Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

INTRODUCTION: Vertebral deformities are a common consequence of osteoporosis and are known to decrease quality of life. The Qualeffo-41 is a quality-of-life questionnaire especially developed for measuring quality of life in patients with vertebral deformities. It consists of 41 questions arranged in five domains: pain, physical function, social function, general health perception, and mental function. The objectives of this study were: (1) to develop a shorter version of the Qualeffo-41 by removing redundant questions; and (2) to investigate the scale characteristics, reliability, and validity of this shorter version. METHODS: The study was performed using data from the Qualeffo validation study and the Multiple Outcomes of Raloxifene Evaluation (MORE) study. The analyses were performed in patients with vertebral deformities (n=579). Factor analysis on polychoric correlations and an item response theory (IRT) model, i.e., the generalized partial credit model (GPCM), were used to create a shorter version of Qualeffo-41. Using GPCM, scoring weights were computed for all items. RESULTS: Three items were removed from the data set because of too many missing values. Factor analysis identified three instead of five domains: (1) pain, (2) physical function, and (3) mental function. Five items had factor loadings <0.4 and were not included in the GPCM. After excluding several items, the domains pain (four items), physical function (18 items), and mental function (nine items) showed a good, reasonable, and excellent fit, respectively. This indicates that the mental function domain and the pain domain are more unidimensional than the physical function domain. All three domains showed a very high correlation (r > or =0.95) with the corresponding domains of the Qualeffo-41. CONCLUSIONS: Qualeffo-31 was developed, consisting of three domains with a reasonable to excellent fit to the GPCM. Although the fit to the GPCM supports the construct validity of the Qualeffo-31, validation in a new study should be performed before using it in practice.

Original publication

DOI

10.1007/s00198-005-0024-7

Type

Journal article

Journal

Osteoporos int

Publication Date

2006

Volume

17

Pages

543 - 551

Keywords

Activities of Daily Living, Humans, Mental Disorders, Osteoporosis, Pain, Quality of Life, Reproducibility of Results, Spinal Fractures, Surveys and Questionnaires