bluuebunny/crossref_metadata_2025 huggingface dataset:
590Online + In-person: A Model for the Instruction of Contemporary Epidemiologic Methods in Resource-Limited Settings
Authors: Avelino-silva Vivian , Semeere Aggrey , Laker-Oketta Miriam , Byakwaga Helen , Pletcher Mark , Martin Jeffrey
Published: September 2021

Focus of Presentation

Many low-income countries cannot support faculty to develop contemporary graduate-level courses in epidemiology and biostatistics. There are also insufficient resources to support all students who are interested in traveling abroad to study in resource-rich settings. To address this, we describe our experience with training a few students from resource-limited countries in the U.S. who have subsequently returned to their home countries and became instructors in a novel online plus in-person teaching model.

Findings

Most courses at our major U.S. training program in epidemiology videotape lectures for viewing on one’s own and post all other materials (e.g., homework) on the course’s website. The weekly learning cycle culminates with an in-person high-level small group discussion, led by a faculty member who facilitates 10-15 students. For the past 5 years, non-U.S. scholars from Africa and South America who have taken our courses in the U.S. have travelled back to their countries and become small group leaders for our courses. Identical to U.S. students, the students in these international venues view videotaped lectures, access other materials online, and have weekly in-person small group discussions. These international students represent another concurrent small group for the U.S-based course; they have identical access and evaluation.

Conclusions

By pairing online resources from a resource-rich setting with local in-person instruction, we provide students in resource-limited settings access to contemporary instruction in epidemiology at very low cost.

Key messages

Online plus local in-person teaching is a feasible model for providing instruction regarding epidemiologic methods in resource-limited settings.
1377Did patient blood management guidelines reduce the rate of blood transfusion in pregnancy?
Authors: Baldwin Heather , Randall Deborah , Nippita Tanya , Torvaldsen Siranda , Patterson Jillian
Published: September 2021

Background

Concern about increasing transfusion rates, adverse effects and increased costs have led to international efforts to reduce transfusion rates. Australian patient blood management guidelines were first introduced for critical bleeding in 2011, followed by obstetric guidelines in 2015. This study examines obstetric transfusion rates before and after the introduction of the critical bleeding and obstetric guidelines, accounting for pregnancy characteristics and prior trajectories.

Methods

Data were obtained from linked birth and hospital records from NSW between January 2002 and December 2017. Changes in raw and risk adjusted transfusion rates over time were investigated using interrupted time series analysis to assess changes in the trend in rate of transfusion among pregnant women with the introduction of each set of guidelines. Sensitivity analysis was performed to identify patterns in the data independently from the interventions.

Results

Data for 1,477,001 births in NSW from 2002 to 2017 were available for analysis. Preliminary analysis suggests the increasing rate of transfusion from 2002 was flattened after the introduction of the 2011 guidelines, with a significantly decreasing trend observed after the 2015 obstetric guidelines were introduced.

Conclusions

Patient blood management guidelines were associated with a reduction in the rate of obstetric transfusion in NSW.

Key messages

A focus on patient blood management was associated with an approximately 30% reduction in the transfusion rate, compared to the predicted rate, by the end of the study period. Future work will investigate whether this change in transfusion rates is associated with a change in rates of adverse outcomes.
1000Quantifying multiple causes of death: A systematic review and audit of methods and practice
Authors: Balogun Saliu , Bishop Karen , Eynstone-Hinkins James , Martin Melonie , Moreno-Betancur Margarita , Rao Chalapati , Joshy Grace
Published: September 2021

Background

Mortality reporting and research are typically focused on a single underlying cause of death (UCoD) selected from multiple reported causes. The need to incorporate multiple causes of death (MCoD) in mortality statistics is now recognised internationally, but there is scant methodological work to guide analytical approaches. This review aims to identify and appraise current methods and practices used to analyse MCoD data.

Methods

The Web of Science, Medline, Pubmed and Scopus (from inception to December 2019) were queried. Studies reporting MCoD alone or in comparison with single UCoD were included. The review is supplemented by qualitative interview with international experts.

Results

3491 studies were identified; 141 full texts were included in the review. The measures usually estimated when analysing MCoD can be broadly categorised into descriptive measures (n = 93 studies), measures of associations between diseases (n = 46 studies) and advanced statistical methods (n = 11 studies). Descriptive statistics commonly used include standardized ratio of multiple to underlying cause (SRMU) and mortality rates based on any mention of a disease. Approaches used to assess measures of associations between diseases include the Cause-of-Death Association Indicator (CDAI) and social network analysis. The advanced statistical methods include weighting MCoD and lethal defect-wear model of mortality. Audit results will be discussed.

Conclusions

This review provides a comprehensive and updated summary of methodological approaches used to analyse MCoD data. The merit of each analytical framework is discussed.

