SCHFI 6.2 Self-Care Confidence Scale - Brazilian version: psychometric analysis using the Rasch model

Area of Science:

• Cardiology
• Psychometrics
• Health Sciences

Background:

• Heart failure (HF) management requires effective patient self-care.
• Assessing self-care confidence is crucial for improving patient outcomes in HF.
• The Self-Care Confidence Scale (SCCS) is a tool used to measure this confidence.

Purpose of the Study:

• To evaluate the psychometric properties of the Brazilian version of the Self-Care Confidence Scale for patients with heart failure.
• To apply Rasch model criteria for a rigorous psychometric analysis of the scale.
• To determine the reliability and validity of the SCCS in a Brazilian heart failure population.

Main Methods:

• Secondary analysis of psychometric data using the Rasch model.
• The study included 409 outpatients with heart failure.
• Six items of the Self-Care Confidence Scale were analyzed.

Main Results:

• One item exhibited poor fit to the Rasch model (Infit = 1.84, Outfit = 1.99).
• After item exclusion, the remaining scale demonstrated good fit, unidimensionality, and explained 55% of data variance.
• Reliability (person separation = 2.13, Cronbach's alpha = 0.87) and response categories were adequate.

Conclusions:

• The Self-Care Confidence Scale, with the exclusion of one item, exhibits favorable psychometric properties for assessing self-care confidence in heart failure.
• Caution is advised when interpreting results from the original six-item scale.
• The findings support the use of a revised SCCS for Brazilian heart failure patients.