Association of diagnostic delay with impairment severity among institutional care facility residents diagnosed with dementia in Ontario, Canada.

Aim: To compare the levels of cognitive function at the time of diagnosis among institutional care facility residents with dementia, who were diagnosed either before or after admission to a facility in Ontario, Canada.

Methods: The study utilized a population-based secondary data analysis approach, using data from the Canadian Institute for Health Information's Continuing Care Reporting System from 2009 to 2011. Cognitive function within 30 days of diagnosis was measured by a seven-point cognitive performance scale (CPS) - 0 (intact) to 6 (very severe impairment).

Results: Data were extracted from 39633 institutional care facility residents who had a diagnosis of dementia on record. The average CPS score was higher for residents whose diagnosis was made after admission to a facility than for residents whose diagnosis was made before admission (3.1 vs 2.9, P=0.009). The proportion of diagnosis at CPS ≥ 4 (moderately severe to very severe impairment) was also higher in the diagnosis after admission group (29.7% vs 24.6%, P=0.001). Multivariable analysis showed that diagnoses made after admission were more likely to be at a severe stage of cognitive decline (CPS ≥ 4) than diagnoses made before admission (adjusted odds ratio 1.49, P=0.001). A similar result was also noted when comparison was made between mild and moderate-to-severe stages of cognitive decline. After admission diagnoses were more likely to be at moderate-to-severe stages of cognitive decline (CPS ≥ 3) than before admission diagnoses (adjusted odds ratio 1.70, P=0.001).

Conclusion: Our findings suggest that dementia diagnoses after admission to institutional care facilities are more likely to be made at poorer stages of cognitive function decline.