Thurs., 10/16/08 Tibia/Polytrauma, Paper #8, 3:49 pm OTA-2008
A Comparison of the Discriminative Ability and Responsiveness of the Short Musculoskeletal Function Assessment Questionnaire Function Index and the Short Form-36 Physical Summary Score among Tibial Fracture Patients
The SPRINT Investigators (n); CLARITY Methods Centre, McMaster University, Hamilton, Ontario, Canada
Purpose: General quality of life measures allow comparisons of patients with different clinical conditions, while disease-specific instruments are often but not always more responsive to change. Therefore, methodologists recommend use of both types of instruments to assess functional status in randomized trials. If, in a particular clinical context, a general measure proves as responsive and valid as a specific measure, investigators could with confidence restrict use to the generic instrument. We therefore compared the Short Musculoskeletal Function Assessment (SMFA) Questionnaire Dysfunction Index and the Short-Form 36 Physical Component Summary (SF-36 PCS) score among patients undergoing operative management of tibial fractures.
Methods: We enrolled 1319 skeletally mature patients with open (Gustilo types I-IIIB) or closed fractures (Tscherne types 0-3) of the tibial shaft that were managed with intramedullary nailing. Patients were asked to complete the SMFA and SF-36 at discharge and 3, 6, and 12 months after surgical fixation. At each time point, we calculated the correlation between instrument scores. We compared the difference in SMFA Dysfunction Index and SF-36 PCS standardized response means from 3 to 12 months with a paired t test. Discriminative properties were assessed by comparing SMFA Dysfunction Index and SF-36 PCS scores of patients with healed versus nonhealed fractures.
Results: SMFA Dysfunction Index and SF-36 PCS scores were highly correlated at 3 months (n = 906; r = –0.71), 6 months (n = 787; r = –0.80), and 12 months (n = 700; r = –0.81) after surgical fixation. All correlations were significant at P <0.0001. Comparison of standardized change scores for the SMFA Dysfunction Index and the SF-36 PCS score, from 3 to 12 months after surgical fixation, was nonsignificant (P = 0.13). Both SMFA Dysfunction Index and SF-36 PCS scores were able to discriminate between healed and nonhealed tibial fractures at 3, 6, and 12 months after surgery.
Conclusion and Significance: In patients with tibial shaft fractures, the SMFA Dysfunction Index offered no advantages over the SF-36 PCS. These results, along with the usefulness of the SF-36 PCS for comparing populations, recommends the instrument for assessing physical function in studies of patients with tibial fractures. Generalizing these results beyond this specific population is currently not warranted, and will require similar specific comparisons.
If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.
• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.