return a checkbox value in jade. using node.js ,express and Mongoose

I saved the checkbox value in mongoDB. passed the value to the page by

if (req.session.user.Single === undefined) {single_status= 'false'} else {single_status= ''};

res.render('user-profile', { 
    Single: single_status,
)};

Then i have this in jade

.col-md-4
 label-option(for="checkbox")
 input(type="checkbox", checked="#{Single}", name='single', id='single')

on the rendered view. It appears checked="false" so it is always checked. how to a return the valve to the checkbox to present the existing checked / unchecked?

<label-option for="checkbox">
 <input type="checkbox" checked="false" name="single" id="single"> Single Status
</label-option>