Predicting non return to work after orthopaedic trauma: the Wallis Occupational Rehabilitation RisK (WORRK) model.
BACKGROUND
Workers with persistent disabilities after orthopaedic trauma may need occupational rehabilitation. Despite various risk profiles for non-return-to-work (non-RTW), there is no available predictive model. Moreover, injured workers may have various origins (immigrant workers), which may either affect their return to work or their eligibility for research purposes. The aim of this study was to develop and validate a predictive model that estimates the likelihood of non-RTW after occupational rehabilitation using predictors which do not rely on the worker's background.


METHODS
Prospective cohort study (3177 participants, native (51%) and immigrant workers (49%)) with two samples: a) Development sample with patients from 2004 to 2007 with Full and Reduced Models, b) External validation of the Reduced Model with patients from 2008 to March 2010. We collected patients' data and biopsychosocial complexity with an observer rated interview (INTERMED). Non-RTW was assessed two years after discharge from the rehabilitation. Discrimination was assessed by the area under the receiver operating curve (AUC) and calibration was evaluated with a calibration plot. The model was reduced with random forests.


RESULTS
At 2 years, the non-RTW status was known for 2462 patients (77.5% of the total sample). The prevalence of non-RTW was 50%. The full model (36 items) and the reduced model (19 items) had acceptable discrimination performance (AUC 0.75, 95% CI 0.72 to 0.78 and 0.74, 95% CI 0.71 to 0.76, respectively) and good calibration. For the validation model, the discrimination performance was acceptable (AUC 0.73; 95% CI 0.70 to 0.77) and calibration was also adequate.


CONCLUSIONS
Non-RTW may be predicted with a simple model constructed with variables independent of the patient's education and language fluency. This model is useful for all kinds of trauma in order to adjust for case mix and it is applicable to vulnerable populations like immigrant workers.
Department for Musculoskeletal Rehabilitation, Clinique romande de réadaptation suvacare, Sion, Switzerland; Institut de Recherche en Réadaptation, Clinique romande de réadaptation suvacare, Sion, Switzerland; Hôpital Orthopédique, Département de l'Appareil Locomoteur, Lausanne University Hospital, Lausanne, Switzerland.
François
F
Luthi
Institut de Recherche en Réadaptation, Clinique romande de réadaptation suvacare, Sion, Switzerland.
Olivier
O
Deriaz
Institut de Recherche en Réadaptation, Clinique romande de réadaptation suvacare, Sion, Switzerland; Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland.
Philippe
P
Vuistiner
Department for Musculoskeletal Rehabilitation, Clinique romande de réadaptation suvacare, Sion, Switzerland; Institut de Recherche en Réadaptation, Clinique romande de réadaptation suvacare, Sion, Switzerland.
Cyrille
C
Burrus
Institut de Recherche en Réadaptation, Clinique romande de réadaptation suvacare, Sion, Switzerland; School of Health Sciences, University of Applied Sciences and Arts Western Switzerland Valais, Sion, Switzerland.
Roger
R
Hilfiker
D000063:Accidents, Traffic / Q000523:psychology / Q000706:statistics & numerical data; D000328:Adult; D001134:Arm Injuries / Q000208:ethnology / Q000523:psychology / Q000534:rehabilitation; D019567:Back Injuries / Q000208:ethnology / Q000523:psychology / Q000534:rehabilitation; D003469:Culture; D004185:Disability Evaluation; D004522:Educational Status; D054242:Emigrants and Immigrants / Q000523:psychology / Q000706:statistics & numerical data; D005260:Female; D005544:Forecasting; D006801:Humans; D007406:Interview, Psychological; D007802:Language; D007869:Leg Injuries / Q000208:ethnology / Q000523:psychology / Q000534:rehabilitation; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009104:Multiple Trauma / Q000208:ethnology / Q000523:psychology / Q000534:rehabilitation; D009140:Musculoskeletal Diseases / Q000208:ethnology / Q000523:psychology / Q000534:rehabilitation*; D060051:Occupational Injuries / Q000208:ethnology / Q000523:psychology / Q000534:rehabilitation*; D011446:Prospective Studies; D011584:Psychology; D012372:ROC Curve; D015203:Reproducibility of Results; D062707:Return to Work / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D013557:Switzerland / Q000453:epidemiology; D055815:Young Adult