Psychometric Properties of the Asthma Symptom Diary (ASD), a Diary for Use in Clinical Trials of Persistent Asthma.

BACKGROUND: No currently available asthma symptom diary has sufficient validation to be recommended for use as a core asthma outcome measure. OBJECTIVE: The objective of this study was to provide validation data for the 10-item asthma symptom diary (ASD). METHODS: Data were collected in a 4-week prospective, observational study. Subjects completed 3 study visits, completing the ASD twice daily at home for 28 days. Psychometric properties in terms of dimensionality, reliability, validity, and responsiveness were assessed. RESULTS: Data from 276 subjects were analyzed; mean age was 42.9 (standard deviation [SD] = 16.4) years, mean asthma duration was 23.3 (SD = 16.8) years, and 69.6% were female. Confirmatory factor and Rasch analysis supported the ASD as unidimensional and adequately measuring the spectrum of asthma symptom severity. High Cronbach's α (0.94) and intraclass correlation coefficients (0.89-0.95) supported reliability. A high correlation between the 7-day average ASD score and the Asthma Control Questionnaire (ACQ) total score (r = 0.75) and Asthma Quality of Life Questionnaire total scores (r = -0.76), and a moderate correlation with FEV1% predicted (r = -0.30) supported convergent validity. Significant differences (P < .001) between groups classified by ACQ scores supported known-group validity. The 7-day average ASD scores were responsive to change, with significantly higher score changes (P < .001) in responders versus nonresponders. Minimally important differences were calculated and found to be in the range of 0.1-0.3. CONCLUSION: Results of this study indicated that the ASD is a reliable and valid asthma symptom measure for use in adult and adolescent asthma patients to evaluate the effect of treatment on asthma in clinical trials.

Comparison of physician and patient global assessments over time in patients with rheumatoid arthritis: a retrospective analysis from the RADIUS cohort.

BACKGROUND: In rheumatoid arthritis (RA), there is discordance between patient and physician assessments of disease severity and treatment response. OBJECTIVE: This retrospective analysis of the RADIUS (RA Disease-Modifying Anti-Rheumatic Drug Intervention and Utilization Study) 1 cohort examined specific factors that influence differences in global assessments for therapeutic effectiveness of disease-modifying antirheumatic drugs made by physicians (physician global assessment [PhGA]) and patients (patient global assessment [PtGA]). METHODS: The RADIUS 1 cohort consisted of primarily community-based private practice patients with RA requiring either the addition of or a switch to a new biologic or nonbiologic disease-modifying antirheumatic drug and who were followed for up to 5 years by their rheumatologists. Periodic assessments included PhGA, PtGA, Health Assessment Questionnaire-Disability Index (HAQ-DI), 28-item tender/painful joint count (TJC28), swollen joint count (SJC28), pain Visual Analog Scale (VAS), and acute-phase reactants. RESULTS: Among 4359 patients (mean disease duration, 7.3 years), PhGA most highly correlated with TJC28 (0.6956; 95% confidence interval [CI], 0.6881-0.7030) and SJC28 (0.6757; 95% CI, 0.6678-0.6834). Moderate overall correlations were observed for PtGA with TJC28 (0.5000; 95% CI, 0.4890-0.5108) and less 50 with SJC28 (0.3754; 95% CI, 0.3628-0.3878). Patient global assessment most strongly correlated with pain VAS (0.8349; 95% CI, 0.8305-0.8392) and moderately correlated with HAQ-DI (0.5979; 95% CI, 0.5886-0.6071). Acute-phase reactants poorly correlated with PhGA and PtGA. CONCLUSIONS: Low correlations between PhGA and acute-phase reactants suggest that these measurements have a limited contribution compared with the physical examination when physicians make global assessments. These results also suggest that physicians should consider patients' assessments of their disease activity (HAQ, pain VAS, and PtGA) and put joint counts into proper context.