bluuebunny/crossref_metadata_2025 huggingface dataset:
The cumulative proportion of children receiving social care services in England: a whole population administrative data cohort study.
Authors: Jay Matthew , Mc Grath-Lone Louise , Pearson Rachel , Gilbert Ruth
Published: September 2022

ObjectivesChildren who receive social care services have high levels of need, but the proportion of the population they comprise is unknown. We aimed to estimate the cumulative proportion of children in England who ever become looked after (CLA) or placed on a child in need (CiN) plan by age 18.
ApproachWe analysed longitudinal administrative children’s social care data: the CLA dataset (available from 1992) and the CiN census (from 2011/12) which respectively contain information on all children in England who become CLA and are assessed as being CiN. The number of CLA in birth cohorts from 1992 to 2016 was divided by Office for National Statistics population denominators to estimate the overall cumulative proportion and by EthPOP denominators to describe ethnic variation. Because of incomplete coverage of CiN data, we combined estimates from different birth cohorts, making reductions to the numerator to address left-censoring.
ResultsThe cumulative proportion of children who became CLA before their 18th birthday was 3% for those born in 1992, rising to 4% for those born in 2000. For subsequent cohorts (who had not yet reached age 18), the cumulative proportion by earlier ages also rose over time, but plateaued with the 2012 birth cohort. The cumulative proportion varied by ethnicity: among children born in 2000, it was 18% for those of other ethnicity (many of whom were unaccompanied asylum seeking children), 11% for black children and 7% for those of mixed ethnicity. Most children first became looked after before age 2, with a secondary peak around age 16. Finally, we estimated that 42% of all children in England were recognised as CiN before age 18.
ConclusionSignificant proportions of children receive social care services in England. The ethnic variation we observed may indicate systematic differences in how the care system responds to CLA from different backgrounds. These results have implications for service design, as well as preventive strategies to improve child health and well-being.
Using an Alternative Method to Estimate Overcount for Census 2021.
Authors: White Zoe , Hall Johanna , Xhaferaj Kristina
Published: September 2022

ObjectivesThe project aimed to test an alternative method to estimate the number of duplicate responses  in the 2021 England and Wales Census. The method utilises information from all census records instead of relying on samples. It requires less clerical review  than the original inverse sampling method used for overcount estimation.
ApproachWe used the Splink implementation of Fellegi-Sunter to match the 2021 Census to itself. The resulting linked dataset was filtered to retain only the top scoring record pair for each unique census record, giving a final dataset of around 71.5 million record pairs. These pairs were divided by score into 13 homogeneous buckets. Random samples of 1000 pairs per bucket were clerically reviewed to determine whether each pair was a true duplicate or not. The clerical results were used to assign an estimated probability of being a duplicate to each bucket and hence to every census record within the bucket.
ResultsA dashboard was created which contained percentages of duplicates by region and ‘overcount group’ for the original and alternative methods. This enabled us to view the data side by side and create visualisations to aid analysis. The alternative method had higher average duplicate percentages in overcount groups for communal establishments and was also higher for 9 out of 10 regions in the armed forces overcount group. We found that both the original and alternative methods of overcount estimation followed the same pattern in terms of minimum and maximum duplicate percentages except for those in communal establishments where minimum and maximums were both higher than the original method. Additionally, the minimum was marginally higher for the student and armed forces overcount groups for the alternative method.
ConclusionOn initial comparison, estimated rates of duplication resulting from the different methods are comparable. We plan to conduct further analysis on the similarities and differences of the two methods, and research whether the new method could be applied to estimate the duplication rate in other large datasets including administrative data.
Sleep Medication Use by people with Cerebral Palsy: A Population Level Data Linkage Study.
Authors: Kent Lisa , McCavert Mary-Elaine , McConnell Karen , Perra Oliver , Maguire Aideen , Kerr Claire
Published: September 2022

ObjectivesTo (1) compare proportions of the population dispensed sleep medication, and rate (dispensations/month) and amount (milligrams/month) of dispensed sleep medication, in individuals with and without cerebral palsy (CP); and (2) describe dispensation of sleep medication within CP and non-CP cohorts with respect to sociodemographic and clinical characteristics.
ApproachIndividuals aged 6 -36 years (aligning with those known to the Northern Ireland CP Register [NICPR]), registered with a general practitioner at 01-January-2018, were identified within the National Health Application and Infrastructure System.  Sleep medications dispensed 01-January-2018 to 31-December-2019 were extracted from the Enhanced Prescribing Database.  Analysis was limited to melatonin due to small counts in other medications.  Routine healthcare data was sourced from the Honest Broker Service (HBS).  NICPR clinical data (CP-type, Gross Motor Function Classification System (GMFCS), gestation and birthweight) were linked to routine healthcare data using the Health and Care Number by HBS. Descriptive statistics are presented.
ResultsComplete matching was achieved between NICPR and healthcare data using the HCN.  Final cohorts consisted of 1,598 individuals with CP and 790,097 without CP. A greater proportion of those with CP were dispensed melatonin compared to those without CP (4.6% vs 1.0%).  The CP cohort were also dispensed melatonin at a greater rate (median(IQR) CP 0.33(0.71) vs non-CP 0.25(0.54) dispensations/month) and in greater amounts (median(IQR) CP 30(74.7) vs non-CP 17.5(55.0) mg/month).  Within the CP cohort, differences in melatonin dispensation were observed across sociodemographic groups (male 5.1% vs female 3.9%; children 8.2% vs young adults 2.2%; urban 6.5% vs rural 5.0%); deprived 5.1% vs affluent 4.2%).  Clinical characteristics associated with greatest dispensation of melatonin were non-spastic CP (6.83%), GMFCS IV&V (5.29%), or extremely premature birth (6.85%).
ConclusionIndividuals with CP, particularly children, are more likely to be dispensed sleep medications compared to the general population.  Awareness of this disparity could encourage further research on assessment and management of sleep in CP and facilitate discussions between healthcare providers and families on underlying causes of sleep problems.
Linkage of Routinely-Collected Maternity Data with a Cerebral Palsy Register: Comparison of baseline maternal characteristics in offspring with and without cerebral palsy.
Authors: Kent Lisa , Kerr Claire , McConnell Karen , Perra Oliver , Eastwood Kelly-Ann
Published: September 2022

