Limited evidence was found for the psychometric properties and clinical usability of these instruments .
However , the CFS-activities and participation question naire ( APQ ) is a disease-specific instrument with moderate content and construct validity .
PURPOSE To summarize measurement instruments used to evaluate activity limitations and participation restrictions in patients with chronic fatigue syndrome ( CFS ) and review the psychometric properties of these instruments .
Chronic fatigue syndrome causes activity limitations and participation restrictions in one or more areas of life .
Disability evaluation in chronic fatigue syndrome: associations between exercise capacity and activity limitations/participation restrictions
Objective : In an attempt to examine whether impairments in cardiorespiratory fitness are associated with daily functioning in patients with chronic fatigue syndrome ( CFS ) , this study addresses the correlations between exercise capacity and activity limitations /participation restrictions . Design : Prospect i ve observational study . Setting : An outpatient tertiary care , chronic fatigue clinic at the Vrije Universiteit Brussel ( VUB ) , Belgium . Subjects : Seventy-seven patients fulfilling the 1994 Centers for Disease Control and Prevention ( CDC ) case definition for CFS . Interventions : All patients filled in the Chronic Fatigue Syndrome Activities and Participation Question naire ( CFS-APQ ) and performed a maximal exercise stress test on a bicycle ergometer . Heart rate was monitored continuously by use of an electrocardiograph .  Metabolic and ventilatory parameters were measured through spirometry .  Results : A statistically significant correlation between the score obtained with the CFS-APQ and the body weight-adjusted peak oxygen uptake ( Spearman rho = -0.32 ; p = 0.005 ) , functional aerobic impairment ( rho = 0.33 ; p = 0.004 ) , workload/body weight ( rho = -0.30 ; p = 0.009 ) , exercise duration ( rho = -0.30 ; p = 0.008 ) , and the percentage of target heart rate achieved ( rho = -0.33 ; p = 0.004 ) was observed . The correlations between the remaining exercise capacity parameters and the scores obtained with the CFS-APQ all indicated a trend towards association ( 0.01<p<0.05 ) . Conclusions : These results suggest a moderate association between exercise capacity and activity limitations /participation restrictions in patients with CFS . The observed correlations lack strength to predict activity limitations / participation restriction based on exercise capacity parameters . Disability evaluation in CFS should therefore encompass both exercise capacity testing and measurements at the activity/participation dimension
Limited evidence was found for the psychometric properties and clinical usability of these instruments .
However , the CFS-activities and participation question naire ( APQ ) is a disease-specific instrument with moderate content and construct validity .
PURPOSE To summarize measurement instruments used to evaluate activity limitations and participation restrictions in patients with chronic fatigue syndrome ( CFS ) and review the psychometric properties of these instruments .
Chronic fatigue syndrome causes activity limitations and participation restrictions in one or more areas of life .