Health start-up Omada is investing in virtual care so you can stay out of the doctor’s office

Omada Health started almost a decade ago to help people at risk of diabetes — about one in three Americans — avoid getting the full-blown disease. Unlike traditional health-care providers, the company only gets paid when its tools are effective, like when patients lose weight or show improvements in their blood sugar levels.

After gaining traction in diabetes prevention, Omada moved into hypertension, mental health and other chronic conditions, where coaching and monitoring can lead to behavioral change and better health, ultimately saving insurers...