ObjectivesThis feasibility and hypothesis generating study aimed to compare maternal characteristics between pregnancies in which at least one infant received a diagnosis of CP (case pregnancies) and pregnancies in which all infants did not receive a diagnosis (control pregnancies).
ApproachData for individuals with cerebral palsy (CP) born between 1990 (commencement of Northern Ireland Maternity System (NIMATS)) and 2012 (latest fully validated birth year in Northern Ireland Cerebral Palsy Register (NICPR)) were transferred to the Honest Broker Service, who performed linkage to NIMATS.  Offspring were primarily matched between NICPR and NIMATS using the unique Health and Care Number. Where this was unavailable in NIMATS, matching from offspring to mother-infant pairs was performed using surname, gender, date of birth and/or postcode.  Chi-square tests were used to test for differences in maternal characteristics between case and control pregnancies.
ResultsCohorts consisted of 486 case and 266,260 control pregnancies.  After missing values were removed, case pregnancies had a greater proportion of mothers under 25 years (case: 28.0% vs control: 23.1%, p<0.05), multiple births (7.8% vs 1.5%, p<0.001), nulliparous mothers (47.5% vs 41.1%, p<0.05), unplanned pregnancies (42.8% vs 34.4%, p<0.001), late booking appointments (14.0% vs 9.7%, p<0.01), hypertension during pregnancy (11.9% vs 8.5%, p<0.05), no recorded folic acid intake (46.7% vs 34.8% p<0.001), family history of congenital abnormality (33.3% vs 24.4%, p<0.001), medical problems with potential to affect labour (respiratory, cardiac, diabetes, other) (6.6% vs 3.9%, p=0.004).  A non-significant trend was observed suggesting that case pregnancies had a higher proportion of mothers with BMI≥30kg/m2 (21.4% vs 13.2%, p=0.086).
ConclusionThis feasibility study has highlighted a range of potential maternal characteristics that may be associated with a diagnosis of cerebral palsy in offspring and mirrors findings from other studies.  A future data extraction update and predictive model development is planned.
DASSL “Data Access Sharing Storage & Linkage” Proof-of-Concept: Health and Related Data Linkage in Ireland.
Authors: Fennelly Orna , Voisin Bruno , Olszewska Marta , Corrigan Derek , Moriarty Frank , Fahey Tom , Sarkar Divyajyoti , Nagy Sherif , Wong Simon
Published: September 2022

ObjectiveThe DASSL Model, conceived by the Health Research Board, aims to overcome challenges to linking data in Ireland including lack of unique patient identifiers, inconsistent application of legislation and siloed data. The objective of the Proof-of-Concept is to develop and test a demonstrator technical infrastructure to support this model.
ApproachA stakeholder committee of representatives from government, health services, data controllers, patients/public and researchers was established. National and international data sharing and linkage landscapes were reviewed via interviews, scientific papers and grey literature. Five case studies were developed to demonstrate different linkages, data and research purposes, with synthetic data mimicking real health/social datasets generated using data dictionaries, data controller input, national statistics and Synthpop, Synthetic Data Vault and General Adversarial Networks. The technical infrastructure remains under development with linkage software being evaluated. Stakeholders will test this infrastructure and a final report will outline considerations for a national solution.
ResultsSynthetic versions of administrative data, patient registries, electronic patient records, longitudinal cohorts, imaging and genomics are being generated. Matching variables and content data will be split and securely shared respectively with the Trusted Third Party (TTP) and Health Data Hub (HDH) on a project-by-project basis and at regular intervals. The selected linkage software will be used to match both unique identifiers and personally-identifiable data using probabilistic and deterministic techniques between datasets and with a population spine. The encrypted linkage key will be shared with the HDH, where the data view for each case study will be created by the Research Support Unit using the content data. A locked down virtual Safe Haven will support researcher access with disclosure control check on any outputs.
ConclusionA DASSL infrastructure could support sharing, linking and analysis of health and social data in Ireland. However, high quality data including matching variables need to be collected to produce beneficial findings. A national rollout requires a governance and legislative model, improvements in data collection, further public engagement and significant resourcing.
Linkage of Routinely-Collected Maternity Data with a Cerebral Palsy Register: Matching Success and Temporal Assessment of Data Quality and Maternal Characteristics.
Authors: Kent Lisa , Kerr Claire , McConnell Karen , Perra Oliver , Eastwood Kelly-Ann
Published: September 2022

