Capturing the Patient's View of Change as a Clinical Outcome Measure

• Published in: JAMA : the journal of the American Medical Association 1999-09, Vol.282 (12), p.1157-1162
• Main Authors: Fischer, David, Stewart, Anita L, Bloch, Daniel A, Lorig, Kate, Laurent, Diana, Holman, Halsted
• Format: Article
• Language: English
• Subjects: Aged; Anti-Inflammatory Agents - therapeutic use; Arthritis - therapy; Arthroplasty; Biological and medical sciences; Chronic Disease; Clinical outcomes; Clinical trials; Clinical Trials as Topic; Disability; Disabled Persons; Diseases of the osteoarticular system; Female; Health; Health care; Health Status Indicators; Humans; Longitudinal Studies; Male; Measurement; Medical sciences; Middle Aged; Miscellaneous. Osteoarticular involvement in other diseases; Outcome Assessment (Health Care); Pain; Patient Education as Topic; Patient Satisfaction; Patients; Sickness Impact Profile; Studies; United States
• ISSN: 0098-7484; 1538-3598
• DOI: 10.1001/jama.282.12.1157

CONTEXT Measurement of change in patients' health status is central to both clinical trials and clinical practice. Trials commonly use serial measurements by the patients at 2 points in time while clinicians use the patient's retrospective assessment of change made at 1 point in time. How well these measures correlate is not known. OBJECTIVE To compare the 2 methods in measurement of changes in pain and disability. DESIGN Longitudinal survey of patients starting new therapy for chronic arthritis in 1994 and 1995. Surveys were completed at baseline (before intervention) and at 6 weeks and 4 months. SETTING Community health education program and university medical and orthopedic services. SUBJECTS A total of 202 patients undertaking self-management education (n=140), therapy with prednisone or methotrexate (n=34), or arthroplasty of the knee or hip (n=28). MAIN OUTCOME MEASURES Concordance between serial (visual analog scale for pain and Health Assessment Questionnaire for disability) and retrospective (7-point Likert scale) measures, sensitivities of these measures, and their correlation with patients' satisfaction with the change (7-point Likert scale). RESULTS When change was small (education group), serial measures correlated poorly with retrospective assessments (eg, r=0.13-0.21 at 6 weeks). With greater change, correlations improved (eg,r=0.45-0.71 at 6 weeks). Average agreement between all pairs of assessments was 29%. Significant lack of concordance was confirmed in all 12 comparisons by McNemar tests (P=.02 to