Objectively measured activity is not associated with average pain intensity 1 week after surgery: A cross-sectional study

BACKGROUND: Measures of physical activity and pain-related patient-reported outcomes are important components of patient recovery after surgery. However, little is known about their association in the early post-operative period. This study aims to increase this knowledge. Our primary objective was to determine the association between average pain intensity and activity (in steps) 1 week after surgery. Secondary objectives were the association of activity with other patient-reported outcomes, age, sex, comorbidities and body mass index.

METHODS: Data were obtained from the PROMPT sub-project of IMI-PainCare. Patients after breast and endometriosis-related surgery, sternotomy and total knee arthroplasty completed pain-related outcomes questionnaires and wore an ActiGraph activity-tracking device. We correlated steps with average pain intensity on post-operative days 6 and 7. Secondary analyses were done using correlations and t-tests.

RESULTS: In 284 cases, there was no statistically significant correlation between steps and average pain intensity. In addition, none of the 28 secondary analyses showed a statistically significant result.

CONCLUSIONS: Pain-related patient-reported outcome measures and physical activity are separate entities. Both should be measured after surgery to assess patient recovery and to identify treatment deficiencies.

SIGNIFICANCE STATEMENT: Measuring recovery is a multi-dimensional challenge. After surgery, clinicians need to be aware that neither pain intensity nor activity levels tell the whole story. Each can hint to problems and treatment requirements.