ORB 117: Introduction to Scientific Research - Fall Semester 2022 PDF

ORB - 117 PICO: Asking Good Clinical Questions and Finding the Evidence Sonia M. Rocha-Sanchez M.S., Ph.D., M.B.A. Fall Semester 2022  The PICO Model for Clinical Questions Asking the right question is a difficult skill...

ORB - 117 PICO: Asking Good Clinical Questions and Finding the Evidence Sonia M. Rocha-Sanchez M.S., Ph.D., M.B.A. Fall Semester 2022  The PICO Model for Clinical Questions Asking the right question is a difficult skill to learn yet is fundamental to evidence-based practice. The process almost always begins with a patient question or problem. A “well-built” question should include four parts, referred to as PICO, that identify the patient or population (P) problem, Intervention (I), comparison (C), and outcome(s) (O). How to Effectively Use PICO The PICO Model for Clinical Questions P Patient or Population How would I describe a group of patients similar to mine? I Intervention, Prognostic Factor, or Which main intervention, prognostic factor, or Exposure exposure am I considering? C Comparison or Intervention (if What is the main alternative to compare with appropriate) the intervention? O Outcome you would like to measure or What can I hope to accomplish, measure, achieve improve, or affect? What Type of question are you asking? Diagnosis, Etiology/Harm, Therapy, Prognosis, Prevention Type of Study you want to find What would be the best study design/methodology? Say Hello to Gail! Say Hello to Gail! During examination, you find that: o There is no infection or oral lesions and verify that she doesn’t have Sjogren syndrome. o Gail’s medical history and discuss her most recent medication regimen. o Her current medication is the most accurate evidence-based treatment appropriate for her conditions. o You conclude that the dry mouth is caused from the side effects of her antidepressants and pain medications. o Knowing she cannot discontinue the use of her current medications and that she has already tried gum and lozenges, you set out to find a solution for Gail. Defining a clinical question in terms of the specific patient problem will help you finding clinically relevant evidence in the literature and gather the information needed to make the right decision at the right time. That’s when PICO becomes your best friend!  First, the question should be directly relevant to the problem at hand. How to Second, it should be phrased to facilitate Effectively searching for a precise answer Use PICO Third, it should be focused and well- articulated Fourth, it should contain all four PICO elements Background and Foreground Questions Background questions are general knowledge inquiries that ask who, what, where, when, how, or why. o They’re used to help narrow a broad scope and search about a topic  Background questions are helpful in identifying articles that provide more specific details that can be used in developing foreground (PICO) questions.  Finding a good article that reviews the management of a problem often provides the necessary details to structure a well-built question o They may be necessary to identify specific interventions for a disease or problem or to learn more about one particular disorder, intervention, or drug therapy that you may not be familiar with. Background and Foreground Questions Example of background questions for Gail’s specific situation include: o What causes xerostomia? o What minimizes drug-induced dry mouth? o What are saliva substitutes? o What are saliva stimulants? o What are specific saliva substitutes that are effective for decreasing dry mouth? o What are specific saliva stimulants that are effective for decreasing dry mouth? o How are xerostomia patients managed? o What are the suggested therapies for drug-induced xerostomia? Often these questions can best be answered by consulting a research data base (e.g., PUBMED, GoogleScholar) or using a textbook. Background and Foreground Questions Foreground Questions – Arises from an observed problem, a patient question, to explore a new material or procedure, to clarify differences, or compare cost-effectiveness. o They are normally specific question that are structured in such a way to find a precise answer that may affect clinical decisions. o These are the questions that generally require a search of the medical literature and are best suited for the PICO format. A foreground question in Gail’s case may be: “For a patient with drug-induced dry mouth, will saliva substitutes as compared to saliva stimulants increase salivary flow and decrease dry mouth?” o Although saliva substitutes and saliva stimulants are very broad topics, the fact that you started your search by looking at background information/questions will make it easier to narrow down the terms to specific therapy (as in the question above). Summary of Differences Between Background and Foreground Questions Background Questions Foreground Questions General knowledge, broad Specific Ask who, what, where, when, how, or Identify