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

The data came from a single public specialized cardiology service, so the findings may not apply to other heart failure populations. The sample was convenient, not randomly selected. The study analysed existing responses from another study, so some primary-study procedures are not detailed here. Item 1 was removed based on this sample, and the authors say the wording may need content validity review before a revised version is used. Other studies have disagreed about whether this scale is one-dimensional or two-dimensional. Only sex was tested for differential item functioning, not other groups such as patients from different services.

Do not conclude that removing item 1 makes heart failure self-care better or improves outcomes. The study only tested how well the scale measured confidence in one Brazilian outpatient sample; it did not test treatment effects.