Key concepts for searching evidence: an introduction for healthcare professionals

The currently abundant bibliography on healthcare can make the search process an exhausting and frustrating experience. For this reason, it is essential to learn the basic concepts of research question formulation, information sources, and search strategies to make this process more efficient and user-friendly. The search strategy is an iterative process that allows the incorporation of tools and terms in the strategy design to optimize evidence retrieval. Each strategy varies according to the questions, the language used, the source of information accessed, and the available tools. This article is part of a methodological series of narrative reviews on biostatistics and clinical epidemiology. This narrative review describes the essential elements for developing a literature search strategy and identifying the relevant evidence concerning a clinical question through familiar and accessible sources (such as Google and Google Scholar), as well as search interfaces and technical-scientific databases focused on biomedical knowledge (PubMed and The Cochrane Library).

Respondent-driven sampling: Advantages and disadvantages from a sampling method

This article summarizes the main elements, advantages, and disadvantages of Respondent-driven Sampling (RDS). Some criticisms regarding the feasibility of the inherent assumptions, their point estimators, and the obtained variances are pointed out. This article also comments on the problems observed in the quality of reports. Surveys using RDS should be methodologically sound as they are being applied to define priorities in health programs and develop national and international policies for financing service delivery, among other uses. However, there is considerable potential for bias related to implementation and analytical errors. There is limited empirical evidence on how representative the results obtained by RDS are, and the quest to improve the methodology is still in progress. Nevertheless, to have confidence in RDS results, we must verify that the social structure of the networks conforms to the assumptions required by the theory, that the sampling assumptions are reasonably fulfilled, and that the quality of the report is optimal, particularly for methodological and analytical items.

Perspectives of patients and consumers on the use of generic medicines

INTRODUCTION Access to medicines constitutes a public health challenge worldwide. Promoting utilization of generic medicines is one of the strategies that has been proposed to optimize pharmaceutical spending and thus allow greater coverage. However, its use is not yet widespread enough. This study seeks to explore the perspectives and acceptability to the use of generic medicines from patients and consumers. METHODS We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a evidence synthesis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS We identified four systematic reviews that together include 47 primary studies, of which one corresponds to a randomized trial. A low rate of patients or consumers has a negative perception regarding generic medicines, including dimensions such as risk, quality, safety, risk of adverse effects, among others.

Predictors of recurrence of venous thromboembolic disease after discontinuing of anticoagulation: a prospective cohort study

Objective We aim to evaluate factors associated with the recurrence of thromboembolic episodes among patients with a first episode of venous thromboembolic disease during anticoagulation treatment and at least one year after treatment suspension. Methods A prospective cohort of patients with a first episode of deep vein thrombosis confirmed by Doppler ultrasound and initiated anticoagulation treatment. Participants were registered in the Institutional Registry of Thromboembolic Disease between June 2015 and March 2019. Patients with cancer, with permanent inferior vena cava filter implant, and those who refused to participate or did not provide informed consent were excluded. All patients were evaluated within treatment at 30 days and at least one year after the suspension of anticoagulation with a D-dimer study and an ultrasound. All patients were evaluated for recurrence, bleeding (major and minor), and death. Results A total of 304 patients were recruited during the study period. Seventy-three percent were female, and the median age was 80 years. The rate of recurrence rate during anticoagulation treatment was 5% (N = 16/303; 95% confidence interval: 3 to 8), and 5% during post-suspension follow-up (N = 11/202; 95%CI: 3 to 9). The overall bleeding rate was 13% (N = 39; 95%CI: 9 to 17), and 5% for major bleeding. Patients who recurred had higher basal D-dimer mean, higher neutrophils and monocytes, and a higher prevalence of age-adjusted D-dimer ratio greater than 0.5 before discontinuation. In addition, they more frequently had complete leg involvement by ultrasound and received a shorter treatment. Conclusions Although some baseline and pre-suspension parameters had a higher recurrence incidence, statistical significance was not reached, probably due to small statistical power and a short-term follow-up.

Radiosurgery for brain oligometastases in lung cancer

INTRODUCTION Brain metastases are a common problem in oncology patients, especially in lung cancer. The usual treatment for cerebral oligometastases is whole brain radiation therapy. Given the persistent poor prognosis of this disease, other therapeutic alternatives such as stereotactic radiosurgery have been considered. However, there is no clarity regarding the effectiveness of its addition. METHODS We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS We identified 17 systematic reviews including seven studies overall, of which four were randomized trials. All trials assessed patients with brain oligometastases, but none of them included exclusively lung cancer population. We concluded that it is not possible to clearly establish whether radiosurgery decreases neurological functionality, cognitive impairment, mortality or serious adverse effects, as the certainty of the existing evidence has been assessed as very low.

