Non-adherence to COVID-19 containment behaviours: results from an all-Ireland telephone survey.

BACKGROUND: COVID-19 public health measures like handwashing and social distancing can help stem the spread of the virus. Adherence to guidelines varies between individuals. This study aims to identify predictors of non-adherence to social distancing and handwashing guidelines. METHODS: A cross-sectional weekly telephone survey was conducted over eight weeks (11/06/2020-05/08/2020). The sample included adults resident on the island of Ireland (75:25 split between ROI and NI). Data were collected on demographics, threat perceptions, fear of COVID-19, response efficacy and self-efficacy, response cost and social norms, COVID-19 behaviours, mood, loneliness, and self-reported health. RESULTS: 3011 participants were surveyed. Handwashing non-adherers were more likely to be male (OR: 5.2, 95% CI: 2.4 - 11.3), to have higher levels of loneliness (OR: 1.86, 95% CI: 1.1 - 3.1), and higher perceptions of handwashing costs (OR: 3.4, 95% CI: 2.2 - 5.2). Those reporting rarely engaging in social distancing were more likely to be members of lower socioeconomic groups, to be younger (OR: 0.97, 95% CI: 0.96 - 0.98), male (OR: 1.67, 95% CI: 1.1 - 2.5), healthcare workers (OR: 1.98, 95% CI: 1.1 - 3.4), to report lower mood (OR: 1.72, 95% CI: 1.3 - 2.2), were less likely to live in households with people aged under-18 (OR: 0.75, 95% CI: 0.6 - 0.9), and to have lower fear of COVID-19 (OR: 0.79, 95% CI: 0.6 - 0.9). CONCLUSIONS: Non-adherers to handwashing differ to social distancing non-adherers. Public health messages should target specific demographic groups and different messages are necessary to improve adherence to each behaviour.

Global cognitive performance at 4-year follow-up in individuals with atrial fibrillation-findings from The Irish Longitudinal Study on Ageing.

INTRODUCTION: Atrial fibrillation (AF) has been proposed as a risk factor for cognitive impairment, even in the absence of a history of stroke. This study investigates whether AF is associated with increased risk of cognitive decline in a community-dwelling population of adults over the age of 50. METHODS: Data from the 1st and 3rd waves of The Irish Longitudinal Study on Ageing (TILDA) were used (4-year follow-up period). TILDA is a large prospective cohort study of community-dwelling adults over the age of 50 in Ireland. AF was assessed via electrocardiogram. Global cognitive function was assessed at baseline and follow-up using Montreal Cognitive Assessment (MOCA). Analysis of global cognition was repeated stratifying by age. Mixed-effects Poisson regression was used to assess for change in rate of errors on MOCA and MOCA subdomains. RESULTS: A total of 3,417 participants were included in the study. Results found that participants with AF had a greater increase in rate of errors on MOCA over 4-year follow-up (incident rate ratio (IRR) 1.18; 95% confidence interval (CI) 1.02, 1.37; P-value 0.023). However, this was no longer significant on controlling for age, sex and level of education (IRR 1.08; 95% CI 0.93, 1.25; P-value 0.332). There was no difference when stratifying by age group, or when separating MOCA into subdomains. CONCLUSION: Individuals with AF were more likely to show an increase in rate of errors between waves 1 and 3 (4-year follow-up period) in the TILDA population; however, results were not significant when controlling for age, sex and level of education.

Discrete choice experiment for eliciting preference for health services for patients with ALS and their informal caregivers.

