bluuebunny/crossref_metadata_2025 huggingface dataset:
Advancing cross-centre research networks: learning from experience, looking to the future
Authors: Jones Kerina , Heys Sharon , Daniels Helen
Published: September 2018

IntroductionMany jurisdictions have programmes for the large-scale reuse of health and administrative data that would benefit from greater cross-centre working. The Advancing Cross centre Research Networks (ACoRN) project considered barriers and drivers for joint working and information sharing using the UK Farr Institute as a case study, and applicable widely.

Objectives and ApproachACoRN collected information from researchers, analysts, academics and the public to gauge the acceptability of sharing data across institutions and jurisdictions. It considered international researcher experiences and evidence from a variety of cross centre projects to reveal barriers and potential solutions to joint working. It reviewed the legal and regulatory provisions that surround data sharing and cross-centre working, including issues of information governance to provide the context and backdrop. The emerging issues were grouped into five themes and used to propose a set of recommendations.

ResultsThe five themes identified were: organisational structures and legal entities; people and culture; information governance; technology and infrastructure; and finance and strategic planning. Recommendations within these included: standardised terms and conditions including agreements and contractual templates; performance indicators for frequency of dataset sharing; communities of practice and virtual teams to develop cooperation; standardised policies and procedures to underpin data sharing; an accredited quality seal for organisations sharing data; a dashboard for data availability and sharing; and adequate resource to move towards greater uniformity and to drive data sharing initiatives.

Conclusion/ImplicationsThe challenges posed by cross-centre information sharing are considerable but the public benefits associated with the greater use of health and administrative data are inestimable, particularly as novel and emerging data become increasingly available. The proposed recommendations will assist in achieving the benefits of cross-centre working.
Mortality among single fathers as compared with single mothers and partnered fathers: a cohort study
Authors: Chiu Maria , Rahman Farah , Vigod Simone , Lau Cindy , Cairney John , Kurdyak Paul
Published: September 2018

IntroductionSingle-parent families are becoming increasingly common around the world with a particularly steep rise in households headed by single fathers. Research suggests that single parenthood is associated with adverse outcomes, however, little is known about the health profile or risk of death of single fathers compared to other parents.

Objectives and ApproachWe aimed to examine mortality risk in single fathers compared to single mothers and partnered parents, which is the first head-to-head comparison of single and partnered parent groups. Our population consisted of 871 single fathers, 4590 single mothers, 16,341 partnered fathers and 18,688 partnered mothers. We combined cross-sectional samples derived from the Ontario component of Statistics Canada’s Canadian Community Health Survey (2001 to 2012) linked to health administrative databases to identify medical conditions, health service use, all-cause mortality and cause of death. We investigated differences in mortality using Cox proportional hazards models adjusted for socio-demographic characteristics, lifestyle and clinical factors.

ResultsEach family group was followed up for a median of 11.10 years (IQR 7.36–13.54). Single fathers had a poor risk profile, particularly among lifestyle factors, such as low fruit and vegetable consumption and alcohol consumption. The mortality rate was three-fold higher for single fathers compared to single mothers and partnered fathers (5.81, 1.74 and 1.94, respectively). Even after adjustment, single fathers had a significantly higher risk of death compared to both single mothers (hazard ratio (HR): 2.49 (95% CI: 1.20 – 5.15, p=0.01)) and partnered fathers (HR: 2.06 (95% CI: 1.11 – 3.83, p=0.02). Small sample sizes precluded us from identifying the leading cause of death for single fathers.

Conclusion/ImplicationsWe found that single fathers had the least favorable risk factor profile and greatest risk of mortality, which may be mitigated by physician intervention. Our study highlights that through cross-sectoral data linkages we can further advance our knowledge of social factors and their profound effects on health.
The Overlap Between the Child Welfare and Youth Justice Systems in Manitoba, Canada
Authors: Brownell Marni , Nickel Nathan , Turnbull Lorna , Au Wendy , MacWilliam Leonard , Ekuma Oke , Valdivia Jeff , McCulloch Scott , Lee Janelle Boram
Published: September 2018

IntroductionManitoba has one of the highest rates of children taken into care of child welfare services (Child and Family Services; CFS) in the world, and also one of the highest youth incarceration rates in Canada. Policy-makers recognize there is overlap between these systems; the extent of that overlap is unknown.

Objectives and ApproachWe linked CFS, Justice, and Population Health Registry data to quantify the overlap between having a history of CFS during childhood (0-17 years) and being charged with a crime as a youth (12-17 years). Using a cohort approach, we selected all individuals in Manitoba who were born in 1988 (N=28,178); those not in the province at any time from 12-17 years were excluded, leaving a final cohort of 18,182. The cohort was divided into 3 groups according to CFS involvement: CFS out-of-home care (1,148); CFS in-home services (3,395); no CFS (13,639). Criminal charges between 12-17 years were identified.