ObjectivesThis study aimed to 1) establish the success rate of matching offspring in the Northern Ireland Cerebral Palsy Register (NICPR) to mother-infant pairs within the Northern Ireland Maternity System (NIMATS); and explore changes in 2) quality of maternal data (NIMATS) and 3) maternal characteristics over the study period.
ApproachData for individuals with cerebral palsy (CP) born between 1990 (commencement of NIMATS) and 2012 (latest fully validated birth year in NICPR) were transferred to the Honest Broker Service, who performed data linkage.  Offspring were primarily matched between NICPR and NIMATS using the unique Health and Care Number (HCN).  Where this was unavailable in NIMATS, matching from offspring to mothers/pregnancies was performed using surname, gender, date of birth +/- postcode.  Changes in completeness and quality of data and maternal characteristics were explored per year and visualised using histograms.  All pre-processing and analyses were performed using R.
ResultsFrom 1263 included CP cases, 377(30%) were matched using HCN.  A further 121(9%) were matched by secondary strategies.  Substantial improvements in completeness of maternal data were observed over time (body mass index (46.2% to 97.7%); BP (44.8% to 95.3%); age 100% complete throughout).  An apparent tendency to round systolic and diastolic blood pressure to the nearest ten was observed.  This tendency decreased over time which potentially led to an overestimation of hypertension detected in earlier years.  Characteristics of mothers also changed over the study duration, seen in increasing proportions with BMI≥30 kg/m2 (9.97% to 18.9%). Age of mothers also increased with decreasing proportions aged<25y (33.7% to 19.6%) and increasing proportions aged≥35y (9.7% to 20.4%).  No change over time was observed in maternal blood pressure variables.
ConclusionMatching success was affected by incomplete NIMATS coverage in earlier years and lag time in CP diagnosis being confirmed by NICPR (typically beyond the age of 4 years).  Over time, completeness and quality of maternal variables in NIMATS has improved meaning future studies using these linkages will be more reliable.
Coronavirus (COVID-19) infection rates and vaccination uptake in school pupils in England.
Authors: Kelly Joe , Judd Alison
Published: September 2022

ObjectivesCOVID-19 vaccination uptake was lower in school-age children compared to older age groups. Our study aims to understand factors associated with uptake in school-age children and how vaccination programme affected infection rates in school settings.
ApproachThis study utilises existing administrative data sources to create a children’s health data asset. The core study population includes over 8 million pupils registered in English state schools whose records have been linked to NHS Test and Trace data and National Immunisation Management Service (NIMS) data. Census 2021 data will also be included enriching the data on background characteristics of each pupil. Taking into account the school attended will allow for analysis into the clustering of infections and the impact of overall school vaccination rates on infections.
ResultsInitial analyses have provided detailed insights into vaccine uptake and its impact on infection. For example, vaccination uptake was found to vary by ethnic group, with Chinese (75%) and Indian (65.7%) 12–15-year-olds most likely to be vaccinated by January 2022. Those in receipt of free school meals (FSM) were less likely to have been vaccinated than non-FSM pupils (35.9% compared with 58.9%); However, there was a wide range in vaccination rates between different schools with similar levels of deprivation.
We also found that the rate of reporting a positive test in the first half of the Autumn 2021 term was estimated to be 38% higher for unvaccinated pupils in comparison to pupils vaccinated with one dose (following 14 days after vaccination).
ConclusionThe size and longitudinal nature of the dataset provides the potential to answer a wide variety of research questions. We must, however, be mindful of inherent biases that might occur when relying on using Test and Trace data to identify COVID-19 infections. Work is currently ongoing to expand this asset to include other data sources.
Impact of the COVID-19 pandemic on commencement of psychotropic medications in Northern Ireland: a population-wide, administrative data linkage study.
Authors: Kent Lisa , O'Reilly Dermot , Maguire Aideen
Published: September 2022

