Biostatistics Commons^™

Dietary Inflammatory Index Is Related To Heart Failure Risk And Cardiac Function: A Case-Control Study In Heart Failure Patients, Jalal Moludi, Nitin Shivappa Mbbs, Mph, Ph.D., Soghra Alisgharzadeh, James R. Hébert Scd, Mohammad Alizadeh

Faculty Publications

Aims: Previous studies suggest that diet and inflammation are important risk factors for heart failure (HF); however, the associations remain unclear. The Dietary Inflammatory Index (DII®) was established to measure the inflammatory capacity of individuals' diet. This study aimed to explore the DII in HF subjects compared with controls. Methods and Results: We conducted a case–control (116 cases and 113 controls) study that recruited in the similar clinics. DII scores were calculated based on dietary intakes. N-Terminal pro-brain natriuretic peptide (NT-proBNP) levels and ejection fraction (EF) were assessed in both groups. In order to analyze DII scores with HF as …

Timing Of Term Elective Cesarean Section And Adverse Neonatal Outcomes: A Multi-Center Retrospective Cohort Study, Ayah Al Bizri, Nansi Boghossian, Anwar Nassar, Pascale Nakad, Dina Jaber, Rabih Chahine, Gaby Fallakha, Gjaotj Makhoul, Khalid Yunis

Faculty Publications

Background Rate of cesarean section (CS), including elective CS has globally increased. Studies have found that term elective CS before 39 weeks of gestation is associated with increased risk of adverse respiratory outcomes.

Objective To determine the rate of elective CS and examine the association between timing of elective term CS and adverse neonatal outcomes in a large population of Lebanese women.

Methods A Multi-Center Study was conducted using data from the National Collaborative Perinatal Neonatal Network database. Simple and multivariable logistic regression models were used to examine the association between timing of term elective CS and adverse neonatal outcomes. …

Age And Sex Are Associated With The Plasma Lipidome: Findings From The Goldn Study, Emily Slade, Marguerite R. Irvin, Kevin Xie, Donna K. Arnett, Steven A. Claas, Tobias Kind, David W. Fardo, Gregory A. Graf

Biostatistics Faculty Publications

Background
Developing an understanding of the biochemistry of aging in both sexes is critical for managing disease throughout the lifespan. Lipidomic associations with age and sex have been reported, but prior studies are limited by measurements in serum rather than plasma or by participants taking lipid-lowering medications.

Methods
Our study included lipidomic data from 980 participants aged 18–87 years old from the Genetics of Lipid-Lowering Drugs and Diet Network (GOLDN). Participants were off lipid-lowering medications for at least 4 weeks, and signal intensities of 413 known lipid species were measured in plasma. We examined linear age and sex associations with …

Interplay Between Social Media Use, Sleep Quality, And Mental Health In Youth: A Systematic Review, Rea Alonzo, Junayd Hussain, Saverio Stranges, Kelly K. Anderson

Epidemiology and Biostatistics Publications

Social media applications are increasingly prominent among youth. This systematic review provides a comprehensive assessment of the literature on the relationship between active social media use, sleep quality, and common mental health outcomes (anxiety, depression, and psychological distress) among youth. MEDLINE, PsychINFO, EMBASE and Scopus were searched for observational studies investigating this relationship among youth (aged 16–25). Thirty-six cross-sectional studies and six prospective cohort studies met the inclusion criteria. Among cross-sectional studies, significant associations between excessive social media use with poor mental health outcomes (n = 33), poor sleep quality (n = 24), and significant associations between poor sleep quality …

Quality Of Diabetes Care In Blended Fee-For-Service And Blended Capitation Payment Systems., Mary Aderayo Bamimore, Rose Anne Devlin, Gregory S Zaric, Amit X Garg, Sisira Sarma

Epidemiology and Biostatistics Publications

OBJECTIVES: In the middle to late 2000s, many family physicians switched from a Family Health Group (FHG; a blended fee-for-service model) to a Family Health Organization (FHO; a blended capitation model) in Ontario, Canada. The evidence on the link between physician remuneration schemes and quality of diabetes care is mixed in the literature. We examined whether physicians who switched from the FHG to FHO model provided better care for individuals living with diabetes relative to those who remained in the FHG model.

