Clinical practice guidelines are the most important documents for the incorporation of scientific evidence in health decision making through the formulation of recommendations. There is a variable terminology used to refer to the documents that guide health professionals in decision making. When clinical practice guidelines are of high quality, they appraise contextual aspects such as the use of resources, applicability, and patients values and preferences. Even so, they are not recipe books, since they may have limitations. In this review, we propose to clarify the different denominations across the various types of documents available to guide the health professional when making clinical decisions. We discuss the main characteristics of clinical practice guidelines, quality assessment, challenges, and limitations.

Observational studies evaluate variables of interest in a sample or a population, without intervening in them. They can be descriptive if they focus on the description of variables, or analytical when comparison between groups is made to establish associations through statistical inference. Cross-sectional studies and ecologicalalso called correlationalstudies are two observational methodological designs. Cross-sectional studies collect the data of the exposure variable and the outcome at the same time, to describe characteristics of the sample or to study associations. Ecological studies describe and analyze correlations among different variables, and the unit of analysis is aggregated data from multiple individuals. In both types of studies, associations of interest for biomedical research can be established, but no causal relationships should be inferred. This is the second of a methodological series of articles on general concepts in biostatistics and clinical epidemiology developed by the Chair of Scientific Research Methodology at the School of Medicine, University of Valparaíso, Chile. In this review, we address general theoretical concepts about cross-sectional and ecological studies, including applications, measures of association, advantages, disadvantages, and reporting guidelines. Finally, we discuss some concepts about observational designs relevant to undergraduate and graduate students of health sciences.

Aging is a physiological process accompanied by cognitive decline, principally in memory and executive functions. Alterations in the connectivity of the default mode network (DMN) have been found to participate in cognitive decline, as well as in several neurocognitive disorders. The DMN has antisynchronic activity with attentional networks (task-positive networks (TPN)), which are critical to executive function and memory. Findings pointing to the regulation of the DMN via activation of TPN suggest that it can be used as a strategy for neuroprotection. Meditation is a noninvasive and nonpharmacological technique proven to increase meta-awareness, a cognitive ability which involves the control of both networks. In this review, we discuss the possibility of facilitating healthy aging through the regulation of networks through meditation. We propose that by practicing specific types of meditation, cognitive decline could be slowed, promoting a healthy lifestyle, which may enhance the quality of life for the elderly.

A body of evidence indicates an association between ultraprocessed foods (UPFs) and health outcomes. Most of it has been obtained through preclinical studies, although a number of observational studies substantiate how a high intake of these products increases the risk of neuropsychiatric disorders, and an increasing amount of dietary intervention studies confirm these findings. The aim of this narrative review is to describe some of the putative mechanisms involved in the deleterious effects of a high intake of UPFs on neuropsychiatric outcomes. A myriad of unhealthy actions may be associated with the consumption of UPFs, and some mechanisms are being discussed. They include UPFs’ high caloric density; their high sugar, sodium, and additives content and low amounts of fiber; and a high palatability that induces overconsumption, acting as obesogens. Moreover, thermal treatment of these foods generates oxidative products such as glycotoxins, lipotoxins, and acrolein, all of which affect the brain. The chemical products act, directly or indirectly, on the gut microbiome and affect the gut–brain axis, causing neuroinflammation, oxidative stress, and neurodegeneration. UPFs also exert various epigenetic effects that affect mental health and might explain the intergenerational inheritance of neuropsychiatric disorders. A diet containing a high proportion of these foods has a low nutritional density, including bioactive protective agents such as antioxidant and anti-inflammatory compounds that promote eubiosis. The evidence shows that UPFs intake affects neuropsychiatric outcomes such as neurodegeneration, cognitive decline, dementia, and mood disorders and reinforces the need to promote a healthy dietary pattern throughout all life stages, thus interfering with the current commercial determinants of health.

Cohort studies evaluate the relationship between exposure to a specific event or phenomenon and the occurrence of an associated out-come of interest (or lack thereof). This methodological design has been widely used in certain areas of medicine, such as the study of cardiovascular risk factors and the effects of ionizing radiation in humans. It is a useful study design, especially for research involving low-occurrence exposures, because it can be easily adapted to various contexts. This article, which provides an overview of observational cohort studies, is part of a methodology series on general concepts in biostatistics and clinical epidemiology developed by the Chair of Scientific Research Methodology at the University of Valparaísos School of Medicine in Chile. It describes historical, practical, and theoretical concepts related to cohort studies; essential elements in cohort study design, and variations and derivations of it; potential types and sources of bias in these types of observational/longitudinal studies, and various methods researchers can use to address/minimize them.

Introduction Chile has an incipient policy regarding humanized birth practices. Obstetric violence is becoming an issue in the public discussion, as brought up by women. Despite this advancement, no initiatives were observed to overcome the conflict. Questions arise from the different points of view of the main stakeholders involved. These questions help identify strategies contributing to the development of health policies that consider influencing actors. Objectives To identify stakeholders' perceptions of humanized care in childbirth and obstetric violence. Methods We conducted a scoping review that included articles and analysis of texts reflecting the scientific communities' point of view. We included statements from governmental, social, professional, and political actors as expressed in institutional websites. Moreover, we performed a qualitative inductive, thematic content analysis. Results We included seventy documents. The scientific community is visualized as aligned with ministerial recommendations for personalized childbirth. Several researchers analyze the difficulties for its improvement due to the historical, socio-cultural, and economic construction of the predominantly biomedical model for birthing. Convergence is observed among the scientific community and other stakeholders in recognition of humanized birth benefits and the need to overcome institutional obstacles within the health sector. However, the progress of the proposed change is slow, and health professionals' resistance to address women's complaints towards obstetric violence and claim of quality care is observed. This discussion finds its reflection in a parliamentary discussion. Conclusions The stakeholders' analysis reflects areas of conflict and consensus, as well as the diverse interacting dimensions that hinder the advance of humanized care in childbirth. This broad analysis strategy contributes to identifying critical aspects to be addressed in the development of integral and effective health policies.