Clarifying thresholds for defining levels of physical function and pain interference using bookmarking in orthopaedics.

Purpose: Bookmarking is a qualitative method used to assign descriptive labels to ranges of patient-reported outcome (PROM) scores. We aimed to evaluate variability between bookmarking samples and test score ranges where there was variability in expert opinion in previous studies.

Methods: We conducted two bookmarking sessions with patients who experienced orthopaedic fractures (n = 11) and one session with orthopaedic clinicians (n = 10). Participants reviewed vignettes comprised of PROM items and responses that represented hypothetical patients with a range of severity. Vignettes were constructed for PROMIS Upper Extremity Function, Physical Function, and Pain Interference measures. Participants placed bookmarks between vignettes that reflected different levels of severity (e.g., mild, moderate). The score reflecting the midpoint between vignettes was used as the recommended threshold between categories. We evaluated the variability in thresholds across participants, bookmarking panels, and previous studies.

Results: Although patients and clinicians were not unanimous, the majority agreed on thresholds separating levels of severity for PROMIS Upper Extremity (≥ 40 = within normal limits, 30-39 = mild, 23-29 = moderate, < 23 = severe), PROMIS Physical Function (≥ 46 = within normal limits, 38-45 = mild, 26-37 = moderate, < 26 = severe), and PROMIS Pain Interference (≤ 50 = within normal limits, 51-60 = mild, 61-68 = moderate, > 68 = severe).

Conclusion: Testing new vignette scores within the same patient population enables more nuanced testing of score ranges without clear consensus and provides additional evidence for recommending thresholds for severity categories. These thresholds can be utilized to help interpret PROMIS scores from patients receiving orthopaedic care.