METHODS: Using longitudinal health administrative data from 2006 to 2016, we investigated the impact of physicians switching from …

Perceived Discrimination And Racism On The Treatment And Medication Adherence Of Hypertension In African Americans, Ifeoluwa Kayode, Daisy Tovar, Logan Cowan

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

No abstract provided.

The Dietary Inflammatory Index Is Associated With Low Muscle Mass And Low Muscle Function In Older Australians, Marlene Gojanovic, Kara L. Holloway-Kew, Natalie K. Hyde, Mohammadreza Mohebbi, Nitin Shivappa Mbbs, Mph, Ph.D., James R. Hébert Scd., Adrienne O'Neil, Julie A. Pasco

Faculty Publications

Age-associated chronic, low grade systemic inflammation has been recognised as an important contributing factor in the development of sarcopenia; importantly, diet may regulate this process. This cross-sectional study examined the association of diet-related inflammation with components of sarcopenia. Participants (n = 809) aged 60–95 years from the Geelong Osteoporosis Study were studied. Body composition was measured by dual energy X-ray absorptiometry. In this study, low appendicular lean mass (ALM/height2, kg/m2) was defined as T-score < −1 and low muscle function as Timed-Up-and-Go >10 s over 3 m (TUG > 10). Dietary inflammatory index (DII®) scores, based on specific foods and nutrients, were computed using dietary data collected from a …

Neurodevelopment Correlates With Gut Microbiota In A Cross-Sectional Analysis Of Children At 3 Years Of Age In Rural China, Sarah E. Rothenberg, Qiurong Chen, Yanfen Nong, Hua Nong, Eva P. Trinh, Fred J. Biasini, Jihong Liu, Xiaoyun Zeng, Yunfeng Zou, Fengxiu Ouyang, Susan A. Korrick

Faculty Publications

We investigated cross-sectional associations between children’s neurodevelopment and their gut microbiota composition. Study children (36 months of age) lived in rural China (n = 46). Neurodevelopment was assessed using the Bayley Scales of Infant Development, 2nd Edition, yielding the Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI). Children's gut microbiota was assessed using 16S rRNA gene profiling. Microbial diversity was characterized using alpha diversity patterns. Additionally, 3 coabundance factors were determined for the 25 most abundant taxa. Multivariable linear regression models were constructed to examine the relationships between Bayley scores (MDI and PDI) and children's gut microbiota. In adjusted …

The Pharmaceutical Industry Contributes To Public Health, Karl E. Peace, Mario Keko

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

No abstract provided.

Sars-Cov-2 Transmission In Alberta, British Columbia, And Ontario, Canada, December 25, 2019, To December 1, 2020, Isaac Chun-Hai Fung, Yuen Wai Hung, Sylvia Ofori, Kamalich Muniz-Rodriguez, Po-Ying Lai, Gerardo Chowell

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

Objective:

This study aimed to investigate coronavirus disease (COVID-19) epidemiology in Alberta, British Columbia, and Ontario, Canada.

Methods:

Using data through December 1, 2020, we estimated time-varying reproduction number, R t , using EpiEstim package in R, and calculated incidence rate ratios (IRR) across the 3 provinces.

Results:

In Ontario, 76% (92 745/121 745) of cases were in Toronto, Peel, York, Ottawa, and Durham; in Alberta, 82% (49 878/61 169) in Calgary and Edmonton; in British Columbia, 90% (31 142/34 699) in Fraser and Vancouver Coastal. Across 3 provinces, R t dropped to ≤ 1 after April. …

Characterization, Bio-Uptake And Toxicity Of Polymer-Coated Silver Nanoparticles And Their Interaction With Human Peripheral Blood Mononuclear Cells, Sahar Pourhoseini, Reilly T. Enos, Angela E. Murphy, Bo Cai Ph.D., Jamie Lead

Faculty Publications

Silver nanoparticles (AgNPs) are widely used in medical applications due to their antibacterial and antiviral properties. Despite the extensive study of AgNPs, their toxicity and their effect on human health is poorly understood, as a result of issues such as poor control of NP properties and lack of proper characterization. The aim of this study was to investigate the combined characterization, bio-uptake, and toxicity of well-characterized polyvinylpyrrolidone (PVP)-coated AgNPs in exposure media during exposure time using primary human cells (peripheral blood mononuclear cells (PBMCs)). AgNPs were synthesized in-house and characterized using a multimethod approach. Results indicated the transformation of NPs …

