Patient expectations assessed before randomisation and after the first treatment session, and their associations with pain outcome at 3 months in patients with tennis elbow: a secondary analysis of a randomised controlled feasibility trial in Norwegian secondary care.
Expectations measured after randomisation and one treatment session were associated with pain at 3 months for patients with tennis elbow, whereas pre-randomisation expectations were not.
Key Findings
Results
Post-treatment expectations (T2) were positively associated with pain outcomes at 3 months, while pre-randomisation expectations (T1) were not.
Expectations at T2 were positively associated with T3 pain (b=0.61, 95% CI 0.33 to 0.89, p<0.01, R2=0.27)
Higher expected pain at T2 was associated with higher reported pain at T3
Expectations at T1 (before randomisation) showed no statistically significant association with T3 pain
54 participants were included in the analysis across three treatment arms
Results
Adding education level and baseline pain to the model modestly increased the explained variance beyond expectations alone.
Adding education and baseline pain increased explained variance from R2=0.27 to R2=0.32
The increase in adjusted R2 was described as 'modest'
Univariable and multivariable linear regression models were used to assess associations
Baseline factors and demographics were evaluated alongside expectations at both time points
Results
Patients in the shock wave therapy group were more likely to expect greater improvement after their first treatment session, while patients in the advice group were more likely to expect less improvement.
In the shock wave group, nine participants (47%) came to expect greater improvement from T1 to T2
In the advice group, seven participants (41%) expected less improvement from T1 to T2
Changes in expectations from T1 to T2 were summarised descriptively
The study compared heavy slow resistance training, shock wave therapy, and advice in a 1:1:1 randomisation
Methods
The study was a secondary exploratory analysis of a three-arm randomised controlled feasibility trial conducted in Norwegian secondary care.
The trial was conducted at an outpatient clinic at Oslo University Hospital
Participants were adults with lateral epicondylalgia (tennis elbow)
54 participants were included in total
Expected pain and present pain were both rated on a Numeric Rating Scale (NRS, 0-10) at T1, T2, and T3 respectively
Trial registration: NCT04803825
Conclusions
The authors recommend larger, prospectively designed studies to further investigate how post-randomisation expectations relate to clinical outcomes in non-blinded musculoskeletal trials.
The current study was an exploratory secondary analysis, limiting causal inference
The sample size of 54 participants was noted as a feasibility trial, suggesting underpowering for definitive conclusions
The authors specifically highlight non-blinded musculoskeletal trials as an important context for future research
The findings suggest treatment type may influence expectation updating after the first session
What This Means
This research suggests that what patients expect their pain level to be after receiving one session of treatment for tennis elbow is a meaningful predictor of how much pain they actually report three months later. Specifically, patients who expected higher pain levels after their first treatment session went on to report higher pain at the three-month follow-up. Interestingly, expectations measured before treatment began — before patients knew which treatment they would receive — did not show this same relationship with later pain outcomes.
The study also found that the type of treatment influenced how expectations changed after the first session. Nearly half of patients receiving shock wave therapy updated their expectations to anticipate greater improvement, while a similar proportion of patients in the advice-only group shifted toward expecting less improvement. This suggests that the treatment experience itself may shape patient outlook in ways that then influence how they experience and report pain going forward.
This research matters because it highlights that measuring patient expectations at a single pre-treatment time point — as is common in clinical research — may miss important expectation changes that occur once treatment begins. The study was small and exploratory, so the findings should be interpreted cautiously, but they point to the potential value of tracking how patient expectations evolve during treatment in future, larger studies of musculoskeletal conditions.
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Sveinall H, Røe C, Engebretsen K, Skatteboe S, Pripp A, Brox J, et al.. (2026). Patient expectations assessed before randomisation and after the first treatment session, and their associations with pain outcome at 3 months in patients with tennis elbow: a secondary analysis of a randomised controlled feasibility trial in Norwegian secondary care.. BMJ open. https://doi.org/10.1136/bmjopen-2026-122686