Predicting optimal treatment outcomes using the Personalized Advantage Index for patients with persistent somatic symptoms

ABSTRACT

Objective: Because individual patients with persistent somatic symptoms (PSS) respond differently to treatments, a better understanding of the factors that predict therapy outcomes are of high importance. Aggregating a wide selection of information into the treatment-decision process is a challenge for clinicians. Using the Personalized Advantage Index (PAI) this study aims to deal with this. Methods: Data from a multicentre RCT comparing CBT (N = 128) versus CBT enriched with emotion regulation training (ENCERT) (N = 126) for patients diagnosed with somatic symptom disorder were used to identify based on two machine learning approaches predictors of therapy outcomes. The identified predictors were used to calculate the PAI. Results: Five treatment unspecific predictors (pre-treatment somatic symptom severity, depression, symptom disability, health-related quality of life, age) and five treatment specific moderators (global functioning, early childhood traumatic events, gender, health anxiety, emotion regulation skills) were identified. Individuals assigned to their PAI-indicated optimal treatment had significantly lower somatic symptom severity at the end of therapy compared to those randomised to their non-optimal condition. Conclusion: Allowing patients to choose a personalised treatment seems to be meaningful. This could help to improve outcomes for PSS and reduce its high costs to the health care system.

Keywords:

• Personalized Advantage Index
• prediction
• persistent somatic symptoms
• somatic symptom disorder
• tailoring treatment
• personalised medicine
• treatment selection

Acknowledgements

The trial entitled “Enriching Cognitive-behavioral Therapy (CBT) with Emotion Regulation Training (ERT) in Patients with Multiple Somatoform Symptoms: ENCERT” has been funded since 2013 by the DFG (German Research Foundation). Applicants are Winfried Rief and Matthias Berking, the principal investigator is Winfried Rief. Collaborating centres were Gießen (Justus-Liebig-University, Dep. of Clinical Psychology and Psychotherapy), Hamburg (Department of Psychosomatic Medicine, University Medical Center Hamburg-Eppendorf), Landau (University Koblenz-Landau, Dep. of Clinical Psychology and Psychotherapy), Mannheim (Central Institute of Mental Health), Marburg (Philipps-University, Dep. of Clinical Psychology and Psychotherapy), Munich (Department of Psychosomatic Medicine and Psychotherapy, Rechts der Isar Hospital, University of Technology) and Wuppertal (Bergische University, Dep. of Clinical Psychology and Psychotherapy). The independent Methods Centre is located in Marburg (KKS, Philipps- University Marburg).

Ethical Standards

The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008.

Additional information

Funding

This work was financially supported for the trial entitled “Enriching Cognitive-behavioural Therapy (CBT) with Emotion Regulation Training (ERT) in Patients with Multiple Somatoform Symptoms: ENCERT” from the German Research Foundation (Deutsche Forschungsgemeinschaft), DFG; RI 574/24-1).