Validation of quality of life and functional measures for older people for telephone administration

Abstract

INTRODUCTION: Quality of life (QoL) and functional status are important aspects of health especially for older people. Efficient and valid ways of measuring older people’s health is of great importance. AIM: This project aims to establish the reliability of use of (1) a quality of life measure, the WHOQOL-BREF, and (2) a functional measure, the Nottingham Extended Activities of Daily Living scale (NEADL), for use over the telephone. METHODS: With ethical approval, patients over age 75 years (65 years if Maori) have been enrolled in the BRIGHT trial; a randomised controlled trial testing a practice-based screening initiative to prevent disability. Participants with possible disability, defined as being unable to get in and out of the car or take hot drinks from one room to another, completed a telephone interview including the two measures. Seventy participants repeated the two measures during a face-to-face interview within three months. RESULTS: Both WHOQOL-BREF and NEADL scores for the two forms of administration produced high Pearson correlation coefficients. There was good agreement for the WHOQOL-BREF as shown by the Bland-Altman graphs; however there was a tendency of a greater negative difference the greater the average score became (higher level of function) for the NEADL. DISCUSSION: This study shows that telephone interviews can generally provide a valid method to assess the quality of life and function in older people. KEYWORDS: Reliability; Quality of life; WHOQOL-BREF; functional status; NEADL; telephone administration