ENHANCEMENT OF THE VALUE OF HIP QUESTIONNAIRES BY TELEPHONE FOLLOW-UPEVALUATION

Errors, omissions, false understanding, and contradictory answers can compromise the use of questionnaires to generate follow-up data. To as sess the utility of and effort involved in adding routinely a telephon e interview to clarify the questionnaire, a study of total hip arthrop lasty patients was carried out. Thirty-six patients with 37 primary an d 13 revision total hip arthroplasties filled out a standardized quest ionnaire (which asks a number of demographic questions as well as ques tions that allow calculation of the Medical Outcome Studies [MOS] 36-I tem Short-form Health Survey [SF-36], Western Ontario MacMaster Arthri tis Center [WOMAC] osteoarthritis index, and Harris hip score) prior t o returning for routine follow-up evaluation a minimum of 1 year after surgery. Two hundred thirty-two of a possible 4,350 responses (5.3%) were missing, contradictory, or answered with two or more answers on t he questionnaire. Only eight such defects occurred following the telep hone interview by a skilled orthopaedic surgeon, representing a signif icant reduction in these defects (P < .005). The average time of the t elephone call was 2.8 minutes (range, 1-12 minutes), and the average n umber of attempts to contact the patient was 1.4 (range, 1-6). All que stionnaire data and questionnaire data plus telephone data were compar ed with data obtained from a subsequent face-to-face interview by a di fferent skilled orthopaedic surgeon who was blinded to the data from b oth the questionnaire and the telephone interview. It is demonstrated that a telephone call to follow up a standardized, self-administered q uestionnaire is a very effective way to augment the quality and quanti ty of questionnaire responses.