 Hello friends, in my previous video of high yield topics in BCBR course, people have given immense response for that. I am very glad for all your response. Now I am making this second part, some of the topics in BCBR course which has been missed in the first part. First is about the dimensions of the research, so where we can see the different dimensions of health research, that is theoretical research and applied research, then preventive and therapeutic research, bench based research and bedside research, then exploratory and confirmatory research, implementation research and translation research. These dimensions has not been individually described in detail, but these dimensions can be asked in MCQs. Then we are moving to the pilot study. Pilot study, as we all know, it is a small scale preliminary research project, that is to test the large research project, we need to do the same study in a small scale, that is your pilot study. This is conducted to test and refine the study methodologies, data collection instruments or experimental procedures before conducting the full scale study. The main purpose is to calculate the time and do some modifications, whether it is ethical or not and sometimes to validate the questionnaire and sometimes to calculate the sample size, all are the additional uses of pilot study. But the main purpose is to identify any potential issues or limitations in the study tool, so that we can make necessary adjustments to ensure that limitations or issues are avoided when we are doing in the larger study. So this is about the pilot study, which is conducted in a small scale. The main purpose is to refine the methodology. Additionally, we can calculate the time, validate the questionnaire, calculate sample size also. We move on to the uses of cross-sectional surveys. Cross-sectional surveys are otherwise called as prevalence studies. So in uses of cross-sectional surveys, we calculate the prevalence of a particular disease or their risk factors. We can also calculate the distribution of the health problem in terms of time, place and person. We can plan health service delivery based on this cross-sectional surveys. We can set priorities for disease control. We can generate hypothesis. Descriptive studies and cross-sectional studies, we can generate hypothesis. But to test hypothesis, we need to move on to analytical study designs. So anything above this cross-sectional study design, that is case control, cohort, test the hypothesis. You can test any intervention, then you can go for RCT. That is basis about research. Then we can examine evolving trends. We can do before and after surveys for studying the effectiveness of interventions. Then we can do iterative cross-sectional surveys also. So the main purpose of cross-sectional surveys is to study the prevalence and plan for health care service delivery. Set priorities, generate hypothesis. Now what are all the advantages and disadvantages of cross-sectional survey? Advantages include, this is fairly quick and easy to perform. Most of the research which we conduct will be falling under this cross-sectional study design or descriptive study design. It is comparatively very less expensive. On the other hand, about the limitations, it is not useful to study the disease etiology. As when we are studying the disease etiology, we go for a causal association. That is, we can find only association in this type of cross-sectional studies. To make that as a causation, we need to have a higher order of study design. That is above cross-sectional study. Because we are not testing any hypothesis, we are generating hypothesis. Then these are all not suitable for study of rare diseases. Because when we are doing prevalence, these rare diseases may not appear in the population. Now we move on to types of cohort studies. In the first part, we have seen the difference between case control and cohort. Case control means we start from the outcome, look back the exposure, outcome or disease. On the other hand, for cohort studies, we start from exposure, look for the outcome. So when we look at the time here, time will be in this direction. But for case control study, time will be in the opposite direction. So that is the basic difference. If you start from outcome, that is the case control study. Or if you start from a case, that is the case control study. If you start from exposure, that is the cohort study. But when it comes to the types of cohort study, there are three types of cohort study based on the position where you stand. That is prospective, ambi-spective, retrospective. Prospective means this is the pure proper cohort study. That is, you start the study. By the time there is no exposure and the outcome or the disease has not happened. You measure the exposure followed by the disease. So the time will go like this. So this is called as a prospective cohort study. On the other hand, look at this retrospective study design where you start at this point of time where exposure and the disease has already occurred. Start collecting the exposure data from here and follow up for the disease. Then this study design is a retrospective cohort study. On the other hand, if you start in between somewhere, collect the exposure and later also you have a follow up. This is called bi-directional or ambi-spective cohort study. For example, if you are studying antenatal care and low birth weight, if you take low birth weight children and normal children and look for the antenatal care, then that is a case control study. If you take antenatal care, good antenatal care and poor antenatal care, look for the low birth weight children, then that is a cohort study. So that is the basic study design. If you conduct the study after the delivery, that is a retrospective cohort study. If you are starting the study during the registration of