BACKGROUND: Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative condition with a mean life expectancy of 3 years from first symptom. Understanding the factors that are important to both patients and their caregivers has the potential to enhance service delivery and engagement, and improve efficiency. The Discrete Choice Experiment (DCE) is a stated preferences method which asks service users to make trade-offs for various attributes of health services. This method is used to quantify preferences and shows the relative importance of the attributes in the experiment, to the service user. METHODS: A DCE with nine choice sets was developed to measure the preferences for health services of ALS patients and their caregivers and the relative importance of various aspects of care, such as timing of care, availability of services, and decision making. The DCE was presented to patients with ALS, and their caregivers, recruited from a national multidisciplinary clinic. A random effects probit model was applied to estimate the impact of each attribute on a participant's choice. RESULTS: Patients demonstrated the strongest preferences about timing of receiving information about ALS. A strong preference was also placed on seeing the hospice care team later rather than early on in the illness. Patients also indicated their willingness to consider the use of communication devices. Grouping by stage of disease, patients who were in earlier stages of disease showed a strong preference for receipt of extensive information about ALS at the time of diagnosis. Caregivers showed a strong preference for engagement with healthcare professionals, an attribute that was not prioritised by patients. CONCLUSIONS: The DCE method can be useful in uncovering priorities of patients and caregivers with ALS. Patients and caregivers have different priorities relating to health services and the provision of care in ALS, and patient preferences differ based on the stage and duration of their illness. Multidisciplinary teams must calibrate the delivery of care in the context of the differing expectations, needs and priorities of the patient/caregiver dyad.

What is the prevalence of untreated depression and death ideation in older people? Data from the Irish Longitudinal Study on Aging.

ABSTRACTObjective:Late life depression (LLD) confers significant morbidity and mortality but is well recognized that it often goes undetected or untreated. The objective of this study is to quantify the burden of untreated depression and death ideation (DI) at a population level. DESIGN: Cross-sectional study ascertaining the prevalence of, and factors associated with, untreated depression and DI. SETTING: This study, embedded within the Irish Longitudinal Study on Ageing, involves over 7,000 community-dwelling people aged ≥50 years. MEASUREMENTS: Depression was defined as Centre for Epidemiological Studies Depression scale ≥16 indicating current clinically relevant depressive symptoms or Composite International Diagnostic Interview indicative of major depressive episode within the last year. Participants not prescribed antidepressants/antipsychotics were defined as untreated. To define DI, participants were asked "In the last month, have you felt like you would rather be dead?" RESULTS: In total, 12% (839/7,055) met criteria for depression with 29% (241/839) on pharmacological therapy. Those with untreated depression were less likely to endorse symptoms of persistent low mood or worthlessness, but there was no difference in age or general practitioner (GP) visits compared to those on treatment. Over 3% (223/7,055) of participants had DI and less than one-third had visited their GP within the last year. CONCLUSIONS: This study demonstrates that two-thirds of depressed older people are not prescribed antidepressant/antipsychotic therapy. It is important to raise awareness of depression among older people and healthcare professionals, with particular focus on the fact that LLD is not an inevitable consequence of ageing and effective treatment is available.

No association between soil constituents and amyotrophic lateral sclerosis relative risk in Ireland.

INTRODUCTION: We have recently mapped ALS spatial risk in Ireland using Bayesian and cluster analysis methods at electoral division (ED) and small area (SA) levels. As a number of metal elements (both minerals and toxins) have been proposed as risk factors for ALS, here we extend this analysis to include soil constituents from the Irish National Soils Database as Bayesian conditional auto-regression covariates to determine associations with small area ALS risk. METHODS: Data on 45 different soil parameters were obtained under license from National Soils Database (via Irish EPA). We interpolated average values of each soil constituent for each small area using ordinary kriging. All cases of ALS in Ireland from January 1995 to December 2013 were identified from the Irish ALS register and observed and age and gender standardised expected cases were calculated for each SA. Besag-York-Mollié (BYM) models were then built including each parameter from the national soils database in turn as a Bayesian covariate in the BYM model. Models were compared using the deviance information criterion (DIC) and separate models were built for ALS subtypes. RESULTS: 1701 ALS patients were included - 959 (56%) were male, 938 (55%) had limb onset ALS. 315 Bayesian models were built in total. Of the 315 models built, only one resulted in a coefficient that did not overlap zero. For limb onset cases, total magnesium had a mean coefficient of 0.319 (credible interval 0.033-0.607). DISCUSSION: We report the first spatial analysis of potential association between ALS and soil minerals using a population-based dataset collected over 18 years. Our sole non-zero finding is likely a random finding due to the high number of models built. We did not find any evidence to support soil mineral and toxin levels as risk factors for ALS. However as soil parameters are an ecological assessment of exposure in a given area, individual level measures of exposure are required.

