Abstract
Background: Adults with chronic illness frequently experience bothersome symptoms (e.g., pain). Decisions about how to manage these symptoms are complex and influenced by factors related to the patient, their illness, and their environment. The naturalistic decision-making framework describes decision-making when conditions are dynamically evolving, and the decision maker is uncertain because the situation is ambiguous and missing information. The contextual factors influencing decisions include time stress, the perception of high stakes, and input from other individuals, which may facilitate or complicate the decision about the self-care of symptoms. There is no valid instrument to measure these contextual factors. The purpose of this study was to develop and test a self-report instrument measuring the contextual factors that influence self-care decisions about symptoms. Methods: Items were drafted from the literature and refined with patient input. Content validity of the instrument was evaluated using a Delphi survey of expert clinicians and researchers, and cognitive interviews with adults with chronic illness. Psychometric testing included exploratory factor analysis to test dimensionality, item response theory-based approaches for item recalibration, confirmatory factor analysis to generate factor determinacy scores, and evaluation of construct validity. Results: The content validity of the Self-Care Decisions Scale is excellent with all items achieving a content validity index of greater than 0.78 in the Delphi survey of experts (n=12). Adults with chronic illness (n=5) endorsed the relevance, comprehensiveness, and comprehensibility of the instrument during cognitive interviews. Initial psychometric testing (n=431) revealed a 6-factor multidimensional structure that was further refined for precision, and high multidimensional reliability. In construct validity testing, there were modest associations with some scales of the Melbourne Decision Making Questionnaire and the Self-Care of Chronic Illness Inventory. Conclusion: The Self-Care Decisions Scale is a 27-item self-report instrument that measures the extent to which contextual factors influence decisions about symptoms of chronic illness with six scales reflecting naturalistic decision making (external, urgency, uncertainty, cognitive/affective, waiting/cue competition, and concealment). The scale can support research that aims to better understand how adults with chronic illness make decisions in response to symptoms. Additional testing of the instrument is needed to evaluate clinical utility.
Psychometric Testing of the Self-care of Hypertension Inventory