Results6.3% of our cohort had CFS out-of-home care, 18.7% received CFS in-home services, and 75% had no CFS involvement. 10.5% of the cohort were charged of a crime between 12-17 years. Almost half (46.6%) of youth who had CFS out-of-home care had criminal charges, compared to 19.4% of youth who had CFS in-home services, and 5.3% of youth with no CFS. Despite accounting for only 6.3% of the cohort, youth who had out-of-home care accounted for 28.0% of youth with criminal charges. Indigenous (First Nations (FN) and Metis) children/youth were over-represented in both systems; for example, 24.5% of FN youth had been in care compared to 3.1% of non-Indigenous; and 32.2% of FN youth were charged with a crime compared to 6.6% of non-Indigenous youth.

Conclusion/ImplicationsThere is substantial overlap between the child welfare and youth justice systems, with overrepresentation of Indigenous youth in both systems. Culturally appropriate programs and policies aimed at supporting parents, families and communities to care for their own children will likely have long-term positive impacts on the youth justice system.
Population survival impact of new targeted and immune based therapies for metastatic or unresectable melanoma
Authors: Nguyen Paul , Baetz Tara , Booth Christopher , Eisenhauer Elizabeth , Hanna Timothy
Published: September 2018

IntroductionNew classes of drugs for metastatic or unresectable melanoma (MM) have shown improved survival in randomized trials (e.g., anti-CTLA-4, anti-PD-1, BRAF/MEK inhibitors). We sought to describe uptake of these new drugs and their impact on population-based survival outcomes of MM.

Objectives and ApproachWe sought to describe uptake of these new drugs and their impact on population-based survival outcomes of MM. This was a retrospective, population-based cohort study of all treated MM in Ontario 2007-2015. Administrative data sources from the Institute for Clinical Evaluative Sciences (ICES) were utilized. Within ICES, cutaneous and non-cutaneous primaries were identified in the Ontario Cancer Registry. Administrative sources from Cancer Care Ontario, Ministry of Health and Long-Term Care, and Canadian Institute for Health Information identified patients treated with palliative systemic therapy, radiotherapy and metastatectomy. Temporal trends in utilization and survival were investigated. Survival by drug class was described.

ResultsWe identified 2,793 MM patients. First treatment was systemic therapy (46%), radiotherapy (41%) or metastatectomy (14%). MM patient number increased from 270 in 2007 to 418 in 2015. Systemic treatment rose from 125 MM first treated in 2007 to 343 in 2015. New drug treatments increased from <6% of reported first-line regimens in 2007 to 82\% in 2015. 1-year and 2-year overall survival (OS) was 28% and 15% respectively for all MM in 2007-2009, rising to 46% and 35% for 2014-2015 (logrank p<0.001; adjusted hazard ratio (AHR) 0.56, 95% confidence interval (CI): (0.49,0.63)). Survival gains were largely in the subset treated primarily systemically, where new drugs were increasingly utilized (2-year OS 16% 2007-2009 vs. 44% 2014-2015 logrank p<0.001; AHR 0.46, 95% CI: (0.38,0.56)).

Conclusion/ImplicationsUtilization of systemic therapy for MM has increased considerably in routine practice during 2007-2015; at least some of this increase relates to use of novel agents since 2011. In line with randomized trial findings, new drug adoption was associated with substantial increases in population-based MM survival.
Analysing complex linked administrative data in health services research: Issues and solutions
Authors: Rachael Rachael , David David , Harris Mark
Published: September 2018

IntroductionLinked administrative data are increasingly being used to evaluate the impact of health policy on health-service use/cost because they can comprehensively capture whole of population interactions with the health system. These analyses are complex comprising unbalanced panels and are at risk of endogeneity and associated problems.

Objectives and ApproachWe evaluated the impact of changes in regularity of general practitioner contact on diabetes related hospitalisation before and after care coordination policies using whole of population, person-level linked primary care, hospital, Electoral Roll and death records. Complex panel random-effects modelling techniques were required due to the unbalanced structure of the data (individuals could exit and re-enter the study repeatedly), over-dispersion and high proportion of zeros, changes in availability of tests (ascertainment bias), the likelihood of prior health service use influencing the dependent variable (initial conditions and simultaneity/reverse causality bias) and likely correlation of observed and unobserved variables.

ResultsMultivariable zero-inflated negative binomial and Cragg-hurdle clustered robust regression, which include separate components to model zero and non-zero outcomes, were required for these data. Mundlak variables (group-means of time-varying variables) were used to relax the assumption in the random-effects estimator that the observed variables were uncorrelated with the unobserved ones. Prior health service use was adjusted for using 4-year lags of GP contact and one-year lag of hospitalisation. The initial value of the dependent variable resolved the “initial condition” problem. Ascertainment bias was addressed using the number of years available for identification for each person as a covariate. AIC/BIC values were used to identify the best model. We found that more regular GP contact was associated with fewer hospitalisations, however this attenuated over time.

