Development and initial testing of the self-care of chronic illness inventory.

Abstract

The aim was to develop and psychometrically test the self-care of chronic illness Inventory, a generic measure of self-care. Existing measures of self-care are disease-specific or behaviour-specific; no generic measure of self-care exists. Cross-sectional survey. We developed a 20-item self-report instrument based on the Middle Range Theory of Self-Care of Chronic Illness, with three separate scales measuring Self-Care Maintenance, Self-Care Monitoring, and Self-Care Management. Each of the three scales is scored separately and standardized 0-100 with higher scores indicating better self-care. After demonstrating content validity, psychometric testing was conducted in a convenience sample of 407 adults (enrolled from inpatient and outpatient settings at five sites in the United States and ResearchMatch.org). Dimensionality testing with confirmatory factor analysis preceded reliability testing. The Self-Care Maintenance scale (eight items, two dimensions: illness-related and health-promoting behaviour) fit well when tested with a two-factor confirmatory model. The Self-Care Monitoring scale (five items, single factor) fitted well. The Self-Care Management scale (seven items, two factors: autonomous and consulting behaviour), when tested with a two-factor confirmatory model, fitted adequately. A simultaneous confirmatory factor analysis on the combined set of items supported the more general model. The self-care of chronic illness inventory is adequate in reliability and validity. We suggest further testing in diverse populations of patients with chronic illnesses.