Evaluation of the Completeness of ALS Case Ascertainment in the US 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 USA 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 year 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 nonwhite than white patients. The uncorrected ALS prevalence was 4.3/100,000 in 2011 (in 2014, 5.0/100,000), but after correction for underascertainment, 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.

Reproductive History and Age of Onset for Women Diagnosed with Amyotrophic Lateral Sclerosis: Data from the National ALS Registry: 2010-2018.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurological disease of largely unknown etiology with no cure. The National ALS Registry is a voluntary online system that collects demographic and reproductive history (females only) data from patients with ALS. We will examine the association between demographic and reproductive history among female patients aged >18 years and various ages of onset for ALS. METHODS: Data from a cross-sectional study were collected and examined for 1,018 female ALS patients. Patient characteristics examined were demographics including race, BMI, and familial history of ALS. Among patients, information on reproductive history, including age at menopause, ever pregnant, and age at first pregnancy was collected. Unadjusted and adjusted logistic regression models were used to estimate OR and 95% CI in this study. RESULTS: Women were more likely to be diagnosed with ALS before age 60 if they were nonwhite (p = 0.015), had attended college (p = 0.0012), had a normal BMI at age 40 (p < 0.0001), completed menopause before age 50 (p < 0.0001), and had never been pregnant (p = 0.046) in the univariate analysis. Women diagnosed with ALS before age 60 were also more likely to have limb site of onset (p < 0.0001). In the multivariate analysis, those who completed menopause before age 50 were more likely to be diagnosed with ALS before age 60 (OR = 1.8, 95% CI: 1.4-2.3) compared with women who completed menopause at or after age 50, after controlling for race, ever pregnant, age at first pregnancy, family history of ALS, education status, smoking history, and BMI at age 40. For women who were diagnosed with ALS before age 50, the odds of them entering menopause before age 50 climb to 48.7 (95% CI: 11.8, 200.9). The mean age of ALS diagnosis for women who completed menopause before age 50 was 58 years and 64 years for women who entered menopause after age 50 (p < 0.0001). CONCLUSION: Women who reported completing menopause before age 50 were significantly more likely to be diagnosed with ALS before age 60 compared with those who reported entering menopause after age 50. More research is needed to determine the relationship between female reproductive history, especially regarding endogenous estrogen exposure and early-onset ALS.

Recruitment of Patients With Amyotrophic Lateral Sclerosis for Clinical Trials and Epidemiological Studies: Descriptive Study of the National ALS Registry's Research Notification Mechanism.

BACKGROUND: Researchers face challenges in patient recruitment, especially for rare, fatal diseases such as amyotrophic lateral sclerosis (ALS). These challenges include obtaining sufficient statistical power as well as meeting eligibility requirements such as age, sex, and study proximity. Similarly, persons with ALS (PALS) face difficulty finding and enrolling in research studies for which they are eligible. OBJECTIVE: The aim of this study was to describe how the federal Agency for Toxic Substances and Disease Registry's (ATSDR) National ALS Registry is linking PALS to scientists who are conducting research, clinical trials, and epidemiological studies. METHODS: Through the Registry's online research notification mechanism (RNM), PALS can elect to be notified about new research opportunities. This mechanism allows researchers to upload a standardized application outlining their study design and objectives, and proof of Institutional Review Board approval. If the application is approved, ATSDR queries the Registry for PALS meeting the study's specific eligibility criteria, and then distributes the researcher's study material and contact information to PALS via email. PALS then need to contact the researcher directly to take part in any research. Such an approach allows ATSDR to protect the confidentiality of Registry enrollees. RESULTS: From 2013 to 2019, a total of 46 institutions around the United States and abroad have leveraged this tool and over 600,000 emails have been sent, resulting in over 2000 patients conservatively recruited for clinical trials and epidemiological studies. Patients between the ages of 60 and 69 had the highest level of participation, whereas those between the ages of 18 and 39 and aged over 80 had the lowest. More males participated (4170/7030, 59.32%) than females (2860/7030, 40.68%). CONCLUSIONS: The National ALS Registry's RNM benefits PALS by connecting them to appropriate ALS research. Simultaneously, the system benefits researchers by expediting recruitment, increasing sample size, and efficiently identifying PALS meeting specific eligibility requirements. As more researchers learn about and use this mechanism, both PALS and researchers can hasten research and expand trial options for PALS.

Prevalence of Amyotrophic Lateral Sclerosis - United States, 2015.