Conclusion/ImplicationsAvailability of linked data, together with increases in computing power, has vastly increased its potential for use. This has also increased the complexity of analyses being undertaken necessitating recognizing and addressing problems, such as endogeneity, that arise due to the observational nature of the studies undertaken.
Linking the Narcotics Monitoring System Database to Quantify the Contribution of Prescribed and Non-Prescribed Opioids to Opioid Overdoses in Ontario, Canada
Authors: Martins Diana , Singh Samantha , Khuu Wayne , Tadrous Mina , Paterson Michael , Juurlink David , Mamdani Muhammad , Gomes Tara
Published: September 2018

IntroductionThe Ontario Narcotics Monitoring System (NMS) captures information on all prescriptions for controlled medications dispensed from outpatient pharmacies in Ontario, Canada, regardless of payer. This system was introduced in 2012, as a strategy to promote appropriate prescribing and dispensing practices.

Objectives and ApproachWe sought to explore the degree to which prescriptions in the NMS can be linked to other health claims databases, and describe the types of medications dispensed between July 2012 and December 2016. We also linked opioid prescriptions to hospitalization and mortality data to examine the relative contributions of prescribed and non-prescribed opioids to opioid toxicity events in 2016. A recent opioid prescription was defined as a prescription with a days’ supply that overlapped the opioid toxicity event. Analyses were stratified by gender and age.

ResultsWe examined 1.3 million prescriptions in the NMS during the study period: 72.8% for opioids, 21% for benzodiazepines, 4.4% for stimulants and <2% for other medications. Approximately 97% of prescriptions in the NMS could be linked because an Ontario health card was used at the time of dispensing. In 2016, we found that 52.8% of individuals with an opioid-related hospitalization (N=804/1,524) and 32.5% of those with an opioid-related death (N=278/855) had a recent opioid prescription. The proportion of opioid-related hospitalizations and deaths with a recent opioid prescription was significantly higher among females vs. males (57.2% vs. 48.0% and 45.6% vs. 26.4%, respectively; p<.001), and older (aged 45-64) vs. younger (aged 0-24) individuals (66.9% vs 9.9% and 46.4% vs 11.6% respectively; p<.001).

Conclusion/ImplicationsLinkage was possible for the majority of prescriptions in the NMS. We found that a large proportion of opioid overdoses involved a non-prescribed opioid, particularly among men and younger individuals. These findings highlight an important difference in patterns of opioid use and toxicities in the population that policy-makers should consider.
Automatic coding of nearly 2 million hospitalisation events to ICD-10 in the China Kadoorie Biobank
Authors: Sansome Sam , Turnbull Iain , McDonnell John
Published: September 2018

IntroductionUsing linkage to the Chinese National Health Insurance (HI) system, we identified disease outcomes from a prospective cohort study of 512,000 middle-aged Chinese adults. Mandarin free-text diagnosis data were supplied by over 30 different agencies across 10 areas, often without an accompanying International Classification of Diseases 10th revision (ICD-10) code.

Objectives and ApproachTo facilitate a genome-wide association study (GWAS) of all our genotyped participants, we needed to code as many of our 2.02 million hospitalisation events as possible. We developed software to assign ICD-10 codes to unique disease descriptions and stored the coded diagnoses in an internal corpus. The software used an interface which allowed clinicians to select and code disease descriptions individually, or collectively using Chinese keywords. All coded disease descriptions were subsequently validated by an independent Mandarin-speaking clinician. All new events with descriptions which matched exactly those already in the corpus were automatically coded to ICD-10.

ResultsBy the end of 2016, there were 2,021,352 hospitalisation events coded to ICD-10. 436,702 (21.6%) were automatically assigned codes where disease descriptions corresponded to those in the Chinese version of the ICD-10 codebook. A further 1,084,197 (53.6%) were coded by a clinician using our standardisation software; all disease descriptions linked to 200 or more events were included. Finally, a remaining 454,237 (22.5%) events were given the ICD-10 codes supplied by the health insurance agency (after cleaning). In total, 97.7% of all health insurance events were coded to ICD-10. Overall, over 17,000 unique disease descriptions have been clinically classified.

Conclusion/ImplicationsAutomatic coding of hospitalisation events to ICD-10 has enabled our study to investigate a greater range of diseases and use GWAS to detect novel genetic variants. We are now well positioned to test semantic matching and machine learning strategies for coding of the remaining 46,216 (2.3%) uncoded events.
Validating Self-reported Chronic Conditions in Alberta’s Tomorrow Project Cohort: Data Linkage to Administrative Healthcare Data
Authors: Ye Ming , Vena Jennifer , Xu Jian-Yi , Robson Paula , Eurich Dean , Johnson Jeffrey
Published: September 2018

IntroductionAlberta’s Tomorrow Project (ATP) is a province-wide cohort study of cancer and chronic diseases in Canada. Approximately 55,000 Albertans aged 35-69 years with no history of cancer, other than non-melanoma skin cancer, had joined the ATP. Nearly all (>96%) ATP participants consented to data linkage to administrative healthcare databases.

Objectives and ApproachTo validate chronic conditions self-reported by the ATP participants, individual-level data of a total of 52,851 ATP participants were linked to Alberta Health (AH) administrative datasets using Personal Health Number. Cases of chronic conditions, including diabetes, cardiovascular diseases and gastrointestinal disorders, were identified by algorithms for disease diagnosis using International Classification of Diseases (ICD) codes in administrative healthcare data. Cases were identified as “prevalent” if the index date of diagnosis was before or within 6 months of ATP enrollment date. Self-reported chronic conditions were validated by the cases identified as “prevalent” using the linked AH datasets.

