Scientifc valid evidence may be acquired from a number of studies capable of supporting or denying a theory about a healthcare treatment, a diagnostic intervention, or about the frequency of occurrence of a health event. However, the translation of scientifc knowledge into decisions in healthcare requires methodological expertise and comprehension of the potentials and limitations of each type of evidence. In this chapter, we invite the readers to think more scientifcally in their daily practice. We didactically discuss relevant aspects related to the clinical question and study design, and we use this discussion to guide the reader to an improved comprehension of how to use systematic reviews in the context of evidence-based healthcare. Finally, we present some tools and resources to help professionals to search for qualifed and preapraised evidence to inform their clinical decisions.

Primary lung cancer is the leading cause of cancer mortality in the world and its incidence is expected to rise in the next several decades, especially in more recently industrialized countries such as China. This high mortality is largely explained by the fact that patients with lung cancer often present with advanced stage disease. Imaging is important in the early detection and clinical staging of lung cancer. Indeed, both the therapeutic options and the management of patients with lung cancer are to a considerable degree dependent upon disease stage at presentation. Detailed knowlegde and the appropriate use of imaging in the staging evaluation of patients with non-small cell lung cancer (NSCLC) are required to avoid unnecessary procedures, excess radiation, and redundant information. This is facilitated by the use of guidelines as well as the participation of multidisciplinary teams in which radiologists, pathologists, pulmonologists, surgeons, and medical and radiation oncologists discuss and reach a consensus on individualized imaging and treatment. The main objective of this chapter is to review the basic concepts related to the detection, staging, and follow-up of patients with NSCLC.

Periodontal disease, or periodontitis, is a globally widespread pathology of the human oral cavity. Indeed, approximately 10% of the global adult population is highly vulnerable to severe periodontitis. Another 10–15% appears to be completely resistant to it, while the remainder vary between these two extremes . Moreover, the prevalence of periodontitis is peaking at the fourth decade of life and increasing to 70–85% in the age group of 60–65 . Strikingly, despite major improvements in oral hygiene practices today, these proportions are not far from what was reported in possibly the frst epidemiological report of periodontitis in humans back in 1918 (then defned as periodontoclasia or pyorrhea alveolaris). According to that, the prevalence of the disease in the Chicago area was 13% in the age range of 20–24, 68% in 30–39, and 88% over 50. Much recent data from USA showed that there is not a drop but rather an increase in these numbers among the older individuals . That means that periodontitis is an inevitable oral pathology of the human population, and its prevalence increases with age. Taking also underconsideration the increasing life expectancy, periodontitis is a growing health problem. Despite the persistence of severe periodontitis even in the twenty-frst century, the last 100 years have witnessed a signifcant progress in our understanding of its pathogenesis, that is, the conglomerate of biological processes that lead to the disease. Nevertheless, the actual “coordinator(s) ”of the disease is still an issue of intense debate. Microbiology researchers place emphasis in seeking species, or combinations of them, associated with different clinical forms of the disease. On the other side, immunologists are in pursuit of cells and molecules that orchestrate the tissue-destructive inflammation, as a result of the bacterial challenge.