Amyotrophic lateral sclerosis (ALS), commonly known as Lou Gehrig's disease, is a progressive and fatal neuromuscular disease; the majority of ALS patients die within 2-5 years of receiving a diagnosis (1). Familial ALS, a hereditary form of the disease, accounts for 5%-10% of cases, whereas the remaining cases have no clearly defined etiology (1). ALS affects persons of all races and ethnicities; however, whites, males, non-Hispanics, persons aged ≥60 years, and those with a family history of ALS are more likely to develop the disease (2). No cure for ALS has yet been identified, and the lack of proven and effective therapeutic interventions is an ongoing challenge. Treatments currently available, Edaravone and Riluzole, do not cure ALS, but slow disease progression in certain patients (3,4). This report presents National ALS Registry findings regarding ALS prevalence in the United States for the period January 1-December 31, 2015. In 2015, the estimated prevalence of ALS cases was 5.2 per 100,000 population with a total of 16,583 cases identified. Overall, these findings are similar to the 2014 ALS prevalence and case count (5.0 per 100,000; 15,927 cases) (2). Prevalence rates by patient characteristics (most common in whites, males, and persons aged ≥60 years) and U.S. Census regions are consistent with ALS demographics and have not changed from 2014 to 2015 calendar years. The algorithm used to identify cases from national administrative databases was updated from the International Classification of Diseases, Ninth Revision (ICD-9) to the ICD-10 codes for claims starting on October 1, 2015, with no apparent effect on case ascertainment. Data collected by the National ALS Registry are being used to better describe the epidemiology of ALS in the United States and to facilitate research on the genetics, potential biomarkers, environmental pollutants, and etiology for ALS.

Prevalence of Amyotrophic Lateral Sclerosis - United States, 2014.

Amyotrophic lateral sclerosis (ALS), commonly known as Lou Gehrig's disease, is a progressive and fatal neuromuscular disease; the majority of ALS patients die within 2-5 years of receiving a diagnosis (1). Familial ALS, a hereditary form of the disease, accounts for 5%-10% of cases, whereas the remaining sporadic cases have no clearly defined etiology (1). ALS affects persons of all races and ethnicities; however, whites, males, non-Hispanics, persons aged >60 years, and those with a family history of ALS are more likely to develop the disease (1-3). No cure for ALS has yet been identified, and the lack of proven and effective therapeutic interventions is an ongoing challenge. Current treatments available do not cure ALS but have been shown to slow disease progression. Until recently, only one drug (riluzole) was approved to treat ALS; however, in 2017, the Food and Drug Administration approved a second drug, edaravone (4).

Summary of Notifiable Noninfectious Conditions and Disease Outbreaks: Surveillance Data Published Between April 1, 2016 and January 31, 2017 - United States.

The Summary of Notifiable Noninfectious Conditions and Disease Outbreaks: Surveillance Data Published Between April 1, 2016 and January 31, 2017 - United States, herein referred to as the Summary (Noninfectious), contains official statistics for nationally notifiable noninfectious conditions and disease outbreaks. This Summary (Noninfectious) is being published in the same volume of MMWR as the annual Summary of Notifiable Infectious Diseases and Conditions (1). Data on notifiable noninfectious conditions and disease outbreaks from prior years have been published previously (2,3).

Blood Lead Levels in Children Aged <5 Years - United States, 2007-2013.

This report provides data concerning childhood blood lead levels (BLLs) in the United States during 2007-2013. These data were collected and compiled from raw data extracts sent by state and local health departments to CDC's Childhood Blood Lead Surveillance (CBLS) system. These raw data extracts have been de-identified and coded into a format specifically for childhood lead reporting. The numbers of children aged <5 years reported to CDC for 2013 with newly confirmed BLLs ≥10 µg/dL are provided in tabular form by month (Table 1) and geographic location (Table 2). The incidence of BLLs ≥10 µg/dL is reported by age group for 2007-2013 (Table 3). The numbers of children aged <5 years with BLLs 5-9µg/dL for 2013 are reported (Table 4). For the period 2007-2013, the numbers of children newly confirmed with BLLs ≥70 µg/dL are summarized (Figure 1) as well as the percentage of children with BLLs ≥5 µg/dL (Figure 2). This report is a part of the Summary of Notifiable Noninfectious Conditions and Disease Outbreaks - United States, which encompasses various surveillance years but is being published in 2016 (1). The Summary of Notifiable Noninfectious Conditions and Disease Outbreaks appears in the same volume of MMWR as the annual Summary of Notifiable Infectious Diseases (2).

Blood Lead Levels Among Children Aged <6 Years - Flint, Michigan, 2013-2016.