P.I.C.O. why Help narrow a broad scope Structured to find a precise answer and phrased to facilitate an on-line search Identify articles that provide more Identify valid evidence to answer a specific details to a broad question specific question  The PICO Process One of the greatest difficulties in developing each aspect of the PICO question is providing an adequate amount of information without being too detailed. It is important to stay focused on the main components that directly affect the situation. The formality of using PICO to frame the question serves three key purposes: o It forces you to focus on what the patient believes to be the most important single issue and outcome. o It facilitates the next step in the process, the on-line search, by selecting language or key terms that will be used in the search. o It forces a clear identification of the problem, results and outcomes related to the specific care provided to that patient. This, in turn, o helps to determine the type of evidence and information required to solve the problem and to measure the effectiveness of the intervention.  The PICO Process Asking the right question is perhaps the hardest skill to learn, and yet it is fundamental to the EBD process PICO Components for Gail and Three Additional Patients Examples Patient/Population Intervention Comparison Outcome Gail Drug-induced xerostomia or Pilocarpine Bethanechol Increase salivary flow xerostomia or drug-induced dry and decrease her mouth or dry mouth perception of dry mouth Malory Burning mouth syndrome Antidepressants Alpha-lipoic acid Prevent or minimize the burning sensation on the lips, tongue, or in the mouth Gavin Tetracycline staining Chairside bleaching At-home Decrease stain and Professional increase tooth bleaching whiteness Logan Moderate plaque Powered toothbrush Manual Remove plaque toothbrush  The PICO Process P: Patient/Population (Medical condition) The first step in developing a well-built question is to identify the patient problem or population. This is done by describing either the patient’s chief complaint or by generalizing the patient’s condition to a larger population. It’s helpful to consider the following when identifying the P in PICO: - How would you describe a group/population with a problem similar to your patient? - How would you describe the patient/population to a colleague? - What are the most important characteristics of this patient/population? o Primary problem underlying patient chief complaint o Patient’s main concern or chief complaint o Disease (including severity) or health status o Age, race, gender, previous ailments, current medications o Should these characteristics be considered as a search for evidence?  The PICO Process P: Patient/Population (Medical condition) For some questions, it may be most appropriate to identify a general population instead of focusing on a patient or chief complaint. - Example of populations that may be investigated for a specific case are dental educators, dentists, menopausal women, pregnant women, etc. In Gail’s case, with a specific question, we do want to be specific. The P in PICO, on this situation, will stand for “Patient Problem,” which can be described as “drug-induced xerostomia,” “xerostomia,” “drug-induced dry mouth,” or “dry mouth.” The P phrase could be more detailed if the added information influences the results of the search. Additional items may include age, gender, health history, or medications. - For example, it may be necessary to define the patient as an adult in the case of periodontitis or a middle- aged female if the results are regarding postmenopausal women.  The PICO Process I: Intervention It is important to identify what you plan to do for a patient. This may include the use of a specific diagnostic test, treatment, adjunctive therapy, medication, or the recommendation to the patient to use a product or procedure. The intervention is the one main consideration for that patient. In Gail’s case, the main intervention to consider could be pilocarpine based on the findings from the background question.  The PICO Process C: Comparison It’s the main intervention/alternative being considered. It should be specific and limited to one alternative to facilitate an effective on-line search. The comparison is the only optional component in the PICO question. Often, one may only look at the intervention without exploring alternative. The comparison can be the golden standard, specially if a new therapy is being considered. For Gail, a comparison could be bethanechol.  