Population-based surveillance of amyotrophic lateral sclerosis in New Jersey, 2009-2011

Prevalence of infratentorial superficial siderosis in a large general population sample from the UK Biobank

BACKGROUND

Classical infratentorial superficial siderosis (iSS) is considered a rare but potentially disabling neurological disorder. It results from slow chronic blood extravasation into the cerebrospinal fluid and deposition of the iron degradation product hemosiderin within the subpial layers of the central nervous system. Susceptibility-weighted (SW) magnetic resonance imaging (MRI) is the reference diagnostic modality. Few studies have described the population prevalence of cerebellar or infratentorial siderosis, and there are none from the UK population. The aim of this cross-sectional observational study was to estimate the prevalence of iSS in the UK Biobank sample using pre-defined radiological criteria.

METHODS

We reviewed SW MRIs of participants from the UK Biobank, looking for the radiological features of classical iSS: involvement of infratentorial structures (superior vermis, cerebellar folia, brainstem, or craniocervical junction). We calculated the point prevalence as the number of identified cases per total number of cases reviewed and 95% confidence intervals (CI) using Wilson's Score formula.

RESULTS

Of 10,305 SW MRIs reviewed, five cases with radiological features of iSS were identified demonstrating cerebellar/superior vermis involvement. The estimated prevalence of iSS was calculated as 48.5 (95%CI 20.7-113.5) cases per 100,000 population.

CONCLUSIONS

This is the first study to estimate iSS prevalence in the UK population. The prevalence of iSS is higher than that reported for other rare neurological and neuro-otological disorders, suggesting an important unmet healthcare need for early diagnosis and targeted management strategies. Further studies are needed to determine the clinical associations and prognostic significance of radiologically defined iSS in the general population.

Prevalence of ALS in all 50 states in the United States, data from the National ALS Registry, 2011-2018

Objective: To summarize the prevalence of ALS in all 50 states and Washington, DC in the United States from 2011 to 2018 using data collected and analyzed by the National ALS Registry. In October 2010, the federal Agency for Toxic Substances and Disease Registry (ATSDR) launched the congressionally mandated Registry to determine the incidence and prevalence of ALS within the USA, characterize the demographics of persons with ALS, and identify the potential risk factors for the disease. This is the first analysis of state-level ALS prevalence estimates. Methods: ALS is not a notifiable disease in the USA, so the Registry uses a two-pronged approach to identify cases. The first approach uses existing national administrative databases (Medicare, Veterans Health Administration, and Veterans Benefits Administration). The second method uses a secure web portal to gather voluntary participant data and identify cases not included in the national administrative databases. Results: State-level age-adjusted average prevalence from 2011-2018 ranged from 2.6 per 100,000 persons (Hawaii) to 7.8 per 100,000 persons (Vermont), with an average of 4.4 per 100,000 persons in the US. New England and Midwest regions had higher prevalence rates than the national average. Conclusions: These findings summarize the prevalence of ALS for all 50 states from 2011 to 2018. This is a continuing effort to identify ALS cases on a national population basis. The establishment of the National ALS Registry has allowed for epidemiological trends of this disease and the assessment of potential risk factors that could cause ALS.

Adherence to practice parameters in Medicare beneficiaries with amyotrophic lateral sclerosis

OBJECTIVE

Physician adherence to evidence-based clinical practice parameters impacts outcomes of amyotrophic lateral sclerosis (ALS) patients. We sought to investigate compliance with the 2009 practice parameters for treatment of ALS patients in the United States, and sociodemographic and provider characteristics associated with adherence.

METHODS

In this population-based, retrospective cohort study of incident ALS patients in 2009-2014, we included all Medicare beneficiaries age ≥20 with ≥1 International Classification of Diseases, Ninth Revision, Clinical Modification ALS code (335.20) in 2009 and no prior years (N = 8,575). Variables of interest included race/ethnicity, sex, age, urban residence, Area Deprivation Index (ADI), and provider specialty (neurologist vs. non-neurologist). Outcomes were use of practice parameters, which included feeding tubes, non-invasive ventilation (NIV), riluzole, and receiving care from a neurologist.

RESULTS

Overall, 42.9% of patients with ALS received neurologist care. Black beneficiaries (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.47-0.67), older beneficiaries (OR 0.964, 95% CI 0.961-0.968 per year), and those living in disadvantaged areas (OR 0.70, 95% CI 0.61-0.80) received less care from neurologists. Overall, only 26.7% of beneficiaries received a feeding tube, 19.2% NIV, and 15.3% riluzole. Neurologist-treated patients were more likely to receive interventions than other ALS patients: feeding tube (OR 2.80, 95% CI 2.52-3.11); NIV (OR 10.8, 95% CI 9.28-12.6); and riluzole (OR 7.67, 95% CI 6.13-9.58), after adjusting for sociodemographics. These associations remained marked and significant when we excluded ALS patients who subsequently received a code for other diseases that mimic ALS.