ResultsAmong the ATP cohort, 804 participants self-reported ever being diagnosed with myocardial infarction (MI), 451 with stroke, 2,907 with diabetes, 566 with ulcerative colitis, 362 with Crohn’s disease and 112 with liver cirrhosis before or at the time of ATP enrollment. Using the linked AH administrative data, 339 participants were identified as prevalent cases with MI, 200 with stroke, 2,702 with diabetes, 208 with ulcerative colitis, 283 with Crohn’s disease and 55 with liver cirrhosis. The sensitivity and specificity of self-reporting having chronic conditions by the ATP participants were 71.1% and 97.0% for MI, 44.4% and 99.3% for stroke, 78.1% and 98.4% for diabetes, 73.6% and 99.2% for ulcerative colitis, 65.7% and 99.7% for Crohn’s disease and 50.9% and 99.8% for liver cirrhosis.

Conclusion/ImplicationsBy linking with administrative healthcare data, we were able to validate the accuracy of self-reporting chronic conditions in ATP participants. The sensitivity of self-reporting was acceptable for MI, diabetes, ulcerative colitis and Crohn’s disease, but low for stroke and liver cirrhosis. The specificity was high for all chronic conditions.
Preterm birth, unplanned hospital contact and mortality in infants born to teenage mothers in five countries: a cross-country comparison using linked administrative data
Authors: Harron Katie , Verfuerden Maximiliane , Ibiebele Ibinabo , Liu Can , Kopp Alex , Guttmann Astrid , Ford Jane , Van der Meulen Jan , Hjern Anders , Gilbert Ruth
Published: September 2018

IntroductionChildren born to teenage mothers have greater healthcare needs than those born to mothers in their 20s and older, including higher rates of childhood hospitalisations. We performed a direct cross-country comparison of maternal age-related inequalities in infant outcomes in England, Scotland, Sweden, New South Wales (NSW; Australia) and Ontario (Canada).

Objectives and ApproachWe used administrative hospital data capturing 3,002,749 singleton births surviving to discharge between 2010-2014 (2008-2012 for Sweden). We derived risk ratios and risk differences to compare rates of preterm birth (24-37 weeks of gestation), unplanned hospital admissions, emergency department (ED) visits, and mortality within 12 months of postnatal discharge, for infants born to mothers aged 15-19, 20-24, 25-29 and 30-34 years.

ResultsInfants born to teenage mothers experienced higher rates of preterm birth, unplanned admissions, ED visits, and mortality compared with older mothers in all countries. Despite variation in the distribution of maternal characteristics between countries, inequalities according to maternal age were similar. Infants of teenage mothers were between 1.37 (95% CI for risk ratio 1.28-1.47, Sweden) and 1.56 (95% CI 1.49-1.64, NSW) times more likely to have ≥1 unplanned hospital admission and between 2.25 (95% CI 1.92-2.64, England) and 3.87 (95% CI 2.07-7.36, Sweden) times more likely to die, compared with those born to mothers aged 30-34.

Conclusion/ImplicationsA similar excess of adverse outcomes was observed for teenage mothers in all five countries, despite different prevalence rates and support for young families. Public health strategies are needed to address these inequalities, which may be due to social risk factors associated with both young motherhood and adverse infant outcomes.
Quantifying inequalities in mortality in Australia: the value of linked Census-morality data
Authors: Korda Rosemary , Biddle Nicholas , Eynstone-Hinkins James , Banks Emily , Lynch John , Priest Naomi
Published: September 2018

IntroductionMortality rates are higher in disadvantaged communities. However, accurate quantification of inequalities in Australia has been limited by data availability. The Australian Bureau of Statistics has recently created a resource linking Death Registrations to Australian Census data, enabling quantification of mortality by whole-of-population individual-level measures.

Objectives and ApproachWe present the first analysis of linked Deaths Registrations to Census data, which quantifies mortality inequality in Australia in relation to individual-level socioeconomic position (SEP), and compares these estimates to those based on area-level-SEP measures. The Deaths Registrations-Census file contains deaths within 13 months of the 2011 Census date, linked probabilistically to 2011 Census data. We used Poisson regression to quantify inequalities according to education, weighted to adjust for relative under- and over-representation of selected subpopulations. We compared these inequality estimates with those based on area-SEP measures. We also examined the effect of missing Census data.

ResultsMortality rates decreased with education in all age groups (25-44, 45-64, 65-84, 85+ years), for both males and females. Estimates of relative inequality decreased with age, while estimates of absolute inequalities increased. Total excess deaths associated with lower education were highest in those aged 64-84 years. Inequality estimates for education were higher than those for area-SEP in the youngest age groups (25-45 years), but were lower in the 45-64 age group. Socioeconomic gradients in education remained apparent among individuals within each area-SEP quintile, highlighting the socioeconomic variation among individuals within these area-based socioeconomic groups. The proportion of deaths with missing education data increased with age and area-level SEP; however there was little difference in the area-based inequality estimates across subgroups with and without education missing.

