The etiology of motor neuron disease (MND) is still unknown. The aims of this study were to: (1) analyze MND mortality at a fine-grained level; and (2) explore associations of MND and heavy metals released into Spanish river basins. MND deaths were extracted from the Spanish nationwide mortality registry (2007–2016). Standardized mortality ratios (SMRs) for MND were estimated at a municipal level. Sites that emitted quantities of heavy metals above the regulatory thresholds were obtained from the European Pollutant Release and Transfer Register database (2007–2015). The relative risks for non-exposed and exposed municipalities (considering a downstream 20 km river section) by type of heavy metal were analyzed using a log-linear model. SMRs were significantly higher in central and northern municipalities. SMRs were 1.14 (1.10–1.17) higher in areas exposed to heavy metals than in non-exposed areas: 0.95 (0.92–0.96). Considering the different metals, we found the following increased MND death risks in exposed areas: 20.9% higher risk for lead, 20.0% for zinc, 16.7% for arsenic, 15.7% for chromium, 15.4% for cadmium, 12.7% for copper, and 12.4% for mercury. This study provides associations between MND death risk and heavy metals in exposed municipalities. Further studies investigating heavy metal exposure are needed to progress in MND understanding.

This study aimed to analyse population-based mortality attributed to rare congenital anomalies (CAs) and assess the associated time trends and geographical differences in Spain. Data on CA-related deaths were sourced from annual mortality databases kept by the National Statistics Institute of Spain (1999–2013). Based on the ICD-10, only CAs corresponding to rare diseases definition were included in this study. Annual age-adjusted mortality rates were calculated and time trends were evaluated by joinpoint regression analysis. Geographical differences were assessed using standardised mortality ratios and cluster detection. A total of 13,660 rare-CA-related deaths (53.4% males) were identified in the study period. Annual age-adjusted mortality rates decreased by an average of −5.2% (−5.5% males, −4.8% females, p < 0.001). Geographical analysis showed a higher risk of rare-CA-related mortality in regions largely located in the south of the country. Despite their limitations, mortality statistics are essential and useful tools for enhancing knowledge of rare disease epidemiology and, by extension, for designing and targeting public health actions. Monitoring rare-CA-related mortality in Spain has shown a 15-year decline and geographical differences in the risk of death, all of which might well be taken into account by the health authorities in order to ensure equality and equity, and to adopt appropriate preventive measures.

The aim of this study is to analyze population-based mortality attributed to cystic fibrosis (CF) over 36 years in Spain. CF deaths were obtained from the National Statistics Institute, using codes 277.0 from the International Classification of Diseases (ICD) ninth revision (ICD9-CM) and E84 from the tenth revision (ICD10) to determine the underlying cause of death. We calculated age-specific and age-adjusted mortality rates, and time trends were assessed using joinpoint regression. The geographic analysis by district was performed by standardized mortality ratios (SMRs) and smoothed-SMRs. A total of 1002 deaths due to CF were identified (50.5% women). Age-adjusted mortality rates fell by −0.95% per year between 1981 and 2016. The average age of death from CF increased due to the annual fall in the mortality of under-25s (−3.77% males, −2.37% females) and an increase in over-75s (3.49%). We identified districts with higher than expected death risks in the south (Andalusia), the Mediterranean coast (Murcia, Valencia, Catalonia), the West (Extremadura), and the Canary Islands. In conclusion, in this study we monitored the population-based mortality attributed to CF over a long period and found geographic differences in the risk of dying from this disease. These findings complement the information provided in other studies and registries and will be useful for health planning.