During April 25, 2014-October 15, 2015, approximately 99,000 residents of Flint, Michigan, were affected by changes in drinking water quality after their water source was switched from the Detroit Water Authority (DWA), sourced from Lake Huron, to the Flint Water System (FWS), sourced from the Flint River.* Because corrosion control was not used at the FWS water treatment plant, the levels of lead in Flint tap water increased over time. Adverse health effects are associated with lead exposure (1). On January 2, 2015, a water advisory was issued because of detection of high levels of trihalomethanes, byproducts of disinfectants.(†)(,)(§) Studies conducted by local and national investigators detected an increase in the prevalence of blood lead levels (BLLs) ≥5 µg/dL (the CDC reference level) among children aged <5 years living in Flint (2) and an increase in water lead levels after the water source switch (3). On October 16, 2015, the Flint water source was switched back to DWA, and residents were instructed to use filtered tap water for cooking and drinking. During that time, pregnant and breastfeeding women and children aged <6 years were advised to consume bottled water.(¶) To assess the impact on BLLs of consuming contaminated drinking water, CDC examined the distribution of BLLs ≥5 µg/dL among children aged <6 years before, during, and after the switch in water source. This analysis enabled determination of whether the odds of having BLLs ≥5 µg/dL before the switch differed from the odds during the switch to FWS (before and after the January 2, 2015, water advisory was issued), and after the switch back to DWA. Overall, among 9,422 blood lead tests in children aged <6 years, 284 (3.0%) BLLs were ≥5 µg/dL during April 25, 2013-March 16, 2016. The adjusted probability of having BLLs ≥5 µg/dL was 46% higher during the period after the switch from DWA to FWS (and before the January 2, 2015, water advisory) than during the period before the water switch to FWS. Although unrelated to lead in the water, the water advisory likely reduced tap water consumption and increased consumption of bottled water. Characterizing exposure to lead contaminated drinking water among children aged <6 years living in Flint can help guide appropriate interventions.

A brief report on juvenile amyotrophic lateral sclerosis cases in the United States National ALS Registry: 2010-2018.

Juvenile ALS (jALS) is a rare form of ALS, defined as symptom onset before age 25. This report describes the demographic characteristics of confirmed and likely jALS cases in a large cohort of ALS patients ascertained in the National ALS Registry (Registry) from 2010 to 2018. Patients in the Registry must be at least 18 years of age. Of the 44 identified patients, 37.8% were diagnosed at age 24, were more likely to be nonwhite (54.5%), male (79.5%), and live in the Midwest or Northeast regions (54.5%) of the US. Some 68.9% of the jALS cases were received from federal administrative databases, and 16% came from the web portal only. Demographic characteristics for jALS cases in the Registry differed from previous publications examining ALS cases for all adults. More research is needed to better understand risk factors contributing to jALS, which could lead to earlier diagnosis and therapeutic interventions.

What do you think caused your ALS? An analysis of the CDC national amyotrophic lateral sclerosis patient registry qualitative risk factor data using artificial intelligence and qualitative methodology.

Objective: Amyotrophic lateral sclerosis (ALS) is an incurable, progressive neurodegenerative disease with a significant health burden and poorly understood etiology. This analysis assessed the narrative responses from 3,061 participants in the Centers for Disease Control and Prevention's National ALS Registry who answered the question, "What do you think caused your ALS?" Methods: Data analysis used qualitative methods and artificial intelligence (AI) using natural language processing (NLP), specifically, Bidirectional Encoder Representations from Transformers (BERT) to explore responses regarding participants' perceptions of the cause of their disease. Results: Both qualitative and AI analysis methods revealed several, often aligned themes, which pointed to perceived causes including genetic, environmental, and military exposures. However, the qualitative analysis revealed detailed themes and subthemes, providing a more comprehensive understanding of participants' perceptions. Although there were areas of alignment between AI and qualitative analysis, AI's broader categories did not capture the nuances discovered using the more traditional, qualitative approach. The qualitative analysis also revealed that the potential causes of ALS were described within narratives that sometimes indicate self-blame and other maladaptive coping mechanisms. Conclusions: This analysis highlights the diverse range of factors that individuals with ALS consider as perceived causes for their disease. Understanding these perceptions can help clinicians to better support people living with ALS (PLWALS). The analysis highlights the benefits of using traditional qualitative methods to supplement or improve upon AI-based approaches. This rapidly evolving area of data science has the potential to remove barriers to accessing the rich narratives of people with lived experience.

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.

Blood lead level analysis among refugee children resettled in New Hampshire and Rhode Island.

