title: Validity of the Patient Specific Functional Scale in patients following upper extremity nerve injury.
abstract: OBJECTIVE
  This study evaluated the validity of the Patient Specific Functional Scale (PSFS) in patients with upper extremity nerve injury.
  
  
  METHODS
  Following Research Ethics Boards (REB) approval, we included English-speaking adults, with greater than 6 months after an upper extremity nerve injury. Patient reported questionnaires included: PSFS, 36-item short-form health survey (SF-36), Disabilities of the Arm, Shoulder and Hand (DASH), McGill Pain Questionnaire, Pain Catastrophizing Scale (PCS) and Pain Disability Index (PDI). Statistical analyses evaluated the relationships among the outcome measures and the independent variables (age, gender, nerve injured, time since injury, work status, worker's compensation/litigation). Linear regression was used to evaluate the variables that predicted the PSFS.
  
  
  RESULTS
  There were 157 patients (53 women, 104 men); median time since injury of 14 months. The mean ± SD scores were: PSFS 3.1 ± 2.3, DASH 44 ± 22, PCS 16 ± 15, pain intensity 4.2 ± 3.0, pain rating index 13 ± 11, PDI 28.3 ± 17.6 and SF-36 component scores physical (41.8 ± 8.7) mental (45.9 ± 12.6). There were moderate correlations between the PSFS and the DASH, and the SF-36 physical role domain. The PSFS was significantly lower in brachial plexus injuries. The final model explained 20.7 % of the variance and independent variables were DASH, nerve injured and age.
  
  
  CONCLUSIONS
  This study provides evidence of construct validity of the PSFS for patients with upper extremity nerve injury. The PSFS is a valid method to assess functional limitations identified by the individual and can be completed in a shorter period of time than the DASH.
authors.affiliation: Toronto Western Hospital Hand Centre, Division of Plastic and Reconstructive Surgery, University of Toronto, Toronto, Ontario Canada ; University of Toronto, TWH Hand Centre, 399 Bathurst Street, EW 2-422, Toronto, ON Canada M5T 2S8.
authors.forename: Christine B
authors.initials: CB
authors.lastname: Novak
authors.affiliation: Toronto Western Hospital Hand Centre, Division of Plastic and Reconstructive Surgery, University of Toronto, Toronto, Ontario Canada.
authors.forename: Dimitri J
authors.initials: DJ
authors.lastname: Anastakis
authors.affiliation: Mobility Program Clinical Research Unit, St. Michael's Hospital, University of Toronto, Toronto, Ontario Canada.
authors.forename: Dorcas E
authors.initials: DE
authors.lastname: Beaton
authors.affiliation: Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, St. Louis, MO USA.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Mackinnon
authors.affiliation: Department of Psychology, York University, Toronto, Ontario Canada ; Department of Anesthesia and Pain Management, Toronto General Hospital, Toronto, Ontario Canada ; Department of Anesthesia, University of Toronto, Toronto, Ontario Canada.
authors.forename: Joel
authors.initials: J
authors.lastname: Katz
keywords: Nerve injury; Outcome; Self-report function; Upper extremity; Validity