Relationship Between Diet Quality Scores And The Risk Of Frailty And Mortality In Adults Across A Wide Age Spectrum, Kulapong Jayanama, Olga Theou, Judith Godin, Leah Cahill, Nitin Shivappa Mbbs, Mph, Ph.D., James Hébert, Michael David Wirth Msph, Phd, Yong-Moon Park, Teresa T. Fung, Kenneth Rockwood

Faculty Publications

Background

Beyond intakes of total energy and individual nutrient, eating patterns may influence health, and thereby the risk of adverse outcomes. How different diet measures relate to frailty—a general measure of increased vulnerability to unfavorable health outcomes—and mortality risk, and how this might vary across the life course, is not known. We investigated the associations of five dietary indices (Nutrition Index (NI), the energy-density Dietary Inflammatory Index (E-DII™), Healthy Eating Index-2015 (HEI-2015), Mediterranean Diet Score (MDS), and Dietary Approaches to Stop Hypertension (DASH)) with frailty and mortality.

Methods

We included 15,249 participants aged ≥ 20 years from the 2007–2012 cohorts …

Lag Effects Of Ozone, Pm2.5, And Meteorological Factors On Covid-19 New Cases At The Disease Epicenter In Queens, New York, Atin Adhikari, Jingjing Yin

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

The influences of environmental factors on COVID-19 may not be immediate and could be lagged for days to weeks. This study investigated the choice of lag days for calculating cumulative lag effects of ozone, PM2.5, and five meteorological factors (wind speed, temperature, relative humidity, absolute humidity, and cloud percentages) on COVID-19 new cases at the epicenter of Queens County, New York, before the governor’s executive order on wearing of masks in public places (1 March to 11 April 2020). Daily data for selected air pollutants and meteorological factors were collected from the US EPA Air Quality System, weather observation station …

Exclusive Breastfeeding History Risk Factor Associated With Stunting Of Children Aged 12–23 Months, Nurhalina Sari, Marlida Yuliza Manjorang, Zakiyah Zakiyah, Madeleine Randell

Kesmas

Stunting (low height-for-age) remains a global and national health problem because it increases the risk of disturbances in growth and development and mortality. Banjar Margo District, Tulang Bawang Regency, has the second-highest prevalence in Lampung Province, Indonesia. This study aimed to analyze the association of exclusive breastfeeding history and stunting in children aged 12–23 months in Banjar Margo District. This study used a cross-sectional design on 193 children aged 12–23 months. It was primary data conducted between April and May 2018 with a questionnaire. Data analysis was performed using the chi-square test and multiple logistic regression. The result showed that …

Junk Food Consumption And Symptoms Of Mental Health Problems: A Meta-Analysis For Public Health Awareness, Muhammad Hafizurrachman, Risky Kusuma Hartono

Kesmas

Junk food consumption increases the risk of having symptoms of mental health problems. This study aimed to conduct a meta-analysis to assess the association between junk food and symptoms of mental health problems. Six researchers, two primary researchers, and four assistant researchers, from October to December 2020 conducted a systematic literature review. The data sources were selected from Pubmed and Science Direct articles published from 2010 to 2020. Those websites were check-marked for text availability for original articles, using keywords for junk foods and mental health. This study had inclusion criteria for selecting and organizing articles using the Preferred Reporting …

Assessment Of Characteristics And Conditions Before The End Of Lockdown, David San-Martín-Roldán, Francisca Rojo-Lazo, Aracelis Calzadilla-Núñez, Pablo San-Martín-Roldán, Patricia Díaz-Calzadilla, Víctor P. Díaz-Narváez

Kesmas

After months of blockades and restriction, the decision of the best time to end the lockdown after the first wave of the COVID-19 pandemic is the big question for health rectors. This study aimed to evaluate the characteristics and conditions for ending the blockade after the first wave of COVID-19. Data on the variables of interest were subjected to linear and non-linear regression studies to determine the curve that best explains the data. The coefficient of determination, the standard deviation of y in x, and the observed curve of the confidence interval were estimated. Regression which was estimated subsequently revealed …

Analysis Of Measles Vaccination Refusal On Social Media (Facebook) Among Anti-Vaccine Communities In Indonesia, Dwi Meilani, Evi Martha, Hadi Pratomo, Indah Jamiatun Hasanah, Somporn Rungreangkulkij

