Reinforcement of Placebo Response in Knee Osteoarthritis: A Randomised Trial

Frederiksberg University Hospital

Status: Completed

Conditions: Knee Osteoarthritis

Treatments: Behavioral: Illness perception conversation; Behavioral: research motivation conversation

Study type: Interventional

Funder types: Other

Identifiers

NCT05225480

APPI2-OA-2022-01

Details and patient eligibility

About

Saline intra-articular injections used as placebo treatments have been shown to provide pain relief in knee osteoarthritis (OA) It has further been shown that beneficial effects can be induced merely by having a conversation with a health professional.

The aim of this study is to determine whether an individual conversation based on the individual's illness perception related to knee OA affects the response to an intra-articular treatment with saline in individuals with knee OA.

Full description

Despite many years of research, there is still considerable uncertainty on what causes placebo effects and how these are mediated. Saline is a pharmacologically inert agent frequently used as placebo comparator in clinical trials of intra-articular (IA) treatments for knee osteoarthritis (OA) and patients often experience a significant pain improvement from this treatment even when it is administered as an open label placebo treatment.

It has further been shown that beneficial effects can be induced merely by having a conversation with a health professional and several studies have found the alliance between therapist and patient to have a positive effect on treatment outcome in physical rehabilitation indicating that positive attention by itself leads to beneficial treatment outcomes. Still it is unclear wether the effect of an open label placebo treatment can be influenced by a conversation and if the extent of this infleuence depends on the focus of the conversation.

The aim of this study is to determine whether a conversation about the individual's illness perception related to knee OA affects the response to a placebo treatment (saline injection) in individuals with knee OA.

Enrollment: 103 patients

Sex: All

Ages: 50+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age ≥50 years
• A clinical diagnosis of tibiofemoral OA in the target knee according to the American College of Rheumatology
• Average knee pain in the last week during weight bearing activities of at least 4 on a 0 to 10 points scale (0=no pain; 10=worst possible pain).

Exclusion criteria

• Not able to speak or understand Danish
• Scheduled surgery during study participation
• History of target knee surgery within 12 months
• History of arthroplasty in the target knee
• Injection therapy in either knee within 3 months
• Current use of oral glucocorticoids
• Current use of synthetic or non-synthetic opioids
• Contraindications to intra-articular injections, such as wounds or skin rash over injection site.
• Planning to start or discontinue other treatment for knee OA in the study participation period
• Inflammatory arthritis, such as rheumatoid arthritis or psoriatic arthritis.
• Regional pain syndromes
• Generalised pain syndromes such as fibromyalgia
• Lumbar or cervical nerve root compression syndromes
• Any other condition or impairment that, in the opinion of the investigator, makes a potential participant unsuitable for participation or which obstruct participation, such as large knee joint effusion, uncontrolled diabetes, psychiatric and/or neurological disorders, or opiate dependency

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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103 participants in 2 patient groups

intervention arm

Experimental group

Description:

The illness perception conversation will be delivered in one session during around 15 minutes. The conversation will be based on responses to the eight item Brief illness perception questionnaire and a rating of the most relevant item made by the patient on the same day. The aim of the conversation will be to get an overview of the patient's illness perceptions concerning their knee OA and what is deemed the most maladaptive perceptions by the participant. Participants will be invited to elaborate on their thoughts concerning these perceptions.Although any maladaptive perceptions will be corrected if natural during the conversation, the conversation will not lead to any active attempts of changing illness perceptions. Rather, the conversation focusses on giving patients time and opportunity to express knee pain related perceptions and worries concerning their knee pain.

Treatment:

Behavioral: Illness perception conversation

control arm

Active Comparator group

Description:

The control conversation will be delivered in one session during around 15 minutes. In order to create two similar conversational settings where the only difference is the actual content of the conversations. The conversation will be based on responses to an eight item questionnaire concerning motivation for research participation and - similar to the illnes perception conversation - a rating of the most relevant item made by the patient. The aim of the conversation will be to get an overview of the patient's motivation for research participation and let them elaborate on their thoughts concerning their motivation.

Treatment:

Behavioral: research motivation conversation