ObjectivesThis study aimed to explore changes in commencement of psychotropic medications in first 20 months of the pandemic and associated restrictions in Northern Ireland (NI).
ApproachAntidepressant, anxiolytic, hypnotic and antipsychotic medications dispensed in all community pharmacies in NI (Jan-2012 to Oct-2021, Enhanced Prescribing Database) were linked to sociodemographic data (National Health Application and Infrastructure Services) for everyone alive and resident in NI aged ≥10years. Commencement of new medication was identified on a rolling monthly basis as a dispensation in a given month but not in the previous 24 months. Auto Regressive Integrated Moving Average (ARIMA) models were trained taking trends and seasonal effects into consideration. Monthly forecasts were compared to actual numbers, at population level and within sociodemographic groups (gender, age, rurality, living-alone, deprivation).
ResultsThere were consistent increased numbers of individuals commencing antipsychotic medications in the group aged ≥65years, with observed to expected ratio ranging from 1.12 to 2.1.  Commencement of hypnotics was decreased throughout the study in individuals aged <18years (OER ranged from 0.28 to 0.70) but remained as expected for other sociodemographic groups.  Across all sociodemographic groups, commencement of antidepressants decreased initially (Mar-May 2020 population-level OER ranged from 0.61 to 0.79) and in Jan 2021 (population-level OER 0.78) corresponding with stricter stay at home restrictions but resumed the expected trend outside of these periods.  There were no obvious deviations from expected trends in commencement of anxiolytics.
ConclusionThere was a clear impact on older people with regards commencement of antipsychotic medications throughout the pandemic. Hypnotic commencement in children was lower than expected throughout the pandemic, which may reflect reduced need or reduced access to specialist paediatric services. (NHS-REC:20/YH/0254; Data sourced from the Honest Broker Service)
Maternal Mental Health, Child Distress and Family Strain During the COVID-19 Pandemic: Linking the Provincial Longitudinal Cohort with the COVID-19 Impact Survey Data in Canada.
Authors: Lee Janelle Boram , Ntanda Henry , Ross Kharah , Letourneau Nicole
Published: September 2022

ObjectiveTo understand the impact of the COVID-19 pandemic on families in Canada by specifically examining the relationship between maternal mental distress (MD), child distress (CD) and family strain (FS) trends over time. We linked the Alberta Pregnancy Outcomes and Nutrition (APrON) longitudinal cohort data and COVID-19 Impact Survey (CIS).
ApproachThree waves of CIS (March 2020 to July 2021), collected from APrON longitudinal cohort, were used. Demographic variables from APrON were linked with CIS. Mothers’ depression, anxiety, and/or stress scores were standardized separately for different symptoms, averaged at each wave, and combined as one maternal MD variable (low/medium/high). CD was measured across emotional, conduct, hyperactivity, and peer problem scales (low/high). FS was defined as COVID-19 straining family relationships, including partners, parent-child, and siblings (yes/no). Latent class analyses were performed to identify and categorize membership across the variables. To address the objective, multiple logistic regression models were conducted.
ResultsThe sample consisted of 157 participants were included in the study; 19.1% reported FS during COVID-19. Three latent classes were formed for maternal MD: consistently low (36.9%), medium (44.0%), and high (19.1%) across the follow-up period. Two latent classes were formed for CD: consistently low (79.6%) and high (20.4%). When adjusted for COVID-19 related covariates (e.g., maternal worries about child’s well-being/education, family difficulty with childcare/schoolwork) and socioeconomic status, mothers with medium and high levels of maternal MD were at increased odds of experiencing FS during the COVID-19 pandemic compared to those with a low level of distress (medium aOR = 3.90[1.08, 14.03]; high aOR = 4.57[1.03, 20.25]). The adjusted association between child distress and FS was not statistically significant (aOR = 1.75[0.59, 5.20]).
ConclusionUnderstanding how MD could affect family strain is important as many families recover from the pandemic. More distressed individuals experience greater FS over time, suggesting this association as a chronic problem. Stakeholders should tailor support systems to longer-term, family-level interventions improving family relationships and maternal-child MHD impacted by COVID-19.
Costs of missed work among employed people with inflammatory bowel disease: a cross-sectional population-representative study.
Authors: Kuenzig Ellen , Lebenbaum Michael , Mason Joyce , Vyas Manav , Kaplan Gilaad , Murthy Sanjay , Targownik Laura , Benchimol Eric
Published: September 2022

ObjectivesInflammatory bowel disease (IBD) is a chronic inflammatory disease primarily affecting the gastrointestinal tract. Periods of relapsing and remitting abdominal pain and diarrhea result in decreased quality of life. We report the impact of IBD on missed work and associated costs using population-representative data to understand population-level indirect costs.
ApproachWe used the 2014 Canadian Community Health Survey to compare missed work and associated costs among employed respondents aged 20 to 64 years with and without self-reported physician-diagnosed IBD. Students and individuals with non-IBD bowel disorders were excluded. Costs of missed work were derived from reported annual income and the number of workdays missed. Survey weights were used for descriptive statistics. Logistic regression compared odds of employment. Negative binomial models compared the number of days missed and the cost of lost work in the two groups. All costs are in Canadian dollars and adjusted for inflation to 2022 dollars.
ResultsAmong 33,344 eligible respondents, 1.0% had IBD. Employment in the last 3 months was reported among 72% of people with IBD and 81% of people without IBD (OR: 0.60, 95% CI 0.59-0.74). During this time, 48% of people with IBD and 31% of those without IBD missed work with a mean (sd) of 1.99 (5.17) and 1.03 (3.67) days of work missed, respectively (RR for days missed: 2.19, 95% CI 1.63-3.03). This corresponds to a cost of $608 (1635) among individuals with IBD and $298 (1063) among those without IBD every 3 months (RR: 2.18, 95% CI 1.22-4.43). Extrapolating to the estimated 133,030  employed Canadians with IBD, the attributable indirect cost of missed work due to IBD is nearly $165 million annually.
ConclusionThe economic burden of IBD resulting from missed work is substantial. Since IBD is most often diagnosed during adolescence and early adulthood, employability and workplace productivity are important long-term outcomes for patients. Future interventions should be developed to help address these challenges.
Assessing the reliability of ethnicity data recorded in health-related administrative datasets in England.
Authors: Ward Isobel , Razieh Cameron , Drummond Rose , Nafilyan Vahé , Bannister Neil , Glickman Myer
Published: September 2022