the pregnancy, then that will be the prospective cohort study. In between, if you are starting the second trimester, you collect the data of the antenatal care history previously and follow them up for the antenatal care. Then you look for the appearance of low birth weight babies. Then that is called as bi-directional or ambi-spective cohort studies. The basis remains the same. If you start from exposure, look for the outcome, then that is a cohort study. If you start from outcome, look for exposure, that is a case control study. Depending upon where you start the study with the timeframe, it is prospective ambi-spective or retrospective cohort study. Then why clinical trials are conducted? Clinical trials are usually conducted to evaluate the new form of therapy or prevention methods which may be either a new drug or a new form of treatment which may be surgical or any other intervention. We can evaluate new technology. We can evaluate new delivery system of healthcare. We can evaluate any other methods of primary prevention. We can evaluate programs of screening or early detection also. So we can evaluate these interventions in clinical trials. Advantages and disadvantages of RCTs or randomized controlled trials. We all know randomized controlled trial is a type of intervention study where the study and control group are randomly assigned. The advantages of these randomized controlled trials are their effective method to control the selection bias and the confounding will be taken care. It facilitates effective blending in some trials. The advantages of all with cohort studies will be carried over in randomized controlled trials. On the other hand, when it comes to the disadvantages, RCT study design is complex and also expensive. It lacks representativeness. When volunteers are presented for the study, their characteristics may differ from the population of interest and the ethical challenges are immense with these RCTs. So the disadvantages are it is complex, expensive, volunteer bias will be present, then ethical challenges are present. Then what is the difference between inclusion and exclusion criteria? Inclusion criteria represents the main characteristics of the target population that pertain to the research question. In other words, it is specifying the populations relevant to the research question and efficient for the study. So inclusion criteria is the characters of the population. You can get the best results. Exclusion criteria will be the subset of individuals that might interfere with the follow up efforts, quality of the data or acceptability of the randomized treatment or any other bias inducing characteristics will be excluded from the study. What are all the steps in organized research in literature review? So first we need to organize the information, that is we need to relate it to our research question. Then we need to synthesize the results out of the organized information. We need to get a summary of what is known and what is not known. Then we need to identify the lack on a are the gaps in the current knowledge as it appears in the literature. Then we develop the questions for the further research with an intention to fill the lack may or gap in the existing literature. So this is the organized search in literature review. So we need to follow these steps for a literature review. Then what are all the characteristics of good hypothesis? A good hypothesis should be simple, specific and it should be stated in advance. Simple means it should have one exposure and one outcome at the same time. So it is like stuff at the same time. So it should be specific that there should not be any ambiguity with reference to the study participants and variables and operational definitions also. It should be stated in advance, written at outset and it should be focused on the primary objective. What is information retrieval? It is identifying within a large document collection a subset of documents whose content is most relevant to the user's need. That is information retrieval. Then we move on to the incidents and prevalence. So in the previous presentation we have seen the tub story where the tub containing water is the prevalence, water inflowing is the incidence and this may be cure or death. So there may be migrants coming in and immigrants going out. So that was described in the earlier class. So the relationship between incidence and prevalence is, prevalence is equal to incidence into duration and also prevalence is an indicator used in chronic disease, incidence is an indicator used in acute disease. That's what we have seen in the first part. There are some additions now. So causes of increase and decrease of prevalence is increase in prevalence is due to the longer duration of the disease which may be due to the low cure rate and low case fatality rate. Increase in new cases, immigration of the patients, improved detention, immigration of healthy people. All these can cause increase in prevalence. On the other hand, decrease in prevalence may be due to the shorter duration of the disease which may be due to high cure rate or high case fatality rate. It is just the opposite of the increase in the prevalence. So decrease in new case here, immigration of patients, improved cure rate or immigration of healthy people. So all these causes increase and decrease of prevalence. Now they have added some more points with relation to prevalence that is period prevalence and point prevalence. Point prevalence is old cases divided by the population at risk for the particular year. So that was a formula given for the point prevalence. So period prevalence means we need to add the existing cases that is prevalent cases at the beginning of the time and incident cases. Suppose if we are doing it for the 2022. So 2022 January 1, how many cases were there? We need to add that plus