An interventional study of Pain Reprocessing Therapy in Chronic Pain, sponsored by Karolinska Institutet. Recruiting at 1 site in Sweden. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-27.
Sponsored by Karolinska Institutet · Not applicable, Interventional, and Treatment
Long-term pain, which is pain that lasts for more than three months, is a major health problem. It can severely impact a person's physical and mental well-being, quality of life, and ability to work. It also carries high costs for society, mainly due to high rates of sick leave.
For many people with long-term pain, there is no clear injury or disease that fully explains why it hurts. In these cases, the pain is believed to be caused by how the brain and nervous system process pain signals. This is sometimes called "nociplastic pain."
Even though there are many treatments for pain-like medications and therapies-they don't work for everyone, and many people are left without meaningful relief. Because of this, it is important to find and test new ways to treat pain. In this study, the investigators evaluate a relatively new psychological treatment called Pain Reprocessing Therapy (PRT), which has been tested in the US with promising results.
PRT helps individuals with chronic pain to understand and change how they think about their pain by explaining how the brain works. The treatment focuses on teaching the difference between acute (new) pain and long-term pain. It also involves exercises to help people alter emotions related to their pain. A key part of the treatment is a technique where patients practice paying attention to what is happening in their bodies in a safe, relaxed way. The goal is to teach the brain that the pain signals are not a threat. This can help break the vicious cycle of fear, avoiding activities, and worsening pain.
While many people are interested in treatments like PRT, it hasn't yet been tested in specialized care for patients with complex pain. This trial is a pilot study-a smaller, initial investigation to evaluate how well the treatment works in a clinical setting, and to determine if both patients and therapists find it acceptable and practical to use. This will give us important information to help prepare for larger studies in the future.
The main goal of this pilot study is to see if PRT is a practical and accepted treatment in a Swedish pain rehabilitation setting. The investigators also want to look at whether the treatment helps reduce pain, psychological distress, negative thoughts about pain, and the fear of moving. Finally, the investigators will explore how a patient's expectations and thinking skills (such as memory and focus) might affect how well the treatment works, and take physical measurements before and after the treatment to see if the nervous system becomes better at regulating pain.
The overall aim of this project is to conduct a pilot study investigating the feasibility, patient satisfaction, and acceptability of a recently developed psychological treatment for pain: Pain Reprocessing Therapy (PRT). The study will be conducted within a clinical pain rehabilitation setting, where patients frequently present with severe pain, psychiatric comorbidity, and reduced or absent work capacity.
Within the framework of this project, the investigators will evaluate whether PRT can be effectively implemented in a pain rehabilitation context and whether the treatment is perceived as acceptable and feasible by both patients and clinicians. Furthermore, the investigators intend to conduct exploratory analyses to determine if specific clinical subgroups appear more responsive to the intervention.
A secondary aim is to evaluate changes in pain intensity, functional capacity, fear of movement (kinesiophobia), pain catastrophizing, as well as symptoms of anxiety and depression. Although study participants will not be randomized, the results will be compared to a matched reference group drawn from the Swedish Quality Registry for Pain Rehabilitation (SQRP). This reference group, comprising individuals who have undergone standard multimodal pain rehabilitation, is included to provide a contextualizing indication of whether PRT is associated with clinically relevant changes in the outcome measures.
The project is designed as a single-arm pilot study in which all participants will receive PRT. Data collection will occur at baseline, during the intervention, and post-treatment. PRT, which has previously been evaluated primarily in a selected population with chronic back pain and limited comorbidity, aims to modify the patient's interpretation of the cause of their pain and its perceived threat value. By targeting fear-avoidance responses triggered by somatic signals, the ultimate objective of the treatment is to facilitate sustained symptom relief.
Primary Objective:
The primary objective is to investigate whether a 9-week treatment with Pain Reprocessing Therapy (PRT) meets predefined criteria for feasibility and acceptability.
