Psychometric properties of the external Housing-Related Control Belief Questionnaire among people with Parkinson's disease.

BACKGROUND: Housing-related control beliefs are associated with aspects of health among older people in general. Research on Parkinson's disease (PD) focusing on perceptions of the home are rare and instruments capturing perceived aspects of home have seldom been used. AIMS: To evaluate psychometric properties of the external Housing-related Control Beliefs Questionnaire (HCQ) among people with PD. METHODS: The external HCQ were administrated to 245 participants with PD, (mean age = 69.9 years; mean PD duration = 9.7 years). External HCQ has 16-items, with five response options. The psychometric properties evaluated were data quality, structural validity (factor analysis), floor and ceiling effects, corrected item total correlations, internal consistency and construct validity (testing correlations with relevant constructs according to pre-defined hypotheses). RESULTS: Data quality was high. Structural validity showed a unidimensional construct with removal of two items. Homogeneity was questionable, but strengthened after the removal of the two items. For the 14-item version internal consistency was α = 0.78 and SEM 4.47. Corrected item total correlation ranged between 0.31 and 0.54 and no floor or ceiling effects. Significant correlations with relevant constructs supported the construct validity. CONCLUSIONS: Taken together, the psychometric results suggest a 14-item version of the external HCQ to be sufficiently reliable and valid for use in the PD population. The results pave the way for further studies, using the HCQ to analyse how perceptions of control of the home may be associated with health among people ageing with PD.