ObjectivesDuring the COVID-19 pandemic, higher mortality among some ethnic minority groups was identified and has become the subject of significant public and government interest, highlighting an urgent requirement to quantify the reliability of ethnicity classification across health administrative data sets, which are utilised in health analysis and pandemic planning.
ApproachThe aim of our work was to assess how ethnicity data recorded in Census and health admin records varied across ethnicities and provide recommendations for how missingness can be accounted for by statisticians. Combining population level data from general practice (GP) records with hospital episode statistics (HES) for patients in England, we created a linked data set with Census 2011 data to reliably assess coverage and missingness between data sources. Most recent and modal ethnicity classifications were derived on a person-level from both HES and GP administrative data for comparison to gold-standard Census 2011 records.
ResultsAgreement rates were calculated to assess the reliability of ethnicity data recorded in health administrative datasets compared to Census data. We found that the agreement rates vary by ethnic group and other demographic characteristics. Furthermore, we highlighted groups of people who exist in one health-admin source, but not Census, and vice versa, illustrating the importance of accounting for the sample bias in health analysis when relying solely on primary or secondary care data sources. Implementation of techniques to account for bias and missingness were tested to propose methodology to improve reliability of ethnicity estimates from both HES and GP data, in order to ensure estimates of health disparities are as accurate as possible.
ConclusionWe have linked GP records to Census 2011 and HES data to provide population-based ethnicity estimates of coverage, missingness and bias between data sources, in order to improve our understanding of ethnicity data quality. This work aims to inform policies tackling ethnic health inequalities in England.
Direct and indirect effects of the COVID-19 pandemic on mortality: an individual-level population-scale analysis.
Authors: Owen Rhiannon , Lyons Jane , Akbari Ashley , Davies Gareth , Griffths Rowena , Torabi Fatemeh , Lyons Ronan
Published: September 2022

ObjectivesThe COVID-19 pandemic has had a detrimental impact on healthcare utilisation, resulting in increased mortality both directly and indirectly associated with COVID-19. We aimed to assess the impact of the COVID-19 pandemic on all-cause and disease-specific mortality and further explore the impact of potential inequalities, deprivation status and ethnicity.
ApproachPopulation-scale, individual-level, anonymised linked, routinely-collected electronic health records from demographic and administrative sources were used for two cohorts: i) C19-COHORT16 included individuals alive and resident in Wales on the 1st January 2016 with follow-up until death, break-in Welsh residency, or 31st December 2019; ii) C19-COHORT20 included individuals alive and resident in Wales on 1st January 2020 with follow-up until death, break-in Welsh residency, or study end. We used time-series analysis to investigate trends in mortality over time. We fitted negative binomial models to estimate expected all-cause and disease-specific mortality and compared these estimates to observed mortality in C19-COHORT20.
ResultsExcess all-cause and COVID19-related deaths were higher during the period where the alpha variant was dominant. The trend in deaths decreased during the omicron dominant period. The Asian population had increased mortality during the period where the delta variant was dominant. Mortality was increased for most deprived groups compared to least deprived groups, however, the magnitude of this effect remained unchanged during the pandemic. COVID-19 indirectly affected cancer, circulatory, trauma, digestive and mental health related deaths, with a higher than expected mortality. The majority of trauma related deaths occurred early on in the pandemic, where a higher than expected number of deaths occurred outside of an NHS establishment. Mortality associated with respiratory disease (unrelated to COVID-19) was significantly lower than expected during the COVID-19 pandemic.
ConclusionIncreased all-cause and disease-specific mortality was observed during the COVID-19 pandemic. Excess deaths may be a result of reduced healthcare utilisation, delayed investigation and/or treatment of chronic diseases. As healthcare systems recover from COVID-19, investigation of mortality trends will play a central role in healthcare planning, utilisation and resource use.
Changes in social support and the emotional health of immigrant, refugee, and non-immigrant children across middle childhood: A three year follow up study.
Authors: Thomson Kimberly , Magee Carly , Petteni Monique Gagne , Gadermann Anne
Published: September 2022

