Using the Capture-Recapture Method to Estimate the Incidence of Amyotrophic Lateral Sclerosis in Beijing, China

Population-based incidence rates of 15 neuromuscular disorders: a nationwide capture-recapture study in the Netherlands

Most neuromuscular disorders are rare, but as a group they are not. Nevertheless, epidemiological data of specific neuromuscular disorders are scarce, especially on the incidence. We applied a capture-recapture approach to a nationwide hospital-based dataset and a patients association-based dataset to estimate the annual incidence rates for fifteen neuromuscular disorders in the Netherlands. The annual incidence rates per 100,000 population varied from 0.03/100,000 (95% CI 0.00 ‒ 0.06) for glycogenosis type 5 to 0.9/100,000 (95% confidence interval 0.7 ‒ 1.0) for myotonic dystrophy type 1. The summed annual incidence rate of these disorders was 4.1 per 100,000 per population. Nine of the provided incidence rates were previously unavailable, three rates were similar to the rates in the literature, and three rates were generally higher compared to previous findings but with overlapping confidence intervals. This study provides nationwide incidence rates for fifteen neuromuscular disorders predominantly diagnosed in adult life, nine which were previously unavailable. The capture-recapture approach provided estimates of the total number of individuals with neuromuscular disorders. To complete the gaps in the knowledge of disease frequencies, there is a need for estimates from an automated, obligatory data collection system of diagnosed and newly diagnosed patients with neuromuscular disorders.

Prevalence of amyotrophic lateral sclerosis in the United States using established and novel methodologies, 2017

Objective:To estimate the prevalence of amyotrophic lateral sclerosis (ALS) in the United States for 2017 using data from the National ALS Registry (Registry) as well as capture-recapture methodology to account for under-ascertainment. Established in 2010, the Registry collects and examines data on ALS patients in the US to better describe the epidemiology of ALS (i.e. risk factor exposures, demographics).Methods: The Registry compiled data from national administrative databases (from the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration) and a voluntary enrollment data through a web portal (www.cdc.gov/als). To estimate the number of missing cases, capture-recapture methodology was utilized.Results: The Registry conservatively identified 17,800 adult persons (lower-bound estimate) who met the Registry definition of ALS for an age-adjusted prevalence of 5.5 per 100,000 US population. Using capture-recapture methodology, we obtained a "mean case count" of 24,821 ALS cases (prevalence of 7.7 per 100,000 U.S. population) and estimated the upper-bound estimate to be 31,843 cases (prevalence of 9.9 per 100,000 U.S. population). The pattern of patient characteristics (e.g. age, sex, and race/ethnicity) remained unchanged from previous Registry reports. Overall, ALS was most common among whites, males, and persons aged 60-69 years. The age groups with the lowest number of cases were persons aged 18-39 years. Males had a higher prevalence than females overall and across all data sources.Conclusions: Existing Registry methodology, along with capture-recapture methodology, are being used to better describe the epidemiology and demographics of ALS in the US.

Incidence, Prevalence, and Geographical Clustering of Motor Neuron Disease in the Netherlands

OBJECTIVE

To assess time trends in motor neuron disease (MND) incidence, prevalence, and mortality and to investigate geographic clustering of MND cases in the Netherlands from 1998 to 2017, we analyzed data from the Netherlands Personal Records database, the Netherlands MND Center, and the Netherlands Patient Association of Neuromuscular Diseases.

METHODS

In this prospective cohort study, Poisson regression was used to assess time trends in MND risk. We calculated age- and sex-standardized, observed, and expected cases for 1,694 areas. Bayesian smoothed risk mapping was used to investigate geographic MND risk.

RESULTS

We identified 7,992 MND cases, reflecting an incidence of 2.64 (95% confidence interval [CI] 2.62-2.67) per 100,000 person-years and a prevalence of 9.5 (95% CI 9.1-10.0) per 100,000 persons. Highest age-standardized prevalence and mortality rates occurred at a later age in men than in women (p < 0.001). Unadjusted mortality rates increased by 53.2% from 2.57 per 100,000 person-years in 1998 to 3.86 per 100,000 person-years in 2017. After adjustment for age and sex, an increase in MND mortality rate of 14.1% (95% CI 5.7%-23.2%, p < 0.001) remained. MND relative risk ranged from 0.78 to 1.43 between geographic areas; multiple urban and rural high-risk areas were identified.

CONCLUSIONS

We found a significant national increase in MND mortality from 1998 through 2017, explained only partly by an aging Dutch population, and a geographic variability in MND risk, suggesting a role for environmental or demographic risk factors.

Incidence and prevalence of amyotrophic lateral sclerosis in urban China: a national population-based study

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease and information on disease burden of ALS in mainland China was limited. We aimed to estimate the prevalence and incidence of ALS in China.

METHODS

We used 2012-2016 data from China's Urban Employee Basic Medical Insurance and Urban Residence Basic Medical Insurance, covering approximately 0.43 billion individuals. ALS cases were identified by the primary diagnosis (International Classification of Diseases code or text of diagnosis) in the insurance database.

RESULTS

The crude prevalence and incidence in 2016 were 2.91 per 100 000 person-years (95% CI 2.31 to 3.58) and 1.65 (95% CI 1.33 to 2.01), respectively. The standardised prevalence and incidence based on 2010 Chinese census data were 2.97 (95% CI 2.91 to 3.03) and 1.62 (95% CI 1.58 to 1.67), respectively. The annual prevalence between 2013 and 2016 remained relatively constant, ranging from 2.91 (95% CI 2.31 to 3.58) in 2016 to 3.29 (95% CI 2.51 to 4.17) in 2014 (linear regression: β=-0.129, p=0.104). Both rates peaked in the group aged 75-79 years.

CONCLUSIONS

The prevalence and incidence of ALS in mainland China were lower than those in developed countries, and maintained a relatively stable trend. The age at onset and age at diagnosis for ALS patients were younger than those in developed countries. Further research is expected to clarify the potential pathophysiological mechanism of ALS.