A comparison of patients' responses about their disability with and without attribution to their affected area

The purpose of this study was to determine whether individual items in a di sability questionnaire were answered differently depending on whether or no t the questions were attributed to the upper limb (i.e., "do you have diffi culty eating due to your arm or hand problem?" or "do you have difficulty e ating?", respectively). The a priori hypothesis was that the same or more d isability would be detected by non-attributed items. Four hundred sixty-sev en patients with upper extremity disorders completed the SF-36 general heal th survey, which does not attribute health problems to affected areas. Pati ents also completed six additional questions, modified from the SF-36, rega rding work (four questions) and social function with friends and family (tw o questions), which attributed their disability to their affected upper ext remity. Of 467 patients, 419-31 (89-92%) responded to both versions of the questions, Although we demonstrated a significant order effect (Generalized Estimating Equation; P=.003), comparison of the responses to the six quest ions showed that for five of the six questions (Generalized Estimating Equa tion; P less than or equal to .001) patients reported more disability when the questions were worded with attribution to the upper extremity. Even con sidering the order effect, patients demonstrated a counterintuitive result by reporting more disability when questions were attributed to their affect ed area. Thus, both the wording of questions and order of questions can sig nificantly affect patients' responses about their disability and raises que stions about the validity of patients' reports of their disability. (C) 200 1 Elsevier Science Inc. All rights reserved.