The PICO Process O: Outcome The outcome specifies the result(s) of what you plan to accomplish, improve, or affect. Outcomes should be measurable and may consist of relieving or eliminating specific symptoms, improving or maintain function, or enhancing esthetics. Specific outcomes also will yield better search results. When defining the outcome, “more effective” is not acceptable unless it describes how the intervention is more effective (e.g., more effective in decreasing caries incidence or more effective in preventing tooth fractures). The outcome that we are hoping to achieve for Gail is to increase salivary flow and decrease her perception of dry mouth. Writing The PICO Question Patient/Population Insert the patient’s chief complaint or condition. Gail’s PICO question could start with: “drug-induced xerostomia” or “xerostomia” or “drug-induced dry mouth” or “dry mouth”. (what you plan to accomplish) Writing The PICO Question Patient/Population Insert the main intervention being considered for the patient. For Gail it could be “Pilocarpine” (what you plan to accomplish) Writing The PICO Question Patient/Population The comparison is stated as “compared to” the main alternative given that there is one. Gail’s question now would read as: “In a patient with xerostomia will pilocarpine as compared with bethanechol. (what you plan to accomplish) Writing The PICO Question Patient/Population The outcome(s) are then phrased as the result you would like to happen. In Gail’s case the final PICO question would read as “In a patient with (what you plan to accomplish) xerostomia will pilocarpine as compared with bethanechol increase salivary flow and decrease dry mouth?” Writing The PICO Question Patient/Population We’ll look into the relationship between the type of questions and the type of studies later. (what you plan to accomplish) For now, let’s focus on the questions.  The four Types of PICO Questions Identifying the type of question being asked facilitates understanding the type of research studies that will best answer the question. o Therapy/Prevention questions look for an answer that determine the effect of treatments that avoid adverse events improve function and are worth the effort and cost. Gail’s question is an example of a therapy question. o Diagnosis questions look for evidence to determine the degree to which a test, intervention or diagnostic method is reliable and useful. The selection and interpretation of diagnostic methods or tests that establish the power of an intervention to differentiate between those with and without a target condition or disease is the aim of diagnosis questions Ex.: In a 55-year-old woman with pain, swelling, and stiffness in the hands and wrists, will a red blood cell test that measures erythrocytes sedimentation rate as compared with C-reactive protein test most accurately identify rheumatoid arthritis (RA)? The four Types of PICO Questions o Harm, etiology, causation questions are used to identify causes of a disease or condition including iatrogenic forms and to determine relationships between risk factors, potentially harmful agents, and possible causes of a disease or condition. Ex.: In a woman with RA, does cardiovascular disease increase the likelihood of death? o Prognosis questions look for studies that estimate the clinical course or progression of a disease or condition over time and anticipate likely complications (and prevent them). Ex.: In a 55-year-old woman will severe RA cause loss of fine motor skills, eliminating her ability to crochet? Research Design And Source of Evidence Sources of Evidence Scientific evidence is the product of well-designed and well-controlled research investigations that minimize sources of bias. o Evidence is considered the synthesis of all valid research studies that answer a specific question. o A single research study does not constitute “the evidence,” but rather contributes to a body of knowledge that has been derived from multiple studies investigating the same phenomena. o The body of evidence evolves over time as more research is conducted, underscoring the importance of staying current with the scientific literature. o The evidence can help inform decisions about whether a method of diagnosis or a treatment is effective relative to other diagnostic methods or treatment and under what circumstances. o There’re two types of evidence-based sources: Primary and secondary. Sources of Evidence Primary sources are original research publications that have not been filtered or synthetized (e.g., individual research articles). o Primary research consists of both quantitative/analytical and qualitative/descriptive research. o Most of the research and literature related to EBD refers to quantitative/analytical research o Quantitative/analytical research focuses on establishing cause-and-effect relationships through testing a specific hypothesis and reporting the results in statistical terms. o Qualitative/descriptive research is exploratory and uses an interpretative, naturalistic approach that focuses on how individuals or groups view and understand their surroundings and construct meaning out of their experiences. o Qualitative research investigates the why and how of decision making. Data are typically reported using narrative terms and not displayed mathematically. Quantitative/Analytical Primary Research Experimental or Nonexperimental Experimental studies are those in which the researcher controls or manipulates the variable under investigation (e.g., as when testing the effectiveness of a treatment).  