It will often take someone using a screen reader longer to hear a page read to them than it will somebody reading on a monitor. Likewise if they have to fill out a form or complete an action it will takelonger because they have to make certain they understand the instructions given. They will also need to be more careful about the information they provide as they cannot see what they are entering. If your site has automatic time outs on pages or actions this can cause problems for users who need a screen reader. So ideally you should not have anything on your site which times out. If for reasons of security, privacy or anything else you need to set time limits for your users - you should at the very least warn the user about the amount of time they have to complete a task and then warn them again when the time is about to expire. Furthermore it would help to provide users with a means to extend the time they have to complete a task.

Read more about how Time Outs criterion scoring works.