Cardiac troponins: current information on the main analytical characteristics of determination methods and new diagnostic possibilities

The methods used to diagnose cardiovascular diseases are constantly being improved, leading to an expanded perception of the diagnostic value of biomarkers and their new diagnostic possibilities. One striking example are the main biomarkers used to diagnose acute myocardial infarction: cardiac troponins. The first methods for determining cardiac troponins (proposed 30 years ago) were characterized by extremely low sensitivity. Therefore, they could only detect large acute myocardial infarctions. These methods were also characterized by low specificity, expressed as a high probability of cross-reactivity with skeletal troponin isoforms, which generated false-positive results in the presence of skeletal myopathies and skeletal muscle lesions. With the introduction of high-sensitivity cardiac troponins into clinical practice, the possibility of early diagnosis and exclusion of acute myocardial infarction by assessing troponin concentrations in the first few hours (from admission to the first hour, second hour, or third hour) has become more specific. Our knowledge about cardiac troponins has changed over the years and promising new medical uses have emerged. This paper reviews current data on the diagnostic value of cardiac troponins, the main methods used for their determination, and their analytical characteristics from historical and modern insights.

Clinical and epidemiological characterization in the follow-up of newborns with COVID-19: a descriptive study

Introduction COVID-19 disease affects newborns, but its middle and long-term effects are still unclear. Objective To describe the clinical and epidemiological characteristics and follow-up of newborns infected with SARS-CoV-2. Methods An observational and descriptive study. We included newborns with SARS-CoV-2 positive RT-PCR born from SARS-CoV-2 seropositive mothers. Delivery and newborn care were provided at the 'Instituto Nacional Materno Perinatal' from Peru between June 1 and September 30, 2020. Perinatal information was collected from medical records. Remote follow-up and face-to-face evaluations gathered epidemiological and clinical information, in addition to serological and RT-PCR tests for SARS-CoV-2. Descriptive statistics were used for analysis. Results During the study period, 4733 neonates were born at the institution. We found that 1488 (31.4%) were born from seropositive for SARS-CoV-2 mothers. Finally, we included the 34 (2.3%) newborns with positive RT-PCR for SARS-CoV-2. Regarding the included newborns, 29.4% were delivered by cesarean section, 26.5% had low birth weight, 11.8% were preterm, 26.5% were hospitalized, and one died. Twenty-eight had a remote follow-up, and 18 also had a face-to-face follow-up. A total of 64.3% were exclusively breastfed, 28.6% were mixed breastfed, and 7.1% used a substitute formula. The face-to-face evaluation was performed between one and four months of chronological age. We found that 100% had negative control RT-PCR test for COVID-19, 38.9% had a negative serological test (IgM, IgG), and 61.1% positive IgG. Conclusions Neonatal SARS-CoV-2 infection is rare, and most infected infants are asymptomatic. Vaginal delivery, breastfeeding, and joint isolation did not related with complications during hospital care. Infants under remote and in-person follow-up showed favorable clinical evolution during the study period.

Protective association exhibited by a single nucleotide polymorphism of the IFIH1 gene in patients with psoriasis: A case-control study

Introducción La psoriasis es una dermatosis inflamatoria crónica, con presentación clínica variable y cuya etiología involucra un componente genético importante. Alrededor del mundo se han descrito múltiples variaciones genéticas asociadas a la enfermedad. Sin embargo, en población colombiana se desconocen estas variantes. En este estudio se evalúa el polimorfismo de nucleótido único rs10930046 (His460Arg) en el gen IFIH1 y su asociación con el desarrollo de psoriasis en población colombiana. Además, se caracteriza a los individuos demográfica y clínicamente. Métodos Se realizó un estudio observacional de casos y controles, no pareado, que incluyó 51 individuos con psoriasis y 151 controles poblacionales, todos de ancestría paisa (proveniente de la región de Antioquia) auto reportada. A todos los individuos se les realizó genotipificación del polimorfismo de nucleótido único rs10930046 (His460Arg) en el gen IFIH1 y se les determinó la asociación con la enfermedad. Se caracterizaron demográficamente ambos grupos y los casos clínicamente. Resultados Se encontró que los casos presentaron una menor frecuencia del polimorfismo de nucleótido único rs10930046 (His460Arg) en el gen IFIH1 en relación a los controles, 5 versus 22,67% respectivamente, con un análisis de asociación alélico. No hubo diferencias significativas en edad ni en sexo. La psoriasis vulgar fue la variante de presentación más común (78%). Alrededor de la mitad de los casos presentaron psoriasis ungular (56%), en menor frecuencia artritis psoriásica (19,6%) y el 45% de los casos tuvo alguna comorbilidad. Conclusiones Los resultados obtenidos confirman que los portadores del polimorfismo de nucleótido único rs10930046 (His460Arg) en el gen IFIH1, presentan un riesgo disminuido de desarrollar psoriasis.

Isthmusectomy for well-differentiated thyroid carcinoma located to the isthmus: A report of two cases and review of the literature

Papillary thyroid cancer is the most common endocrine malignancy, and due to its favorable prognosis, the extent of surgery has been a matter of debate. About 10% of these tumors are located in the thyroid isthmus, with no specific management in current guidelines. In the last decades, isthmusectomy has been proposed as a therapeutic option for isthmic papillary thyroid carcinoma, although there is no consensus on its management. We present two cases of patients from our institution with solitary isthmic papillary thyroid carcinoma without clinical macroscopic extrathyroidal extension or clinical-radiological lymph node involvement who were treated with isthmusectomy without prophylactic lymph node dissection. Neither of them had any postoperative complications. Both had an intermediate risk of recurrence due to aggressive variants. None of them had signs of recurrence during follow-up. We intend to show that isthmusectomy seems to be an effective and safe surgical alternative in selected patients through these cases.