The  Childhood Health Assessment Question naire ( C-HAQ )  was the most extensively studied instrument and had high reliability , but only moderate correlations with other indices of disease activity and poor responsiveness to change in disease status .
The physician global assessment of disease activity ( PGA ) and articular indices had the strongest association with disease activity and were the most responsive to change .
Measures of psychosocial function and quality of life were moderately associated with measures of disease activity , but were less responsive to changes in disease status .
In children with JIA , no single instrument was superior in reliability or validity or in describing the impact of JIA .
Although the C-HAQ has been extensively evaluated , the PGA and articular indices appear to have the highest responsiveness to change and , therefore , the highest potential for detecting important differences in treatment response
OBJECTIVE To review the performance characteristics of the instruments most commonly used to measure clinical outcomes in juvenile idiopathic arthritis ( JIA ) , including global assessment s , articular indices , functional/disability assessment s , and quality of life measures .
METHODS As part of an Agency for Healthcare Research and Quality comparative effectiveness review of antirheumatic drugs , we explored the characteristics of commonly used outcome measures for JIA .
Preliminary definition of improvement in juvenile arthritis.
OBJECTIVE To identify a core set of outcome variables for the assessment of children with juvenile arthritis ( JA ) , to use the core set to develop a definition of improvement to determine whether individual patients demonstrate clinical ly important improvement , and to promote this definition as a single efficacy measure in JA clinical trials . METHODS A core set of outcome variables was established using a combination of statistical and consensus formation techniques . Variables in the core set consisted of 1 ) physician global assessment of disease activity ; 2 ) parent/patient assessment of overall well-being ; 3 ) functional ability ; 4 ) number of joints with active arthritis ; 5 ) number of joints with limited range of motion ; and 6 ) erythrocyte sedimentation rate . To establish a definition of improvement using this core set , 21 pediatric rheumatologists from 14 countries met , and , using consensus formation techniques , scored each of 72 patient profiles as improved or not improved . Using the physicians ' consensus as the gold st and ard , the chi-square , sensitivity , and specificity were calculated for each of 240 possible definitions of improvement . Definitions with sensitivity or specificity of < 80 % were eliminated . The ability of the remaining definitions to discriminate between the effects of active agent and those of placebo , using actual trial data , was then observed . Each definition was also ranked for face validity , and the sum of the ranks was then multiplied by the kappa statistic . RESULTS The definition of improvement with the highest final score was as follows : at least 30 % improvement from baseline in 3 of any 6 variables in the core set , with no more than 1 of the remaining variables worsening by > 30 % . The second highest scoring definition was closely related to the first ; the third highest was similar to the Paulus criteria used in adult rheumatoid arthritis trials , except with different variables . This indicates convergent validity of the process used . CONCLUSION We propose a definition of improvement for JA . Use of a uniform definition will help st and ardize the conduct and reporting of clinical trials , and should help practitioners decide if a child with JA has responded adequately to therapy . We are in the process of prospect ively validating this definition and several others that scored highly
The  Childhood Health Assessment Question naire ( C-HAQ )  was the most extensively studied instrument and had high reliability , but only moderate correlations with other indices of disease activity and poor responsiveness to change in disease status .
The physician global assessment of disease activity ( PGA ) and articular indices had the strongest association with disease activity and were the most responsive to change .
Measures of psychosocial function and quality of life were moderately associated with measures of disease activity , but were less responsive to changes in disease status .
In children with JIA , no single instrument was superior in reliability or validity or in describing the impact of JIA .
Although the C-HAQ has been extensively evaluated , the PGA and articular indices appear to have the highest responsiveness to change and , therefore , the highest potential for detecting important differences in treatment response
OBJECTIVE To review the performance characteristics of the instruments most commonly used to measure clinical outcomes in juvenile idiopathic arthritis ( JIA ) , including global assessment s , articular indices , functional/disability assessment s , and quality of life measures .
METHODS As part of an Agency for Healthcare Research and Quality comparative effectiveness review of antirheumatic drugs , we explored the characteristics of commonly used outcome measures for JIA .