These studies are the among some of most complex and include randomized controlled trials, (nonrandomized) controlled trials, and uncontrolled trials. Randomized controlled trial (RCT) provides the strongest evidence for demonstrating cause and effect relationships (i.e., the treatment has caused the effect, rather than it is happening by chance). An RCT study design involves the following:  At least one experimental and one control treatment that can be a placebo or no treatment.  Concurrent enrollment of subjects for the entire study  Random assignment of subjects to either the experimental group or the control/placebo group  Follow-up of both groups at completion of the study to determine the outcome. The most important characteristics of RCTs are the ability to randomly assign subjects to either the experimental or control group and to randomly allocate treatments. Other unique features of RCTs that reduce bias and strengthen validity are that they are prospective in nature and can include blind or double-blind strategies. Quantitative/Analytical Primary Research: Experimental Studies RCTs can be: Double-blinded: The best and most reliable form of research.  It keeps both researchers and participants in the dark as to who is receiving which (intervention or placebo) treatment.  Eliminate the power of suggestion. Single-blinded: The researchers, but not the study participants, know which treatment has been allocated. Open label: An open label trial is type of clinical trial in which information is not withheld from trial participants. Quantitative/Analytical Primary Research: Experimental Studies Controlled Trials often rely on historical controls that cannot establish true equivalence so that there is less confidence in the findings.  For example, in a cancer research, patients receive a new treatment, and their responses are compared with controls from previous studies. The controls may not provide a good comparison depending on how long ago the study was conducted, or differences in treatment, technology, and even changes in patient care since that first study. Controlled Trials also are used to screen new therapies or new diagnostic studies.  The purpose is not to prove the treatment is efficacious, but that there is sufficient activity to be tested in a randomized study.  The outcomes from a new test under evaluation are compared with outcomes from the reference or gold standard (i.e.., the test or measure considered the ultimate or ideal). These studies require fewer patients; They are subject to investigator and placebo bias because all patients are treated in an unblinded manner. Quantitative/Analytical Primary Research: Experimental Studies In controlled trials, there is no (or at least no true) randomization. Controlled trials can be: Quasi-randomized: It is a method of allocating participants to different forms of care/research groups that is not truly random; for example, allocation by date of birth, day of the week they’ll be seen, medical record number, month of the year, or the order in which participants are included in the study (alternation). Non-randomized: A study in which the participants are not assigned by chance to different treatment/research groups. Participants may choose which group they want to be in, or they may be assigned to the groups by the researchers. Quantitative/Analytical Primary Research: Experimental Studies Uncontrolled trials are defined as trials with one single treatment group during which all patients receive the same intervention. They can be:  Before-After studies: Measures outcomes in a group of participants before introducing a product or other intervention, and then again afterwards. Any changes in the outcomes are attributed to the product or intervention.  Time series: Longitudinal research design that involve single research subjects or variables measured repeatedly at regular intervals over time. Quantitative/Analytical Primary Research: Nonexperimental Studies Nonexperimental Studies in which the researcher does not give a treatment, intervention, or provide an exposure (i.e., data is gathered without intervening to control variables).  Examples of nonexperimental studies include cohort studies, case-control studies, cross-sectional studies, case series, and case reports. Cohort studies make observations about the association between a particular exposure or a risk factor (e.g., tobacco use) and the subsequent development of a disease or condition (e.g., lung cancer). As in experimental studies, both groups are followed prospectively and there is the ability to establish a temporal sequence for the relationship between exposure to risk factor and development of a particular disease or condition. Quantitative/Analytical Primary Research: Nonexperimental Studies – Cohort Studies Persons with and without the Prospective Cohort Study 2022 exposure of interest (e.g., tobacco) are identified at the beginning of the study. Information is then collected Design looking