CONCLUSIONS

ALS patients treated by neurologists received care consistent with practice parameters more often than those not treated by a neurologist. Black, older, and disadvantaged beneficiaries received less care consistent with the practice parameters.

Racial disparities in ALS diagnostic delay: a single center's experience and review of potential contributing factors

OBJECTIVE

Outcomes for amyotrophic lateral sclerosis (ALS) patients are improved with prompt diagnosis, earlier initiation of disease-modifying treatments, and participation in a multidisciplinary clinic. We studied diagnostic delay and disease severity at time of clinic presentation between Black and non-Hispanic Caucasian ALS patients.

METHODS

We performed a retrospective analysis of non-Hispanic Caucasian and Black ALS patients seen in the Virginia Commonwealth University Health System multidisciplinary ALS clinic between 2017 and 2023. Diagnostic delay, ALS Functional Rating Scale-Revised (ALSFRS-R) and upright forced vital capacity (FVC) scores at baseline appointment were collected. Patient's distance from clinic and affluency of residential neighborhood were evaluated.

RESULTS

We analyzed 172 non-Hispanic Caucasian and 33 Black ALS patients. Black patients had a 64% increase in diagnostic delay compared to non-Hispanic Caucasian patients. Black patients had a lower performance on ALSFRS-R (5.3 points, p < 0.001) and FVC (17.9 percentage points p < 0.001) at time of first clinic visit. Black patients lived closer to clinic, with higher proportion living in the city of Richmond, but in less affluent areas with lower median house income ($55,300 ± 22,600 vs $69,900 ± 23,700).

DISCUSSION

Our findings demonstrate a large racial difference in ALS diagnostic delay, and greater disease severity and lower respiratory function at time of diagnosis for Black ALS patients. Delay in diagnosis prolongs access to disease-modifying therapies, multidisciplinary care, durable medical equipment, and respiratory and nutritional support. Potential sources of these racial disparities include providers' implicit bias and structural racism.

Survival and epidemiology of amyotrophic lateral sclerosis (ALS) cases in the Chicago and Detroit metropolitan cohort: incident cases 2009-2011 and survival through 2018

Amyotrophic lateral sclerosis (ALS) is a fatal, progressive neurodegenerative disorder. The National ALS Registry launched surveillance projects to understand the distribution of ALS in targeted geographic cohorts. Objective: To describe the demographics, incidence, and survival of persons with ALS (PALS) identified in the Chicago and Detroit area population-based cohort. Methods: Neurologists in the catchment area provided case reports for eligible ALS cases diagnosed and/or cared for from 1 January 2009 through 31 December 2011. Crude incidence rates were calculated for 2009-2011 and stratified by race and ethnicity. Using data from the National Death Index through 2018, we modeled the effect of patient covariates on mortality using the Cox proportional hazard regression. Results: Of the 574 cases, 372 (64.8%) were diagnosed from 2009 to 2011. The combined crude incidence rates for 2009, 2010, and 2011 were 1.44, 1.53, and 1.73 cases per 100,000 person-years, respectively. Of the 486 subjects with complete survival data, 81% were deceased at the end of follow-up. Median survival time was 2.2 years, with 30% and 9% of subjects surviving past 5 and 10 years after diagnosis, respectively. Additionally, female PALS and PALS with longer time between symptom onset and diagnosis experienced longer survival. Nonwhites also experienced longer survival than Whites, except for those cases diagnosed in the younger age categories. Conclusion: Understanding the survival of ALS patients can aid in understanding variable prognostic factors, which can potentially extend survival and improve disease management.

Incidence of amyotrophic lateral sclerosis in the United States, 2014-2016

Objective: To estimate the incidence of amyotrophic lateral sclerosis (ALS) in the United States for calendar years 2014-2016 using data from the National ALS Registry (Registry). The Registry collects data on ALS patients in the United States to better describe the epidemiology of ALS, examine risk factors such as environmental and occupational exposures, and characterize the demographics of those living with the disease. Methods: To identify adult incident cases of ALS, the Registry compiles data from three national administrative databases (maintained by the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration). For cases that are not included in these databases, the Registry includes data collected from patients who voluntarily enroll via a secure web portal. Results: The Registry identified 5695 ALS cases in 2014; 6045 cases in 2015; and 4861 cases in 2016 for age-adjusted incidence rates of 1.7 (2014), 1.5 (2015), and 1.5 (2016) per 100,000 U.S. population, respectively. ALS was more common among whites, males, and persons aged 60-79 years. Conclusions: This is the first time administrative and self-reported databases have been used to describe the incidence of ALS for the United States resulting in a better estimate of disease demographics.

Incidence of amyotrophic lateral sclerosis in older adults

INTRODUCTION/AIMS

We investigated the age- and sex-specific incidence and survival of Medicare beneficiaries with amyotrophic lateral sclerosis (ALS) in patients 66 to 90 years of age.

