REGISTRATION

The parent clinical study was registered in the German Clinical Trials Register (ID: DRKS00024152, registered 05/02/2021, https://drks.de/search/en/trial/DRKS00024152 ).

Efficacy and cost-effectiveness of a Transdiagnostic group-based exercise intervention: study protocol for a pragmatic multi-site randomized controlled trial

BACKGROUND

Mental disorders are prevalent and cause considerable burden of disease. Exercise has been shown to be efficacious to treat major depressive disorders, insomnia, panic disorder with and without agoraphobia and post traumatic stress disorder (PTSD).

METHODS

This pragmatic, two arm, multi-site randomised controlled trial will evaluate the efficacy and cost-effectiveness of the manualized, group-based six-months exercise intervention "ImPuls", among physically inactive patients with major depressive disorders, insomnia, panic disorder, agoraphobia and PTSD within a naturalistic outpatient context in Germany. A minimum of 375 eligible outpatients from 10 different study sites will be block-randomized to either ImPuls in addition to treatment as usual (TAU) or TAU only. ImPuls will be conducted by trained exercise therapists and delivered in groups of six patients. The program will combine (a) moderate to vigorous aerobic exercise carried out two-three times a week for at least 30 min with (b) behavior change techniques for sustained exercise behavior change. All outcomes will be assessed pre-treatment, post-treatment (six months after randomization) and at follow-up (12 months after randomization). Primary outcome will be self-reported global symptom severity assessed with the Brief Symptom Inventory (BSI-18). Secondary outcomes will be accelerometry-based moderate to vigorous physical activity, self-reported exercise, disorder-specific symptoms, quality-adjusted life years (QALY) and healthcare costs. Intention-to-treat analyses will be conducted using mixed models. Cost-effectiveness and cost-utility analysis will be conducted using incremental cost-effectiveness and cost-utility ratios.

DISCUSSION

Despite its promising therapeutic effects, exercise programs are currently not provided within the outpatient mental health care system in Germany. This trial will inform service providers and policy makers about the efficacy and cost-effectiveness of the group-based exercise intervention ImPuls within a naturalistic outpatient health care setting. Group-based exercise interventions might provide an option to close the treatment gap within outpatient mental health care settings.

TRIAL REGISTRATION

The study was registered in the German Clinical Trials Register (ID: DRKS00024152 , 05/02/2021).