ObjectivesChildren who are new to Canada have unique circumstances that can be associated with their emotional health. Using linked immigration and child self-report data, we examined associations between changes in children’s social support and emotional health from ages 9 to 12, for immigrant, refugee, and non-immigrant children.
ApproachA population sample of N = 4664 immigrant, refugee, and non-immigrant children reported on their peer support and school belonging, as well as their emotional health (life satisfaction, self-esteem, sadness), in Grades 4 and 7. Social support and emotional health were measured using the Middle Years Development Instrument (MDI). Migration background including age at arrival, migration class, generation status, and source region, was obtained from the Immigration, Refugees, and Citizenship Canada database, individually linked to MDI records using children’s Personal Education Number and child date of birth. Multi-level modelling assessed associations adjusting for confounders.
ResultsIn the linked sample, 19% of children were first- or second-generation economic immigrants (themselves or their parents were born outside of Canada), 8% were family immigrants, and 5% were refugees. Children with refugee backgrounds reported lower life satisfaction and self-esteem and higher sadness in Grade 4 compared to all other groups. Children with immigration backgrounds reported lower life satisfaction and self-esteem and higher sadness compared to non-immigrants. Refugee children had significantly more positive changes in emotional health from Grades 4 to 7 compared to non-immigrants, and significantly more positive changes in social supports. Positive changes in social supports were associated with positive changes in emotional health of similar magnitude for all children, regardless of migration background. Children with refugee backgrounds on average experienced improved emotional health during middle childhood, and changes in peer support partially accounted for these changes.
ConclusionResults suggest that children with migration backgrounds enter school with lower emotional health and are likely to benefit from increased social supports. Likewise, incorporating opportunities to build peer relationships and school belonging is likely to benefit all children, regardless of migration background.
Developing non-response weights to account for attrition-related bias in a longitudinal pregnancy cohort.
Authors: Pitt Tona , Adhikari Kamala , Premji Shainur , McDonald Sheila
Published: September 2022

ObjectiveThe prospective cohort study design is ideal for examining diseases of public health importance. A main source of potential bias for longitudinal studies is attrition. In this study, we compare the performance of two models developed to predict sources of attrition and develop weights to adjust for potential bias.
ApproachThis study used the All Our Families longitudinal pregnancy cohort of 3351 maternal-infant pairs. Logistic regression models were developed to predict study continuation versus drop-out from baseline to the three-year data collection wave.
Two methods of variable selection took place. One method used previous knowledge and content expertise while the second used Least Absolute Shrinkage and Selection Operator (LASSO). Model performance for both methods were compared using area under the receiver operator curve values (AUROC) and calibration plots. Stabilized inverse probability weights were generated using predicted probabilities. Weight performance was assessed using standardized differences with and without weights (unadjusted estimates).
ResultsLASSO and investigator prediction models had good and fair discrimination with AUROC of 0.73 (95% Confidence Interval [CI]: 0.71 – 0.75) and 0.69 ( 95% CI: 0.67 – 0.71), respectively. Calibration plots and non significant Hosmer-Lemeshow Goodness of Fit Tests indicated that both the LASSO model (p = 0.10) and investigator model (p = 0.50) were well-calibrated.
Unweighted results indicated large (>10%) standardized differences in 15 demographic data variables (range: 11% - 29%), when comparing those who continued in study with those that did not. Weights derived from the LASSO and investigator models reduced standardized differences relative to unadjusted estimates, with ranges of 0.1% - 5.3% and 0.3% - 12.7%, respectively.
ConclusionThe data-driven approach produced robust weights that addressed non-response bias more than the knowledge-driven approach. The data driven approach, did, however still require content knowledge in how data were grouped, combined, or split. The weights can be applied to analyses across multiple waves of data collection to reduce bias.
Ethnic differences in COVID-19 mortality in the second and third waves of the pandemic in England during the vaccine roll-out.
Authors: Bosworth Matt , Nafilyan Vahé
Published: September 2022

ObjectivesThis study aims to assess whether ethnic differences in COVID-19 mortality in England have continued into the third wave and to what extent differences in vaccination rates contributed to excess COVID-19 mortality after accounting for other risk factors. 
ApproachThis Cohort study of 28.8 million adults living in private households or communal establishments in England is based on data from the Office for National Statistics (ONS) Public Health Data Asset (PHDA). The ONS PHDA is a linked dataset combining the 2011 Census, mortality records, the General Practice Extraction Service (GPES) Data for Pandemic Planning and Research (GDPPR), Hospital Episode Statistics (HES) and vaccination data from the National Immunisation Management System (NIMS). We calculated hazard ratios (HRs) for death involving COVID-19 during the second (8 December 2020 to 12 June 2021) and third wave (13 June 2021 to 1 December 2021) of the pandemic separately for males to females to assess the association between ethnic group and death involving COVID-19 in each wave, sequentially adjusting for age, residence type, geographical factors, sociodemographic characteristics, pre-pandemic health, and vaccination status.
ResultsAge-adjusted HRs of death involving COVID-19 were higher for most ethnic minority groups than the White British group during both waves, particularly for groups with lowest vaccination rates (Bangladeshi, Pakistani, Black African and Black Caribbean). In both waves, HRs were attenuated after adjusting for geographical factors, sociodemographic characteristics, and pre-pandemic health. Further adjusting for vaccination status substantially reduced residual HRs for Black African, Black Caribbean, and Pakistani groups in the third wave. The only groups where fully-adjusted HRs remained elevated were the Bangladeshi group (men: 2.19, 95% CI 1.72 to 2.78; women: 2.12, 95% CI 1.58 to 2.86) and men from the Pakistani group (1.24, 95% CI 1.06 to 1.46). 
ConclusionPublic health strategies to increase vaccination uptake in ethnic minority groups could reduce disparities in COVID-19 mortality that cannot be accounted for by pre-existing risk factors.
Developing a population-scale harmonised ethnicity-spine in Wales.
Authors: Akbari Ashley , Bedston Stuart , Abbasizanjani Hoda , Davies Gareth , Fry Richard , Lowthian Emily , Lyons Jane , Owen Rhiannon , Torabi Fatemeh , Khunti Kamlesh , Lyons Ronan
Published: September 2022