A multidisciplinary clinic approach improves survival in ALS: a comparative study of ALS in Ireland and Northern Ireland.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a progressive debilitating neurodegenerative disease, with a life expectancy of 3-5 years from first symptom. There is compelling evidence that those who attend a multidisciplinary clinic experience improved survival. The purpose of the study was to explore the survival of patients with ALS ascertained through population-based Registers in the Republic of Ireland (RoI) and Northern Ireland (NI), and to determine whether centralisation of services confers advantage compared with community-based care supported by a specialist care worker. METHODS: The island of Ireland is divided into two countries, RoI and NI, each with an independent healthcare system. Both countries have population-based ALS Registers with full ascertainment. Data from all 719 incident ALS cases from Ireland and NI, diagnosed between 1 January 2005 and 31 December 2010, were used in the analysis. RESULTS: A survival benefit was identified for patients who attended the multidisciplinary ALS clinic in the RoI. (HR 0.59, 95% CI 0.49 to 0.71, p<0.001). This difference was preserved following multivariate analysis. A trend towards improved survival was noted for patients with ALS from NI when compared with RoI patients who did not attend a multidisciplinary clinic. CONCLUSIONS: Centralised multidisciplinary care confers a survival advantage for patients with ALS and is superior to devolved community-based care. We propose that multiple decision-making processes within a multidisciplinary setting lead to an enriched set of clinical encounters for the patient and carer that enhances clinical outcome.

Social deprivation and population density are not associated with small area risk of amyotrophic lateral sclerosis.

INTRODUCTION: Evidence of an association between areal ALS risk and population density has been previously reported. We aim to examine ALS spatial incidence in Ireland using small areas, to compare this analysis with our previous analysis of larger areas and to examine the associations between population density, social deprivation and ALS incidence. METHODS: Residential area social deprivation has not been previously investigated as a risk factor for ALS. Using the Irish ALS register, we included all cases of ALS diagnosed in Ireland from 1995-2013. 2006 census data was used to calculate age and sex standardised expected cases per small area. Social deprivation was assessed using the pobalHP deprivation index. Bayesian smoothing was used to calculate small area relative risk for ALS, whilst cluster analysis was performed using SaTScan. The effects of population density and social deprivation were tested in two ways: (1) as covariates in the Bayesian spatial model; (2) via post-Bayesian regression. RESULTS: 1701 cases were included. Bayesian smoothed maps of relative risk at small area resolution matched closely to our previous analysis at a larger area resolution. Cluster analysis identified two areas of significant low risk. These areas did not correlate with population density or social deprivation indices. DISCUSSION: Two areas showing low frequency of ALS have been identified in the Republic of Ireland. These areas do not correlate with population density or residential area social deprivation, indicating that other reasons, such as genetic admixture may account for the observed findings.

Preferences of Older People With a Life-Limiting Illness: A Discrete Choice Experiment.

CONTEXT: There is limited evidence about which elements and characteristics of palliative care service provision improve the experiences of older people living with life-limiting illness. OBJECTIVES: To evaluate older patients' (≥65 years) preferences for elements of services and supports and to explore relationships between patient characteristics and the patterns of preferences. METHODS: A cross-sectional survey undertaken in Ireland and England using a Discrete Choice Experiment with people accessing specialist palliative care services. A random-effects probit model was used to estimate patient preferences. RESULTS: Of the 77 patients were interviewed, 51 participated in the Discrete Choice Experiment component of the interview (response rate = 66%). Participants prioritized support that minimized unpaid caregiver burden (P < 0.001). They also preferred ease of access to services including out-of-hours access (P < 0.001) and free care at home (P < 0.001). Quality of life was prioritized over quantity of life (<0.001). CONCLUSION: People living with a life-limiting illness value care that focuses on quality of life, ensures barrier-free access to services and provides sufficient support for relatives. In the context of limited resources and growing demand for care, this study provides evidence about the service elements palliative care delivery models should prioritize and evaluate.