Primary Research Questions:
Secondary Objective:
The secondary objective is to exploratively investigate whether PRT is associated with changes in predefined clinical outcome measures.
Secondary Research Questions:
Exploratory Research Questions:
Behavioral: Pain Reprocessing Therapy
A 9-week intervention with 9 individual sessions and 3 group sessions based on Pain Reprocessing Therapy.
Retention rate
The retention rate is defined as the percentage of participants who successfully complete the PRT intervention. To be considered a completer, a participant must attend at least 6 of the 9 individual sessions and complete all post-treatment outcome measures. The benchmark for study feasibility is set at 75%
Time frame: From enrollment to 9 weeks (post treatment).
Recruitment rate
Feasibility of recruitment, defined as percentage of eligible participants who give informed consent and are enrolled in the study. The predefined benchmark for feasibility of recruitment rate is set as at least 70%
Time frame: From study start to recruitment completion, an estimated 6 months
Patient treatment satisfaction
Assessed using the Client Satisfaction Questionnaire (CSQ-8). The total score ranges from 8 to 32. Higher scores indicate greater satisfaction with the treatment received, representing a better outcome. The predefined benchmark for acceptability is set to a mean total score of 24 or higher (out of a maximum of 32).
Time frame: Post treatment (9 weeks)
Adherence to treatment
Adherence to the in-between session work with home assignments, as logged by the therapists during the 9-week program. The predefined benchmark for adequate adherence is at least 70% of assigned homework tasks.
Time frame: From enrollment to the end of the treatment at 9 weeks
Therapists treatment fidelity
The degree to which the therapists adhere to the core interventions of the treatment. Evaluated by therapist self-report using a study-specific PRT fidelity checklist completed after each session. The predefined benchmark for adequate treatment fidelity is set to an average adherence score of at least 80%.
Time frame: From treatment start to the end of treatment at 9 weeks
Pain Catastrophizing Scale (PCS)
The PCS assesses negative thoughts and emotions associated with past, present or anticipated pain. The total score ranges from 0 to 52. Higher scores indicate greater levels of pain catastrophizing.
Time frame: Baseline and week 9
Tampa Scale of Kinesiophobia (TSK)
The TSK assesses fear of movement or re-injury. The 17-item version is used. Total scores range from 17 to 68. Higher scores indicates a higher degree of kinesiophobia.
Time frame: Baseline and week 9
Hospital Anxiety and Depression Scale (HADS)
The HADS scale measures anxiety and depression symptoms. The HADS contains of 14 items, divided into 2 subscales (anxiety and depression). For each subscale, the total score ranges from 0 to 21. Higher scores indicate greater severity of anxiety and depression symptoms.
Time frame: Baseline and week 9
EQ-5D
The EQ-5D measures health-related quality of life across five dimensions. Responses are converted into a single index score. The index score typically ranges from a minimum of less than 0 (often around -0.59, representing a health state worse than death) to a maximum of 1.0 (representing full health). Higher index scores indicate a better health-related quality of life.
Time frame: Baseline and week 9 (post treatment)
EQ-5D VAS
Measures self-rated overall health using a Visual Analogue Scale (EQ-VAS). Participants rate their overall health using a vertical visual analogue scale rangeing from 0-100. Higher scores indicates a better self-percieved health.
Time frame: Baseline to 9 week (post treatment)
Sickness Questionnaire (SicknessQ)
The SicknessQ assesses self-reported sickness behavior (e.g., fatigue, social withdrawal. The scores ranges from 0 tp 30. Higher scores indicate a higher degree of sickness behavior.
Time frame: Baseline and week 9.
Multidimensional Fatigue Inventory (MFI-20)
The MFI-20 assesses five dimensions of fatigue. The total score ranges from 20-100 where higher scores indicate higher levels of fatigue.
