How do physicians respond to new medical research?

What happens when the findings of a prominent medical study are overturned? Using a medical trial on breech births, we estimate the effect of the reversal of such a medical study on physician choices and infant health outcomes. Using the United States Birth Certificate Records from 1995 to 2010, we employ a difference-in-differences estimator for C-sections, low Apgar, and low birth weight measures. We find that the reversal of a multi-site, high profile, randomized control trial on the appropriate delivery of term breech births, the Term Breech Trial, led to a 15%-23% decline in C-sections for such births at a time when the overall trend in C-sections was rising. We find our largest estimated effects amongst traditionally disadvantaged groups (i.e., non-white, and minimal education). However, we do not find that such a change in practice had significant impacts on infant health. Contrary to prior studies, we find that physicians updated their beliefs quickly, and do indeed adjust to new medical research, particularly young physicians, prior to mandatory policy or professional guidelines.

Multivariate extension of penalized regression on summary statistics to construct polygenic risk scores for correlated traits.

Genetic correlations between human traits and disorders such as schizophrenia (SZ) and bipolar disorder (BD) diagnoses are well established. Improved prediction of individual traits has been obtained by combining predictors of multiple genetically correlated traits derived from summary statistics produced by genome-wide association studies, compared with single trait predictors. We extend this idea to penalized regression on summary statistics in Multivariate Lassosum, expressing regression coefficients for the multiple traits on single nucleotide polymorphisms (SNPs) as correlated random effects, similarly to multi-trait summary statistic best linear unbiased predictors (MT-SBLUPs). We also allow the SNP contributions to genetic covariance and heritability to depend on genomic annotations. We conducted simulations with two dichotomous traits having polygenic architecture similar to SZ and BD, using genotypes from 29,330 subjects from the CARTaGENE cohort. Multivariate Lassosum produced polygenic risk scores (PRSs) more strongly correlated with the true genetic risk predictor and had better discrimination power between affected and non-affected subjects than previously published sparse multi-trait (PANPRS) and univariate (Lassosum, sparse LDpred2, and the standard clumping and thresholding) methods in most simulation settings. Application of Multivariate Lassosum to predict SZ, BD, and related psychiatric traits in the Eastern Quebec SZ and BD kindred study revealed associations with every trait stronger than those obtained with univariate sparse PRSs, particularly when heritability and genetic covariance depended on genomic annotations. Multivariate Lassosum thus appears promising to improve prediction of genetically correlated traits with summary statistics for a selected subset of SNPs.

Evaluation of an interprofessional primary healthcare team as a new model of primary care in Quebec: a protocol for a type 2 effectiveness-implementation hybrid study.

INTRODUCTION: One family medicine group (FMG) in Quebec has commenced a 5-year pilot project, which is herein referred to as the Archimède model, to implement a patient-centred model based on interprofessional care and the optimal use of healthcare providers' practice scopes. A research project will be conducted to: (1) assess this model's effect on the FMG's operational performance, and its users' resource utilisation at the public health system level; (2) investigate its optimisation with respect to professional roles, interprofessional teamwork and patient-centredness and (3) document users' experience with the model. The aim of this article is to describe the protocol that will be used for this research. METHODS AND ANALYSIS: A hybrid implementation approach (type 2 model) will be used. We will collect both quantitative and qualitative data. Regarding the quantitative dimension, and because this is a single-unit intervention study, we will use either or both synthetic control methods and one-sample generalised linear models for analyses at the FMG level. To evaluate the broader impact of Archimède on the public health system, we will use mixed-effects models and propensity score matching methods. Regarding the qualitative research dimension, using an interpretative descriptive approach, we will document users' experience and identify the factors that optimise professional scopes of practice, collaborative practices and patient-centredness. We will conduct individual in-depth semistructured interviews with healthcare providers, administrative staff, stakeholders involved in the Archimède model implementation and patients. ETHICS AND DISSEMINATION: This study was approved by the Ethics Committee of the Sectoral Research in Population Health and Primary Care of the Centre intégré universitaire de santé et de services sociaux de la Capitale-Nationale (#2019-1503). The results of the investigation will be presented to the stakeholders involved in the advisory committees and at several scientific conferences. Manuscripts will be submitted to peer-reviewed journals.

Public drug insurance, moral hazard and children's use of mental health medication: Latent mental health risk-specific responses to lower out-of-pocket treatment costs.