The COVID-19 pandemic has placed a spotlight on existing and enduring health inequalities experienced by different ethnic groups. There has been a longstanding call to generate and improve the use of ethnicity data available across different data sources, in order to improve our understanding of health risks, behaviours and outcomes.
We used multiple anonymised individual-level population-scale data sources available within the Secure Anonymised Information Linkage (SAIL) Databank to develop a harmonised ethnicity spine for the population of Wales. We documented ethnicity information in multiple longitudinal records from January 2000 onwards. Data sources included: health and social care, birth and mortality records, national census records, specialist clinical audits and registers, surveys and other routine electronic data. To enable multi-source harmonisation, we explored the ethnicity categorisation as well as temporal changes in recording and classifications by obtaining distribution of records for population, which informed our harmonisation algorithm for standardisation of ethnicity records.
We used over 20-data sources on ~5-million individuals, spanning varying time-periods starting from January 2000 upto a maximum of 22-years. We harmonised available recorded ethnicity values into standardised ethnic classification groups within a national ethnicity-spine. Furthermore, we investigated the impact of different harmonisation methods, including composite, latest date of recording, modal and weighted modal results. With the main focus of the methodological development being in response to the COVID-19 pandemic, when linked to the ~3.1 million individuals alive and resident in Wales from January 2020, we generated harmonised ethnic groups towards ~95% completeness in data coverage for the whole population of Wales. The predominant ethnic group in Wales observed was White, accounting for 89% of the population when using the latest date of recording method.
This research highlights challenges in using longitudinal ethnicity data across different sources. Further work is needed to understand the basis on which individuals / organisations record ethnicity overtime. We recommend improvements recognising differences between ethnicity and other social constructs (e.g. ancestry, nationality, country of origin) are better documented / understood.
Predicting Surgical Service Demands: A Modeling challenge using Administrative Data.
Authors: Katz Alan , Taylor Carole , Okechukwu Ekuma , Soodeen Ruth-Ann
Published: September 2022

ObjectivePublicly funded healthcare delivery systems use projections to ensure the availability of adequate future service delivery.  Planning cycles need to consider infrastructure, human resources, and other essential requirements with an adequate lead time. Projections are fraught with challenges due to multiple unknowns but new developments in modeling may be useful.
ApproachWe explored the available data to determine the best approach to modeling surgical demand. The Manitoba Population Research Data Repository includes 90+ databases linkable at the person level over time. These include the population registry which includes all Manitobans registered for the universal healthcare benefit. Hospital discharge abstracts include over 20 relevant diagnoses (ICD10) and procedure codes for each admission. Medical services claims include all physician services provides with ICD 9CM codes. Fee-for-service physicians are paid based on these and alternate funded physicians are required to submit shadow claims.
ResultsWe found 349,171 orthopedic procedures of which 18.1% were absent from the Medical claims files and 551,508 medical claims of which 27.5% lacked a corresponding hospital abstract. We also identified 230,717 ophthalmologic procedures in the hospital data of which 2.5% had no corresponding medical claim; of the 648,826 medical claims 66.2% had no matching hospital abstract. Resource requirements of procedures are reflected in the number and complexity of each procedure performed. Historical changes over time reflect changing demand (population growth and aging) balanced by available resources. Available resources cannot be predicted via modelling. The best fit based on the validation dataset was a Seasonal Autoregressive Integrated Moving Average model with a Mean Absolute Percentage Error (MAPE) of 5.327%. which translates to 94.7% accuracy.
ConclusionDespite the limitations of modeling based on past behavior, we were able to predict surgical demand with 95% accuracy. These projections are valid partly due to the persistence of historical constraints through the validation period. Policies that address these service provision limitations would precipitate a need to adjust the model.
The impact of not having a primary care provider on emergency department utilization and hospitalizations before and during COVID-19: A novel retrospective cohort study linking primary care waitlists with administrative billing data.
Authors: Marshall Emily Gard , Stock David , Buote Richard
Published: September 2022