Adherence to Discounting Guidelines: Evidence from Over 2000 Published Cost-Effectiveness Analyses.

Previous studies have shown that not all cost-effectiveness analyses (CEAs) adhere to recommended guidelines on intertemporal discounting. This analysis investigates adherence in a sample of over 2000 CEAs from seven countries. Guideline discount rates were retrieved for Australia, Belgium, Canada, Ireland, The Netherlands, New Zealand and the UK. Data on the rates applied in published CEAs were retrieved from the Tufts CEA Registry from the sample countries within the periods covered by the discounting guidelines. The relationship between adherence and candidate explanatory factors were assessed using logistic regression. The analysis appraised 2270 CEAs. The overall rate of adherence to discounting recommendations was 79%. Country-specific adherence ranged from 28% in New Zealand to 87% in Belgium and the UK. Adherence in Australia and Canada was 73% and 66%, respectively. Adherence is statistically significantly higher in more recent studies, countries currently applying differential discounting and manufacturer-sponsored studies. Relative to the reference case of Australia, adherence is statistically significantly higher in the UK and lower in Canada and New Zealand. There is notable variation in the rates of adherence to discounting recommendations between countries and over time. Incomplete adherence raises concerns regarding the comparability of evidence between studies. In turn, this raises concerns regarding equity of access to scarce healthcare resources. Journal editors should ensure that adherence to discounting recommendations is assessed as part of the peer review process.

Study protocol for the COvid-19 Toolbox for All IslaNd (CONTAIN) project: A cross-border analysis in Ireland to disentangle psychological, behavioural, media and governmental responses to COVID-19.

COVID-19 represents a serious challenge to governments and healthcare systems. In addition to testing/contact tracing, behavioural and social responses such as handwashing and social distancing or cocooning are effective tools for mitigating the spread of the disease. Psychological (e.g., risk perceptions, self-efficacy) and contextual factors (government, public health messaging, etc.) are likely to drive these behaviours. Collated real-time information of these indicators strengthens local, national and international public health advice and messaging. Further, understanding how well public health and government messages and measures are understood, communicated via (social) media and adhered to is vital. There are two governments and public health jurisdictions on the island of Ireland, the Republic of Ireland (ROI) and Northern Ireland (NI). This represents an opportunity to explore implications of differing measures and messaging across these two jurisdictions as they relate to COVID-19 on two similar populations. The expert research team are drawn from a range of disciplines in the two countries. This project has four nested studies: Assessment of key behavioural, social and psychological factors through a large, prospective representative telephone survey of individuals aged over-18 on a weekly basis over eight weeks (n=3072); and conduct qualitative focus groups over the same period.Interrogation of social media messaging and formal media responses in both jurisdictions to investigate the spread of (mis)information.Modelling data from Studies 1 and 2, plotting the psychosocial/behavioural and media messaging information with international, ROI and NI incidence and mortality data. Conducting an assessment of health policy transfer in an attempt to incorporate the most significant public health and political insights from each jurisdiction. The CONTAIN project will develop an evidence-based toolbox for targeting public health messaging and political leadership and will be created for use for the anticipated second wave of COVID-19, and subsequently for future epidemics/pandemics.

Religious Attendance, Religious Importance, and the Pathways to Depressive Symptoms in Men and Women Aged 50 and Over Living in Ireland.