OBJECTIVE: To examine the association between refugee status and elevated blood lead levels (EBLLs) among children living in two U.S. cities and to assess the effect of the Centers for Disease Control and Prevention recommendations for BLL testing of newly emigrated refugee children for EBLLs. DESIGN AND SAMPLE: A longitudinal study was conducted of 1,007 refugee children and 953 nonrefugee children living, when blood testing occurred, in the same buildings in Manchester, New Hampshire and Providence, Rhode Island. MEASURES: Surveillance and blood lead data were collected from both sites, including demographic information, BLLs, sample type, refugee status, and age of housing. RESULTS: Refugee children living in Manchester were statistically significantly more likely to have an EBLL compared with nonrefugee children even after controlling for potential confounders. We did not find this association in Providence. Compared with before enactment, the mean time of refugee children to fall below 10 µg/dL was significantly shorter after the recommendations to test newly emigrated children were enacted. CONCLUSIONS: Refugee children living in Manchester were significantly more likely to have an EBLL compared with nonrefugee children. And among refugee children, we found a statistically significant difference in the mean days to BLL decline <10 µg/dL before and after recommendations to test newly emigrated children.

Comparing Amyotrophic lateral sclerosis (ALS) patient characteristics from the National ALS Registry and the Massachusetts ALS Registry, data through 2015.

OBJECTIVE: To compare, for completeness, ALS patients identified in the National ALS Registry (National Registry) from MA to those in the Massachusetts ALS Registry (MA Registry) through 2015. METHODS: Sensitivity analyses were conducted to determine the completeness among patients reported in both registries. Patients were matched on first and last name, month and year of birth, sex, as well as Soundex name matching. Demographics for matching and nonmatching ALS patients were also examined using bivariate analyses and logistic regression. RESULTS: There were 1,042 ALS patients in the MA Registry, and 642 patients matched (61.6%) in the National Registry. Sensitivity analyses found the National Registry had a sensitivity of 87.7% and specificity of 60%. For these matched patients, 522 (81.2%) came from Medicare. Of the 400 patients in the MA Registry not matched to the National Registry, 11.1% were nonwhite, compared to 6.0% in the matched group) (p = 0.0091) and 59.2% were diagnosed before age 60, compared to 28.6% in the matched group (p < 0.0001). Multivariate logistic regression analysis showed being an ALS case (p < 0.0001) and having an ALS diagnosis at age 60 or later (p < 0.0001) were associated with being more likely to match between the two registries. CONCLUSIONS: These findings show that ALS's non-notifiable condition status at the national level continues to pose a challenge in identifying all ALS patients. This analysis also showed missing cases at the state level even with a reporting statute. Additional strategies are needed for better patient-ascertainment to quantify all ALS patients in the U.S.

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.

A revision to the United States national ALS registry's algorithm to improve Case-Ascertainment.

OBJECTIVE: To evaluate the impact of 1) updating the existing algorithm to improve case-finding sensitivity and 2) reclassifying the Registry's diagnostic status nomenclature into four new categories ("confirmed ALS," "likely ALS," "undetermined ALS," or "not ALS") versus the current three ("definite ALS," "possible ALS," or "not ALS") to be more inclusive and descriptive of cases and individuals. METHODS: A retrospective analysis of Registry data from 2011-2017 was conducted to follow "possible ALS" individuals over time to determine what qualifier caused them to convert, if at all and when, to Registry-eligible cases (i.e. "confirmed ALS" or "likely ALS"). RESULTS: In 2011, 720 individuals were classified by the Registry algorithm as having "possible ALS". By 2017, 42% of these had converted to Registry-eligible ALS cases. Approximately 14% of those who were identified solely based on an ALS prescription drug never converted to Registry-eligible cases. This analysis indicates that "possible ALS" individuals with a single prescription for an ALS drug should be converted to Registry-eligible cases which would add between 300-500 cases per year on average. CONCLUSIONS: The Registry's existing algorithm likely results in the under-ascertainment of ALS cases. However, updating the algorithm with the inclusion of patients having been prescribed ALS-specific drugs, even with a single prescription, leads to improved epidemiologic estimates of ALS in the US. This and future algorithmic updates will help the Registry more accurately depict the true disease burden of ALS in the US.

Prevalence of amyotrophic lateral sclerosis in the United States, 2018.