Kesmas

Measles is one of the main causes of global mortality in the under-fives. The existence of groups that reject immunization caused a decrease in immunization coverage. Anti-vaccine messages are widely delivered on social media. Identification of vaccine rejection behavior can be used as the basis to formulate effective program strategies. The design of this study used rapid assessment procedures (RAP). The informants were from two anti-vaccine communities in the Facebook group. In-depth interviews and observations were done for data collection, and data analysis was performed using the Framework Method. The results found that determinants, such as knowledge, beliefs in health …

Parity And Marital Status As Factors Influencing Contraceptive Use Among Adolescents In Indonesia, Anni Fithriyatul Mas'udah, Terry Yr Pristya, Sulistyo Andarmoyo

Kesmas

Adolescent pregnancy has a higher health risk compared to adult pregnancy. One approach to control pregnancy among adolescents is through contraceptive use. The data on contraceptive use has increased in 2018 and is still controversial among adolescents. Thus, it is necessary to determine the factors encou - rag ing the use of contraceptives among adolescents. This study aimed to determine the relation of parity and marital status on contraceptive use among adolescents. This quantitative study used a cross-sectional design. The population of this study was adolescents aged 15–19 years in Indonesia. The total sample of 936 adolescents was selected from …

Low Knowledge And Unawareness Of The Health Promotion As The Determinant Factors In Non-Compliance To The Mass Drug Administration Program, Nissa Noor Annashr, Icca Stella Amalia, Hoa Thi Phuong Dinh

Kesmas

From the total population of the community in Kuningan District, 78.61% were taking filariasis drugs in the Mass Drug Administration (MDA) program in 2017. Cilimus Subdistrict became a filariasis-endemic area in Kuningan with 72.39% of the MDA program coverage in 2017 (government target >86%). The purpose of this study was to analyze the determinant factors of compliance with the MDA program. The study was an analytical study with a cross-sectional design and conducted from May to June 2018. The sample of 106 people was taken from the population living in Cilimus Subdistrict, Kuningan District, using a simple random sampling technique. …

Patterns And Determinants Of Open Defecation Among Urban People, Vera Yulyani, Christin Angelina Febriani, Shaharuddin Ms, Dessy Hermawan

Kesmas

At the present time, an estimated of 673 million people defecate in the open space, not in private. Indonesia is a densely populated country with a lot of open defecation (OD) both in urban (37%) and rural areas (43%). Tanjung Karang Pusat Subdistrict is an area in Bandar Lampung City with the highest percentage of OD practice (45%). This study aimed to explore and explain the patterns and determinants of OD among urban people in the Tanjung Karang Pusat Subdistrict in- volving 377 respondents for quantitative analysis. Quantitative data were analyzed using the chi square and regression analysis. After controlling …

Risk Perception For Developing Erectile Dysfunction Among Malaysian Men With Type 2 Diabetes Mellitus, Anuar Mohamad, Hizlinda Tohid, Saharuddin Ahmad, Seng Fah Tong, Mahadir Ahmad

Kesmas

Risk perception for developing erectile dysfunction (ED) is an appreciation of the susceptibility to having ED and its severity. This study examined this risk perception and its associated factors among 180 men with type 2 diabetes mellitus (T2DM), who claimed not to have ED. This cross sectional study was conducted at a public health clinic using a validated self-administered questionnaire, which assessed participant characteristics, perceived susceptibility to developing ED, perceived severity of ED, and knowledge on risk factors for ED. About 71.1% had an inaccurate perception of susceptibility to developing ED and their perception on its severity was moderate (median …

Determinants Of Exclusive Breastfeeding Practices Of Female Healthcare Workers In Jakarta, Indonesia, Siti Rapingah, Nova Muhani, Besral Besral, Poppy Yuniar

Kesmas

The World Health Organization (WHO) recommended that mothers worldwide exclusively breastfeed their infants for the child's first six months to achieve optimal growth, development, and health. Indonesia had not fulfilled the global standard of breastfeeding rate so that there was low coverage of exclusive breastfeeding in East Jakarta, especially for female healthcare workers. This study aimed to determine the factors associated with exclusive breastfeeding practices of healthcare workers. This was a quantitative study using a cross-sectional design. The recruited sample consisted of 85 female public health center workers with infants aged 6-24 months. Data were collected using self-administered questionnaires. Logistic …