Background: Huntington's disease (HD) is a progressive neurodegenerative condition characterized by chorea, dystonia, behavioral disturbances and cognitive decline. The aim of this study is to assess temporal and spatial changes on mortality attributable to HD over 30 years in Spain. Methods: HD data were extracted from the nationwide mortality registry for the period 1984-2013. Annual and 5-year gender- and age-specific rates adjusted for the standard European population were calculated. Geographic analysis was performed by districts from 1999 through 2013, and then estimated standardized mortality ratios (SMRs) and smoothed SMRs. Results: There were 1,556 HD-related deaths across the study period. An increasing trend in age-adjusted HD mortality was in evidence, specifically from 1994 through 1998. On a year-by-year basis, age-adjusted mortality rates increased from 0.076 per 100,000 population in 1984 to 0.157 in 2013. Geographical differences among districts were evident in specific areas and in the southwest of Spain with a significantly higher HD mortality risk. Conclusion: HD mortality rising trends in Spain might be attributable to improvements in diagnosis leading to a rise in prevalence. Geographical variability in HD mortality could be related to regional differences in disease prevalence, health-care disparities, or other factors which call for in-depth assessment in future studies.

Official mortality statistics provide population-based data and serve to improve epidemiological knowledge of rare diseases (RDs), by helping with the description of the natural history of the disease. They are an important complement of registries and estimates of disease burden and costs. At the same time, they heighten both the visibility of these diseases and the interest in their study and the search for treatments that may increase survival. This chapter contains a European analysis of hereditary ataxia mortality, which considers the time trend in different countries and the geographical variability in risk of death. Despite the limitations of applying this data source to RDs, mortality statistics share criteria which facilitate international comparisons and are of great utility for obtaining sufficiently uniform and robust time series for analysis of low-prevalence diseases.

Background Tetralogy of Fallot (TOF) is the most frequent cyanotic congenital heart defect. TOF mortality has fallen remarkably in recent years due to therapeutic advances. Accordingly, the aim of this study was to assess temporal and spatial variability in TOF-related mortality in Spain across the period 1981–2016, using data drawn from the nationwide population-based registry. Methods Annual deaths due to TOF were sourced from the Spanish National Institute of Statistics database by reference to International Classification of Diseases (ICD), 9th and 10th Revision codes, namely, ICD-9 code 745.2 (period 1981–1998) and ICD-10 code Q21.3 (period 1999–2016). Age-specific and age-adjusted mortality rates were calculated, as were standardised mortality ratios (SMRs) by province, district and municipality for the period 1999–2016. Results A total of 1035 deaths were attributed to TOF (57.78% of them were men and 42.22% were women). The age-adjusted mortality rate ranged from 0.75 per 1,000,000 inhabitants (95% confidence interval [CI]: 0–1.36) in 1981 to 0.03 per 1,000,000 (95% CI: 0.01–0.06) in 2016 for both sexes. In 2011, there was a change in the mortality trend, with a significant decrease of 49.22% per year ( p < 0.001). In terms of geographical analysis, some areas with a significantly higher risk of TOF mortality were identified in the south of Spain, though no specific spatial pattern was in evidence. Conclusion The decrease in TOF mortality may be related to improvements in diagnostic and treatment techniques. More studies are needed to analyse regions with a higher mortality risk, in order to improve medical planning and resource allocation, and identify risk factors and preventive measures.

Muscular dystrophies (MD) are a group of rare hereditary degenerative diseases. Our aim was to analyze the mortality pattern in Spain from 1981 to 2016 to assess the temporal trend and discern possible geographic differences using population-based data. Annual deaths related to MD were obtained from the National Statistics Institute with codes 359.1 of the ICD-9 (1981–1998) and G71.0 of the ICD-10 (1999–2016). Age-adjusted mortality rates were calculated and changes in mortality trends were identified. The standardized mortality ratios (SMR) and their respective 95% confidence intervals were calculated by district for 1999–2016. Smoothed SMRs and posterior probability were also assessed and then mapped to look for patterns or geographic distribution. All rates were expressed per 1,000,000 inhabitants. A total of 2,512 deaths (73.8% men) were identified. The age-adjusted mortality rates varied from 0.63 (95% CI 0.40–0.95) in 1981 to 1.51 (95% CI 1.17–1.93) in 2016. MD mortality showed a significant increase of 8.81% per year (95% CI 5.0–12.7) from 1981 to 1990, remaining stable afterwards. Areas with risk of death higher than expected for Spain as a whole were identified, not showing a specific regional pattern. In conclusion, the rising trend in MD mortality might be attributable to advanced improvements in diagnostic techniques leading to a rise in prevalence. Further research on the districts with the highest mortality would be necessary.

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