Key messages

More work is needed to develop methodological frameworks that could be used to support routine consideration of MCoD in practice.
934Prevalence by proxy: Estimating youth smoking prevalence using nationally representative household surveys
Authors: Barrett Eden , Marmor Alexandra , Maddox Raglan , Thandrayen Joanne , Johnson Fiona , Banks Emily , Lovett Raymond , Thurber Katherine
Published: September 2021

Background

Reducing youth (15-17 years) smoking uptake is critical to tobacco control; accordingly, youth smoking prevalence is a key monitoring and evaluation outcome. Many nationally representative surveys collect youth smoking behaviour data from, or in the presence of, the youth’s parent or caregiver. We aimed to quantify the potential bias conferred by this.

Methods

We compared youth smoking prevalence when reported by parent proxy, with parent present or by private self-report, in Australian Bureau of Statistics Health Surveys. National youth current smoking prevalence if all data were collected by youth self-report was estimated.

Results

Smoking behaviour data for over 75% of youth participants in the health survey were collected by proxy or with parent present. Ever-smoking prevalence using private self-report versus report by proxy was 1.29 (95%CI:0.96-1.73) to 1.99 (1.39-2.85) times as high in Aboriginal and Torres Strait Islander youth, and 1.83 (0.92-2.63) to 2.72 (1.68-4.41) times as high in total population youth. Predicted national current smoking prevalence if all youth were to self-report alone was substantively higher than the estimated national prevalence based on actual responses, but still reveals a decline over time.

Conclusions

Youth smoking estimates drawn from data collected by proxy/with parent present are unlikely to be accurate. Increased youth self-report is crucial to ensure data accuracy to inform effective tobacco control.

Key messages

The accuracy of youth smoking data collected by proxy/with parent present should be further scrutinised before it is used to inform assessment of national prevalence and trends.
1527Effect of a text-messaging intervention on oral self-care practices in antenatal women in Delhi, India
Authors: Basu Saurav , Rajeev Anjali , Garg Suneela , Singh Mongjam
Published: September 2021

Objective

to determine the effect of a mHealth (text-message) intervention compared with a structured health educational session on the oral care and hygiene practices of pregnant women.

Methods

We conducted a pilot Randomized Control Trial parallel design superiority trial with a 1:1 allocation ratio. A total of 76 pregnant women up-to 20 weeks of gestational age and capable of reading mobile phone text-messages were recruited during August-October’ 2020 from the antenatal clinic of a primary health centre in a low-income urban agglomeration in Delhi, India. The mHealth intervention arm participants were sent a daily text-message for 30 days while all participants were provided a face-face, brief didactic structured educational sessions towards oral health promotion.

Results

The baseline characteristics of both groups were comparable in terms of age-structure, education, parity, and oral hygiene but differed in terms of oral health problems. Post-intervention, although, the twice-brushing frequency increased in both arms, only the mHealth arm revealed a statistically significant reduction in the incidence of missed twice daily brushing episodes (p = 0.016). The absolute effect size for the primary outcome signifying the difference in the proportion of participants reporting twice daily brushing frequency habit between the mHealth and comparison arms’ was 0.090, the Cohen’s H was 0.182, and the odds of twice brushing habit in the mHealth arm was 1.44 times higher than in the comparison arm.

Conclusions

a mHealth based daily text-message intervention for one month was not superior to a one-time brief didactic structured educational intervention for oral health promotion in antenatal women.

Keywords

mHealth; Dental health promotion; Dental health education; Antenatal care
1498Community-level risk factors for birth size of child in selected developing countries (1992-2018): multilevel analysis
Authors: Bawankule Rahul , Singh Abhishek
Published: September 2021

Background

We aimed to identify emerging community-level risk factors for birth size in the last two decades in developing countries, particularly in Bangladesh, India, Indonesia, and Nigeria, having the highest burden of low birth weight (LBW) births globally.

Methods

We used data from multiple rounds of the Demographic and Health Surveys (DHS) conducted throughout the last two decades in the selected countries. We applied multilevel binary logistic regression models and estimated the intra-correlation coefficient (ICC) and median odds ratio (MOR) with a 95% confidence interval (CI) to analyze community-level variation in the birth size of child.

Results

The odds of having a smaller than average size birth increased by 1.28 times (95% CI: 1.11-1.79) in Bangladesh (2014), 3.03 times (95% CI: 2.90-3.18) in India (2015-16), 1.40 times (95% CI: 1.28-1.58) in Indonesia (2017) and 2.32 times (95% CI: 2.15-2.53) in Nigeria (2018) when women moved from low-risk to high-risk communities. The children residing in communities with a higher level of female illiteracy, higher level of inadequate antenatal care visits (ANC), higher use of unimproved toilet facilities were more likely to born with smaller than average birth size during 1992-2018.

Conclusions

The study confirms a significant community-level variation in smaller than average birth size among all analysed countries. Community with higher levels of female illiteracy, inadequate ANC visits, use of unimproved toilet facilities emerged as significant risk factors throughout the last two decades.

Key messages

The community-level risk factors have an independent association with the birth size of child regardless of individual-level characteristics of women and children.
939Longitudinal trends of work productivity in a representative sample of Australians living with multiple sclerosis
Authors: Bessing Barnabas , Blizzard Leigh , Hussain Mohammad A. , Claflin Suzi B. , Taylor Bruce V. , Mei Assoc Ingrid van der
Published: September 2021

Background

studies have documented increased employment rates and MS-related work productivity loss in people living with multiple sclerosis (PwMS). Little is known about the longitudinal trends of work productivity of PwMS.

