Keywords

Control Attitudes Scale, item response theory, LVAD, perceived control, psychometrics

 

Authors

  1. Thompson, Jessica Harman PhD, RN
  2. Moser, Debra PhD, RN, FAAN
  3. Lee, Christopher S. PhD, RN, FAHA, FHFSA, FAAN

Abstract

Background: Perceived control, an indicator of the patient's ability to cope and thrive with a chronic illness, is a common target of nursing interventions. As of 2019, more than 25 000 patients had been implanted with a left ventricular assist device (LVAD) as a treatment of advanced heart failure. Patients with an LVAD experience significant life changes that affect anxiety, depression, health-related quality of life, and, presumably, perceived control. To adequately intervene and improve perceived control, a reliable and valid measure is needed.

 

Objectives: The objectives of this analysis were to (1) assess item discrimination and anticipated range of scores of the Control Attitudes Scale-Revised (CAS-R), (2) assess the internal consistency and validity of the CAS-R, and (3) examine perceived control in a sample of patients with an LVAD.

 

Methods: Two cohorts of patients with an LVAD (n = 113) were combined to evaluate the psychometric qualities of the CAS-R. Correlations among patient-reported outcomes and perceived control were used to evaluate validity. Cronbach [alpha] was used to test internal consistency. Item response theory was used to measure item discrimination and anticipated scores. Descriptive statistics describe perceived control in the sample.

 

Results: Overall, the CAS-R demonstrated good internal consistency and convergent validity with other patient-reported outcomes. Using the item response theory, we saw that the CAS-R was a good predictor of lower-moderate scorers but was not good at differentiating high performers. There were several items that were poor discriminators and could be altered or discarded to create a more predictive instrument.

 

Conclusions: The CAS-R is a valid and reliable instrument to measure perceived control in patients who have LVAD implants; however, more work could be done to improve item-level information.