Conclusion/ImplicationsThe newly-created linked Deaths Registrations-Census file, accessible through the virtual ABS Datalab, is a rich resource for generating evidence on mortality. The data show mortality inequalities in education across all age groups and within quintiles of area-level SEP and indicate area-based measures are inadequate for fully capturing inequality.
Data Byte: An Insight on Fetal Alcohol Spectrum Disorder and Educational Achievement
Authors: Piatt Carley , Lamba Navjot , Jia Ruiting , Werk Christine
Published: September 2018

IntroductionData Bytes are bite-sized pieces of data from the longitudinal project, Experiences of Alberta Children and Youth Over Time, 2005-06 to 2010-11. To promote public engagement, the Data Byte series is designed to highlight a finding from a full report to give readers a quick data morsel to chew on.

Objectives and ApproachFetal Alcohol Spectrum Disorder (FASD) is a complex disorder caused by alcohol exposure during pregnancy. To understand how young people with FASD in Alberta are performing in schools, individually linked administrative data were used from 2005/06 to 2010/11. An individual was considered to have FASD if, at any point in the 6 years, they received a diagnostic code for fetal alcohol syndrome, or for being newborn affected by maternal use of alcohol (ICD 10-CA Q86.0 or P04.3) from a health service (emergency department or ambulatory care visit, or a hospitalization), or from a child disability service program.

ResultsOf young Albertans with FASD, almost 40% were meeting or exceeding educational expectations compared to 80% of young Albertans without a diagnosis of FASD. Expectations for educational achievement were computed by Alberta Education using age, grade, school type, special education codes, provincial achievement test scores, home education status, number of high school credits earned, number of higher level courses taken, average grade in higher level courses, possession of an Alberta Education certificate or diploma, and Alexander Rutherford scholarship eligibility.

Conclusion/ImplicationsData Bytes are designed to encourage stakeholders to explore:

Is the definition of “meeting educational expectations” used for the general population appropriate for a population with complex needs?

What other outcomes might be used to determine whether services are improving the quality of life for young Albertans with FASD?
Calgary Thrives: Data sharing and linkage in the not-for-profit sector.
Authors: Jagodzinski Robert , Pritchard Katharin , Lau Jason , Berzins Sandy , Perry Robert , Jafri Komal , Armstrong Debra , Pang Lily
Published: September 2018

IntroductionCompared to the public sector, not-for-profits are less focused on cross-agency data linkage. Technical capacity is often secondary to addressing caseloads and protecting clients. Clients’ privacy is paramount and can be perceived as a barrier to collaboration between agencies. However, collaboration could streamline referrals and better assist vulnerable populations.

Objectives and ApproachSix not-for-profit agencies in Calgary, Canada participated in a data sharing project to measure various aspects of poverty and link data to determine cross-agency service usage. With this goal in mind, agencies examined their consent and data sharing practices to assess barriers to data sharing. There was a thorough exploration of client consent and how a client’s context can enable or limit data sharing. Cross-agency program usage was assessed among participating agencies using a privacy-preserving record linkage (PPRL) methodology.

ResultsAmongst the six participating agencies, four were deemed to have adequate technical capacity to share data. A contributing factor to the willingness of agencies to share data was the development of LinkWise: a PPRL software created and developed by PolicyWise. Linkage rates amongst three agencies were compared. Rates ranged from 47.8% to 0.23%. A higher linkage rate between two agencies indicated a small community based agency which provided many referrals to a larger agency, such as a food bank. Lower linkage rates on client intake may indicate an agency with many clients. It may also indicate differing socio-economic brackets for their clients’ catchment area.

Conclusion/ImplicationsWhile capacity, caseloads, and privacy protection restrict data sharing, not-for-profit agencies would benefit from a data sharing strategy. Linking data represent opportunities for collaboration within a significantly resource constrained sector. Moreover, it could more effectively address issues of vulnerable populations, streamline referrals for services, and facilitate quality improvement.
Linking air pollution and administrative health databases to examine health effects of wildfire smoke exposure in Calgary, Canada in 2015
Authors: Mahsin Md , Cabaj Jason , Saini Vineet
Published: September 2018

IntroductionWildfires are increasing in frequency and severity due to climate change. Fine particulate matter (PM2.5) in wildfire smoke is an important indicator of health effects of most combustion sources. The evidence based on adverse health impacts of PM2.5 from wildfire smoke are increasingly being studied but some gaps still remain.

Objectives and ApproachWe examined the association of PM2.5 from Pacific Northwest wildfires with multiple respiratory and cardiovascular morbidity events related physician and emergency department visits, hospital admissions, health-link calls and medications dispensed among Calgary city population from August 1 – September 30, 2015. Physician billing claims, discharge abstract, Pharmaceutical Information Network, Health-link calls databases were linked with the air quality monitoring information database. Quasi-Poisson regression model for time lags of zero to five days and a three-day moving average, and conditional logistic regression model was used with adjustment for air pollutants and meteorological variables. Age and disease-specific stratified analyses were performed.