Evaluation Of Added Sugar And Sugar-Sweetened Beverage Consumption By University Students, Çağdaş Salih Meric, Nurcan Yabanci Ayhan, Hacı Ömer Yilmaz

Kesmas

Today, increased intake of sugar and sugar-sweetened beverages is seen today as an important factor in the growing prevalence of chronic diseases, such as obesity, obesity-related diabetes, and coronary heart diseases. This study involved 214 university students from the Department of Nutrition and Dietetics of Ankara University, Faculty of Health Science, which was intended to evaluate the consumption of sugar and sugar-sweetened beverages. The frequency of student consumption of beverages and the quantities and amounts of sugar taken with beverages were questioned. The average total amount of sugar added to drinks by the students was 4.69 ± 6.35 gram, while …

Maternal Dietary Quality, Inflammatory Potential And Childhood Adiposity: An Individual Participant Data Pooled Analysis Of Seven European Cohorts In The Alphabet Consortium, Ling-Wei Chen, Adrien M. Aubert, Nitin Shivappa, Jonathan Y. Bernard, Sara M. Mensink-Bout, Aisling A. Geraghty, John Mehegan, Matthew Suderman, Kinga Polanska, Wojciech Hanke, Agnieszka Jankowska, Caroline L. Relton, Sarah R. Crozier, Nicholas C. Harvey, Cyrus Cooper, Mark Hanson, Keith M. Godfrey, Romy Gaillard, Liesbeth Duijts, Barbara Heude, James Hébert Scd, Fionnuala M. Mcauliffe, Cecily Kelleher, Catherine M. Phillips

Faculty Publications

Background

Mounting evidence suggests that maternal diet influences pregnancy and birth outcomes, but its contribution to the global epidemic of childhood obesity has not as yet been definitively characterized. We investigated whether maternal whole diet quality and inflammatory potential influence childhood adiposity.

Methods

We harmonized and pooled individual participant data from 16,295 mother-child pairs in seven European birth cohorts. Maternal pre-, early-, late-, and whole-pregnancy (any time during pregnancy) dietary quality and inflammatory potential assessed with the Dietary Approaches to Stop Hypertension (DASH) score and the energy-adjusted Dietary Inflammatory Index (E-DII™) score, respectively. Primary outcome was childhood overweight and obesity …

Whole-Exome Sequencing And Hipsc Cardiomyocyte Models Identify Myrip, Trappc11, And Slc27a6 Of Potential Importance To Left Ventricular Hypertrophy In An African Ancestry Population, Marguerite R. Irvin, Praful Aggarwal, Steven A. Claas, Lisa De Las Fuentes, Anh N. Do, C. Charles Gu, Andrea Matter, Benjamin S. Olson, Amit Patki, Karen Schwander, Joshua D. Smith, Vinodh Srinivasasainagendra, Hemant K. Tiwari, Amy J. Turner, Deborah A. Nickerson, Dabeeru C. Rao, Ulrich Broeckel, Donna K. Arnett

Epidemiology and Environmental Health Faculty Publications

Background: Indices of left ventricular (LV) structure and geometry represent useful intermediate phenotypes related to LV hypertrophy (LVH), a predictor of cardiovascular (CV) disease (CVD) outcomes.

Methods and Results: We conducted an exome-wide association study of LV mass (LVM) adjusted to height^2.7, LV internal diastolic dimension (LVIDD), and relative wall thickness (RWT) among 1,364 participants of African ancestry (AAs) in the Hypertension Genetic Epidemiology Network (HyperGEN). Both single-variant and gene-based sequence kernel association tests were performed to examine whether common and rare coding variants contribute to variation in echocardiographic traits in AAs. We then used a data-driven …

Dietary Quality And Dietary Inflammatory Potential During Pregnancy And Offspring Emotional And Behavioral Symptoms In Childhood: An Individual Participant Data Meta-Analysis Of Four European Cohorts, Kinga Polanska, Pawel Kaluzny, Adrien M. Aubert, Liesbeth Duijts, Hanan El Marroun, Wojciech Hanke, James R. Hébert, Barbara Heude, Agnieszka Jankowska, Giulia Mancano, Sara M. Mensink-Bout, Caroline Relton, Nitin Shivappa Mbbs, Mph, Ph.D., Matthew Suderman, Elzbieta Trafalska, Ewelina Wesolowska, Raquel Garcia-Esteban, Mònica Guxens, Maribel Casas, Catherine M. Phillips

Faculty Publications

Background

The impact of maternal diet during pregnancy on child neurodevelopment is of public health and clinical relevance. We evaluated the associations of dietary quality based on the Dietary Approaches to Stop Hypertension (DASH) score and dietary inflammatory potential based on the energy-adjusted Dietary Inflammatory Index (E-DII) score during pregnancy with emotional and behavioral symptoms of offspring at 7 to 10 years of age.

