Degrees of Recommendations and Levels of Evidence: What you Need to Know?

We can define the practice of Evidence-Based Medicine (EBM) as the conscientious, explicit and judicious of the best available evidence in making decisions about care of a patient that requires integration of best evidence with clinical expertise and the values and circumstances of the patient (Figure 1). EBM requires new skills of the clinician, including efficient literature searching, and the application of formal rules of evidence in evaluating the clinical literature [1-16].

Figure 1: Define the practice of EBM.

This practice basically comprises five steps: A1. Converting the need for information in a question structured; A2. Pursue the best clinical evidence to answer this question; A3. Critically evaluate this evidence with respect to its validity, importance and applicability; A4. Integrate critical appraisal with clinical expertise and with the values and circumstances of the patient; A5. Assess the effectiveness and efficiency in performing the steps above. Steps the EBM processes are presented in Table 1.

Table 1: Steps in the EBM process.

The classification of the grade of recommendation corresponds to the strength of scientific evidence of the work and its main objectives: to provide transparency to the origin of the information, stimulate the search for scientific evidence of force majeure, introduce a didactic and simple way to help critical evaluation of the player, who bears the responsibility for making the decisions the patient being treated [2]. The degrees of recommendations are shown in Table 2.

Table 2: The degrees of recommendations. Data extrapolation can use in a situation that is potentially clinically important differences than the original study situation.

Guidelines can deal with clinical issues such as diagnosis, prognosis, intervention, etiology and tracking. With this different research projects are developed, and consequently requires different hierarchies of evidence that recognize the importance of research designs relevant to the purpose of the guideline. Levels of evidence are presented in Figure 2 [2,16-22].

Figure 2: Evidence hierarchy of primary research and secondary.

Clinical trials are given to evaluate the safety and efficacy:

(1) A new product

(2) A new formulation of the same product or combination of products already in use

(3) A new clinical indication for a product already approved.

The assays can evaluate the therapeutic or prophylactic effect. Studies on the etiology are used in order to analyse the probable causes of the various types of diseases. When the perpetrators are discovered (or cause) of a specific disease, these are called "etiologic agents," precisely because they are the bodies responsible for development of a given pathology. Studies of harm are used to verify the effects of harmful agents on the important outcomes for patients [2].

Table 3: Levels of evidence for therapy, prevention, etiology and harm.

Diagnostic tests are invaluable tools used to distinguish between patients having a disease and those who have not. It is essential to be able to critically appraise published articles on a diagnostic test. The list of questions below can help you better appreciate and understand the diagnostic studies better [2]. Table 4 describes the levels of evidence for diagnosis.

Table 4: Levels of evidence.

Prognosis can be defined as the prediction of the future course of a disease after its installation. Patient groups are listed accompanied in time to measure their clinical outcomes [2]. Table 5 describes the levels of evidence for Prognosis.

Table 5: Levels of evidence for prognosis.

Studies on the differential diagnosis are used in patients with a particular clinical presentation to set the frequency of adjacent disturbances [2]. Table 6 describes the levels of evidence for differential diagnosis / symptom prevalence study.

Table 6: Levels of evidence for differential diagnosis / symptom prevalence study.

Economic analysis is a systematic and comparative assessment of the costs and consequences of two or more alternative treatments or programs of action for the promotion and health care. The basic function of an economic analysis is to identify, quantify, assess and compare the costs and consequences of alternatives considered for promotion and health care. The decision analysis to compare two or more decision options and this process involves identifying all available management options, and potential outcomes of each of a series of decisions that have to be made about patient care [2]. Table 7 describes the levels of evidence for Economic and decision analyses.

Table 7: Levels of evidence for economic and decision analyses.

In conclusion, the conscious use of specific best evidence in making decisions, and the use of levels of evidence and grades of recommendations can benefit the patient and improve their clinical practice.