OBJECTIVES: We aimed to explore the relationship between religiosity and depressive symptoms longitudinally. METHOD: We used four waves (2009-2016) of the Irish Longitudinal Study on Ageing (TILDA) to create growth curve models (GCM) of depressive symptoms and religious attendance/importance in a sample aged 50+ in Ireland and structural models to assess the longitudinal associations between religious attendance/importance and depressive symptoms. We tested whether this relationship was mediated by social connectedness. RESULTS: GCM showed that higher religious attendance at baseline was associated with lower baseline depressive symptoms, while higher religious importance was associated with higher baseline depressive symptoms. Social connectedness partially mediated the baseline associations between religious attendance and lower depressive symptoms. There were no associations between religious factors and the development of depressive symptoms over time. DISCUSSION: This study found that the relationship between religion and depressive symptoms is complex, and any protective effect was driven by religious attendance.

Is Baseline Orthostatic Hypotension Associated With a Decline in Global Cognitive Performance at 4-Year Follow-Up? Data From TILDA (The Irish Longitudinal Study on Ageing).

Background It is postulated that orthostatic hypotension ( OH ), a reduction in blood pressure (≥20/10 mm Hg) within 3 minutes of standing, may increase cognitive decline because of cerebral hypoperfusion. This study assesses the impact of OH on global cognition at 4-year follow-up, and the impact of age and hypertension on this association. Methods and Results Data from waves 1 and 3 of TILDA (The Irish Longitudinal Study on Ageing) were used. Baseline blood pressure response to active stand was assessed using beat-to-beat blood pressure monitoring. Two measures of OH were used-at 40 seconds ( OH 40) and 110 seconds ( OH 110). Global cognition was measured using the Montreal Cognitive Assessment. Mixed-effects Poisson regression assessed whether baseline OH was associated with a decline in global cognition at 4-year follow-up. The analysis was repeated, stratifying by age (age 50-64 years and age ≥65 years), and including an interaction between OH and hypertension. Baseline OH 110 was associated with an increased error rate in Montreal Cognitive Assessment at follow-up (incident rate ratio 1.17, P=0.028). On stratification by age, the association persists in ages 50 to 64 years (incident rate ratio 1.25, P=0.048), but not ages ≥65 years. Including an interaction with hypertension found those with co-existent OH 110 and hypertension (incident rate ratio 1.27, P=0.011), or OH 40 and hypertension (incident rate ratio 1.18, P=0.017), showed an increased error rate; however, those with isolated OH 110, OH 40, or isolated hypertension did not. Conclusions OH is associated with a decline in global cognition at 4-year follow-up, and this association is dependent on age and co-existent hypertension.

Longitudinal predictors of caregiver burden in amyotrophic lateral sclerosis: a population-based cohort of patient-caregiver dyads.

OBJECTIVE: Caregiver burden is a recognised consequence of caring for a patient with neurodegeneration. Amyotrophic lateral sclerosis (ALS) differs from other neurodegenerations by its rapid progression and impairment of motor, cognitive, and behavioural function, which contribute to caregiver burden. However, longitudinal factors that determine the extent of caregiver burden, and in particular the impact of psychological distress among caregivers, have not been fully established. METHODS: Patients with ALS (n = 85) and their primary caregivers (n = 85) completed three serial evaluations. Caregiver burden was measured using the Zarit Burden Interview (ZBI). Anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale (HADS). The Edinburgh Cognitive-Behavioural ALS Screen (ECAS) was used to determine cognitive function in patients. The ALS Functional Rating Scale (ALSFRS-R) measured disease progression. RESULTS: Using the ZBI, caregivers were categorised as high or low burden. In the low burden group, anxiety scores from the HADS predicted caregiver burden (r = 0.410, F = 3.73, p = 0.033), whereas the depression sub-score from the HADS was predictive of caregiver burden in the high burden group (r = 0.501, F = 5.87, p = 0.006) for cross-sectional analyses. Longitudinally, an elevated score on the HADS at Time 1 was the largest predictor of caregiver burden across serial assessments. CONCLUSION: In a patient cohort with relatively preserved cognitive function (65%), anxiety and depression at Time 1, as measured by the HADS, were the best predictors of caregiver burden at Time 3. This observation provides a mechanism by which caregiver burden can be identified by health-care professionals and a stepped care programme of intervention initiated.