forward in the time to identify outcomes (i.e., disease [lung cancer] or no disease). At the start of the study, neither group has the disease or condition of interest. Quantitative/Analytical Primary Research: Nonexperimental Studies The important advantage of this design is the ability to control and monitor data collection and to measure variables accurately. A cohort study is most useful when the disease/condition of interest occurs frequently, and subjects can be readily recruited. It also is useful when the risk factors are known or thought to cause harm (e.g., tobacco use) and when there are ethical considerations. Obvious disadvantages are the time it could take to develop the disease or condition of interest (e.g., lung cancer), the cost of follow-up, and the potential for losing subjects over time. Quantitative/Analytical Primary Research: Nonexperimental Studies Case Control Studies make observations about possible associations between a disease of interest (e.g., lung cancer) and one or more hypothesized risk factors (i.e., tobacco use). Case control studies are retrospective in that subjects already have already acquired a certain disease or condition and are compared with a representative group of disease- free people (controls) from the same population. Quantitative/Analytical Primary Research: Nonexperimental Studies Retrospective Case-Control Study Design Persons of interest (e.g., lung cancer) and controls where no disease have been diagnosed are identified at the initiation of the study. Information is then collected looking backwards in the time to identify potential exposure or risk factors (i.e., tobacco) that could have contributed to getting the disease. Quantitative/Analytical Primary Research: Nonexperimental Studies A case control study is most useful in studying the etiology of rare diseases because they are difficult to study on a population basis.  Case control studies allow multiple etiologic factors to be studied concurrently. The problem with case control studies is that investigators are looking back in time and often must rely on the subjects’ recall or other incomplete sources of information for exposure histories or characteristics that could have put a person at risk for developing the condition or disease of interest.  The assumption is that the differences (between case and control groups) should explain why the cases developed the condition/disease of interest and the controls did not. As a result, this study design lends itself to recall bias more so than a cohort or experimental study. Case control studies also are less reliable because a statistical relationship between two conditions does not mean that one condition actually caused the other.  Ex. Lung cancer rates may be higher for people who earns less than $50,000 per year, but that doesn’t mean that someone can reduce his or her cancer risk just by getting a salary increase to more than $50,000. When possible, researchers should confirm the results with a randomized controlled trial or a prospective cohort study. Quantitative/Analytical Primary Research: Nonexperimental Studies Cross-sectional studies involve looking at data from a population at one specific point in time. In a cross-sectional study, the investigator measures the outcome and the exposures in the study participants at the same time. There’s not a control group. It’s normally used for population-based surveys and only require a one-time interaction. Quantitative/Analytical Primary Research: Nonexperimental Studies Case Series and Case Reports are often reported in the dental and dental hygiene literature. These consist either of collections of reports on the treatment of several patients, or a report of a single patient.  Ex. If a patient has a condition that a clinician has never seen or heard of before and is uncertain what to do, a search for case series or case reports may reveal information that will assist in a diagnosis. However, for any reasonably well-known condition, there should be better evidence. Case series and case reports have no statistical validity, because they report observations and do not use a control group with which to compare outcomes. They can be extremely important in identifying new health concerns and often generate a hypothesis that then sparks the initiation of more rigorous prospective studies and clinical trials.  Qualitative/Descriptive Primary Research Is nonexperimental in that it conducts studies in natural settings to understand an event from the point of view of the participants. Information is collected without changing the environment (i.e., nothing is manipulated) It seeks to provide depth of understanding and does so through answering questions such as what, how, and why. It explores issues in more depth with those experiencing the issue rather than testing a hypothesis to answer questions such as how many or what proportion. Qualitative/Descriptive Primary Research In many cases, qualitative research generates new theory. It complements quantitative research by attempting to clarify the meaning of how many or by providing a greater understanding of why an intervention works.  