DOES THE MODE OF DATA-COLLECTION CHANGE RESULTS IN A SUBJECTIVE KNEE SCORE - SELF-ADMINISTRATION VERSUS INTERVIEW

Our objective was to compare the effect of two methods of data collect ion on results in a functional knee score. Two Lysholm scores were obt ained for 61 patients 1 year after anterior cruciate ligament surgery at the same clinic visit, First, the patients completed a self-adminis tered questionnaire, and second, the Lysholm score form was completed by the investigator in the course of a patient interview, A comparison of the scores revealed that the mean score was significantly lower wi th self-administration (self, 89.3 +/- 10.6; interviewer, 92.2 +/- 7.4 ) (P = 0.0035, Wilcoxon rank sum test). The assignment to one of four categories (excellent, good, fair, poor) was also significantly altere d by the manner of data collection, Nineteen patients (31%) were assig ned to different categories based on the mode of data collection. We b elieve that the major reason for a better score result with an intervi ew was the presence of interview bias, The more the investigator is in volved in the treatment of the patient, the greater the influence of t his bias may be, To avoid such potential bias we suggest that a standa rdized self-administered questionnaire be used as the method of choice for obtaining subjective data in clinical settings.