Time frame: Baseline to 9-week (post treatment)
Numeric Rating Scale For Pain
The NRS measures pain intensity where participants rate their pain intensity during the past week on an 11 point scale from 0 to 10. Higher scores indicate worse pain intensity.
Time frame: Baseline and week 9 (Post treatment)
Consultation and Relational Empathy Measure (CARE)
The CARE-scale assesses the participants perception of the therapists empathy during sessions. The maximum score is 50. Higher scores indicate greater percieved empathy from the treating clinician
Time frame: Week 2 and 9 (post treatment)
Credibility/Expectancy Questionnaire (CEQ)
The CEQ assesses how logical the treatment seems to the patient, and how much improvement they expect. Scores for each subscale range from 3 to 27. Higher scores indicate higher perceived credibility and expectancy of clinical improvement.
Time frame: Week 2
Pressure Pain Threshold (PPT)
Assessed using a pressure algometer. Measures are recorded in kPa at predefined anatomical sites. Higher values indicate higher pain thresholds.
Time frame: Baseline and 9-week
Thermal Pain Thresholds
Assessed using a computerized thermotest device. Heat Pain Threshold (HPT) and Cold Pain Threshold (CPT) are measured in degrees Celcius. For HPT, higher temperatures indicate a higher pain threshold. For CPT, lower temperatures indicate a higher pain threshold.
Time frame: Baseline and week 9 (Post treatment)
PrePain Questionnaire
The PrePain questionnaire assesses attitudes, emotions and behaviors related to pain. The six dimensional questions (assessing perceived pain-sensitivity, avoidance, distress, relief, focus on symptoms, and negative thoughts) are analyzed individually rather than as a total score. Each item is scored on a Visual Analog Scale (VAS) with a minimum value of 0 and a maximum value of 100. A VAS-score of 100 means respectively low pain-sensitivity, low degree of avoidance, low degree of distress, low degree of relief, low degree focus on symptoms and low degree of negative thoughts. Because higher scores represent a lower degree of these pain-related attitudes and emotions, higher scores indicate a better outcome.
Time frame: Before treatment start and 9 weeks (post treatment)
Stroop-test
Executive control, attention, and inhibition are assessed using a digital version of the Stroop test administered via the 'Health Catcher' application. Participants are instructed to respond to the color of a written word rather than the word itself. Performance is measured by the total number of correct responses completed within a 90-second time limit. The minimum possible score is 0. There is no predefined maximum score, as the total number of items presented depends on the participant's response speed. Higher scores (more correct responses within the time limit) indicate better cognitive performance and inhibition.
Time frame: Baseline and 9 weeks (post treatment)
Go/no-go Test
Sustained attention and response inhibition are assessed using a digital Go/no-go test administered via the 'Health Catcher' application. Participants respond to a target stimulus while withholding responses to a non-target stimulus. Performance is measured by the total number of correct responses completed within a 90-second time limit. The minimum possible score is 0. There is no predefined maximum score, as the total number of items presented depends on the participant's response speed. Higher scores (more correct responses within the time limit) indicate better sustained attention and response inhibition.
Time frame: Baseline and 9 weeks (post treatment)
Verbal Recognition Memory Test
Verbal episodic memory is assessed using a digital verbal recognition memory test administered via the 'Health Catcher' application. Participants report whether mixed lists of words were included in a previously presented sequence. Performance is measured by the total score of correct recognitions. The score ranges from a minimum of 0 to a maximum of 24. Higher scores indicate better memory function.
Time frame: Baseline and 9 weeks (post treatment)
Visual Working Memory Test
Visuospatial working memory and attention are assessed using a digital visual working memory test administered via the 'Health Catcher' application. Participants memorize and reproduce sequences of illuminated squares in a 4x4 grid. Performance is measured by the total score of correctly identified locations. The score ranges from a minimum of 0 to a maximum of 6. Higher scores indicate better visuospatial working memory, representing a better outcome
Time frame: Baseline and 9 weeks (post treatment)
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