Objectives

To describe the longitudinal patterns of work productivity of PwMS, and examine the factors associated with longitudinal change of work productivity of PwMS.

Methods

Study participants were from the Australian MS Longitudinal Study (AMSLS) followed from 2015 to 2018 (n = 2724) who were employed. We described the longitudinal patterns of work productivity and determined the correlates of the changes in work productivity of PwMS. We used linear mixed effect modelling to analyse the data.

Results

From our mixed effect model analysis, feelings of depression, walking difficulties, and spasticity problems were independently associated with -1.45 (-1.95 to -0.95), -1.35 (-1.98 to -0.72) and -1.04 (-1.63 to -0.45) per annum change in work productivity respectively. Annual changes in MS symptom clusters: difficulties with walking, balance and spasticity; anxiety and depression; and fatigue and cognitive symptoms were independently associated with -2.53 (-3.53 to -1.52), -1.51 (-2.27 to -0.74), -0.86 (-1.67 to -0.06) percent annual change in work productivity of PwMS respectively.

Conclusion

Symptoms cluster like ‘difficulties with walking, balance and spasticity’, ‘feelings of anxiety and depression’, and ‘fatigue and cognitive symptoms’ impact significantly on work productivity.

Key messages

MS related annual work productivity loss is marginal but is strongly driven by annual changes in walking difficulties, feelings of depression and spasticity problems
1324Clinical Registry for Acute Respiratory Infections in Children in Western Australia
Authors: Bhuiyan Mejbah , Pavlos Rebecca , O'Brien Sharon , Borland Meredith , Doyle Sarah , Blyth Christopher
Published: September 2021

Background

Acute respiratory infections (ARIs) are the leading cause for emergency presentation and a major driver for antibiotic use in children. In 2020, we established an ARI clinical registry to: evaluate clinical care for ARI to inform clinical guidelines; and as a platform for clinical trials assessing antimicrobial interventions.

Methods

Any child <16 years presenting to Perth Children’s Hospital Emergency Department (ED) with cough, fever, sore throat and/or difficulty breathing was eligible for enrolment. Using an automated survey sent to parents’ mobile phones, each enrolled child was followed weekly until 28 days or disease recovery (whichever occurred first). Data collected included clinical symptoms, antibiotic prescription, adherence, and duration to return to regular activity (recovery).

Results

From Feb 2020-April 2021, 448 participants were enrolled (84% <5 years). Fever and cough were the most frequently reported symptoms. Of 448, 274 (61%) ARI cases completed all surveys until recovered. The median recovery length was 9 days (IQR:6-12). The recovery days were longer, although not statistically significant (p > 0.05), in: children who received antibiotics versus those who did not (9.5 days vs. 8); children <5 years versus those over (9 days vs. 7); and children with chronic illnesses versus those without (9 days vs. 8).

Conclusions

Most children presenting to ED with ARI recover within 10 days. The length of recovery does not vary significantly by age, chronic illnesses, or antibiotic usage.

Key messages

Registry data provides baseline data to inform clinical trials assessing the role and duration of antibiotics for ARI.
1025Social interaction of middle-aged and older people with and without cardiovascular disease in Australia
Authors: Sayeed Muhammad Shahdaat Bin , Joshy Grace , Banks Emily , Korda Rosemary
Published: September 2021

Background

Social interaction is important for social wellbeing and may be adversely affected in people with cardiovascular disease (CVD). Large-scale evidence on social interaction among older people with versus without CVD is limited. We quantified and compared social interaction in older people with and without CVD.

Methods

Survey data (2006-2009) from the 45 and Up Study were linked to hospitalisations data through CHeReL to ascertain CVD status. Four items from the Duke Social Support Index (social-visits/week, telephone-contacts/week, social-group-contact/week, and number of people to depend on) were examined, using generalised linear models to estimate prevalence ratios (PRs) of no social interaction in people with versus without CVD, adjusting for relevant factors, and separately according to CVD subtype and level of physical disability.

Results

There were 266,504 study participants, 21.4% had CVD. People with CVD were 8%, (95%CI: 5-11%), 7% (2-12%), 4% (3-5%) and 7% (3-11%) more likely than people without CVD to have no social-visits/week, telephone-contacts/week, social-group-meetings/week and people to depend on respectively. The magnitude but not direction of results varied by CVD subtype. People with CVD and severe physical functioning limitations were 30-80% more likely than those with neither of these to have no social interaction.

Conclusions

Levels of social interaction were slightly lower in people with versus without CVD, but they varied by social interaction items, CVD subtypes, population characteristics and physical disability.

Key messages

Management to improve quality of life for people living with CVD should consider the role of physical disability for social connectedness.
1369Probabilistic data linkage of health facility and individual data using PMA2020 surveys
Authors: Blumenberg Cauane , Hellwig Franciele , Barros Aluisio
Published: September 2021

Background

Most studies rely on clustered analyses to study how the characteristics of health facilities influence individual outcomes. Our aim was to perform a probabilistic linkage between individual and health facility data to enable individual-level analyses.

