Psychometric properties of a patient-reported outcome set in acute stroke patients

OBJECTIVES: Impairments after stroke may affect multiple domains of health-related quality of life (HRQoL). Patient-reported outcome measures (PROMs) have proven valuable in measuring patients' well-being. We examine the psychometric properties of a standard set of PROMs assessing global health, anxiety, and depression, and functioning in a German health care setting.

METHOD: We included inpatients at the Department of Neurology at the University Medical Center Hamburg-Eppendorf, diagnosed with stroke. Following the stroke-specific standard set of the International Consortium for Health Outcome Measurement, we collected demographic and clinical information at baseline, and PROMs for global health (PROMIS-10), three items for self-reported functioning, anxiety, and depression (PHQ-4) at 90 days follow-up. We calculated confirmatory factor analyses to test factorial validity and correlation analyses to test construct validity. We further conducted item and reliability analyses.

RESULTS: In a sample of 487 patients (mean age, SD: 71.1, 12.6; 47% female) with mild and moderate symptoms, model fit for the PROMIS-10 was acceptable for the two-factor and single-factor models. Factor loadings ranged from 0.52 to 0.94. The postulated single-factor model for functioning was saturated with zero degrees of freedom. Factor loadings ranged from 0.90 to 0.96. For the PHQ-4, the two-factor model showed excellent model fit. Factor loadings ranged from 0.78 to 0.87. Internal consistency was acceptable to good. Construct validity was generally confirmed.

CONCLUSIONS: The PROMIS-10 is a valid and reliable instrument to measure HRQoL among German stroke patients. While the PHQ-4 was confirmed as a screening measure for mental disorders, further research is needed on items assessing self-reported functioning. Results are limited to patients showing minimal functional deficits.