PATIENTS WITH MUSCULOSKELETAL PAIN SEEM TO KNOW ABOUT THEIR IMPROVEMENT WITHIN A SESSION BUT NOT FOR MUCH LONGER THAN THAT

V. Korakakis^1,2, A. Bjerregaard², R. Kotsifaki², A. Al Jawad², R. Whiteley²

¹King's College London, Department of Population Health Sciences, Physiotherapy Education, London, United Kingdom, ²Aspetar, Orthopaedic and Sports Medicine Hospital, Rehabilitation Department, Doha, Qatar

Background: Treatment effectiveness is often measured using a numeric pain rating scale (NPRS) and the global rating of change (GROC) as overall (since the beginning of therapy), but it’s unknown if patients accurately rate changes over different time periods such as within a session, or between sessions.

Purpose: We aimed to determine the change in NPRS for the patient’s most provocative movement, clinical test, or position that was associated with the GROC following standard physiotherapy care including mainy an active treatment component.

Methods: 275 recreational athletes and physically active individuals (age 38.0±11.5 years) with various non-acute [symptom duration: 12(IQR:6-33) weeks] peripheral musculoskeletal conditions (ankle, shoulder, hip, knee, shin, groin) self-rated their pain before and after a physiotherapy session along with their GROC in a 7-point Likert scale (“very much worse” to “very much improved”) as the change from the initial physiotherapy visit, the last session, and within-session. Data was analysed using mixed-effects models and the best model for each outcome of interest was based on the Akaike information criterion. The outcome variables were analyzed using participant specific random effects and we modelled the parameter estimates for covariates associated with recovery such as age, weight, height, and chronicity. Where a significant main effect or interaction was found, we performed post-hoc testing and Tukey HSD adjustment for multiple comparisons, where applicable. All data was analyzed with JMP Version 16.0, SAS Institute, and the level of significance was set at 0.05.

Results: Significant differences were seen for almost all category comparisons for both GROC and NPRS only for within-session changes (p<0.01). When patients were asked to compare pain from previous session (range from 4 to 6 days) patients only appear to be able to differentiate “worse” from the other categories (including “no change”). There were a few significant differences for any of the comparisons to the initial treatment. For NPRS significant differences were found between "minimally improved" compared to "very much improved" (p=0.031), while for percentage change between "no change" and "minimally improved" compared to "very much improved" (p=0.003 and p<0.001, respectively).

Conclusions: Patients can only differentiate between the different categories of improvement for the current physiotherapy session. In the other two situations, compared to the initial session and to the previous session, they appear only able to distinguish “better” from “worse”.

Implications: Assessing treatment effectiveness requires establishing a cut-point for success. This practice appears to only be valid for within-session changes where a threshold (say, “much improved”) is set. It seems existing research which compares outcomes from the beginning of therapy and even to the previous session are problematic, at least for pain.

Funding acknowledgements: None declared

Keywords:
Pain measurement
Clinical trials
Treatment outcome

Topics:
Research methodology, knowledge translation & implementation science
Pain & pain management
Musculoskeletal

Did this work require ethics approval? Yes

Institution: Aspetar, Orthopaedic and Sports Medicine Hospital

Committee: Aspire Zone Foundation - IRB

Ethics number: E202009010