Methods

We linked data from the most recent female questionnaire from 11 countries monitored by the Performance Monitoring for Action 2020 to a master health facility dataset (appending all rounds of surveys). Only women that reported which type of facility they visited were considered in the analysis. A probabilistic linkage was performed using 13 blocking variables (e.g., facility type and cluster of residence/location of the woman/facility) and 11 matching variables (e.g., types of contraceptive methods used/offered by the women/facility). Each concordant matching variable received a + 1 score, or a 0 score otherwise. We assessed linkage quality by pooled odds ratio of non-matches according to wealth tertiles (richest vs. poorest) and area of residence (urban vs. rural) using a meta-analytical approach.

Results

A total of 21,102 women and 7,056 facilities were considered in the linkage process. The average match rate was 57.9%, ranging from 42.5% in Indonesia to 69.1% in Burkina Faso. The pooled odds of non-match were 74% higher for the richest women compared to the poorest, and 67% higher for women living in urban areas compared to rural areas.

Conclusions

High match rates were achieved in countries with sufficient information on public and private facilities. The lack of information about private facilities contributed to the higher odds of non-match among the better off.

Key messages

We performed a probabilistic linkage approach to link individual and health facility data, making it possible to understand how the characteristics of health facilities can influence individual-level outcomes. Our findings also bring light to the importance of sampling both public and private facilities, aiming to maximise match rates and reduce differences on match rates according to socio demographic characteristics of the sample.
535The epidemiology of all-cause and cause-specific mortality following release from prison in 11 countries
Authors: Borschmann Rohan , Tibble Holly , Spittal Matthew , Preen David , Pirkis Jane , Larney Sarah , Rosen David , Young Jesse , Kinner Stuart
Published: September 2021

Background

More than 30 million adults are released from incarceration globally each year. Many experience complex physical and mental health problems, and are at markedly increased risk of preventable mortality. Despite this, evidence regarding the global epidemiology of mortality following release from incarceration is insufficient to inform the development of targeted, evidence-based responses. Many previous studies have suffered from inadequate power and poor precision, and even large studies have limited capacity to disaggregate data by specific causes of death, sub-populations or time since release to answer questions of clinical and public health relevance.

Methods

We aimed to comprehensively document the incidence, timing, causes and risk factors for mortality in adults released from incarceration. We created the Mortality After Release from Incarceration Consortium (MARIC), a multi-disciplinary collaboration representing 29 cohorts of adults who have experienced incarceration from 11 countries. Findings across cohorts will be analysed using a two-step, individual participant data meta-analysis methodology.

Results

Using linked data from the 29 individual cohorts, the combined sample includes 1,337,993 individuals (89% male), with 75,795 deaths recorded over 9,191,393 person-years of follow-up. Preliminary analyses indicate a marked elevation in mortality risk following release from incarceration, with this risk beginning on the day of release. At the time of writing, more detailed analyses are underway regarding all-cause and cause-specific deaths – along with risk and protective factors – and findings will be presented at the WCE conference.

Conclusions

The MARIC consortium represents an important advancement in the field, bringing international attention to this problem.

Key messages

The MARIC consortium will provide internationally relevant evidence to guide policymakers and clinicians in reducing preventable deaths in this marginalised population.
1281Prevalence and associated factors of cigarette smoking among youth population in Brazil: a cross-sectional study
Authors: Brito Emerson , Bessel Marina , Moreno Flávia , Kops Natália , Wendland Eliana
Published: September 2021

Background

The transition of adolescence to adulthood involves a variety of physical, behavioral and social transformations including try tobacco product. Understand smoking at this stage is important to tobacco control. Therefore, we aimed to analyze the use of cigarette smoking in Brazilian youth.

Methods

Nationwide study including participants aged 16 to 25 years from all Brazilian capitals between September/2016-December/2017. A standardized questionnaire with behavioral questions was applied by trained health care professionals. The sample was weighted in each capital by age range and sex.

Results

Of 8,581 participants (50.8% women), 15.1% were smokers and 20% former smokers. The average age of first use was 15.5 years. Smoking in men was higher than women (20.1% vs. 10.3%, p < 0.001). Those with elementary school smoked twice more compared to high school (25.6% vs. 13.6%, p < 0.001). Smoking was also associated to do not have a current partner when compared to those with partner (18.3% vs. 14.1%, p = 0.031), and who have had previous homosexual relationship (30.5%) compared to heterosexual individuals (12.5%, p < 0.001). In addition, smoking was associated to the regular use of alcohol compared to those who do not use (28.1% vs. 3.8%, p < 0.001). Skin color and social economic class didn’t show significant differences.

Conclusions

In this study be a man, have low education, a homosexual and alcohol use is associated to smoking among young. These findings are important for creation of policies to combat and prevent smoking in this population.

Key message

Smoking data among young people is important to direct new heath policies.
409The Word Gap: At What Age Does it Emerge? Results from a Prospective Cohort Study
Authors: Brushe Mary , Lynch John , Reilly Sheena , Melhuish Edward , Brinkman Sally
Published: September 2021

Background

Language is a critical development accomplishment of early childhood, enabling later literacy, education and employment. Previous studies have highlighted socioeconomic inequalities in the amount parents speak to their child, with researchers estimating by age four parents from professional backgrounds spoke 30 million more words to their children, than parents who were on welfare.

