Development and psychometric validation of a cystic fibrosis knowledge scale

Well-developed and validated measures of cystic fibrosis (CF) knowledge are scarce. The purpose of the present study is to develop and validate a CF knowledge scale that is brief, easy to use, self-administered and demonstrates clinical utility.

A comprehensive literature search generated a pool of scale items; an expert panel of CF team members reviewed and provided recommendations for item inclusion. A focus group of CF patients and family members (n = 12) then reviewed the items for face validity and reading clarity. To evaluate the validity and reliability of the newly developed CF knowledge scale, it was administered to several different samples including CF patients (n = 45), respirology patients (n = 100), health-care providers (n = 74) and university student samples (psychology students, n = 71; medical students, n = 36).

Internal consistency of the scale was high, with an alpha coefficient for the overall sample of .95 (n = 326). The scale also demonstrated excellent construct validity.

This study is an important first step in a line of research that aims to develop and empirically validate a psycho-educational adherence intervention for improving quality of life and treatment outcomes among adult CF patients. The CF knowledge scale has potential applications as a clinical teaching tool with patients and health-care providers and could be used as an outcome measure in CF educational intervention studies aimed at optimizing CF treatment knowledge, adherence and quality of life among CF patients.