OBJECTIVE: To estimate prevalent ALS cases in the United States for calendar year 2018. METHODS: The National ALS Registry (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 enrollment data voluntarily submitted through a web portal (www.cdc.gov/als). We used log-linear capture-recapture (CRC) model-based methodology to estimate the number of cases not ascertained by the Registry. RESULTS: The Registry identified 21,655 cases of ALS in 2018, with an age-adjusted prevalence of 6.6 per 100,000 U.S. population. When CRC methods were used, an estimated 29,824 cases were identified, for an adjusted prevalence of 9.1 per 100,000 U.S. population. The demographics of cases of ALS did not change from previous year's reports. ALS continues to impact Whites, males, and persons over 50 years of age more so than other comparison groups. The results from the present report suggest case ascertainment for the Registry has improved, with the estimate of missing prevalent cases decreasing from 44% in 2017 to 27% in in 2018. DISCUSSION: Consistent with previous estimates that used CRC, ALS prevalence in the United States is about 29,824 cases per year.

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.

Impact of the National Amyotrophic Lateral Sclerosis Registry: Analysis of Registry-funded Research.

OBJECTIVE: This research aims to examine the impact of the National Amyotrophic Lateral Sclerosis (ALS) Registry-funded research activities. METHODS: Registry-funded research and related publications were identified through the National ALS Registry website, the National Institutes of Health (NIH) Reporter website, and verified by Principal Investigators. Key study characteristics (e.g., study population, sample size) and key impact features (e.g., risk factors) were abstracted and recorded on study abstraction forms. Descriptive statistics were used to analyze the volume, productivity, and findings of the Registry-funded research. RESULTS: Since 2012, the National ALS Registry funded 21 research projects. Of these, 14 were through extramural research grants and included in the analysis. These studies are often related to environmental, medical conditions, and genetic risk factors. On average, the funded grants produced 1 to 2 publications which were cited 114 times by other researchers. The relative citation ratio averaged 1.81 with a weighted relative citation ratio of 16.28. These studies supported the identification and confirmation of candidate risk factors. Environmental and occupational risk factors typically related to heavy metal exposure (e.g., lead, mercury) and agricultural chemicals (e.g., pesticides, herbicides), and the occupations associated with exposure to these substances were most frequently explored. INTERPRETATION: The National ALS Registry is a multifaceted research platform, one component of which is funded research. This Registry-funded research fills an essential gap in the overall ALS scientific community as it is difficult to prevent and treat a disease without a deeper understanding of its causes.

Prevalence of amyotrophic lateral sclerosis (ALS), United States, 2016.

Objective: To estimate the prevalence of amyotrophic lateral sclerosis (ALS) in the United States for 2016 using data from the National ALS Registry (Registry). Established in 2009, the Registry collects data on ALS patients in the U.S. 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 prevalent 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). To ascertain cases not necessarily included in these databases and to better understand risk-factors associated with ALS and disease progression, the Registry also includes data collected from patients who voluntarily enroll via a web portal to complete online surveys. Results: In 2016, the Registry conservatively identified 16,424 adult persons who met the Registry definition of ALS for an age-adjusted prevalence rate of 5.2 per 100,000 U.S. population. The pattern of patient characteristics (e.g., age, sex, and race/ethnicity) has not changed from previous Registry reports. 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. Males had a higher prevalence rate of ALS than females overall and across all data sources. Conclusions: Data collected by the National ALS Registry are being used to better describe the epidemiology and demographics of ALS in the U.S.

Association between children's blood lead levels, lead service lines, and water disinfection, Washington, DC, 1998-2006.

OBJECTIVE: Evaluate the effect of changes in the water disinfection process, and presence of lead service lines (LSLs), on children's blood lead levels (BLLs) in Washington, DC. METHODS: Three cross-sectional analyses examined the relationship of LSL and changes in water disinfectant with BLLs in children <6 years of age. The study population was derived from the DC Childhood Lead Poisoning Prevention Program blood lead surveillance system of children who were tested and whose blood lead test results were reported to the DC Health Department. The Washington, DC Water and Sewer Authority (WASA) provided information on LSLs. The final study population consisted of 63,854 children with validated addresses. RESULTS: Controlling for age of housing, LSL was an independent risk factor for BLLs ≥ 10 µg/dL, and ≥ 5 µg/dL even during time periods when water levels met the US Environmental Protection Agency (EPA) action level of 15 parts per billion (ppb). When chloramine alone was used to disinfect water, the risk for BLL in the highest quartile among children in homes with LSL was greater than when either chlorine or chloramine with orthophosphate was used. For children tested after LSLs in their houses were replaced, those with partially replaced LSL were >3 times as likely to have BLLs ≥ 10 µg/dL versus children who never had LSLs. CONCLUSIONS: LSLs were a risk factor for elevated BLLs even when WASA met the EPA water action level. Changes in water disinfection can enhance the effect of LSLs and increase lead exposure. Partially replacing LSLs may not decrease the risk of elevated BLLs associated with LSL exposure.