Factors associated with slow progression of cognitive impairment following first dementia diagnosis.

OBJECTIVES: To investigate the extent to which slow progression of dementia after diagnosis might be predicted from routine longitudinal healthcare data, in order to clarify characteristics of people who experience this outcome. METHODS: A retrospective observational study was conducted using data from the South London and Maudsley NHS Foundation Trust Biomedical Research Centre Case Register. This study included all patients receiving a first dementia diagnosis between 2006 and 2017, restricted to those with a baseline Mini-Mental State Examination (MMSE) score within 6 months of initial diagnosis of dementia and at least one MMSE score after 3 years post-diagnosis. Slow progression was defined as a change in MMSE score of -1, 0 or an increase at the follow-up point. This group was compared to the remainder with an MMSE decline of -2 or more. RESULTS: Overall, 682 patients with slow progression were compared to 1045 with faster progression. In the confounder-adjusted multivariate logistic regression model, slow progression was more likely in younger patients (age 65-74 years; odds ratio: 1.18; 95% confidence intervals: 1.04-1.37), males (1.24; 1.01-1.53), those with moderate or severe dementia according to MMSE, patients with mixed-type dementia (2.06; 1.11-3.82) compared to Alzheimer's disease and less likely in those receiving acetylcholinesterase inhibitor (AChEI) treatment (0.57; 0.46-0.71). CONCLUSION: Slow dementia progression after diagnosis was common in patients with mixed Alzheimer's and vascular dementia, younger age, males and non-receipt of AChEIs, possibly suggesting non-Alzheimer pathologies and clarifying such predictors is important, as there is currently very limited information on which to base prognosis estimates in post-diagnosis counselling.