METHODS

We identified all incident ALS cases within a population-based sample of Medicare beneficiaries in 2009 (total: 22 000 177 person-years at risk for ALS). We calculated age- and sex-specific incidence in 2009 according to multiple, progressively more stringent case definitions. Our most inclusive definition required one ALS code, whereas the most restrictive definition required at least one additional ALS code more than 6 months after the first code, including one from a neurologist. We identified associated imaging studies and electrodiagnostic testing and followed all cases through the end of 2014 to determine survival.

RESULTS

The overall incidence for our most inclusive definition was 22.84 per 100 000 person-years for men and 16.05 per 100 000 person-years for women. The overall incidence was 5.72 per 100 000 person-years for men and 3.99 per 100 000 person-years for women for our most restrictive definition. For our most inclusive definition, fewer than 39.7% of cases ever had an ALS diagnosis from a neurologist, more than 50% had an electrodiagnostic test or imaging study, and 40.1% survived less than 1 year after diagnosis, with 25.5% of these cases surviving no more than 6 months. Cases not meeting the most restrictive definition were more likely than those who did meet the restrictive definition to be older, black, or Asian.

DISCUSSION

The oldest and marginalized Medicare beneficiaries diagnosed with ALS are less likely to be included in epidemiological studies with restrictive definitions, but future studies will need to assess the accuracy of diagnosis.

Demographics, clinical characteristics, and prognostic factors of amyotrophic lateral sclerosis in Midwest

INTRODUCTION/AIMS

The Midwest has the highest regional prevalence of self-reported amyotrophic lateral sclerosis (ALS) in the United States, but with limited epidemiological studies. We aimed to explore the characteristics of patients with ALS in the Midwest.

METHODS

This was a retrospective cohort study of participants with ALS deceased between January, 2010, and September, 2020, registered with the ALS Association Mid-America Chapter. Demographics and clinical variables included gender, race/ethnicity, military status, site of onset, interventions (gastrostomy, non-invasive ventilation, tracheostomy), and visits to ALS Association-registered clinics. Disease characteristics were compared to the National ALS Registry, and survival analysis was performed followed by sample augmentation with historical data to estimate survival with hypothetical censoring.

RESULTS

The database included 1447 participants with a mean age at diagnosis of 65.7 ± 11.9 y (>60 y at diagnosis: 72%). The median survival from symptom onset was 28.0 mo (95% confidence limit: 26.3, 29.7); sample augmentation increased this to 41.0 mo (38.5, 43.5). Bulbar onset disease and older age at diagnosis were associated with shorter survival. Participants not followed in ALS-Association registered clinics were more frequently male, had familial onset and tracheostomy. Veterans (N = 298) were older at diagnosis but had similar survival after adjustment for age.

DISCUSSIONS

Our cohort had an older age at onset and more frequent bulbar onset than the National ALS Registry, perhaps reflecting ascertainment biases in each registry. Prospective cohort studies with more clinical and functional data are needed to better characterize ALS in Midwest, veterans, and non-clinic populations, and to optimize care.

Evaluation of the Completeness of ALS Case Ascertainment in the U.S. National ALS Registry: Application of the Capture-Recapture Method

INTRODUCTION

The Centers for Disease Control and Prevention (CDC) National Amyotrophic Lateral Sclerosis (ALS) Registry is the first national registry for a chronic neurologic disease in the U.S. and uses a combination of case-finding methods including administrative healthcare data and patient self-registration.

METHODS

We applied capture-recapture methodology to estimate the completeness of the Registry for ascertaining patients with ALS for the first full year and the fourth years of the Registry (2011, 2014). The Registry uses the combination of two national administrative claims databases (Medicare and Veterans Affairs) with a self-register option at the registry portal. We conducted descriptive analyses of the demographic and clinical characteristics of the ALS cases identified by each of the sources and estimated the completeness of case ascertainment for each of the three ALS Registry sources individually, pairwise, and in all combinations.

RESULTS

Case-finding completeness was 54% in 2011 and improved to 56% in 2014. A smaller proportion of ALS patients under age 65 were ascertained than those 65 or older and ascertainment was also lower for non-White than White patients. The uncorrected ALS prevalence was 4.3/100,000 in 2011 (in 2014 5.0/100,000), but after correction for under-ascertainment, annual prevalence in 2011 was 7.9/100,000 (95% CI 7.6-8.2) (in 2014 was 8.9/100,000 (95% CI 8.7-9.2)).

DISCUSSION/CONCLUSION

Our findings indicate that administrative healthcare databases are a very efficient method for identifying the majority of ALS prevalent cases in the National ALS Registry and that the inclusion of a web registry portal for patients to self-register is important to ensure a more representative population for estimating ALS prevalence. Nonetheless, more than 40% of ALS cases were not ascertained by the Registry, with individuals younger than age 65 and people of color underrepresented. Recommendations are provided for additional methods that can be considered to improve the completeness of case ascertainment.