The relationship between kidney function and quality of life among community-dwelling adults varies by age and filtration marker.

BACKGROUND: The impact of a diminished level of kidney function on the well-being of an older individual is poorly understood. We sought to determine the association between estimated glomerular filtration rate (eGFR) and overall quality of life (QoL) among older adults. METHODS: Cross-sectional analysis of 4293 participants from the Irish Longitudinal Study on Ageing, a population-based study of community-dwelling adults ≥50 years of age. We used multivariable negative binomial regression to model the relationship between categories of cystatin C eGFR (eGFRcys) or creatinine eGFR (eGFRcr) and the number of QoL deficits from the Control, Autonomy, Self-realization and Pleasure (CASP-19) scale, a holistic measure of QoL among older adults (range 0-57). We further explored this relationship across age strata. RESULTS: Median age was 61 [interquartile range (IQR) 55-68] years, 53% were female, mean (SD) CASP-19 score was 44.8 (7.4) and median eGFRcys was 81 (IQR 68-93) mL/min/1.73 m2. After multivariable adjustment, participants with eGFRcys <45 mL/min/1.73 m2 had 14% greater QoL deficits {incidence rate ratio 1.14 (95% confidence interval 1.03-1.25)] relative to the reference group (eGFRcys ≥90 mL/min/1.73 m2). This relationship appeared linear across eGFRcys categories and was more pronounced in younger (50-64 years) compared with older participants (65-74 or ≥75 years). There was no substantive relationship between eGFRcr and CASP-19. CONCLUSIONS: Cystatin C but not creatinine eGFR was associated with clinically modest declines in QoL among a large sample of community-dwelling older adults. This relationship varied by age, suggesting that a diminished eGFR contributes little to overall QoL beyond middle age in this population.

Benefits, pitfalls, and future design of population-based registers in neurodegenerative disease.

Population-based disease registers identify and characterize all cases of disease, including those that might otherwise be neglected. Prospective population-based registers in neurodegeneration are necessary to provide comprehensive data on the whole phenotypic spectrum and can guide planning of health services. With the exception of the rare disease amyotrophic lateral sclerosis, few complete population-based registers exist for neurodegenerative conditions. Incomplete ascertainment, limitations and uncertainty in diagnostic categorization, and failure to recognize sources of bias reduce the accuracy and usefulness of many registers. Common biases include population stratification, the use of prevalent rather than incident cases in earlier years, changes in disease understanding and diagnostic criteria, and changing demographics over time. Future registers are at risk of funding shortfalls and changes to privacy legislation. Notwithstanding, as heterogeneities of clinical phenotype and disease pathogenesis are increasingly recognized in the neurodegenerations, well-designed longitudinal population-based disease registers will be an essential requirement to complete clinical understanding of neurodegenerative diseases.

Relating annual migration from high tuberculosis burden country of origin to changes in foreign-born tuberculosis notification rates in low-medium incidence European countries.

The level of immigration from high tuberculosis (TB) burden countries (HBCs) which impacts on the foreign-born TB notification rate is largely unknown. In this work, we performed a cross-sectional analysis of epidemiological data from 2000 to 2013 from nine European countries: Austria, Denmark, Finland, Hungary, Netherlands, Norway, Spain, Sweden, and the United Kingdom. Crude notification rates were calculated for foreign- and native-born populations and a multiple-linear regression model predicting notification rates with HBC population data was generated. From 2000 to 2013, the population percentage with a foreign birthplace increased on average each year in all nine countries, ranging from +0.11%/year in the Netherlands to +0.66%/year in Spain. An annual increase in HBC migrants above +0.43% per year (95% Confidence Interval: 0.24%-0.63%) corresponded with higher TB notification rates in the foreign-born population of the countries analyzed. This indicates that migration from HBCs can exert a measurable effect on the foreign-born TB notification rate. However, an increase in the foreign-born TB notification rate coincided with an average annual rise in national TB notification rates only in countries, Norway (+3.85%/year) and Sweden (+2.64%/year), which have a high proportion (>80%) of TB cases that are foreign-born.