ResultsCompared to the pre-wildfire period (Aug 1 – Aug 23), a 10 µg/m3 increase in PM2.5 increased the risk for respiratory physician visits by 54.8% (95% CI: 41.6% - 69.3%) and 32.6% (95% CI: 10.4% - 58.9%) in the respective post (Sep 1- Sep 30) and during (Aug 24 – Aug 31) wildfire periods. The strongest association of PM2.5 with respiratory physician visits was observed for children aged 0-9 years in the post-wildfire period (Relative Risk [RR] = 2.11, 95% CI: 1.86 - 2.39) compared to during wildfire period (RR = 1.56, 95% CI: 1.21 - 2.02) and was consistent for asthma, acute bronchitis and acute respiratory infection. Statistically significant effects of PM2.5 on cardiovascular hospitalizations, ED and physician visits were not observed during the wildfire period.

Conclusion/ImplicationsWildfire-related PM2.5 led to increased physician visits due to respiratory morbidity during and after the wildfires, particularly for asthma, acute bronchitis and acute respiratory infections in children. The absence of cardiovascular health impact in general population during wildfires provides useful information for targeted public health messaging during adverse air quality events.
Linkage Quality Assessment for Anonymously linked Administrative Data.
Authors: Bhatt Hitesh , Jagodzinski Robert , Scott Allison N , Twilley Leslie , Cui Xinjie
Published: September 2018

IntroductionLinked datasets are important resources for research, but linkage errors can lead to incorrect results. For data security and privacy concerns, when linkage of personal identifiers is performed anonymously, it is difficult to assess the quality of the linked dataset. We describe the method used to perform linkage quality.

Objectives and ApproachWe explored how to check the quality of linkages while preserving the privacy of individuals. We also adopted an approach that minimized time and burden on data providers involved in physical verification using randomly-generated appropriate sample sizes.

To validate these linkages, data providers were given random samples of 50 unique records from both linked and unlinked individuals across two other Government programs. Data providers were asked to look at the records associated with those individuals in their original datasets. Three types of linkage results were validated: cross-program linkages, cross-program non-linkages, and within-program linkages. Proportions of false-matches and missed-matches were estimated.

ResultsTwenty data providers checked their samples with two other programs which gave us a sample of 2000 individuals. The linkage process, based on anonymized personal identifiers, resulted in high true positive and high true negative rates. Agreement between human judges and the linkage software was strong. Results of this exercise and other linkage validation examinations provided confidence in the accuracy of the linkage process. With false matches occurring approximately only 3% of the time and virtually no missed-matches occurring, no adjustments were deemed necessary. Although linkage rates were reassuring, the sample sizes used for comparison were small, so it is expected that there would be significant variation associated with this 3% estimate; caution is advised in its use.

Conclusion/ImplicationsProportions of false-matches and missed-matches determine linkage quality which is the base for research when linkages are performed anonymously. A low proportion of false-matches and an absence of missed-matches was an indication of robust linkages.
Progress with Access to Cross-jurisdictional Linked Data in Australia
Authors: Wray Natalie , Flack Felicity , Smith Merran
Published: September 2018

IntroductionAustralia is a federal, parliamentary, constitutional monarchy which consists of six states and two territories. As a result there is no single national data collection that follows individuals’ interactions with health and human services from birth to death. Therefore researchers need access to linked data from multiple jurisdictions.

Objectives and ApproachThe objective of this project was to evaluate the progress of the PHRN in providing researchers access to linkage infrastructure for cross-jurisdictional and multi-jurisdictional projects.

Data from the PHRN Online Application System (OAS) was analysed to determine:

The number of applications for linked data received

The number of jurisdictions involved in each application

The number of applications involving researchers from multiple jurisdictions

The number of applications involving linkage of state and Commonwealth data

An analysis of peer reviewed publications resulting from the use of the infrastructure was also conducted.

ResultsAustralia has a unique distributed national data linkage system which enables linkage of data both within and between jurisdictions. Each jurisdiction (state/territory and Commonwealth) has a linkage unit which provides linkage services within that jurisdiction. For cross-jurisdictional linkage, depending on the design of the specific project, the linkage is conducted either by the national data linkage unit or a combination of the national linkage unit and the state/territory data linkage units.

Analysis of the data from the OAS shows an increase in the applications for cross-jurisdictional and multi-jurisdictional linked data. There is a mix of requests for only state/territory data and for state/territory/Commonwealth data. The number of national collaborations and publications has also increased.

Conclusion/ImplicationsCross-jurisdictional linkage is challenging in a federated country. There are many legislative, regulatory and policy barriers. Despite these challenges, Australia has developed a national system enabling researchers to apply through a central system and for jurisdictions to work together to link and provide access to cross-jurisdictional and multi-jurisdictional data.
Evaluating the impact of timing of initiation of community-based palliative care on use and cost of unplanned acute care services at the end of life: A study using linked hospital and community based provider service data
Authors: Moorin Rachael , Wright Cameron , Youens David
Published: September 2018

IntroductionExpected time to death is often used to determine eligibility to publicly funded community-based palliative care (CPC) because most acute care costs in the end-of-life period are incurred immediately prior death. We know CPC use reduces acute care costs but the impact of timing of initiation is unknown.