The Incidence of Amyotrophic Lateral Sclerosis in Ohio 2016-2018: The Ohio Population-Based ALS Registry

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a fatal, neuromuscular disease with no cure. ALS incidence rates have not been assessed specifically in Ohio, yet the state contains both metropolitan and rural areas with a variety of environmental factors that could contribute to disease etiology. We report the incidence of ALS in Ohio residents diagnosed from October 2016 through September 2018.

METHODS

We engaged practitioners from 9 Ohio sites to identify newly diagnosed ALS patients and to complete case report forms with demographic and clinical information. ALS was diagnosed according to the Awaji criteria and classified as either definite, probable, or possible. We developed a method to estimate missing cases using a Poisson regression model to impute cases in counties with evidence of undercounting.

RESULTS

We identified 333 newly diagnosed ALS patients residing in Ohio during the 2-year index period and found incidence rates varied in the 88 state counties. After incorporating the estimated 27% of missing cases, the corrected crude annual incidence was 1.96/100,000 person-years, and the age- and gender-standardized incidence was 1.71/100,000 person-years (standardized to the 2010 US census).

DISCUSSION/CONCLUSION

The estimated Ohio incidence of ALS is overall similar to that reported in other states in the USA. This study reveals a geospatial variation in incidence within the state, and areas with higher rates warrant future investigation.

Comparison of Phenotypic Characteristics and Prognosis Between Black and White Patients in a Tertiary ALS Clinic

OBJECTIVE

To compare characteristics between Black and White patients with amyotrophic lateral sclerosis (ALS) in order to identify disparities and phenotypic variability.

METHODS

We performed database review for patients seen between 1997 and 2020 at the Emory ALS Center in Atlanta, Georgia. Patients with ALS were included for analyses if race was self-reported as Black or White and symptom onset was prior to January 1, 2017. Variables examined include race, age at onset, diagnostic delay, site of onset, median income, C9orf72 mutation status, feeding tube and tracheostomy status, vital capacity, Amyotrophic Lateral Sclerosis Functional Rating Scale-revised(ALSFRS-R) score, and survival time.

RESULTS

A total of 2,363 patient records were queried, and 1,298 were included in analysis; 203 self-identified as Black and 1,095 as White. Black patients had younger age at symptom onset, lower frequency of C9orf72 mutations, lower median income, longer diagnostic delay, and lower baseline ALSFRS-R and vital capacity compared to White patients. Black patients had a longer median survival than White patients; however, race was not an independent predictor of survival time when controlling for age at symptom onset, bulbar onset, and C9orf72 positivity.

CONCLUSIONS

Black patients with ALS had longer median survival compared to White patients, but race was not independently associated with survival after controlling for age, site of onset, and C9orf72 status, factors known to predict prognosis. Black patients with ALS had longer diagnostic delay and lower baseline ventilatory and functional status at first clinic visit compared to White patients, which could be suggestive of barriers to tertiary care. Further studies are needed to identify the underlying causes of ALS racial differences.

Characteristics of amyotrophic lateral sclerosis in Lebanon-a chart review

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder primarily manifesting as motor deficits. It is caused by motor neuron death and leads to progressive disability and demise. It can present at any age, manifest as several phenotypes, and may have a variable progression pattern. Methods: This retrospective study is based on chart review of subjects presenting to the American University of Beirut Medical Center from June 2015 till March 2020. It aims to describe the characteristics of ALS in Lebanon. Results: Out of 140 subjects identified, 113 had classical ALS. The mean age in classical and atypical ALS were 55.5 and 55.6 years, male gender was predominant in both groups, and the mean duration from disease onset to diagnosis was 10 months in classic ALS compared to 22 months in atypical ALS. The median survival in subjects with classical ALS was 31 months which was significantly lower than atypical ALS phenotypes of 41.5 months. Additionally, more than half of patients (57%) were found to have a moderate ALSFRS-R progression rate. Conclusions: The study is the first to report the characteristics of amyotrophic lateral sclerosis in Lebanon. Moreover, we were able to categorize patients with classical phenotype according to disease progression using the ALSFRS-R score which can be a useful tool in determining disease prognosis at an early stage.

Increasing Patient Self-Enrollment in the National Amyotrophic Lateral Sclerosis Registry: Lessons Learned From a Direct to Provider Campaign

Objective:

To conduct educational and promotional outreach activities to general neurologists and to increase self-enrollment of persons with amyotrophic lateral sclerosis (ALS) in the National ALS Registry (Registry).

Methods:

A multicomponent project to educate neurologists and increase Registry self-enrollment was delivered. Project components consisted of phone calls, mailings, train-the-trainer presentations, and key informant interviews. Project-specific metrics, continuing education enrollment, and Registry self-enrollment data were analyzed to measure project efficacy.

