BACKGROUND

Epidemiological and economic models for stroke have focused on survival and overall function, neglecting cognitive outcomes.

The aim of the StrokeCog model is to develop an epidemiological model of post-stroke CI and dementia in the Irish population, profiling current prevalence and projecting incidence and prevalence into the future.

This model will facilitate a) policy and service planning, b) economic evaluation of alternative strategies for stroke management and prevention.

Projecting the incidence of post-stroke cognitive impairment and dementia in the Irish population aged

40+ years from 2015-2025: A probabilistic model Eithne Sexton1, Nora-Ann Donnelly2, Maria Guzman-Castillo3, Piotr Bandosz3, Niamh Merriman1, David Williams1, Niall Pender1,

Anne Hickey1, Maev-Ann Wren2,, Martin O’Flaherty3, Kathleen E Bennett1

1Division of Population Health Sciences, Royal College of Surgeons in Ireland, Dublin 2, Ireland;2Social Research Division, Economic and Social Research Institute, Dublin 2, Ireland; 3Department of Public Health and Policy, University of Liverpool, UK

MORE INFORMATION: E: eithnesexton@rcsi.ie T: @strokecog W: www.strokecog.ie

METHODS

• A Markov probabilistic model was programmed in R, with a cycle length of one year and a ten year time horizon (2015-2025).

• The target population was the population resident in Ireland in 2015, aged 40-89. Stroke was defined as any ischaemic or haemorrhagicstroke (ICD codes I63 and I64). Transient ischaemic attack (TIA) was excluded.

• The model estimates stroke incidence in the Irish population, and tracks stroke patient cohorts through seven health states defined by cognitive impairment, dementia, physical disability, stroke recurrence and death (see Figure 1).

• Age and sex specific estimates were calculated where possible. • The model estimates the number of new cases of stroke and post-stroke

CI in Ireland each year, and the number of people alive with these conditions annually.

• Probability of transition from one state to another was estimated using multiple data sources

• Includes official population and hospital episode statistics (CSO, HIPE), population cohort studies (ELSA, TILDA), stroke population studies (NDPSS), systematic review and meta-analysis (1, 2) , and the StrokeCog nursing home survey.

PRELIMINARY RESULTS

CONCLUSION

• Over 30,000 incident cases of PSCI are projected in the Irish population 2015-2025. Currently, there is limited treatment available for PSCI, and limited cognitive assessment for stroke patients.

• This model will allow us to examine alternative scenarios for reduction in post-stroke CIND/dementia incidence – including cognitive rehabilitation and stroke prevention strategies.

Limitations:• The model assumes no change in the incidence of stroke or dementia from 2015-2025. • Limited data available on population prevalence of post-stroke dementia, and post-recurrent stroke

outcomes. Next steps: • Further sensitivity analysis. • Validation/calibration of international estimates against local and alternative data sources. • Decision modelling and economic evaluation.

This work was funded by the Health Research Board (HRB) in Ireland under Grant No. ICE-2015-1048

REFERENCES1. Mohan KM, Crichton SL, Grieve a P, Rudd a G, Wolfe CD a, Heuschmann PU. Frequency and

predictors for the risk of stroke recurrence up to 10 years after stroke: the South London Stroke Register. J Neurol Neurosurg Psychiatry [Internet]. 2009;80(9):1012–8.

2. Sexton, E., McLoughlin, A., Williams, D. J., Merriman, N. A., Donnelly, N., Rohde, D., … Bennett, K. (2019). Systematic review and meta-analysis of the prevalence of cognitive impairment no dementia in the first year post-stroke. European Stroke Journal, 4(2), 160–171. http://doi.org/10.1177/2396987318825484

Figure 1: Markov model of post-stroke cognitive impairment and dementia

NCI = No cognitive impairment

CIND = Cognitive impairment no dementia

Acronyms: CSO = Central Statistics Office (Ireland); TILDA = The Irish Longitudinal Study on Ageing; HIPE = Hospital Inpatient Episodes (for Ireland); ELSA = English Longitudinal Study on Ageing; NDPSS = North Dublin Population Stroke Study

2a: Estimated and projected number of stroke survivors with CIND and dementia (net prevalent cases)

Figure 2: Post-stroke CIND and dementia in Ireland, age 40-89, 2017-2025, by sex

The number of stroke survivors aged 40-89 in Ireland is projected to increasefrom 30,900 to 45,400 in 2025 (increase of 47%, 95% CI 38%-57%).

Post-stroke CIND is projected to increase from ~9000 cases in 2016 to ~15900 in 2025 (see Fig 2a).

Post-stroke dementia is projected to increase from ~4100 cases to ~8700 in 2025 (see Fig 2a).

2,618 annual incident cases of post-stroke CIND are projected (95% CI 2,358-2,900) and 1200 annual incident cases of post-stroke dementia (95%CI 1,042-1,587) (see Fig 2b)

2b: Estimated and projected number of incident cases of post-stroke CIND and dementia

CIND

CIND

Dementia

Dementia