The MMSE is effective as a screening instrument to separate patients
with cognitive impairment from those without it. In addition, when used repeatedly the instrument is able to
measure changes in cognitive status that may benefit from intervention. However, the tool is not able to
diagnose the case for changes in cognitive function and should not replace a complete clinical assessment of
mental status. In addition, the instrument relies heavily on verbal response and reading and writing. Therefore,
patients that are hearing and visually impaired, intubated, have low English literacy, or those with other
communication disorders may perform poorly even when cognitively intact.