Results:

Mailings were sent to 1561 neurologists in 6 states during 2015 to 2016. Sixty-five percent of responding neurologists remembered the mailing 3 months after receipt. Of providers who saw patients with ALS in the 3-month period, 60% read the provider guide, 22% distributed a patient guide, and 15% advised a patient to self-enroll. No changes in self-enrollment rates were observed.

Conclusion:

Targeted mailings to providers can be used to educate them about the Registry; however, most providers did not distribute materials to patients with ALS. Increases in providers receiving Registry material did not lead to increases in patient self-enrollment.

Practice Implications:

General neurologists have competing priorities, and they see patients with ALS infrequently. Neurologists could be the appropriate channel to distribute Registry information to patients, but they are not the appropriate resource to assist patients with self-enrollment. Engaging the support staff of busy specialists can help increase research response rates and information distribution. The lessons learned from this project can be applied to other rare conditions and disease specialists.

Predictors of diagnostic delay in amyotrophic lateral sclerosis: a cohort study based on administrative and electronic medical records data

Objectives: To characterize the timing and pathway of amyotrophic lateral sclerosis (ALS) diagnosis and to identify predictors of delayed diagnosis in a retrospective cohort. Methods: The cohort included all patients with incident ALS between 2010 and 2014 in Friuli-Venezia Giulia (FVG) region, Italy, admitted to two University Hospitals. Information on demographics, clinical presentation, and healthcare use was obtained from health databases and electronic medical records (EMRs). Total diagnostic time (TDT), the interval between ALS symptoms onset and diagnosis, was compared between patient groups through Wilcoxon-Mann-Whitney test. The adjusted odds ratio (aOR), with 95% confidence interval (95% CI), of having a TDT ≥12 months was estimated using unconditional logistic regression. Results: Among 134 patients, median TDT (interquartile range [IQR]) was 11.5 months (7.1-18.3), shorter in those aged <60 years vs. ≥60 years (8.1; 5.1-11.1 vs. 12.4; 7.4-21.5; p = 0.0064), first referred to a neurologist vs. other specialist (10.2; 6.1-16.3 vs. 13.2; 8.1-24.5; p = 0.0386) and without neurologic comorbidities (11.1; 7.1-16.5 vs. 19.7; 8.8-33.7; p = 0.0243). TDT was ≥12 months in 64 (48.5%) patients and was predicted by male sex (aOR: 2.47; 95% CI: 1.06-5.75), age at onset ≥60 years (11.46; 3.13-41.9), spinal onset (2.04; 1.00-5.93), and prior therapies or first referral to a non-neurologist (3.15; 1.36-7.29). Conclusions: In this cohort, delayed diagnosis was common, particularly in older patients and in those with neurological comorbidities. Timely referral to a neurologist may improve diagnostic timing.

Epidemiology of amyotrophic lateral sclerosis in Friuli-Venezia Giulia, North-Eastern Italy, 2002-2014: a retrospective population-based study

OBJECTIVES

To describe the epidemiology of Amyotrophic Lateral Sclerosis (ALS) in Friuli-Venezia Giulia (FVG) region, Italy, over a 13-year period (2002-2014), estimating ALS (a) incidence, prevalence, and clinical features; (b) mortality, also comparing Udine municipality to the rest of FVG.

METHODS

We conducted a retrospective population-based study. ALS incident cases were ascertained using multiple sources and validated through expert review. We calculated crude and standardized incidence rate (IR), point prevalence and mortality rate (MR), each with 95% confidence interval. Standardized incidence (SIR) and mortality (SMR) ratio were calculated to compare Udine to FVG.

RESULTS

Among 444 incident cases (50.0% men, median age 68.5 years), onset was bulbar in 30.2%, spinal in 59.9%, mixed in 9.9%; 3.6% had familial ALS. Crude and 2000 European population standardized IR was respectively 2.81 (2.56-3.09) and 2.09 (1.89-2.29) per 100,000 person-years. Standardized male-to-female incidence ratio was 1.05. IR peaked at age 65-74 years (men: 9.93, 8.04-12.32; women: 7.74, 6.18-9.67) and decreased thereafter. Prevalence was 8.36 (6.74-9.97) cases per 100,000 inhabitants on 30 June 2009 and 7.98 (6.40-9.56) on 30 June 2014. SIR was 1.20 and SMR 1.11.

CONCLUSIONS

When assessed over a long period, incidence of ALS was in the range of Italian and European population-based registries and showed a consistent pattern by age and sex. IR and MR were only slightly higher in Udine vs. FVG.

Estimation of the Prevalence of Amyotrophic Lateral Sclerosis in the United States Using National Administrative Healthcare Data from 2002 to 2004 and Capture-Recapture Methodology

BACKGROUND

National administrative healthcare data may be used as a case-finding method for prevalence studies of chronic disease in the United States, but the completeness of ascertainment likely varies depending on the disease under study.

