For the knee screening algorithm (algorithm #1, knee), we
also included 4 of the original 11 questions: "During the
last 12 months, have you often had pain in one or both
your knees for one month or more?"; "Has a doctor ever
told you that you have osteoarthritis in one or both of
your knees?"; "During the last 12 months, have you had
any limitations rising from a chair or toilet because of
pain or stiffness in one or both of your knees?"; and "During
the last 12 months, have you had stiffness in one or
both your knees for one month or more?" We based our
election on previous studies [13].