Final answer:
The single most important factor in accelerating health information technology (HIT) adoption since 2008 has been the major increase in government spending on healthcare.
Step-by-step explanation:
The single most important factor in accelerating health information technology (HIT) adoption since 2008 has been the government's major increase in spending on healthcare. After President Obama took up health care as a major policy initiative in 2009, his administration negotiated with every major sector of the health-care industry to support its proposals. This resulted in an increase in government spending on healthcare, which played a significant role in encouraging the adoption of health information technology.