Towards evidence-based dementia screening in Australia

To the Editor: In their editorial, Terpening, Hodges and Cordato argue for routine screening for dementia in Australia.1 Most of the editorial is devoted to discussing which test should be used, and the authors contend that the most-used test — the mini-mental state examination — has such poor test characteristics that it would be a very poor basis for routine screening.

However, the discussion about which test to use ignores the elephant in the room — should we screen for dementia in the first place? In their 1968 World Health Organization public health paper on screening for disease, Wilson and Jungner stipulate that “There should be an accepted treatment for patients with recognized disease”.2 There is no evidence whatsoever that this is the case with dementia.

Terpening and colleagues cite an article in their editorial in support of their assertion that “development of effective dementia treatments depends on earlier and more accurate identification of disease”.3 However, that article only states that early intervention might help to slow some forms of cognitive decline or progression to dementia. This is a very slim evidence base for routine mass screening. The development of effective treatments can never be a justification for routine population-wide screening. Even in a study environment, screening the study population with a view to developing treatments rather than testing them, would struggle to find ethics approval.

The evidence is clear — there is no basis for screening for dementia. It would produce many false positives and false negatives, and would cause much anxiety without any benefit from early treatment. As long as no effective treatments are available, the case for screening for dementia is void.