Quantitative research may ask, “how many smokers have tried to quit?” whereas qualitative research explores “What stops smokers from quitting?” Qualitative research has many different research designs and data collection methods based on the questions being explored and the setting being observed. Three common study designs include:  Ethnography asks, “what is the culture of a group of people?” and collects data through participant observation, unstructured interviews, and studying documents and photographs.  Phenomenology answers the question, “What is it like to have a certain experience?” and collects data through in- depth interviews, written anecdotes, philosophy, poetry, or art.  Grounded theory builds on the inductive nature of qualitative research and focuses on theory construction and verification by studying interactions as they occur naturally. Data collection includes taped interviews, participant observations, focus groups, and diaries.  Some Potential Biases in Clinical Research Bias Description Impact Recall bias Occurs when participants do not remember previous events or experiences Recall bias is a problem in studies that use self-reporting, e.g., case- accurately or omit details. control studies and retrospective cohort studies Selection bias It is an error in assigning subjects to a study group where some members are less Potential bias in observational studies such as cohort, case-control, likely to be included than others, i.e., non-randomized selection. and crossectional studies Investigator bias Refer to situations in which researchers convey to research participants in subtle or Can impact qualitative research in general unconscious ways the results or patterns the researcher would prefer to see Placebo bias Occurs when study participants associate a treatment with a specific response. It has Can impact clinical trials in general; It can negatively impact non- a large root in a person’s expectations randomized studies. Social desirability A.k.a. response bias, happens when participants may not answer questions entirely Can impact qualitative research in general, but particularly impactful in bias or truthfully in order to please the experimenter or based on what they wish their observational studies such as cohort, case-control, and crossectional response to be. studies. Length time bias It is an “apparent increase in survival time” resulting from a screening test favorably Normally associated with non-randomized study designs. detecting less aggressive forms of the disease early in the disease process (as compared to another group screened later in the disease course). Allocation bias It is the systematic difference between patients in how they are assigned to This bias can be avoided by following a random assignment of subjects experimental groups. or using a double-blind study design. Surveillance bias Happens when one group of participants is followed more closely than the other A common bias in non-randomized studies group and can result in increased diagnoses in the group being more closely observed. a.k.a. detection bias. Hawthorne effect Happens when an individual’s performance improves on a task simply because they Can impact clinical trials in general; It can negatively impact non- know they are participating in an experiment blinded studies. Classification bias A.k.a. measurement or information bias, results from improper, inadequate, or Because perfect tools to gather data are uncommon, most studies are ambiguous recording of individual factors—either exposure or outcome variables. subject to a certain degree of misclassification Confounding bias It is a spurious association made between the outcome and a factor that is not itself Confounding may be present in any study design causally related to the outcome; It occurs if the factor is associated with a range of other characteristics that do increase the outcome risk.  Characteristics of Quantitative and Qualitative Research Approaches Quantitative/Analytical Qualitative/Descriptive Experimental (Trials) Nonexperimental/Observational Nonexperimental Purpose and Study Begins with hypothesis and tests cause and Observational studies used to systematically Uses a naturalistic approach to answer questions about Design effect, variables are defined and manipulated. describe and interpret conditions/relationship that the meaning, or attitudes, beliefs, or behavior of a group Answers questions related to therapy and harm already exist. Examines the association between a or individual; provides explanation and understanding; in terms of how many or how much; probability particular exposure and a risk factor, or between a uses an inductive process; uses an inductive process; used sampling allows generalizing findings, uses a disease and hypothesized risk factors. to generate hypotheses deductive process A treatment or intervention is not given. Phenomenology, ethnography, and