Evidence map›Paper›PMID 36639204›Full record

ArticleBMJ open2023

Examining the immediate and ongoing impact of the COVID-19 pandemic on population-based estimates of dementia: a population-based time series analysis in Ontario, Canada.

Aaron Jones, Susan E Bronskill, Laura C Maclagan, Liisa Jaakkimainen, David Kirkwood, Alexandra Mayhew, Andrew P Costa, Lauren E Griffith

Abstract read
In one paragraph

Article in BMJ open, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Article
  2. Inequalities in the burden of disease due to dementia, including Alzheimer disease, in British Columbia, Canada, from 2001 to 2022.Health promotion and chronic disease prevention in Canada : research, policy and practice · 2025
    Article
  3. Article
  4. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Aaron JonesDepartment of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada jonesa13@mcmaster.ca.ORCID 0000-0002-6282-3614
Susan E BronskillICES, Toronto, Ontario, Canada.ORCID 0000-0002-7341-0655
Laura C MaclaganICES, Toronto, Ontario, Canada.
Liisa JaakkimainenICES, Toronto, Ontario, Canada.
David KirkwoodICES, Toronto, Ontario, Canada.
Alexandra MayhewDepartment of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.
Andrew P CostaDepartment of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.ORCID 0000-0001-9212-5641
Lauren E GriffithDepartment of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.ORCID 0000-0002-2794-9692

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectivesPopulation-based chronic disease surveillance systems were likely disrupted by the COVID-19 pandemic. The objective of this study was to examine the immediate and ongoing impact of the COVID-19 pandemic on the claims-based incidence of dementia.

methodsWe conducted a population-based time series analysis from January 2015 to December 2021 in Ontario, Canada. We calculated the monthly claims-based incidence of dementia using a validated case ascertainment algorithm drawing from routinely collected health administrative data. We used autoregressive linear models to compare the claims-based incidence of dementia during the COVID-19 period (2020-2021) to the expected incidence had the pandemic not occurred, controlling for seasonality and secular trends. We examined incidence by source of ascertainment and across strata of sex, age, community size and number of health conditions.

resultsThe monthly claims-based incidence of dementia dropped from a 2019 average of 11.9 per 10 000 to 8.5 per 10 000 in April 2020 (32.6% lower than expected). The incidence returned to expected levels by late 2020. Across the COVID-19 period there were a cumulative 2990 (95% CI 2109 to 3704) fewer cases of dementia observed than expected, equivalent to 1.05 months of new cases. Despite the overall recovery, ascertainment rates continued to be lower than expected among individuals aged 65-74 years and in large urban areas. Ascertainment rates were higher than expected in hospital and among individuals with 11 or more health conditions.

conclusionsThe claims-based incidence of dementia recovered to expected levels by late 2020, suggesting minimal long-term changes to population-based dementia surveillance. Continued monitoring of claims-based incidence is necessary to determine whether the lower than expected incidence among individuals aged 65-74 and in large urban areas, and higher than expected incidence among individuals with 11 or more health conditions, is transitory.

Indexed as

COVID-19DementiaHumansOntarioPandemicsTime FactorsCOVID-19dementiageriatric medicinepublic health

Identifiers

PMID36639204
PMCPMC9842601

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LicenceCC BY-NC
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.