METHODS

We used 3 case-finding sources (Medicare, Medicaid, and Veterans Administration data) to estimate the prevalence of amyotrophic lateral sclerosis (ALS) in the United States for 2002-2004, and applied the capture-recapture methodology to estimate the degree of under-ascertainment when relying solely on these sources for case identification.

RESULTS

Case-finding completeness was 76% overall and did not vary by race, but was lower for males (77%) than for females (88%), and lower for patients under age 65 (66%) than patients over age 65 (79%). The uncorrected ALS prevalence ratio was 2.8/100,000 in 2002, 3.3/100,000 in 2003, and 3.7/100,000 in 2004. After correcting for under-ascertainment, the annual prevalence increased by approximately 1 per 100,000 to 3.7/100,000 in 2002 (95% CI 3.66-3.80), 4.4/100,000 in 2003 (95% CI 4.34-4.50), and 4.8/100,000 in 2004 (95% CI 4.76-4.91).

CONCLUSIONS

Federal healthcare claims databases ascertained are a very efficient method for identifying the majority of ALS-prevalent cases in the National ALS Registry, and may be enhanced by having patients self-register through the registry web portal.

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

To evaluate the association between worldwide ALS incidence rates and age, using a dose-response meta-analysis. We reviewed Medline and Embase up to July 2016 and included all population-based studies of newly-diagnosed cases, using multiple sources for case ascertainment. A dose-response meta-analysis was performed. A meta-regression investigated potential sources of heterogeneity. Of 3254 articles identified in the literature, we included 41 incidence studies covering 42 geographical areas. Overall, the fit between observed and predicted age-specific rates was very good. The expected variation of ALS incidence with age was characterized, in each study, by a progressive increase in the incidence from the 40s leading to a peak in the 60s or 70s, followed by a sharp decrease. Cochran's Q test suggested a significant heterogeneity between studies. Overall, estimated patterns of ALS age-specific incidence (at which the peak was reached) were similar among subcontinents of Europe and North America: peak of ALS incidence ranged in these areas between 6.98 and 8.17/100,000 PYFU, which referred to age in the range 71.6-77.4 years. The relationship between age and ALS incidence appeared different for Eastern Asia which was characterized by a peak of ALS incidence at 2.20/100,000 PYFU around 75 years of age. This study confirms the consistency of the age-specific ALS incidence pattern within different subcontinents. Age-specific incidence appears lower in Eastern Asia as compared to Europe and North America.

Variation in worldwide incidence of amyotrophic lateral sclerosis: a meta-analysis

Background

To assess the worldwide variation of amyotrophic lateral sclerosis (ALS) incidence, we performed a systematic review and meta-analysis of population-based data published to date.

Methods

We reviewed Medline and Embase up to June 2015 and included all population-based studies of newly diagnosed ALS cases, using multiple sources for case ascertainment. ALS crude and standardized incidence (on age and sex using the US 2010 population) were calculated. Random effect meta-analysis and meta-regression were performed using the subcontinent as the main study level covariate. Sources of heterogeneity related to the characteristics of the study population and the study methodology were investigated.

Results

Among 3216 records, 44 studies were selected, covering 45 geographical areas in 11 sub-continents. A total of 13 146 ALS cases and 825 million person-years of follow-up (PYFU) were co-nsidered. The overall pooled worldwide crude ALS incidence was at 1.75 (1.55–1.96)/100 000 PYFU; 1.68 (1.50–1.85)/100 000 PYFU after standardization. Heterogeneity was identified in ALS standardized incidence between North Europe [1.89 (1.46–2.32)/100 000 PYFU] and East Asia [0.83 (0.42–1.24)/100 000 PYFU, China and Japan P = 0.001] or South Asia [0.73 (0.58–0.89)/100 000/PYFU Iran, P = 0.02]. Conversely, homogeneous rates have been reported in populations from Europe, North America and New Zealand [pooled ALS standardized incidence of 1.81 (1.66-1.97)/100 000 PYFU for those areas].

Conclusion

This review confirms a heterogeneous distribution worldwide of ALS, and sets the scene to sustain a collaborative study involving a wide international consortium to investigate the link between ancestry, environment and ALS incidence.

Prevalence of Amyotrophic Lateral Sclerosis - United States, 2012-2013

PROBLEM/CONDITION

Amyotrophic lateral sclerosis (ALS), commonly known as Lou Gehrig's disease, is a progressive and fatal neuromuscular disease for which no cure or viable treatment has been identified. ALS, like most noncommunicable diseases, is not a nationally notifiable disease in the United States. The prevalence of ALS in the United States during 2010-2011 was estimated to be 3.9 cases per 100,000 persons in the general population. Updated prevalence estimates are needed to help monitor disease status, better understand etiology, and identify risk factors for ALS.

PERIOD COVERED

2012-2013.