in the full 2022 year how many cases appeared divided by population at risk. So this will give you the period prevalence. So that is the period prevalence. Now we have two different indicators for incidence that is cumulative incidence and incidence density. Cumulated incidence is the number of new cases divided by population at risk. It is otherwise called as attack rate. On the other hand incidence density means the denominator changes as instead of population at risk it is changed into total person time per observation. So which means if we are observing 100 person for 10 years it will yield 1000 person years. So we express this incidence density in terms of time person. So this is otherwise called as incidence rate. Then we move on to the publication ethics are being abstinent from research misconduct. So they have mainly focused on this six topics of publication ethics. So first is the ethical review that is the breach of confidentiality. In that publication ethic they have mentioned about for any research they should obtain institutional ethical committee approval, informed written consent from the patients. The study is about intervention then they should go with CTRI that is clinical trial registry of entry approval. Then the data confidentiality needs to be maintained. Falsification fabrication of data. Falsification means changing the data. Fabrication is data. New data has been made. So in that case that is called as fabrication. They have mentioned about the authorship criteria. In any research the author should do substantial contributions in majority of the stages of the research and drafting the research. Final approval then he should be held responsible for or accountable for the works that has been done. So all these comes under criteria for authorship under ICMJE that is International Committee of Medical Journal Editors. We have guest authorship or gift authorship where you invite somebody to be an author without being contributed for the research. On the other hand we have ghost authorship that is somebody who do substantial contribution for your research. They may not be included as the author in your research. Then the next research misconduct is about the plagiarism. The latin word plagiarism means kidnap which means you are taking away somebody's ideas, thoughts, language without their permission then that is called as plagiarism. And in the case of research we need to cite the ideas, thoughts and language. So plagiarism can be direct plagiarism that is cut copy paste from somebody's article or self-plagiarism that means we can take our own articles and we can cut copy paste into our new research and there is a salami or redundant publication that is instead of making a single publication you cut down into many pieces and publish it into many publications then that is called a salami or redundant publication. If study itself is big then you can do as many as publications you want. If we split up unnecessarily then it is called a salami or redundant publication. Ethics related to submission that is simultaneous submission to different journals is also not acceptable. Duplicate submission copying our own article is also unethical then self citation unnecessarily to increase our own citation score if we cite our own articles unnecessarily that is also unethical that is self citation then we should be careful about predatory journals these are the journals which display false credential in their website and also they don't conduct proper peer review but they claim that they are doing peer review so their acceptance rate will be very high and fast with high amount of publication charges. So the punishment and the consequences related to research misconduct has been given with committee of publication ethics that is scope and last among the publication ethics is about the conflict of interest that is here the conflict is between the researcher and the research objective this may be due to financial personal social and other interests so then that will be considered as a conflict of interest if at all you have a conflict of interest then you need to disclose it in the conflict of interest section if you are not disclosing it then later if the journal identifies it as serious misconduct then they may retract the journal article and sometimes you need to face legal battle also. Now the next most important topic is the confounders and the effect modifiers which is one of my favorite topics also when we are studying an exposure and outcome confounding factor is a third factor which is related to both exposure and outcome and it is unequally distributed among the exposed and a non-exposed group then we get false association that is called as confounding let me explain this about in detail when we are studying smoking and esophageal cancer there may be a third factor alcoholism which is directly related to esophageal cancer and smoking we all think smoking is directly an exposure factor risk factor for developing esophageal cancer but actually alcoholism can play a confounding factor that it may be unequally distributed among smokers and non- smokers and because of that the smoking can show an association which may be false but when we do this stratification in terms of alcoholism then this association will not be present in that case alcoholism will become a confounding factor let me explain with one more example for the confounding when we are studying alcohol use and bladder cancer smoking can be a confounding factor so there will be a significant association with univariate analysis when we are doing a stratified analysis that is among smokers and among non-smokers because smoking is playing a confounding role we are dividing or stratifying based on smokers and non-smokers then alcohol use will not cause will not give any association for bladder cancer same way