Any peer reviewed studies showing that sleep tracking is right?

[m123]

Anyone know of any peer reviewed studies that show that sleep tracking on a fitbit is accurate?  It seems that by tracking movment, you don't get a full picture. 

[mlaccs]

Studies no but based on what my fitbit reports and how I feel there seems to be a decent pattern.  It is a tool and not a major medical device.  I do think the trends over time can be helpful to show a medical professional as it is some easy data to have when asked.