Methods

This study utilises innovative speech recognition technology called Language Environment Analysis (LENA), which counts the number of words children hear and speak over a day. LENA data is collected once every six months from 6 – 48 months of age, across two cohorts of children who are stratified by two levels of maternal education to examine the effects across socioeconomic groups.

Results

Results from the first three waves of data collection demonstrate that differences between education groups in the number of adult words spoken to the child are not evident until the children are 18 months old. Average change in adult word counts per day by maternal education show there is a difference of 17 words at 6 months, 568 words at 12 months and 3,851 words at 18 months.

Conclusions

This is the first study to be able to identify the age when socioeconomic differences in the amount of talk emerge. This has significant implications for the timing of interventions aiming to reduce the word gap, suggesting targeting the implementation of programs prior to 18 months.

Key messages

Socioeconomic differences in the amount parents talk to their children do not emerge until children are 18 months old.
1526Survival of hospitalized COVID-19 patients with multimorbidity in Hidalgo Mexico
Authors: Bustos-Vazquez Eduardo , Padilla-González Eduardo
Published: September 2021

Background

The growing number of patients with complex clinical profiles has contributed to the increasingly deaths. The aim is to estimate survival and risk factors associated with hospitalized COVID-19 patients with multimorbidity in the state of Hidalgo, Mexico during 2020 to April 2021.

Material and Methods

An observational, longitudinal, prospective and analytical study was carried out in 11,955 hospitalized COVID-19 patients with multimorbidity from the Epidemiological Surveillance System for Respiratory Disease of Hidalgo. The variables of interest were survival of hospital stay per day and multimorbidity adjusted for age, sex, occupation, days of demand for care, and days of mechanical ventilation use. Kapplan-Meiner estimators, Log-Rank tests and Cox proportional hazard method were using.

Results

Hospitalized COVID-19 patients with multimorbidity survival was 53.5%. The probability of survival is reduced to 50% from day 17 of hospital stay. The shortest survival rate corresponds to cases with Hypertension + Chronic Kidney Disease (RR: 9.46, 95% CI 2.63-37.92), Diabetes + Hypertension + Chronic Kidney Disease (RR: 1.83, 95% CI 1.52-2.20), Diabetes + Hypertension + Obesity (RR: 1.35, 95% CI 1.16-1.57) and Diabetes + Hypertension (RR: 1.31, 95% CI 1.19-1.45). The use of mechanical ventilation for more than 14 days increases the survival rate (RR: 0.53, 95% CI 0.49-0.57). The survival rate from occupation increase in employees, students and health workers compared to the unemployed.

Conclusions

Multimorbidity increases the effect of the clinical and epidemiological interrelationships of the coexistence of multiple diseases in the same individual and reduces the survival of COVID-19 in hospitalized patients.
1389Do associations between a healthy lifestyle and incidence of cancer differ by genetic risk?
Authors: Byrne Stephanie , Boyle Terry , Benyamin Beben , Lee Sang Hong , Ahmed Muktar , Hypponen Elina
Published: September 2021

Background

It is unknown whether relationships between lifestyle and cancer differ by genetic risk. We investigated this for 13 cancer types using prospective data from the UK Biobank.

Methods

In 2006-2010, participants aged 37-73 years completed an assessment and provided biological samples. Those of European ancestry with no history of malignant cancer were included in our analysis (n = 196,485). For each individual, a healthy lifestyle index (HLI) was calculated based on recommendations, and polygenic risk scores (PRSs) were computed for 13 cancer types. Relationships with cancer incidence were assessed by cox regression, adjusting for age, sex, assessment centre, birth location, and measures of socioeconomic status. Interactions between the HLI and PRSs were explored.

Results

For all cancer outcomes, a high genetic risk was associated with an increased cancer risk, or there was a trend in that direction. Those in the top PRS tertile had a greater than 2-fold increased risk of colorectal cancer (HR[95%CI]=2.18[1.90,2.49]), pancreatic cancer (2.39[1.71,3.32]) and lymphocytic leukemia (2.45[1.67,3.59]). An unhealthy lifestyle was associated with a higher cancer risk for 8 cancer types, with strong relationships observed for lung (3.41[2.76,4.20]), pancreatic (2.06[1.47,2.91]), bladder (1.95[1.43,2.66]) and kidney cancers (1.90[1.43,2.54]). No interactions between HLI and PRSs were detected (all interaction p-values>0.10).

Conclusions

Associations between lifestyle and cancer incidence did not differ by genetic risk.

Key messages

A healthy lifestyle can reduce the risk of several cancers, even in those who are genetically predisposed to develop cancer.
312Long-term survival of women diagnosed with cancer during pregnancy or postpartum
Authors: Cairncross Zoe , Shack Lorraine , Nelson Gregg , Friedenreich Christine , Ray Joel , Sikdar Khokan , Fell Deshayne , Lisonkova Sarka , McMorris Carly , Bhatti Parveen , Metcalfe Amy
Published: September 2021

Background

Cancer is the second leading cause of death in reproductive-aged women, and the incidence of pregnancy-associated cancer is rising. We assessed long-term survival of women diagnosed with cancer during pregnancy or postpartum.

