90 elderly patients that have undergone a total hip arthroplasty were randomized to receive the Short Form 36 (SF-36) and Oxford Hip Questionnaires through the mail or in person via an interview at a median of 11 years after surgery. The results indicated that the SF-36 and Oxford questionnaires more accurately reflect health status when self-administered than when administered through an interview. However, self administration also led to more missing values in the questionnaires. Both of these factors therefore need to be taken into account when deciding the method of questionnaire administration in an elderly population.