Usability measures the quality of a user’s experience when interacting with a website or computer application. Usability testing can help you identify major issues and lead you to workable solutions. It doesn't take long and, if it's done in-house, there is no cost to you.
Complex documents may be difficult to make fully accessible. In that case, you do have the option of creating a text file to post in addition to the PDF. By posting a text file, you are providing a way for those who use screen readers to access the information.