Methods

A population-based retrospective cohort study included all reproductive-aged women (18-50 years) with a cancer diagnosis in Alberta, Canada, 2004 to 2016. Hazard ratios (HR) were calculated for all-cause and cancer-specific mortality, comparing 244 women who were diagnosed with cancer during pregnancy and 670 women diagnosed with cancer within one year postpartum, with 3,680 women diagnosed with cancer outside of these periods as the referent. Cox regression adjusted for age at cancer diagnosis, parity, cancer stage, and type of cancer.

Results

Rates of cancer in pregnancy and postpartum did not increase across the study period (trend p-value=0.49). Women diagnosed with cancer in pregnancy had an adjusted HR of 1.61 (95% CI 1.07-2.41) for all-cause mortality, 1.67 (95% CI 1.09-2.57) for cancer-specific mortality, relative to the referent. Those diagnosed with cancer postpartum did not have a greater risk of all-cause (HR = 1.10, 95% CI 0.80-1.50) or cancer-specific (HR = 1.15, 95% CI 0.82-1.60) mortality.

Conclusions

The risk of all-cause and cancer-specific mortality is increased in women diagnosed with cancer during pregnancy.

Key messages

Women diagnosed with cancer during pregnancy experience poorer survival than those diagnosed in postpartum or remote from a pregnancy. These findings should be used by physicians to guide care of women diagnosed with pregnancy-associated cancers.
810Geographical disparities in diagnosis of myeloproliferative neoplasms in Australia
Authors: Cameron Jessica , Fritschi Lin , Ross David , Anderson Lesley Ann , Cramb Susanna , Aitken Joanne , Mengersen Dist Kerrie , Duncan Earl , Baade Peter
Published: September 2021

Background

Myeloproliferative neoplasms (MPNs) are a relatively new group of blood cancers arising from genetic mutations in haematopoietic stem cells. Diagnostic delay is associated with thromboses, strokes and heart attacks. We investigated geographic variation in diagnosis and survival for classic MPNs.

Methods

Data for classic MPNs were obtained from the Australian Cancer Database. Leroux spatial models for incidence and survival were fitted using CARBayes, WinBUGS via R and tests for spatial clustering were conducted.

Results

The age-standardised incidence rate was 4.9 (95% CI: 4.8-5.0) per 100,000 person-years during 2007-2016 with relative survival of 78% (77%, 79%) at 5 years after diagnosis.

Strong evidence of spatial variation in incidence was observed (p < 0.001), with incidence rates low in Tasmania (4.2 per 100,000 person-years, 95% CI: 3.5-5.0) and Western Australia (6.1, 5.6-6.6) and high in Victoria (9.5, 9.2-9.9) and Queensland (10.6, 10.2-11.1).

Differences between states and territories could not be explained by population rates of genetic testing or the proportion of registered cases with histological evidence.

Conclusions

Stark spatial differences in incidence rates of classic MPNs suggest that varying diagnosis and registration patterns between states results in under-recognition, and potentially undertreatment. It is imperative that reporting is consistent so that sound evidence is available for efforts to reduce disparities in diagnosis and management.

Key messages

Early identification of MPNs is crucial, however, strong spatial geographical variation in incidence rates suggest diagnostic and notification practices may not be consistent across the country.
402Measles vaccine coverage: The rise of vaccine hesitancy in upper-middle income countries
Authors: Cata-preta Bianca , Santos Thiago M , Barros Aluisio JD , Victora Cesar G , Wehrmeister Fernando C
Published: September 2021

Background

With the rise of vaccine hesitancy, which is allegedly more frequent among rich families, we hypothesized that the classical pattern of a positive gradient in coverage with rising wealth may no longer be observable in low- and middle-income countries (LMICs).

Methods

We analysed DHS and MICS surveys conducted from 2010-2018 in 88 LMICs. We estimated inequality in measles vaccination coverage by wealth quintile for children aged 12-23 months using the Slope Index of Inequality (SII). Negative SII values indicate higher coverage among poor children. We correlated the SII with per capita Gross Domestic Product (GDP), using countries as the units.

Results

Pearson’s correlation coefficient between SII and log per capita GDP was -0.35 (p < 0.001). The percentages of countries with higher coverage among children from poor families than among those from wealthy families were 14%, 21% and 54% in low, lower-middle and upper-middle income countries (p level for trend=0.001), respectively (Figure 1).

Conclusions

Our results are consistent with lower vaccination coverage among the wealthy when compared to poor families in countries with higher per capita GDPs.

Key messages

Vaccine hesitancy was initially detected in high-income countries, but our analyses show that it is also present in upper-middle income countries.
596Two approaches for estimating propensity score weights for examining neighbourhood built environment and walking changes
Authors: Christie Chelsea , Vena Jennifer , Friedenreich Christine , McCormack Gavin
Published: September 2021

Background

Walking is associated with the built environment, however, this association may be biased by residential self-selection. This study examined how walking duration changed with residential relocation, while accounting for unbalanced covariates that may contribute to residential self-selection, using two different propensity score inverse probability weight (IPW) methods.

