Developing a questionnaire to measure patients' beliefs about inhaler treatment for asthma: Tests of validity and reliability

Abstract

To develop a valid and reliable questionnaire for measuring patients' beliefs about inhaler treatments for asthma. Methods: In seven general practices, 335 patients prescribed both beclomethasone and salbutamol inhalers completed a 66-item questionnaire. Subscales were developed using factor analysis and a 29-item questionnaire sent to 90 patients in another practice to estimate test-retest reliability. Results: Three factors explained 31.4% of the variance relating to beliefs about inhalers: preventing asthma symptoms, problems with and concerns about inhalers, and relieving asthma symptoms. Cronbach's alpha coefficients of the sub-scales were 0.71, 0.70 and 0.70 respectively. Intra-class correlation coefficients were 0.87 or more for all three sub-scales. The prevention and relief scale scores were significantly correlated with estimates of corticosteroid and β 2-agonist use. Conclusions: A valid and reliable questionnaire has been developed for measuring patients' beliefs about inhaler treatments for asthma. Its utility in predicting adherence and facilitating patient education needs to be tested.

The Dyskinetic Cerebral Palsy Functional Impact Scale: development and validation of a new tool

“…Construct convergent validity, 31 the extent to which the D‐FIS produces similar results as another well‐established tool that measures a related construct (i.e. dystonia severity), was assessed against the BADS.…”

“…Differences in D-FIS total scores between ambulant and non-ambulant children according to the GMFCS (ambulant=levels I, II, and III; non-ambulant=levels IV and V) were compared. The hypotheses were that: (1) children in higher GMFCS/MACS/ 31 the extent to which the D-FIS produces similar results as another well-established tool that measures a related construct (i.e. dystonia severity), was assessed against the BADS.…”

The Dyskinetic Cerebral Palsy Functional Impact Scale: Development and validation of a new tool

“…Construct validity, the degree to which the D-FIS measures the intended construct, was evaluated using known groups methods based on correlation of the D-FIS with the functional levels of the GMFCS, MACS, CFCS, and EDACS, and differences in D-FIS scores across levels within each of these four systems. Each Construct convergent validity, 31 the extent to which the D-FIS produces similar results as another well-established tool that measures a related construct (i.e. dystonia severity), was assessed against the BADS.…”