Age-specific ALS incidence: a dose-response meta-analysis.

Area of Science:

• Neurology
• Epidemiology
• Public Health

Background:

• Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease.
• Understanding the global incidence patterns of ALS is crucial for public health planning and research.
• Age is a known risk factor for ALS, but detailed global incidence patterns by age require comprehensive analysis.

Purpose of the Study:

• To evaluate the association between worldwide Amyotrophic Lateral Sclerosis (ALS) incidence rates and age.
• To perform a dose-response meta-analysis of population-based ALS incidence studies.
• To investigate geographical variations in age-specific ALS incidence.

Main Methods:

• A systematic review of Medline and Embase databases up to July 2016 was conducted.
• Population-based studies of newly-diagnosed ALS cases using multiple ascertainment sources were included.
• Dose-response meta-analysis and meta-regression were employed to analyze 41 incidence studies from 42 geographical areas.

Main Results:

• The overall fit between observed and predicted age-specific ALS incidence rates was very good.
• ALS incidence progressively increased from the 40s, peaking in the 60s or 70s, followed by a sharp decrease.
• Peak ALS incidence in Europe and North America ranged from 6.98 to 8.17/100,000 person-years, occurring around ages 71.6-77.4.
• Eastern Asia showed a lower peak incidence of 2.20/100,000 person-years around age 75.

Conclusions:

• The age-specific pattern of ALS incidence is consistent across different subcontinents.
• Age-specific ALS incidence rates appear lower in Eastern Asia compared to Europe and North America.
• This study confirms the characteristic age-related incidence curve for ALS globally.