Conclusion Based on this literature review , the disease-specificHAQ and the generic SF-36 can currently be most confidently recommended to measure PF in RA for most research purpose s. The HAQ , however , was frequently associated with considerable ceiling effects while the SF-36 has limited content coverage .
Background The aim of this study was to systematic ally review the content validity and measurement properties of all physical function ( PF ) scales which are currently vali date d for use with patients with rheumatoid arthritis ( RA ) .
Responsiveness of the core set, response criteria, and utilities in early rheumatoid arthritis
OBJECTIVE Validation of responsiveness and discriminative power of the World Health Organisation/International League of Associations for Rheumatology ( WHO/ILAR ) core set , the American College of Rheumatology ( ACR ) , and European League for Rheumatology ( EULAR ) criteria for improvement/response , and other single and combined measures ( indices ) in a trial in patients with early rheumatoid arthritis ( RA ) . METHODS Ranking of measures by response ( st and ardised response means and effect sizes ) and between-group discrimination ( unpaired ttest and χ2 values ) at two time points in the COBRA study . This study included 155 patients with early RA r and omly allocated to two treatment groups with distinct levels of expected response : combined treatment , high response ; sulfasalazine treatment , moderate response . RESULTS At week 16 , st and ardised response means of core set measures ranged between 0.8 and 3.5 for combined treatment and between 0.4 and 1.2 for sulfasalazine treatment ( 95 % confidence interval ±0.25 ) . Performance of patient oriented measures ( for example , pain , global assessment ) was best when the questions were focused on the disease . The most responsive single measure was the patient 's assessment of change in disease activity , at 3.5 . Patient utility , a generic health status measure , was moderately ( rating scale ) to poorly ( st and ard gamble ) responsive . Response means of most indices ( combined measures ) exceeded 2.0 , the simple count of core set measures improved by 20 % was most responsive at 4.1 . Discrimination performance yielded similar but not identical results : best discrimination between treatment groups was achieved by the EULAR response and ACR improvement criteria ( at 20 % and other percentage levels ) , the pooled index , and the disease activity score ( DAS ) , but also by the Health Assessment Question naire ( HAQ ) and grip strength . CONCLUSIONS Responsiveness and discrimination between levels of response are not identical concepts , and need separate study . The WHO/ILAR core set comprises responsive measures that discriminate well between different levels of response in early RA . However , the performance of patient oriented measures is highly dependent on their format . The excellent performance of indices such as the ACR improvement and EULAR response criteria confirms that they are the preferred primary end point in RA clinical trials
Conclusion Based on this literature review , the disease-specificHAQ and the generic SF-36 can currently be most confidently recommended to measure PF in RA for most research purpose s. The HAQ , however , was frequently associated with considerable ceiling effects while the SF-36 has limited content coverage .
Background The aim of this study was to systematic ally review the content validity and measurement properties of all physical function ( PF ) scales which are currently vali date d for use with patients with rheumatoid arthritis ( RA ) .