Tenant screening, do you consider debt to income?

[Tyler Bobo]

If you want to see the monthly income of 3x the rental amount (or whatever your standards happen to be) do you ask what they owe and have monthly payments on?  Obviously if their income is already "spoken for" and they're stretched too thin they'll likely run into trouble.  I haven't previously considered this much, yet I've been burned before.  How do you handle high Debt to Income?