The TAM model is a widely applied theory of information systems that determines the beliefs and attitudes of the users relating to the reasons behind adopting a system. TAM describes two variables playing a crucial role in the use of computers. These are the PU (Perceived Usefulness), and PEOU (Perceived Ease of Use) (Pai & Huang, 2011). TAM2 is an extension of TAM that introduced the Subjective Norm (SN) into the model. SN refers the social pressure experienced by the users in using computers especially from those with influence and power in the society. The UTAUT (Unified Theory of Acceptance and Use of Technology) divides computer systems into four main classes, namely Social Influence (SI), Behavioral Intention (BI), Performance Expectancy (PE), and Facilitating Conditions (FC) (Holden & Karch, 2010).
For our case of assessing the benefits of patient online portals, the most promising key variables from UTAUT, TAM and TAM2 include the SI, PU and SN. These variable apply to the use of patient health records (PHRs) and physician/provider endorsements which are common features of online patient portals. Therefore, the TAM theory has offered resolutions that has been existing in the healthcare settings for a long period due to lack of use of patient portals.
Pai, F. Y., & Huang, K. I. (2011). Applying the technology acceptance model to the introduction of healthcare information systems. Technological Forecasting and Social Change, 78(4), 650-660.
Holden, R. J., & Karsh, B. T. (2010). The technology acceptance model: its past and its future in health care. Journal of biomedical informatics, 43(1), 159-172.