Methods

Individual participant data for 11,870 mother–child pairs from four European cohorts participating in the ALPHABET project were analyzed. Maternal antenatal DASH and E-DII scores were generated from self-completed food frequency questionnaires. Symptoms of depression …

The Intersection Of Rural Residence And Minority Race/Ethnicity In Cancer Disparities In The United States, Whitney Zahnd, Cathryn Murphy, Marie Knoll, Gabriel A. Benavidez, Kelsey R. Day, Radhika Ranganathan, Parthenia Luke, Anja Zgodic, Kewei Shi, Melinda A. Merrell, Elizabeth L. Crouch, Heather M. Brandt, Jan Eberth

Faculty Publications

One in every twenty-five persons in America is a racial/ethnic minority who lives in a rural area. Our objective was to summarize how racism and, subsequently, the social determinants of health disproportionately affect rural racial/ethnic minority populations, provide a review of the cancer disparities experienced by rural racial/ethnic minority groups, and recommend policy, research, and intervention approaches to reduce these disparities. We found that rural Black and American Indian/Alaska Native populations experience greater poverty and lack of access to care, which expose them to greater risk of developing cancer and experiencing poorer cancer outcomes in treatment and ultimately survival. There …

A Cluster-Based Approach For Identifying Prognostic Microrna Signatures In Digestive System Cancers, Jun Zhou, Xiang Cui, Feifei Xiao, Guoshuai Cai

Faculty Publications

Cancer remains the second leading cause of death all over the world. Aberrant expression of miRNA has shown diagnostic and prognostic value in many kinds of cancer. This study aims to provide a novel strategy to identify reliable miRNA signatures and develop improved cancer prognostic models from reported cancer-associated miRNAs. We proposed a new cluster-based approach to identify distinct cluster(s) of cancers and corresponding miRNAs. Further, with samples from TCGA and other independent studies, we identified prognostic markers and validated their prognostic value in prediction models. We also performed KEGG pathway analysis to investigate the functions of miRNAs associated with …

Neighborhood Characteristics And The Mental Health Of Caregivers Cohabiting With Care Recipients Diagnosed With Alzheimer’S Disease, Dana M. Alhasan, Jana A. Hirsch, Chandra L. Jackson, Margaret Chandlee Miller, Bo Cai Ph.D., Matthew C. Lohman Ph.D.

Faculty Publications

While studies have documented the influence of caregiver and care recipient factors on caregiver health, it is important to address the potential impact of neighborhood contexts. This study estimated the cross-sectional associations between neighborhood characteristics and mental health among caregivers cohabiting with Alzheimer’s disease care recipients that were experiencing severe or non-severe neuropsychiatric symptoms (NPSs) (e.g., aggression/anxiety). We obtained data collected in 2010 on caregivers and care recipients (n

While studies have documented the influence of caregiver and care recipient factors on caregiver health, it is important to address the potential impact of neighborhood contexts. This study estimated the cross-sectional …

Emergency Department Use Following Incentives To Provide After-Hours Primary Care: A Retrospective Cohort Study., Michael Hong, Amardeep Thind, Gregory S Zaric, Sisira Sarma

Epidemiology and Biostatistics Publications

BACKGROUND: Access to primary care outside of regular working hours is limited in many countries. This study investigates the relation between the after-hours premium, an incentive for primary care physicians to provide services after hours, and less-urgent visits to the emergency department in Ontario, Canada.

METHODS: We analyzed a retrospective cohort of a random sample of Ontario residents from April 2002 to March 2006, and a subcohort of patients followed from April 2005 to March 2016. We linked patient and primary care physician data with emergency department visit data. We used fixed-effects regression models to analyze the association between the …