Tpbm. Suurmeijer et al., THE GRONINGEN ACTIVITY RESTRICTION SCALE FOR MEASURING DISABILITY - ITS UTILITY IN INTERNATIONAL COMPARISONS, American journal of public health, 84(8), 1994, pp. 1270-1273
Objectives. The Groningen Activity Restriction Scale (GARS) is a non-d
isease-specific instrument to measure disability in activities of dail
y living (ADL) and instrumental activities of daily living (IADL). It
was developed in studies of Dutch samples consisting of elderly or chr
onically ill people. The psychometric properties of the GARS demonstra
ted in these studies were highly satisfactory. This paper addresses th
e psychometric properties of the GARS across countries. Methods. Data
of 623 patients with recently diagnosed rheumatoid arthritis from four
European countries were analyzed by means of a principal components a
nalysis and a Mokken scale analysis for polychotomous items. Results.
The results of the analyses were highly satisfactory; there was one st
rong and reliable general factor representing one underlying dimension
of disability in ADL and IADL, and there was a clear hierarchical ord
ering of the items included in the GARS. The validity of the GARS was
strongly suggested by the pattern of associations of the GARS with age
, sex, and other existing health status measures. Conclusions. The psy
chometric characteristics of the GARS, which measures disability in AD
L and IADL simultaneously, make this instrument very useful for compar
ative research across countries.