Objectives and ApproachWe explored the association between timing of CPC initiation and unplanned hospital use, over the final year of life for Western Australian cancer decedents who died between 1/1/2001 and 31/12/2011 using linked Cancer Registry, Mortality System, Hospital Morbidity Data Collection, Emergency Department (ED) Data Collection and CPC records. The relationship between first-time use of CPC and unplanned hospitalisations and ED presentations was evaluated using multivariable negative binomial regression and Cragg-hurdle models. The exposure was month of CPC initiation (adjusted for intensity of use); outcomes were the rate, length of stay and cost of unplanned hospitalisations and emergency department presentations.

ResultsOf the 28,331 decedents residing in the CPC catchment area, 16,439 (58%) accessed CPC, mostly (64%) in the last three months of life. Initiation of CPC prior to the last six months of life was associated with a lower mean number of unplanned hospitalisations in the last six months of life (1.4 versus 1.7 for initiation within six months of death); associated average costs were also lower ((AU$, 2012) 12,976 versus $13,959). While patients initiating CPC earlier showed a trend toward fewer hospital admissions, earlier initiation was associated with a higher cumulative and average length of stay. Indirect adjustment for admission complexity suggests that this may be due to more complicated indications.

Conclusion/ImplicationsThis study provides more detail to guide policy around timing of access to CPC. Our results argue against restricting access to the final few months of life, as earlier initiation may result in fewer and lower the cost of unplanned hospitalisations and ED presentations at the very end of life.
Using routinely collected laboratory and health administrative data to assess influenza vaccine effectiveness: introducing the Flu and Other Respiratory Viruses Research (FOREVER) Cohort
Authors: Kwong Jeff , Buchan Sarah , Chung Hannah , Campitelli Michael , Schwartz Kevin , Crowcroft Natasha , Jackson Michael , Karnauchow Timothy , Katz Kevin , McGeer Allison , McNally Dayre , Richardson David , Richardson Susan , Rosella Laura , Simor Andrew , Smieja Marek , Zahariadis George , Gubbay Jonathan
Published: September 2018

IntroductionAnnual evaluation of influenza vaccine effectiveness (VE) is required because of frequent changes to circulating and vaccine strains. Traditionally, VE studies enroll patients who fulfill case definitions for respiratory infections and are tested for influenza. VE estimates generated from convenience samples of routinely collected specimens might be biased.

Objectives and ApproachWe assessed the validity of using data from respiratory specimens collected during clinical encounters to estimate VE. We created the Flu and Other Respiratory Viruses Research (FOREVER) Cohort by linking respiratory virus laboratory test results from 2009-2014 from 11 public health and 8 hospital laboratories across Ontario to health administrative databases, including databases with billing claims for physician- and pharmacist-administered influenza vaccines. We evaluated the presence of information and selection biases when using these data and estimated VE in community-dwelling older adults (>65) using the test-negative design under conditions that emulated the inclusion criteria in traditional VE studies.

ResultsThe FOREVER Cohort included test results from 283,711 respiratory specimens obtained from 216,730 individuals. The overall linkage proportion to health administrative databases using deterministic and probabilistic linkage methods was 97.5%. Influenza positivity for older adults with unknown lag between illness onset and specimen collection was similar to those for whom illness onset date was documented to be ≤7 days before specimen collection, suggesting minimal outcome misclassification associated with information bias. The likelihood of influenza testing was similar between vaccinated and unvaccinated individuals, suggesting an absence of selection bias that could arise when a case definition for influenza testing is not employed. Lastly, VE estimates were similar under various conditions, demonstrating the robustness of using these data, and were comparable to published estimates.

Conclusion/ImplicationsThe FOREVER Cohort can be used to estimate VE with negligible bias. Compared to traditional VE studies that are limited to recruited patients, routinely collected specimens create a larger, more generalizable sample. Linkage to health administrative databases can identify those with comorbidities and permit evaluation of VE in high-risk groups.
When does the increased mortality risk appear in rheumatoid arthritis? A distributed data analysis comparing mortality in two Canadian provinces
Authors: Widdifield Jessica , Bernatsky Sasha , Huang Anjie , Paterson Michael , Sayre Eric C , Lacaille Diane
Published: September 2018

IntroductionRheumatoid arthritis (RA) is chronic inflammatory arthritis. For decades studies showed that RA patients died earlier than their general population counterparts. Some inception cohorts have failed to detect an increased mortality risk, possibly due to limited follow-up or to improvement in mortality risk in cohorts of more recent onset.

Objectives and ApproachWe evaluated mortality risk in RA patients and estimated when the increased risk appears. Using a common protocol, we conducted distributed analyses using administrative data, of incident RA patients in British Columbia (BC) and Ontario (ON) over 2000-2015. We identified all RA patients (using validated criteria), and identified non-RA comparators, matched 1:2 on age, sex and index years. Adjusted hazard ratios (HRs) were estimated using multivariable Cox regression, controlling for comorbidities and other factors. To estimate when the increased risk appeared we included an interaction with follow-up time, to detect if and how the HR varied by RA duration.

