The validation of the Moorehead-Ardelt Quality of Life Questionnaire II

Abstract

Background: The Moorehead-Ardelt Quality of Life Questionnaire was originally developed as a disease-specific instrument to measure postoperative outcomes of self-perceived quality of life (QoL) in obese patients. 5 key areas were examined: self-esteem, physical well-being, social relationships, work, and sexuality. Each of these questions offered 5 possible answers, which were given + or - points according to a scoring key. The questionnaire was used independently or incorporated into the Bariatric Analysis and Reporting System (BAROS). The instrument is simple, unbiased, user-friendly and can be completed in <1 minute. It has been found useful, reliable and reproducible in numerous clinical trials in different countries. Further research and feedback from some of its users prompted refinements, now included in the Moorehead-Ardelt Quality of Life Questionnaire II (M-A QoLQII). This study tested the validity of the improved instrument.

Methods: The wording of the questions was changed, to make them less suggestive and allow for the use of the survey before and after medical intervention, and with control groups. A 6th question, analyzing eating behavior, was added. The +/-1 point given to the evaluation of self-esteem was split with this new question, thus maintaining the consistency of the scores. The drawings were simplified. Finally, the scoring key was changed to a 10-point Likert scale, to improve response-differentiation. To validate the M-A QoLQII, we examined its concordance with other health and well-being indicators, specifically the MOS 36-Item Short-Form Health Survey (SF-36), the Beck Depression Inventory-II (BDI-II) and the Stunkard and Messick Eating Inventory. The study population included 110 morbidly obese patients (20 males, 90 females, mean BMI=50), participants of gastric bypass support groups. Reliability of the M-A QoLQII was determined using Cronbach's alpha coefficient. Construct validity was measured by conducting a series of Spearman rank correlations.

Results: A Cronbach's alpha coefficient of 0.84 indicated satisfactory internal consistency. The M-A QoLQII was found to be significantly correlated (P <0.01) to 7 of the 8 SF-36 scales: Physical Role (r=0.357), Bodily Pain (r=-0.486), General Health (r=0.413), Vitality (r=0.588), Social Functioning (r=0.517), Emotional Role (r=0.480), and Mental Health (r=0.489). The questionnaire also significantly correlated (P <0.01) to the Beck Depression Inventory-II (r=0.317), as well as to the 'Disinhibition' (r=-0.307) and 'Hunger' (r=-0.254) factors of the Stunkard and Messick Eating Inventory.

Conclusions: The M-A QoLQII correlates well with other widely used health and well-being indicators such as the SF-36, Beck Depression Inventory II and the Stunkard and Messick Eating Inventory. The study established the validity and reliability of this improved disease-specific instrument for QoL measurement in the obese population.