Simple clinical tools improve ability-to-work predictions for individuals 3-24 months after upper limb injury.

Background: Despite numerous previous studies, predicting the ability to work (ATW) after an upper limb injury (ULI) remains difficult for those still not working 3-24 months after their initial injury.

Objectives: We aimed to identify simple prognostic characteristics that were associated with the long-term ATW for individuals who remained unable to work several months after the accident that caused their ULI.

Methods: A single-center prospective observational study in a rehabilitation center in the French-speaking part of Switzerland. We included participants who were 18-60 years old, still unable to work because of persistent pain/disability 3-24 months after an ULI, and who were referred to our rehabilitation center for a 1-month intensive interdisciplinary treatment. Data were collected on personal characteristics, body function/structure variables, activity limitations/participation restrictions, and environmental factors. Participants' evolution during rehabilitation was assessed using functional tests/questionnaires and the 7-level self-reported Patient's Global Impression of Change (PGIC) assessment at discharge. Participant outcomes after 1 year were categorized as either able (ATW>0%) or unable (ATW=0%) to work. The best prognostic characteristics were selected by logistic regression analysis.

Results: Among the 317 participants, 202 (64%) had an ATW>0% at 1 year. A grip strength ≥16 kg (Jamar Hand Dynamometer score - affected side) and "(I) do not take pain medicine" were independent predictors. Overall, 96% (26/27) of participants with these 2 characteristics had an ATW>0% at 1 year. The simultaneous absence of these characteristics predicted an unfavorable prognosis in 50% (59/119) of participants. For those who also had a positive PGIC score then 100% (25/25) of participants with these 3 characteristics had an ATW>0%; for those without, only 42% (19/45) had an ATW>0%.

Conclusions: Grip strength (≥16 kg) and not taking pain medicine are favorable prognostic factors for an ATW after an ULI. Their absence is associated with a poor ATW prognosis for half of people with ULI and should alert caregivers to risk of long-term absenteeism ("red flags"). Including data from a PGIC further improves the ATW prediction. We recommend that these 3 criteria be systematically evaluated.