Studies have shown that reducing out-of-pocket costs can lead to higher medication initiation rates in childhood. Whether the cost of such initiatives is inflated by moral hazard issues remains a question of concern. This paper looks to the implementation of a public drug insurance program in Québec, Canada, to investigate potential low-benefit consumption in children. Using a nationally representative longitudinal sample, we harness machine learning techniques to predict a child's risk of developing a mental health disorder. Using difference-in-differences analyses, we then assess the impact of the drug program on children's mental health medication uptake across the distribution of predicted mental health risk. Beyond showing that eliminating out-of-pocket costs led to a 3 percentage point increase in mental health drug uptake, we show that demand responses are concentrated in the top two deciles of risk for developing mental health disorders. These higher-risk children increase take-up of mental health drugs by 7-8 percentage points. We find even stronger effects for stimulants (8-11 percentage point increases among the highest risk children). Our results suggest that reductions in out-of-pocket costs could achieve better uptake of mental health medications, without inducing substantial low-benefit care among lower-risk children.

Association between child welfare reporting rates and the developmental vulnerability of kindergarten children at the neighborhood level.

BACKGROUND: In Canada, more than one in four children are considered vulnerable in at least one domain of development when they enter kindergarten. Recent studies have suggested that this ratio is higher among those who were previously maltreated. However, little is known about this associations at the neighborhood level, although it may be an interesting way to identify risk areas and highlight child welfare system data to prevent public health issues. OBJECTIVE: Using the census tract as the unit of measurement, this study examines the association between the proportions of vulnerable children in different domains of development upon entering kindergarten, and four indicators of child maltreatment (CM) among 0-5 year olds. PARTICIPANTS, SETTING AND METHOD: This study is based on the secondary use of data from a survey on the development of kindergartners carried out in 2017, combined with data from child welfare records for that same year. The data have been aggregated on the basis of 759 census tracts located in four health regions of Quebec, Canada. RESULTS: The results of spatial regression analyses show that all indicators of maltreatment are positively and significantly associated with each indicator of developmental vulnerability. The size of these associations varies according to the indicators used (ß = 0.192, p < .05 to ß = 1.587, p < .001). CONCLUSION: The results highlight the link between CM and school readiness, including potential externalities on neighborhood children. Neighborhoods at high risk of maltreatment could help identify areas with high rate of vulnerable children in early childhood.

For a structured response to the psychosocial consequences of the restrictive measures imposed by the global COVID-19 health pandemic: the MAVIPAN longitudinal prospective cohort study protocol.

INTRODUCTION: The COVID-19 pandemic and associated restrictive measures have caused important disruptions in economies and labour markets, changed the way we work and socialise, forced schools to close and healthcare and social services to reorganise. This unprecedented crisis forces individuals to make considerable efforts to adapt and will have psychological and social consequences, mainly on vulnerable individuals, that will remain once the pandemic is contained and will most likely exacerbate existing social and gender health inequalities. This crisis also puts a toll on the capacity of our healthcare and social services structures to provide timely and adequate care. The MAVIPAN (Ma vie et la pandémie/ My Life and the Pandemic) study aims to document how individuals, families, healthcare workers and health organisations are affected by the pandemic and how they adapt. METHODS AND ANALYSIS: MAVIPAN is a 5-year longitudinal prospective cohort study launched in April 2020 across the province of Quebec (Canada). Quantitative data will be collected through online questionnaires (4-6 times/year) according to the evolution of the pandemic. Qualitative data will be collected with individual and group interviews and will seek to deepen our understanding of coping strategies. Analysis will be conducted under a mixed-method umbrella, with both sequential and simultaneous analyses of quantitative and qualitative data. ETHICS AND DISSEMINATION: MAVIPAN aims to support the healthcare and social services system response by providing high-quality, real-time information needed to identify those who are most affected by the pandemic and by guiding public health authorities' decision making regarding intervention and resource allocation to mitigate these impacts. MAVIPAN was approved by the Ethics Committees of the Primary Care and Population Health Research Sector of CIUSSS de la Capitale-Nationale (Committee of record) and of the additional participating institutions. TRIAL REGISTRATION NUMBER: NCT04575571.

Local inequality and departures from publicly provided health care in Canada.

This paper examines the relationship between changes in income inequality and the provision of resources in a health care system (the public-private mix). Specifically, we investigate whether increases in income inequality, as separate from overall income levels and growth, have changed the availability of both private clinics and privately financed physicians in a context where the dominant market player is the public system. Our findings provide reasonable evidence that increases in income inequality have led to substantial increases in both. We find that moving from median level of inequality across neighborhoods to the top 1% level of inequality increases the probably of a private clinic by 40% and the probability of having physicians who have opted out of the public system by 170%.

Rising inequality and the implications for the future of private insurance in Canada.

Income and wealth inequality have risen in Canada since its low point in the 1980s. Over that same period we have also seen an increase in the amount that Canadians spend on privately financed health care, both directly and through private health insurance. This paper will explore the relationship between these two trends using both comparative data across jurisdictions and household-level data within Canada. The starting hypothesis is that the greater the level of inequality the more difficult it becomes for publicly provided insurance to satisfy the median voter. Thus, we should expect increased pressure to access privately financed alternatives as inequality increases. In the light of these implications, the paper considers the implications for the future of private insurance in Canada.