ObjectivesPrimary care attachment improves access, chronic disease prevention and management. Growing proportions of Canadians are unattached and registering with provincial primary care waitlists for family doctors or nurse practitioners. We compare emergency department utilization and hospitalization by waitlist registration status both before and during the first two waves of COVID-19.
ApproachThis study is the first to link a provincial primary care waitlist with routinely collected administrative billing data. Access and linking required collaboration and processes to establish permissions and rigour. A descriptive cohort design estimates quarterly population-based rates of emergency department utilization and ambulatory care sensitive condition (ACSC) hospitalizations among persons on and off the waitlist between Jan/01/2017-Dec/24/2020. Emergency department utilization and ACSC hospitalization rates by current waitlist status were quantified from physician claims and hospitalization data. Relative differences during COVID-19 first (Q2 2020; April-June 2020) and second waves (Q4 2020; October-December 2020) were compared with the previous year.
ResultsCentralized waitlist and administrative billing data were successfully linked. During the study period, 100,867 primary care-eligible Nova Scotians (10.1% of the population) were on the waitlist. Those on the waitlist had higher emergency department utilization each quarter, and more ACSC hospitalizations for most quarters, than those not on the waitlist. Emergency department utilization was higher for individuals ≥65 years and females; lowest during the first two COVID-19 waves; and differed more by waitlist status for those <65 years. Emergency department contacts and ACSC hospitalizations decreased during COVID-19 relative to the previous year. Emergency department utilization during COVID-19 was lower compared to analogous previous year quarters and this relative difference was more pronounced for those on the waitlist during the second wave of COVID-19.
ConclusionLinking novel data sources identified that Nova Scotians seeking primary care attachment utilize hospital-based services more frequently than those not on the waitlist. Both groups had lower utilization during the COVID-19 pandemic than the year before. The degree to which forgone services produces downstream health burden remains to be seen.
Methamphetamine Use in Manitoba: An Evidence-to-Action (E2A) approach to a linked administrative data study.
Authors: Freier Amy , Shimmin Carolyn , Chartier Mariette , Enns Jennifer , McCulloch Scott , The Methamphetamine Use In Manitoba Research Team  , Nickel Nathan
Published: September 2022

ObjectiveA multi-disciplinary E2A group was established as part of a linked administrative data study examining methamphetamine use in Manitoba. In this presentation we will share our experiences of establishing an E2A, embedding stakeholders in the research process, and outline an iterative engagement plan for the remaining study years.
ApproachThe E2A group is led by two researchers with expertise in patient and public engagement and guided by Pal’s (2014) work on policy analysis and activation. Pal emphasizes a multidisciplinary and iterative process as the basis of a more inclusive approach to policy development for complex problems, such as the prevalence of methamphetamine use in Manitoba. Our goal in engaging public rightsholders, service providers and knowledge users in the research is to ensure that their first-hand knowledge and perspectives are reflected in the interpretations of the findings and that analyses address identified complexities in a culturally sensitive and equity-focused way.
ResultsIn the fall of 2020 E2A members were recruited, including persons with lived experience using methamphetamines and their families/care-givers, academics, clinicians, government, and non-government stakeholders. Training was provided on the topics of trauma-informed care, public engagement, effects of colonial and racist institutions, and cultural safety. The first E2A meetings co-developed guiding principles, a vision and mission, as well as provided capacity building around administrative data research. This work was done as a foundation for the next two years, wherein the group will make decisions about key variables (ie: between methamphetamine use and mental health), interpretation of results, knowledge mobilization, and policy development using an iterative self-evaluation process. To date challenges addressed included public health restrictions related to Covid-19 and adapting the research flow to centre lived-experience decision making.
ConclusionThe E2A group is a key component of this study and could serve as a model for other administrative data studies. The group prioritizes stakeholder knowledge, interprets results, flags potential biases in the data research process, and ensures the findings are relevant to the people they are meant to support.
Mental health, firearm ownership, and risk of death by suicide: a population-wide data linkage study.
Authors: Ross Emma , O'Reilly Dermot , Maguire Aideen
Published: September 2022

ObjectivesThere is clear evidence from the USA that access to firearms increases suicide risk, but little equivalent evidence exists in the UK. The aim of the current study is to examine the risk of suicide and all-cause mortality for people in Northern Ireland (NI) who hold a licenced firearm.
ApproachWe link information on all registrations from the Firearms Certificate (FAC) Register between 2010-2020 to the health service population spine for NI residents born before 1st January 2005. Further linkage includes prescription medication data and death records with follow-up until 31st December 2020.
Results68,831 individuals held a FAC during the study period. FAC holders were more likely to be older, to reside in rural areas (OR 4.99, 4.89-7.83), and to come from more affluent areas (ORmost deprived 0.46, 0.43-0.50). During follow-up, 3,704 FAC holders died. 36 deaths were due to suicide, of which 16 were suicides by firearm. Only 23% of those who died by firearm suicide in NI were FAC holders. Preliminary findings indicate that after adjustment for age, area-level deprivation, and urbanicity, FAC holders had a lower risk of all-cause mortality (HR 0.64, 0.61-0.66) and death by suicide (HR 0.54, 0.39-0.76).
ConclusionIn contrast to findings from previous studies, individuals with a licensed firearm were less likely to die by suicide.
AcknowledgementThe authors would like to acknowledge the help provided by the staff of the Honest Broker Service (HBS) within the Business Services Organisation Northern Ireland (BSO).  The HBS is funded by the BSO and the Department of Health (DoH).  The authors alone are responsible for the interpretation of the data and any views or opinions presented are solely those of the author and do not necessarily represent those of the BSO.