Adults' learning of complex explanations violates their intuitions about optimal explanatory order.

Should you first teach about the purpose of a microwave or about how it heats food? Adults strongly prefer explanations to present function before mechanism and information about a whole to precede information about its component parts. Here we replicate those preferences (Study 1). Using the same stimuli, we then ask whether those pedagogical preferences reflect ease of learning of labels, function, or mechanism. Surprisingly, explanations that accord with function-before-mechanism and whole-before-part structure show no learning benefits to participants compared to other participants who see lessons that violate one or both intuitions (Study 2). Even when potential scaffolds are removed (i.e., diagrams) the preferred pedagogical order does not predict better learning (Study 3). Finally, explanatory order has only modest effects on experiential outcomes (e.g., curiosity, frustration; Study 4). In all cases, all orders of presentation support learning in comparison to controls and are not constrained by either ceiling or floor effects. Reasons for the clash between intuitions about learning and actual outcomes are explored.

Etiology of hospital mortality in children living in low- and middle-income countries: a systematic review and meta-analysis.

In 2019, 80% of the 7.4 million global child deaths occurred in low- and middle-income countries (LMICs). Global and regional estimates of cause of hospital death and admission in LMIC children are needed to guide global and local priority setting and resource allocation but are currently lacking. The study objective was to estimate global and regional prevalence for common causes of pediatric hospital mortality and admission in LMICs. We performed a systematic review and meta-analysis to identify LMIC observational studies published January 1, 2005-February 26, 2021. Eligible studies included: a general pediatric admission population, a cause of admission or death, and total admissions. We excluded studies with data before 2,000 or without a full text. Two authors independently screened and extracted data. We performed methodological assessment using domains adapted from the Quality in Prognosis Studies tool. Data were pooled using random-effects models where possible. We reported prevalence as a proportion of cause of death or admission per 1,000 admissions with 95% confidence intervals (95% CI). Our search identified 29,637 texts. After duplicate removal and screening, we analyzed 253 studies representing 21.8 million pediatric hospitalizations in 59 LMICs. All-cause pediatric hospital mortality was 4.1% [95% CI 3.4%-4.7%]. The most common causes of mortality (deaths/1,000 admissions) were infectious [12 (95% CI 9-14)]; respiratory [9 (95% CI 5-13)]; and gastrointestinal [9 (95% CI 6-11)]. Common causes of admission (cases/1,000 admissions) were respiratory [255 (95% CI 231-280)]; infectious [214 (95% CI 193-234)]; and gastrointestinal [166 (95% CI 143-190)]. We observed regional variation in estimates. Pediatric hospital mortality remains high in LMICs. Global child health efforts must include measures to reduce hospital mortality including basic emergency and critical care services tailored to the local disease burden. Resources are urgently needed to promote equity in child health research, support researchers, and collect high-quality data in LMICs to further guide priority setting and resource allocation.

A right way to explain? Function, mechanism, and the order of explanations.

People generally prefer functional explanations over mechanistic ones. This preference might arise from attributing greater value to functional information. However, instead of an overall preference for functional explanations, people might simply expect functional information to precede mechanistic information. Here, we ask whether people have such preferences for the order of functional and mechanistic information in explanations and how those preferences might arise. In a first set of studies, we show that adults do in fact prefer functional information to precede mechanistic. In a second set of studies, we show that people have a more general preference for explanations to address the whole before parts. Finally, we show that the preference for function to precede mechanism may be related to the broader whole-before-parts preference.

The Burden of Critical Illness in Hospitalized Children in Low- and Middle-Income Countries: Protocol for a Systematic Review and Meta-Analysis.

Background: The majority of childhood deaths occur in low- and middle-income countries (LMICs). Many of these deaths are avoidable with basic critical care interventions. Quantifying the burden of pediatric critical illness in LMICs is essential for targeting interventions to reduce childhood mortality. Objective: To determine the burden of hospitalization and mortality associated with acute pediatric critical illness in LMICs through a systematic review and meta-analysis of the literature. Data Sources and Search Strategy: We will identify eligible studies by searching MEDLINE, EMBASE, CINAHL, and LILACS using MeSH terms and keywords. Results will be limited to infants or children (ages >28 days to 12 years) hospitalized in LMICs and publications in English, Spanish, or French. Publications with non-original data (e.g., comments, editorials, letters, notes, conference materials) will be excluded. Study Selection: We will include observational studies published since January 1, 2005, that meet all eligibility criteria and for which a full text can be located. Data Extraction: Data extraction will include information related to study characteristics, hospital characteristics, underlying population characteristics, patient population characteristics, and outcomes. Data Synthesis: We will extract and report data on study, hospital, and patient characteristics; outcomes; and risk of bias. We will report the causes of admission and mortality by region, country income level, and age. We will report or calculate the case fatality rate (CFR) for each diagnosis when data allow. Conclusions: By understanding the burden of pediatric critical illness in LMICs, we can advocate for resources and inform resource allocation and investment decisions to improve the management and outcomes of children with acute pediatric critical illness in LMICs.

Pulmonary Embolism as the Initial Presentation of Coronavirus Disease 2019 in Adolescents.

The current coronavirus disease 2019 pandemic has been particularly challenging for the clinician because of the unclear nature of the underlying disease mechanisms. One of the hallmarks of the disease involves an increased risk of thrombosis and hypercoagulable state. Here, we describe 2 cases of patients admitted with submassive pulmonary embolism in the setting of positive tests for severe acute respiratory syndrome coronavirus 2.