Methods

Urban participants (n = 703) of Alberta’s Tomorrow Project with pre- and post-relocation neighbourhood built environment and walking data were included. A walkability index was created by aggregating estimates for population density, street connectivity, and destination diversity. Participants were categorized into three groups based on change in residential walkability (decreased, minimal change, or increased). The association between changes in walkability and walking duration (min/week) was modelled with linear regression. Two types of IPWs were applied: 1) manually generated from multinomial regression models, and 2) generated from generalized boosted models.

Results

All three groups increased walking duration from pre- to post-relocation, however the largest increase was among participants who had increased walkability (M = 73.2, SD = 388), followed by those with minimal change (M = 60.0, SD = 382) and decreased (M = 50.2, SD = 374) walkability. Longitudinal associations between walkability change and walking were not statistically significant (p < 0.05) in models with or without IPWs.

Conclusions

Changes in neighbourhood walkability were not associated with changes in walking, regardless of how the sample was weighted. Further research should examine changes in the neighbourhood environment with different types of walking and physical activity behaviours.

Key messages

IPW methods can be used to account for unbalanced covariates in analyses that involve possible self-selection bias.
1518Preterm birth and trajectories of cardiometabolic health measures from birth to adulthood
Authors: Clayton Gemma , Howe Laura , O’Keeffe Linda , Lewandowski Adam , Lawlor Deborah , Fraser Abigail
Published: September 2021

Background

Preterm birth is associated with increased cardiovascular disease risk, but it is unclear when this risk emerges. We compared life course trajectories from birth to adulthood of multiple cardiometabolic health measures in adults born preterm compared with term.

Methods

Multilevel models were used to compare trajectories from birth to age 25 years of BMI, fat mass, lean mass, systolic and diastolic blood pressure (BP), lipids, glucose and insulin, between participants born preterm (N = 311-560) and term (N = 5365-9262) in a contemporary UK birth cohort study. We also investigated gestational age as a continuum.

Results

Systolic and diastolic BP were higher at age 7 (mean predicted differences 0.8mmHg; 95%CI -0.1, 1.7 and 0.7mmHg; 95%CI 0.03, 1.3, respectively). The difference in SBP persisted and in DBP disappeared by 25 years. Preterm participants had lower BMI between 7 and 18 years, but by age 25, there was no difference. Lean mass and fat mass (measured from age 9 only) trajectories were consistent with BMI. HDL-c was higher, and triglycerides lower at birth in those born preterm, but this difference disappeared by 25 years. No other differences were found.

Conclusions

There were few, modest differences in cardiometabolic health measures during early life in those born preterm versus term. All disappeared by age 25, except SBP. Longer follow-up is needed to establish if and when trajectories diverge.

Key messages

By age 25, there were no differences in measures of cardiometabolic health between people born preterm and term except for a higher SBP in those born preterm.
98Framework for the Treatment And Reporting of Missing data in Observational Studies: The TARMOS framework
Authors: Cornish Rosie , Tilling Kate , Cornish Rosie , Carpenter James
Published: September 2021

Focus of presentation

Missing data are ubiquitous in medical research. Although there is increasing guidance on how to handle missing data, practice is changing slowly and misapprehensions abound, particularly in observational research. We present a practical framework for handling and reporting the analysis of incomplete data in observational studies, which we illustrate using a case study from the Avon Longitudinal Study of Parents and Children.

Findings

The framework consists of three steps: 1) Develop an analysis plan specifying the analysis model and how missing data are going to be addressed. Important considerations are whether a complete records analysis is likely to be valid, whether multiple imputation or an alternative approach is likely to offer benefits, and whether a sensitivity analysis regarding the missingness mechanism is required. 2) Explore the data, checking the methods outlined in the analysis plan are appropriate, and conduct the pre-planned analysis. 3) Report the results, including a description of the missing data, details on how missing data were addressed, and the results from all analyses, interpreted in light of the missing data and clinical relevance.

Conclusions/Implications

This framework encourages researchers to think carefully about their missing data and be transparent about the potential effect on the study results. This will increase confidence in the reliability and reproducibility of results from published papers.

Key messages

Researchers need to develop a plan for missing data prior to conducting their analysis, and be transparent about how they handled the missing data and its potential effect when reporting their results.
743Determinants of childhood mortality sex ratios in low- and middle-income countries
Authors: Costa Janaina Calu , Victora Cesar
Published: September 2021

Background

Child mortality sex ratios may reflect community preferences and gender discrimination in health care. We assessed differences between observed and expected sex ratios of under-five mortality and their association with contextual factors.

Methods

Full birth histories from Demographic and Health Surveys and Multiple Indicator Cluster Surveys (2010–2018) in 77 countries were used to estimate under-five mortality sex ratios (male-to-female). Expected sex ratios and their residuals (difference of observed from expected) were derived from a fractional polynomial model, adjusted for overall mortality. Higher male-to-female residuals indicate lower likelihood of discrimination against girls. The same approach was used for 720 subnational regions from 75 countries. Associations between residuals and national gender and development indices, and with survey-derived child health care indicators were tested using Spearman’s correlation.