grounded theory RCTs (Double- or single-blinded, open-label), Cohort Studies (prospective, retrospective), case Case series and Case report Controlled Trial (quasi-randomized, non- control, cross-sectional studies, and case series, or randomized), Uncontrolled Trial (before/after report studies study, time series) Data Collection Systematic data collection using predefined Gathers data without giving a treatment or Fieldwork to observe people and record in the natural methods of measurements. Often have blinding intervening to control variables. setting. Data collected via focus groups, observation, of examiners to minimize bias when examining Clinical exam, survey, or questionnaires. Can be unstructured interviews, diaries, written anecdotes, experimental and control groups collected once or multiple times over time philosophy, poetry or art. Role of Researcher Tends to remain separate from the subject matter Tends to be immersed in the subject matter, personal involvement Analysis Analysis occur after all data are collected. Involves analysis of numerical data that can be combined Analysis takes place concurrently with data collection and and manipulated using statistical methods. Results reported using numerical relations and statistical is ongoing. Involves analysis of thoughts or concepts, terms pictures, or objects and categorized into themes. Reported in narrative terms Quantitative/Analytical Secondary Research Mostly quantitative in nature Secondary research is filtered or synthesized publications of the primary research literature.  Examples include systematic reviews (SRs) and meta-analyses, evidence-based articles reviews, and evidence-based clinical practice guidelines. With more than 2 million articles published annually and 20,000 biomedical journals, SRs is a way of managing large quantities of information by providing a summary of two or more primary research studies that have investigated the same specific phenomenon or question. Methods used in SRs parallel those of RCTs in that each step is thoroughly documented and reproducible.  There are defined criteria for the inclusion and exclusion of research studies in an SR just as there are predefined criteria for the inclusion and exclusion of subjects in an individual RCT. Quantitative/Analytical Secondary Research: Systematic Reviews Systematic Reviews differ from traditional literature or narrative reviews in that they are narrower in scope and focus on answering specific questions. Those conducting SRs try to find all the literature addressing a specific question, including unpublished or “gray” literature. The gray literature may include reports, working papers, theses/dissertations, government documents, conference proceedings, or meeting abstracts, all of which do not result in a journal article publication, thus making them more difficult to identify. Studies selected for inclusion in an SR must meet specific predefined criteria, such as the type of research design used, sample selection, length of study, and outcome variables of interest.  Cochrane Systematic Review outline Quantitative/Analytical 1. Synopsis Secondary Research: 2. Abstract Systematic Reviews 3. Objectives 4. Criteria for selecting studies: Types of participants A systematic review is a very Types of intervention large aggregation of similar Type of outcome measures studies. Types of studies 5. Search strategy An example of a well-conducted 6. Description of studies 7. Methodological quality systematic review is 8. Results demonstrated in the detail of the 9. Discussion 10. Reviewers’ conclusion outline of a Cochrane systematic 11. Acknowledgments Review as shown in the table on 12. Conflict of interest 13. References the side 14. Tables and figures Quantitative/Analytical Secondary Research: Meta- Analysis Meta-analysis performs statistical analyses to quantify aggregated data, giving his precision/accuracy and providing the highest level of clinical evidence. It involves combining the data from multiple individual studies into one analysis.  Often smaller RCT may have rigorous designs but lack the statistical power to demonstrate a statistically significant effect.  When data from these studies are pooled the sample size and power usually increase.  As a result, the combined effect can increase precision of estimates of treatment effects and exposure risks, more so than a SR review in which the data cannot be statistically combined and analyzed.  