among non-smokers also there will not be any association so in this case if we identify a factor like this it will be a confounding factor on the other hand what is the effect modifier is in the preliminary stage crude analysis that is univariate analysis you are studying the use of oral contraceptive and breast cancer you will get a significant association now you want to look for the confounding role of family history you go for stratified analysis like this based on the family history of breast cancer we stratify into two groups and we do the same association between use of oral contraceptive and breast cancers so this association will get stronger instead of disappearing in confounding if it gets stronger then this family history plays an effect modifier role so how can we address this confounding confounding at the design stage if we are doing restriction of the confounding variable or matching randomization can prevent on the other hand during the analysis stage stratification or multivariate analysis with adjusted odds ratio we can identify the confounding bias so to sum up confounding variable is a third variable which is associated with both the exposure and the outcome and it is unequally distributed among the exposed and unexposed causing or falsely displaying association between the exposure and outcome we move on to the sources of research question we can get sources of research question by mass published literature being alert to new ideas and techniques around our scientific community keeping the imagination roaming and choosing a guide or the mentor we can get the research question then in manuscript structure they have dealt about imrat structure of manuscript that is introduction methodology results and discussion why did you start what did you do what did you find what does it all mean it looks little complex i would suggest you to have why for introduction how for methods results what discussion so what so if you keep like this this is the structure of imrat structure so what it why you are doing the studies introduction how you have done the studies methodology what you have found is the results so what is discussion now we are expanding this imrat structure we have plenty of videos about this imrat structure in our channel knowing about this imrat structure not only helps in answering this bcb course but also helps when we are doing the real research when we are doing introduction we should zoom in the issue that is from broad to specific we should move then we should tell about the background information then we should address the current existing knowledge and the knowledge gaps then we explain the rationale for conducting the study then we end up in the objectives of the study then under methods sections we have different headings that is study settings study design operational definitions sampling strategy sample size study procedures data collection methods data analysis plan human participants protections all are included in the methods this is given in the manuscript writing chapter on the other hand this is given in the concept proposal and study protocol there are slight differences now in the results we should present the study findings in the form of tables and figures tables is for representation of the data we can visualize by figures and images also wherever we are making tables and figures titles footnotes abbreviations should be clear color resolution also should be clear and no need of interpretation of or giving commons in the results section because that you should reserve it for the discussion section in discussion section we will first summarize the findings I repeat it is summarize not the repetition of the findings then we will interpret the results find the reasons for differences and find the reasons for similarities then we obtain some inferences out of it then we compare it with other studies results then we ultimately fill in the gap so we try to fill in the gap so whatever we have mentioned here as the gap knowledge gap so we need to fill here then we need to mention about the strengths limitations recommendations possible bias all should be mentioned in discussion then we move on to the keywords the purpose of keywords is to help the indexing agencies and the search engines to find your own study so we need to use apt words preferably in the mesh terms that is medical subject headings so we need to use so that your articles will be read more and more cited also then abstract or summary is a miniature manuscript it may be structured or unstructured that is it also can follow imbride structure and sometimes you may not follow this imbride structure and it may be unstructured also so most commonly read part will be this abstract usually 100 to 350 words long there will be plain language summary in some journals then most important thing is the references so all the sources of information which you put up should be referred that is it should be cited then the references should be relevant and recent also then you should you can use this bibliography management that is reference manager software the most commonly used are sotiru and mainly we have lots of demonstrations in our channel for that the commonly used styles will be van kover harvard and chicago van kover is the most commonly used by the universities the most important parts of the grant rating is the budget and the justification so here they have mentioned about the budget and the justification so we need to divide it into recurring and non-recurring costs so equipment comes under a non-recurring cost and the recurring cost includes staff consumables and travel also this is more about skill we need to try repeat hopefully this presentation was useful to you if you like this video please share it to your friends all the very best for your examination thanks a lot for watching