DESCRIPTION OF SYSTEM

The National ALS Registry, established in 2009, collects data on ALS patients in the United States to better describe the incidence and prevalence of ALS, examine risk factors such as environmental and occupational exposures, and characterize the demographics of those living with ALS. To identify prevalent cases of ALS, data are compiled from four national administrative databases (maintained by the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration). To identify cases not included in these databases and to better understand risk-factors associated with ALS and disease progression, the Registry also includes data that are collected from patients who voluntarily enroll and complete online surveys.

RESULTS

During 2012 and 2013, the Registry identified 14,713 and 15,908 persons, respectively, who met the surveillance case definition of ALS. The estimated ALS prevalence rate was 4.7 cases per 100,000 U.S. population for 2012 and 5.0 per 100,000 for 2013. Due to revisions to the algorithm and use of death data from the National Death Index, an updated prevalence estimate has been calculated retrospectively for October 19, 2010-December 31, 2011. This updated estimate showed a prevalence rate of 4.3 per 100,000 population and a total of 13,282 cases. Since the inception of the Registry, the pattern of characteristics (e.g., age, sex, and race/ethnicity) among persons with ALS have remained unchanged. Overall, ALS was more common among whites, males, and persons aged 60-69 years. The age groups with the lowest number of ALS cases were persons aged 18-39 years and those aged ≥80 years. Males had a higher prevalence rate of ALS than females overall and across all data sources. These findings remained consistent during October 2010-December 2013.

INTERPRETATION

The Registry is the only available data source that can be used to estimate the national prevalence for ALS in the United States. Use of both administrative national databases and self-report from patients enables a comprehensive approach to estimate ALS prevalence. The overall increase in the prevalence rate from 4.3 per 100,000 persons (revised) during 2010-2011 to 4.7 and 5.0 per 100,000 persons, respectively, during 2012-2013 likely is not an actual increase in the number of ALS cases. Rather, this increase might be attributed to improved case ascertainment due to the refinement of the algorithm used to identify definite ALS cases, along with an increased public awareness of the Registry. Registry estimates of ALS prevalence are consistent with findings from long-established ALS registries in Europe and from smaller-scale epidemiologic studies previously conducted in the United States.

PUBLIC HEALTH ACTIONS

Data collected by the National ALS Registry are being used to better describe the epidemiology of ALS in the United States and to help facilitate research. The combined approach of using national administrative databases and a self-enrollment web portal to collect data is novel and potentially could be used for other non-notifiable diseases such as Parkinson's disease or multiple sclerosis. Increased public awareness of the Registry might lead to more ALS cases being identified from the secure web portal (https://www.cdc.gov/als), which can ascertain cases apart from the national administrative databases. For example, in 2014, the ALS Ice Bucket Challenge, a social media-centered campaign, received extensive public visibility and created increased awareness of ALS. The Agency for Toxic Substances and Disease Registry (ATSDR) works closely with ALS advocacy and support groups, researchers, health care professionals, and others to promote the National ALS Registry and to identify all cases of ALS in the United States. In addition to estimating the prevalence of ALS, the Registry is being used to collect specimens from patient enrollees through a new biorepository, connect patient enrollees with new clinical trials and epidemiologic studies, and fund studies to help learn more about the etiology of ALS. Additional information about the National ALS Registry is available at http://www.cdc.gov/als or by calling toll-free at 1-877-442-9719.

Geographic Variation of Amyotrophic Lateral Sclerosis Incidence in New Jersey, 2009-2011

Few analyses in the United States have examined geographic variation and socioeconomic disparities in amyotrophic lateral sclerosis (ALS) incidence, because of lack of population-based incidence data. In this analysis, we used population-based ALS data to identify whether ALS incidence clusters geographically and to determine whether ALS risk varies by area-based socioeconomic status (SES). This study included 493 incident ALS cases diagnosed (via El Escorial criteria) in New Jersey between 2009 and 2011. Geographic variation and clustering of ALS incidence was assessed using a spatial scan statistic and Bayesian geoadditive models. Poisson regression was used to estimate the associations between ALS risk and SES based on census-tract median income while controlling for age, sex, and race. ALS incidence varied across and within counties, but there were no statistically significant geographic clusters. SES was associated with ALS incidence. After adjustment for age, sex, and race, the relative risk of ALS was significantly higher (relative risk (RR) = 1.37, 95% confidence interval (CI): 1.02, 1.82) in the highest income quartile than in the lowest. The relative risk of ALS was significantly lower among blacks (RR = 0.57, 95% CI: 0.39, 0.83) and Asians (RR = 0.63, 95% CI: 0.41, 0.97) than among whites. Our findings suggest that ALS incidence in New Jersey appears to be associated with SES and race.

Amyotrophic lateral sclerosis surveillance in Baltimore and Philadelphia

INTRODUCTION

Limited epidemiological data on amyotrophic lateral sclerosis (ALS) exist in defined geographic areas in the United States.

METHODS

Neurologists submitted case reports for patients under their care between January 1, 2009, and December 31, 2011, who met the El Escorial criteria. Diagnosis was confirmed for a sample of cases by the consulting neurologist. Death certificate data were used for supplemental case identification.

