Explaining variance in use of a Web-based immunization registry: The influence of cognitive, social, technical, organizational, and work-related factors

This study examined determinants of use of an immunization registry. The technology acceptance model (TAM) was extended with contextual factors (contextualized TAM, cTAM) to develop hypotheses about immunization registry usage. Commitment to change, perceived usefulness, perceived ease of use, job-tasks change, subjective norm, computer self-efficacy and system interface characteristics were hypothesized to affect usage. The study was a prospective design of 100 end-users in a mid-western state. Surveys were done alter training and after system usage. The results show that perceived usefulness, perceived ease of use, subjective norm and job-tasks change influenced usage of the immunization registry directly, while computer self-efficacy and system interface characteristics influenced usage indirectly through perceived ease of use. Perceived ease of use also influenced usage indirectly through perceived usefulness. The effect of commitment to change on immunization registry usage was insignificant. The significance of the study, limitations and future research areas are discussed.