Pollster Gallup is narrowing its focus in an effort to find out why some companies perform better than others.

Gallup partnered with corporate health/well-being consultant Healthways to develop an employee well-being measurement tool the two parties call the Well-Being 5. That's because it analyzes five work- and health-related factors as reported by employees: purpose, social, financial, community and physical.

Gallup decided to examine engagement and well-being at "one large insurance company." The big-picture discovery: "Workgroups with high employee engagement had 8 percent fewer unhealthy days than average over a six-month period — low well-being scores notwithstanding. But workgroups that were engaged and thriving in their well-being had 38 percent fewer unhealthy days, illustrating the added benefit of a well-being focus."