RESULTS

The 248 reported cases were most likely to be 50-69 years old, men, white, and non-Hispanic. The total crude average annual incidence rate was 1.46 per 100,000 person-years.

CONCLUSIONS

The reported demographic characteristics were consistent with previously published findings. The crude annual incidence was slightly lower than the expected rate of 1.6 but was within the range reported previously (0.7-2.5). These findings help quantify the burden of ALS in the United States.

Results of Florida's Amyotrophic Lateral Sclerosis Surveillance Project, 2009-2011

OBJECTIVE

Studies to determine the incidence and prevalence of amyotrophic lateral sclerosis (ALS) in defined geographic areas in the USA are needed. The Florida Department of Health received funding from the federal Agency for Toxic Substances and Disease Registry to implement a state-wide ALS Surveillance Project. The objectives of the project were to describe the demographic characteristics of ALS cases and to calculate the incidence and prevalence of ALS in Florida.

SETTING/PARTICIPANTS

All neurologists were asked to submit case reports for persons with ALS diagnosed and/or under their care during 1 January 2009 through 31 December 2011. A medical record verification form and an electromyogram (EMG) report were requested for a sample of cases and reviewed by an independent consulting neurologist to confirm ALS diagnosis. Death data were used to aid with case report collection.

PRIMARY AND SECONDARY OUTCOME MEASURES

Demographics, relevant history and clinical characteristics, El Escorial classifications, time from symptom onset to diagnosis, crude annual incidence rates and 2009 period prevalence are presented.

RESULTS

The 1450 reported ALS cases were more likely to be older, male, white and non-Hispanic. Slightly more than 4% of cases were reported as also having dementia, and 4.8% were reported to have an immediate family member diagnosed with ALS. Incidence rates ranged from 1.7 to 1.9 per 100,000 person-years during the project period and the 2009 period prevalence was 4.0 per 100,000 persons.

CONCLUSIONS

Project findings are generally consistent with findings of population-based studies in Europe, as well as geographically limited studies in the USA. Our findings add to the growing body of epidemiological literature about ALS in the USA. Future epidemiological studies in the USA should focus on identifying cases from minority groups and those that may have limited access to healthcare, and should consider conducting capture-recapture analysis to assess case ascertainment.

Epidemiology and surveillance of amyotrophic lateral sclerosis in two large metropolitan areas in California

Our objective was to provide demographic profiles and incidence estimates of amyotrophic lateral sclerosis (ALS) in two diverse California metropolitan areas: Los Angeles County (LA) and the San Francisco Bay Area (SFBA). Data were retrospectively collected from multiple sources. Case eligibility criteria included residency in SFBA or LA, and treatment for or diagnosis of ALS between 1 January 2009 and 31 December 2011. Overall incidence rates as well as age-, gender-, race- and ethnicity-specific rates were calculated. We identified 539 ALS cases in SFBA and 545 in LA; 618 were incident cases. Cases were more likely to be male and white. There were considerably more cases (p < 0.05) in LA who were foreign-born (LA, 22%; SFBA, 15%), black (LA, 10%; SFBA, 6%) or Hispanic (LA, 19%; SFBA, 10%). Conversely, the age adjusted incidence rates (per 100,000) were higher in SFBA for whites (LA, 1.40; SFBA, 2.49) and Hispanics (LA, 0.66; SFBA, 1.57) compared with LA. General case demographics and incidence rates in these two areas were similar to published studies. However, the differences between the two areas raise questions about how factors such as geography, access to care, and referral patterns may affect case ascertainment and diagnosis.

Effects of demographic factors on survival time after a diagnosis of amyotrophic lateral sclerosis

BACKGROUND

The Agency for Toxic Substances and Disease Registry established surveillance projects to determine the incidence, prevalence, and demographic characteristics of persons with Amyotrophic Lateral Sclerosis (ALS) in defined geographic areas. There is a need to characterize and account for the survival and prognostic factors among a population-based cohort of ALS cases in the United States.

METHODS

A cohort of incident cases diagnosed from 2009-2011 in New Jersey was followed until death or December 31, 2013, whichever happened first. Survival was assessed using Kaplan-Meier curves and Cox proportional hazards regression was used to identify prognostic factors.

RESULTS

Sixty-four percent of incident cases died between 2009 and 2013, 93.7% specifically from ALS. Among the 456 cases studied in the survival analysis, the median survival from diagnosis was 21 months; 46% of cases survived longer than two years from diagnosis. Older age predicted shorter survival. While there is some indication of differences because of sex, race, and ethnicity, these differences were not statistically significant when accounting for age.

CONCLUSIONS

New Jersey mortality data were queried to determine the vital status of a cohort of incident ALS cases and used to investigate relationships between demographic factors and survival. Results are consistent with other population-based studies. Older age was a strong predictor of shorter survival time. Additional follow-up time is needed to characterize longer-term survival.