General Characteristics of Systematic Reviews and Traditional Narrative Reviews of the Literature Characteristic Systematic Review Traditional Narrative Review of the Literature Focus of the Review Specific problem or patient question Range of issues on a topic Narrow focus Broad focus o Example includes the effectiveness of fluoride varnish as o Example includes measure for preventing root surface caries; can compared with topical SnF fluoride in preventing root include many types of fluorides; may not make comparisons caries between methods Who Conducts Multidisciplinary Team Group or individual Selection of studies to Preestablished criteria based on validity of study design Criteria not preestablished or report in methods. Search on range of include and specific problem issues All studies that meet criteria are included May include or exclude studies based on personal bias or support Systematic bias is minimized based on selection criteria for the hypothesis, if one is started Inherent bias with lack of criteria Reported Findings Search strategy and database searched Literature presented in literature review format and crafted by the Number of studies that met criteria; number that did not individual author meet and why studies were excluded Search strategy, databases, total number of studies pro and con not Description of study design, subjects, length of trial, state always identified of health/disease, outcome measures Descriptive in nature reporting the outcomes of studies rather than their study designs Synthesis of Selected Studies Critical analysis of included studies Reporting of studies that support a procedure or position and those Determination if results could be statistically combined, that do not rather than combining data or conducting a statistical and if so, how meta-analysis was conducted analysis Main Results Summary of trials, total number of subjects Summary of the findings by the author in relation to the purpose of Definitive statements about the findings in relation to the the literature review and specific objectives specified objectives and outcomes measure Conclusions or Comments Discussion of the key findings with an interpretation of the Discussion of the key findings with an interpretation of the results, results, including including limitations and recommendations for future trials Finding the Evidence: Resources Resource URL The Cochrane Database of Systematic Review (full https://www.cochrane.org/reviews/index.htm text of systematic reviews and protocols for reviews currently being prepared) Database of Abstract of Reviews of Effectiveness https://www.cochrane.org/reviews/index.htm or (DARE) www.crd.york.ac.uk/crdwweb The Cochrane Central Register of Controlled Trials https://www.cochranelibrary.com/ (CENTRAL) (bibliography of controlled trials) The cumulative Index to Nursing and Allied https://www.ebsco.com/products/research- Health (CINAHL) (Contains scientific evidence databases/cinahl-complete related to dentistry and dental hygiene) PubMed Clinical Queries – features support https://pubmed.ncbi.nlm.nih.gov/clinical/ evidence-based searching by allowing a specialized methodological search for the highest level of evidence in the literature on questions of therapy, diagnosis, etiology, prognosis, or clinical prediction guides. Finding the Evidence: Boolean Operators Boolean operators are simple words that are used as conjunctions to combine or exclude keywords in a search. Including Boolean operators facilitates a more focused search by eliminating inappropriate hits that might otherwise show up. They are:  AND = requires both terms to be in each item returned. Doing this narrows the search.  OR = either term or both terms will be in items returned. This broadens the search.  NOT or AND NOT = first term is searched, and the records containing the term after the operators are subtracted from the results.  Using parentheses will search for information in the parentheses first then apply any statement that is not enclosed. Levels of Evidence Levels of Evidence Needed to minimize and control biases Rank the validity of evidence, allowing the user to put confidence in the results  Ex. A RCT provides stronger evidence than a cohort or case-control study when testing a therapy Medical researchers and practitioners rank evidence according to its quality. These levels when pictured together form a pyramid with the highest quality evidence at the top of the pyramid as there is less of this available. This pyramid is often referred to as the "Evidence Pyramid". The Evidence Pyramid Level 1 Level 2 Level 3 Levels 4 & 5 The Evidence Pyramid Although each level may contribute to the total body of knowledge, not all levels are equally useful for making patient care decisions. As one progresses up the levels, the number of studies and, correspondingly the amount of available literature decreases, while at the same time their relevance to answering clinical questions increases. Knowing which type of research study provides the strongest level of evidence for the question being asked is important in conducting an evidence-based search of the literature. These models for categorizing studies are helpful in determining the level of evidence available for answering clinically related questions and serve as a basis for identifying the strength of the evidence as being:  Strong (level 1)  Moderate (levels 2),  Limited/weak (level 3), or  Missing evidence related to areas of practice (levels 4 & 5) The Evidence Pyramid Level 1 Strong Level 2 Moderate Level 3 Limited/weak Levels 4 & 5 Missing evidence