Age-period-cohort analysis of trends in amyotrophic lateral sclerosis incidence.

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease with an unknown cause. Studies have reported that the incidence rate of ALS might be changing. As ALS is an age related disease, crude incidence could increase as population structure changes and overall life expectancy improves. Age-period-cohort (APC) models are frequently used to investigate trends in demographic rates such as incidence. Age-specific incidence rate for ALS from 1996 to 2014 were taken from a population-based ALS register in Ireland. To circumvent the well-known identifiability issue in APC models, we apply the method of Partial Least Squares Regression to separate the effects of Age, Period and Cohort on ALS incidence over time. This APC analysis shows no cohort effect and the initial signs of a period effect; increasing incidence of ALS in the most recently diagnosed group. As further years of data accrue to the Irish register it will become clear if this effect emerges as a strong trend in the incidence of ALS in Ireland and replication of these analyses in other populations will show if our findings on temporal patterns in ALS incidence are shared elsewhere.

Survival analysis of geospatial factors in the Irish ALS cohort.

Variations in environmental risk factors potentially influence incidence and progression in complex multifactorial diseases. Few studies have examined the association of survival in amyotrophic lateral sclerosis (ALS) with environmental geospatial variables. Here we use data from the Irish ALS cohort to perform such an analysis. Geographic data sources were used to generate small area values for four geospatial variables (population density, social deprivation, distance to coast, and distance to ALS multidisciplinary (MDT) clinic) for each ALS case on the Irish ALS register. These were combined with follow-up data and used as covariates in Royston-Parmar regression survival analysis including age of onset, site of onset, diagnostic delay, riluzole prescription and MDT clinic attendance as covariates. One thousand, two hundred and thirty-two patients with median survival of 2.31 years from disease onset were included. After addition of the individual geospatial variables in turn, none of the four variables was found to be associated with survival with a p-value <0.05. The results may reflect the public healthcare system that provides riluzole prescription and access to the MDT to all patients free of charge, and is also congruent with our recent finding that social deprivation is not associated with ALS incidence in Ireland.

An exploratory spatial analysis of ALS incidence in Ireland over 17.5 years (1995-July 2013).

INTRODUCTION: There has been much interest in spatial analysis of ALS to identify potential environmental or genetically caused clusters of disease. Results to date have been inconclusive. The Irish ALS register has been recently geocoded, presenting opportunity to perform a spatial analysis on national prospectively gathered data of incident cases over an 18-year period. METHODS: 1,645 cases of ALS in Ireland from January 1995 to July 2013 were identified from the Irish ALS register. 1,638 cases were successfully geocoded. Census data from four censuses: 1996, 2002, 2006 & 2011 were used to calculate an average population for the period and standardized incidence rates (SIRs) were calculated for 3,355 areas (Electoral Divisions). Bayesian conditional auto-regression was applied to produce smoothed relative risks (RR). These were then mapped for all cases, males & females separately, and those under 55 vs over 55 at diagnosis. Bayesian and linear regression were used to examine the relationship between population density and RR. RESULTS: Smoothed maps revealed no overall geographical pattern to ALS incidence in Ireland, although several areas of localized increased risk were identified. Stratified maps also suggested localized areas of increased RR, while dual analysis of the relationship between population density and RR of ALS yielded conflicting results, linear regression revealed a weak relationship. DISCUSSION: In contrast to some previous studies our analysis did not reveal any large-scale geographic patterns of incidence, yet localized areas of moderately high risk were found in both urban and rural areas. Stratified maps by age revealed a larger number of cases in younger people in the area of County Cork--possibly of genetic cause. Bayesian auto-regression of population density failed to find a significant association with risk, however weighted linear regression of post Bayesian smoothed Risk revealed an association between population density and increased ALS risk.