ResultsAmong 13834 RA patients in BC (27668 comparators), 66% were female with a mean age of 58 years at cohort entry. Among 27405 RA patients in ON (54810 comparators), 70% were female with a mean age of 56 years. The prevalence of individual comorbidities was comparable across RA cohorts. During follow-up, 23% of RA patients in each province died, with corresponding crude mortality rates of 2.3 deaths per 100 person-years in both provinces. Multivariable analyses detected an increased mortality risk in RA by 6 years of follow-up, with a linear relationship suggesting further increase over time. By 10 years, the adjusted HR was 1.14 (95% CI 1.07,1.22) in BC and 1.13 (95% CI 1.08,1.18) in ON.

Conclusion/ImplicationsIn 2 large Canadian RA inception cohorts, a small increased mortality risk appeared after 6 years of RA duration and increased to a 14% (in BC) and 13% (in ON) increased mortality risk after 10 years, suggesting increased efforts to prevent disease progression and optimizing comorbidity management are needed.
Supporting the timely, easy and cost effective access to high-quality linked data via the Custodian-Controlled Data Repository
Authors: Schneider Matthias , Radbone Chris , Stanley Andrew , Woollacott Anthony , Churches Timothy , Farrow James , Basso Paul , Hardin Tina , McNamara Martin , Harrison James
Published: September 2018

IntroductionWhile linkage units perform population data linkage with high efficiency, other parts of the workflow from custodians to researchers remain largely outside the control of linkage operators. Most importantly, resource constraints at data custodians often limit quality control (QC) efforts and lead to delays in the data delivery to researchers.

Objectives and Approachovercome these challenges, we have created the Data integration Unit (DIU) to undertake content data management and delivery in conjunction with the custodians who remain the principal data curators. Data is managed in the Custodian-Controlled Data Repository (CDDR) a highly secure virtual repository for data storage, analysis and access, established and operated by the DIU. Stringent controls for user access and data flows ensure that data is provided safely by custodians. Overseen by the custodians, DIU staff undertake QC activities, and integrate and deliver multiple datasets for approved linkage projects.

ResultsLong-term data storage in the CCDR decreases data custodian workloads by reducing the frequency of content data provision to periodic updates. Feedback loops built into the QC process allow custodians to improve their datasets by learning from data issues identified by the DIU.

Extensive QC undertaken by DIU staff on individual datasets and data validation across multiple datasets held in the CCDR ensure that the quality of data provided to researchers is improved. Moreover, DIU staff dedicated to data integration provide faster content data delivery to researchers. Lastly, the CCDR reduces the number of custodians researchers need to liaise with for data provision.

Conclusion/ImplicationsOperational since February 2018, the DIU has delivered content data for several linkage projects, based on key datasets stored in the CCDR. The incorporation of additional datasets is currently negotiated.

Recognising recent developments in secure analytics infrastructure, the further evolution of the CCDR towards a cloud-based model is anticipated.
Automated Referral to Cardiac Rehabilitation following Coronary Artery Bypass Grafting is associated with limited improvements in program completion: a large cohort study
Authors: Liu Hongwei , Wilton Stephen , Southern Danielle , Knudtson Merril , Maitland Andrew , Hauer Trina , Arena Ross , Stone James , Aggarwal Sandeep , Martin Billie-Jean
Published: September 2018

IntroductionCardiac Rehabilitation (CR) reduces residual cardiovascular risk among patients who have received coronary artery bypass grafting (CABG) surgery. However, many patients do not attend and some are never referred. It is unclear whether automated referral is associated with improved CR completion rates.

Objectives and ApproachGeographically inclusive databases were linked to assess the impact of automated referral on rates of referral to and completion of CR post-CABG. Automated referral to CR post-CABG was instituted in Calgary on July 1, 2007. All subjects receiving CABG in Calgary between January 1, 1996 and March 31, 2016 were enrolled in the study. The Alberta Provincial Project for Outcome Assessment in Coronary Heart disease (APPROACH) database, TotalCardiology-Rehabilitation (TC-R) database, and provincial vital statistics were linked using the unique Provincial Health Number available for each patient. The association between CR referral, completion, and survival was assessed using proportional hazard models.

ResultsThere were 28,100 patients referred to the CR program, of which 26,411 were linked to the APPROACH database for a 93.99\% linkage rate. After excluding patients who did not receive CABG, a total of 8,118 patients were identified as the study population [mean age 66.2 (SD 10.2) years, 18.9\% female] during the study period: 5,103 prior to implementation of automated referral, and 3,015 post-automation. Rates of referral increased from 39.5\% prior to automation to 75.0\% post-automation (p

Conclusion/ImplicationsAutomated referral to CR is associated with increased referral rates but less dramatic increases in CR completion rates post-CABG. Given the significant improvement in survival associated with CR completion, further work is needed to improve CR referral, and more importantly, CR completion rates.