Results

Greater positive residuals were found in countries with higher Gross National Product per capita (rho=0.26), women older age at first marriage (rho=0.36), Human Development Index (rho = 0.23), and the Women, Peace and Security Index (rho=0.25). The Gender Inequality Index, which indicates less discrimination among women, was inversely correlated with the residuals (rho=-0.30). None of the survey-based indicators of gender bias in health care were significantly associated with the residuals, either at national or subnational levels.

Conclusion

Contextual variables measured at country level are associated with the sex ratio of under-five mortality.

Key messages

In more developed societies there is less evidence of gender bias in child deaths.
467Hypertension, Dyslipidaemia and Pregnancy Complications in Filipino Women
Authors: Durante Cherry Ann
Published: September 2021

Background

There is an increasing trend of pregnancy complications in the Philippines. However, these are not well documented due to the lack of a national database. This study describes the prevalence of hypertension and lipid abnormalities among Filipino pregnant women, which result to complications during pregnancy.

Methods

Multi-stage stratified random sampling was employed in the National Nutrition Survey and 6,166 pregnant women were included in the study. Demographic data was gathered through an interview questionnaire. Blood samples were drawn to determine fasting blood sugar (FBS), cholesterol, HDL and LDL, and triglycerides levels.

Results

One in ten pregnant women (n = 661) showed signs of pregnancy complications. High risk pregnancies were identified, ranging from heart disease (2.9%), gestational diabetes (3.2%), asthma (3.51%) and goiter (4.12%). Prevalence of pregnancy-induced hypertension is 18.26%. Dyslipidemia is high among sample population with a prevalence of 39.54% (n = 376). Results showed that patients with hypertension are twice more likely to have pregnancy complications than those with normal BP (OR:1.95, CI 0.47, 6.08).

Conclusions

Based on the data, there is a high prevalence of pregnancy complications in the Philippines which is associated with having hypertension and lipid abnormalities.

Key messages

Health policies should be made to cater to the early detection of disease in pregnant women and widespread campaign for affordable prenatal check-ups.
576Is the method of longitudinal data analysis equally relevant for common versus uncommon endpoints?
Authors: Dzikiti Moleen , Laughton Barbara , Innes Steve , Cotton Mark
Published: September 2021

Background

We explored the effects of predominant breastfeeding on infection-related hospitalization (uncommon outcome), over the first year of life, using the Mother Infant Health cohort study (MIHS), and the effect of early antiretroviral treatment (ART) on viral suppression (< 400 copies/mL) (common outcome), in children aged 7 to 12 weeks, using a subset of the Children with HIV Early AntiRetroviral Treatment (CHER) clinical trial data. We assessed the sensitivity of findings to different models to account for dependency of uncommon and common binary outcome.

Methods

We fitted generalized linear mixed model with (1) random intercept and (2) random slope, generalized estimating equations (GEE) with 3) an exchangeable correlation structure; 4) autoregressive correlation structure of order 1 (AR1) and 5) unstructured correlation structure and 6) logistic regression model.

Results

Eighty four and 119 children from MIHS were non-predominantly and predominantly breastfed, respectively. There were 34 infection-related hospitalizations overall. Most infants were hospitalized once, except for four with two hospitalizations. We analysed 88 HIV-infected children from the CHER trial. On average, a child achieved viral suppression twice, range of one to four. The effect of predominant breastfeeding on infection-related hospitalization was similar across all models, except for the GEE with AR1 that had a high estimate (wider confidence intervals). The effect of early ART exposure on viral suppression varied across models.

Conclusions

The sensitivity of estimates to the method of analysis was driven by frequency of the outcome.
1216Combining propensity score-weighting and multiple imputation is not a trivial task
Authors: Eiset Andreas Halgreen , Frydenberg Morten
Published: September 2021

Background

Propensity score (PS)-weighting and multiple imputation are two widely used statistical methods. Combining the two is not trivial and has received little attention in theory and practice. We present our considerations for their combination with application to a study of long-distance migration and post-traumatic stress disorder. We elaborate on the assumptions underlying the methods and discuss the methodological and practical implications of our choices and alternatives.

Methods

We made a number of choices a priori: to use logistic regression-based PS to produce “standardised mortality ratio”-weights and SMC-FCS to multiply impute missing data. We present a methodology to combine the methods by choosing the PS model based on covariate balance, using this model as the substantive model in the multiple imputation, producing and averaging the point estimates from each multiply imputed data set to give the estimate of association and computing the percentile confidence interval by bootstrapping.

Results

In our application, a simple PS model was chosen as the substantive model for imputing 10 data sets with 40 iterations and repeating the entirety 999 times to obtain a bootstrap confidence interval. Computing time was approximately 36 hours.

Conclusions

Our structured approach is demanding in both work-load and computational time. We do not consider the prior a draw-back: it makes some of the underlying assumptions explicit and the latter may be a nuisance that diminishes with time.

Key messages

Combining propensity score-weighting and multiple imputation is not a trivial task.