This article from Harvard Business Review website by the Chief Medical Officer of athenahealth provides insight garnered by patient use of the athenahealth portal. The findings includes the following:

• Adoption and use rates are similar for all age groups.
• Specialists can benefit just as much as primary care providers.
• Default to opt-in for patient use is effective at increasing engagement.
• Poorer people may be at risk due to lower usage rates, but this is not a given.
• Small-size practices can benefit just as much as large-size practices.

This is indeed encouraging news for patient engagement with the management of their health.