Validation of a new multidimensional health locus of control scale (form C) in asthma research

This study developed and validated an Asthma Multidimensional Health Locus of Control (AMHLC) scale using 186 asthmatics aged 13 to 55 years recruited from 46 pharmacies in the Hunter Valley, Australia. The construct validity and internal consistency of the scale were demonstrated using principal components factor analysis and Cronbach's alpha respectively. Although correlations were modest, findings indicate that asthmatics with higher ''Powerful Others'' locus of control perceived they had a better quality of doctor-patient relationship; the opposite was found for those with higher ''Chance'' scores. Powerful Others orientation was also associated with expectations and valuation of services doctors' provide. Knowledge of asthma was not related in the expected direction with the new scale, nor were clinical indices of asthma severity. Younger asthmatics had higher Chance scores while older asthmatics tended toward higher Powerful Others orientation. Overall, the AMHLC instrument achieved suitable measurement properties to allow further investigation of health care behavior in people with asthma.