Validation of a new measure of availability and accommodation of health care that is valid for rural and urban contexts

CONTEXT Patients are the most valid source for evaluating the accessibility of services, but a previous study observed differential psychometric performance of instruments in rural and urban respondents. OBJECTIVE To validate a measure of organizational accessibility free of differential rural-urban performance that predicts consequences of difficult access for patient-initiated care. DESIGN Sequential qualitative-quantitative study. Qualitative findings used to adapt or develop evaluative and reporting items. Quantitative validation study. SETTING Primary data by telephone from 750 urban, rural and remote respondents in Quebec, Canada; follow-up mailed questionnaire to a subset of 316. MAIN MEASURES AND ANALYSES Items were developed for barriers along the care trajectory. We used common factor and confirmatory factor analysis to identify constructs and compare models. We used item response theory analysis to test for differential rural-urban performance; examine individual item performance; adjust response options; and exclude redundant or non-discriminatory items. We used logistic regression to examine predictive validity of the subscale on access difficulty (outcome). RESULTS Initial factor resolution suggested geographic and organizational dimensions, plus consequences of access difficulty. After second administration, organizational accommodation and geographic indicators were integrated into a 6-item subscale of Effective Availability and Accommodation, which demonstrates good variability and internal consistency (α = 0.84) and no differential functioning by geographic area. Each unit increase predicts decreased likelihood of consequences of access difficulties (unmet need and problem aggravation). CONCLUSION The new subscale is a practical, valid and reliable measure for patients to evaluate first-contact health services accessibility, yielding valid comparisons between urban and rural contexts.