One of the biggest barriers to preventative healthcare is that it doesn't pay -- at least not quickly enough to make business sense for an insurer. There's a famous paper that looked for cost-saving interventions in preventing heart attacks and strokes, and it concluded:
"As they are currently delivered, almost all of the prevention activities are expensive. If applied fully, using current protocols and the reference assumptions about costs (Table 2), they would increase health care costs by $8.5 trillion over 30 years (Table 3), or $283 billion per year, or $1700 per person per year (data not shown). The only cost-saving activity is smoking cessation."
You can read the full paper here. It's from 2008, so perhaps some entrepreneur will be able to find the breakthrough that finally bends the cost curve: http://circ.ahajournals.org/content/118/5/576.short