Can we forget the Mini-Mental State Examination? A systematic review of the validity of cognitive screening instruments within one month after stroke

OBJECTIVE: To review systematically studies investigating the convergent, criterion, and predictive validity of multi-domain cognitive screening instruments in the first four weeks after stroke.

DATA SOURCES: Electronic databases (Pubmed, PsycINFO, CINAHL, Embase) were searched until June 2014.

REVIEW METHODS: Studies concerning screening for cognitive dysfunction in stroke patients using multi-domain instruments, within four weeks postinfarct or haemorrhagic stroke, using tests taking no longer than one hour. Convergent, criterion, and predictive validity were examined.

RESULTS: A total of 51 studies investigating 16 cognitive screening instruments were identified. None of the instruments covered all of the most affected cognitive domains. Only one study investigated the convergent validity of a multi-domain test during the (sub)acute phase after stroke. A total of 15 studies examined the criterion validity of cognitive measurements during the acute phase after stroke. The Montreal Cognitive Assessment and Higher Cortical Function Deficit Test had good criterion validity. A total of 24 studies examined the predictive ability of multi-domain cognitive instruments applied in the acute phase after stroke. The Cognistat, Montreal Cognitive Assessment, and Functional Independence Measure-cognitive showed good predictive validity. The Mini-Mental State Examination is the most widely used cognitive screening instrument, but shows insufficient criterion validity.

CONCLUSION: None of the existing instruments fulfils all criteria. The Montreal Cognitive Assessment is the best candidate at present, provided items measuring speed of information processing are added, and further studies investigating the optimal cut-offs are conducted.