Trends in Stroke Incidence in High-Income Countries in the 21st Century

Population-Based Study and Systematic Review

Linxin Li, DPhil; Catherine A. Scott, BMBCh; Peter M. Rothwell, FMedSci

Disclosures

Stroke. 2020;51(5):1372-1380. 

In This Article

Abstract and Introduction

Abstract

Background and Purpose: Population-based studies provide the most reliable data on stroke incidence. A previous systematic review of population-based studies suggested that stroke incidence in high-income countries decreased by 42% between the 1970s and early 2000s. However, it is uncertain whether this trend of steady decline has been maintained in more recent periods.

Methods: Data from OCSP (Oxfordshire Community Stroke Project; 1981–1986) and OXVASC (Oxford Vascular Study; 2002–2017) along with other published population-based stroke incidence studies that reported temporal trends of stroke incidence since 1990 in high-income countries were included. Age-standardized relative incidence rate ratios were calculated for each study and then pooled with inverse-variance weighted random-effects meta-analysis. Projection estimates were calculated for the number of incident stroke patients in the United Kingdom from year 2015 to 2045.

Results: In Oxfordshire, stroke incidence fell by 32% from OCSP to OXVASC, with a similar trend before or after year 2000. With the projected aging population, if the age-specific stroke incidence continued to decrease at its current rate (6% every 5 years), there would still be a 13% increase of the number of first-ever strokes in the United Kingdom up to year 2045. Incorporating the Oxfordshire data with other 12 population-based studies, stroke incidence declined steadily between the 1990s and 2010s within each study, resulting in a 28% decline over an average period of 16.5 years (pooled incidence rate ratio, 0.72 [95% CI, 0.66–0.79]; P<0.0001). The trend was the same for men (0.69 [95% CI, 0.61–0.77]; P<0.0001) and women (0.66 [95% CI, 0.59–0.74]; P<0.0001) and remained consistent after year 2010 in OXVASC. Proportion of disabling or fatal stroke also decreased over time (early versus later period, 53.6% versus 46.1%; P=0.02).

Conclusions: Stroke incidence is continuing to decline with steady rate in Oxfordshire and in other high-income settings. However, the absolute number of strokes occurring is not falling.

Introduction

Stroke is the second leading cause of death worldwide and the main cause of long-term neurological disability in adults.[1] In high-income countries, increased use of preventive treatments and major reductions in premorbid risk factors between the 1970s and early 2000s have coincided with significant falls in stroke incidence during this period.[2] However, it is uncertain whether this trend of steady decline has been maintained in more recent years, particularly in view of the continuing aging of the population and the rise of diabetes mellitus and obesity in recent decades.[3–5] Reliable estimates and projections of the future stroke burden are important for long-term healthcare infrastructure planning, policy making, and are important for the organization of stroke services and prevention activities.

Some studies based on administrative data reported that the reduction of stroke incidence was less marked in the early 2000s.[6,7] However, accuracy of coding of stroke in routinely collected data can also vary over time.[8,9] Prospective population-based incidence studies provide the most reliable data on stroke incidence.[2] Therefore, in a population-based study in Oxfordshire, United Kingdom, we determined the change of stroke incidence in the last 4 decades and estimated the potential burden of stroke incidence in the United Kingdom from year 2015 to 2045. A few other population-based studies also maintained ideal case-ascertainment procedures over a long period of time to provide comparable estimates of stroke incidence change over time. Since the publication of the most recent systematic review of temporal trend of stroke incidence in high-income countries,[10] several population-based studies have reported new data on stroke incidence, particularly after year 2010.[11–18] We, therefore, also combined our results in an updated systematic review to determine the temporal trends of stroke incidence between 1990s and 2010s in high-income settings.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....