Lecture 08

Ajouté : 2026-05-12

[00:00:01][music] [music] Good morning ladies and gentlemen. In the previous lecture we discussed the various kind of systematic literature reviews which were must have been very interesting to all of us. Now we will be discussing some examples of the systematic literature review. This has been a very popular analysis method especially in the medical sciences.

[00:00:54]So we will be discussing these case studies or the examples which people have done so that our concept about it becomes further clear and also as I had told in the beginning that the SLR is being now increasingly used in the other sciences. is also especially the economic science or the development economics. So we will have examples from the medical science also and from the economic science also. So we first begin with the example which boil RJ at all date and the title was probiotics for treating eczema. It has been published in coach and database systematic review 2008.

[00:02:03]So we know we will we will evaluate it by steps. So the first step what we did they did and what we have to do when we do it it is the formulating a research question.

[00:02:21]So the Mr. While at all we're interested in the population of eczema patients, the treatment intervention of probiotics and it had to be compared with either no treatment or placebo or non probiotic treatment. Placebo means the existing treatment going on.

[00:02:50]So it was he they had to do this comparison also and the outcome of the the changes in participants parent and doctor related symptoms of eczema and quality of life that whether the probiotics the eczema has the has reduced or not and the quality of life and in the study design they had the randomized control trials about the randomized control trials we shall be discussing in the in the ensuing lectures in the coming lectures.

[00:03:38]So the question that while atal had was what is the effectiveness of probiotics versus no treatment? A placebo or non-probiotic treatment for reducing eczema symptoms and improving quality of life in patients afflicted with eczema.

[00:04:07]So I have chosen these examples. I am discussing these examples so that it is very clear in your and my all in minds of all of us about the the the the importance and the steps of systematic literature review. So the research question they set up was the was that what is the effectiveness of probiotics versus no treatment a placebo or nonprobiotic treatment for reducing eczema symptoms and improving quality of life in patients afflicted with eczema.

[00:04:55]The second step was to develop a protocol.

[00:04:59]So, Guiltal has published a protocol that included the background information, a research objective, proposed methods, they set up the protocol.

[00:05:21]Then the third step was to search for all relevant studies.

[00:05:27]So boil at all search the following sources for relevant studies. The databases are here. Databases were immace Psych Info AIDS and ISI of science.

[00:05:47]They also did the manual searching of the conference proceedings and reference list of articles.

[00:05:57]There are some gray literatures.

[00:06:00]The coach library, the meta register of control trials and the ongoing eskin trials are registered by the coach library. So they consulted that also.

[00:06:17]and the experts, authors of unpublished registered trials, pharmaceutical companies and manufacturers of manufacturers of probiotics.

[00:06:32]That was the third to search for all relevant studies through those sources.

[00:06:40]Then the fourth step was to apply the selection criteria.

[00:06:48]Valentine boil at all independently read the titles and abstract of the studies that were identified during their research.

[00:06:59]So as we have said that there are three persons, three researchers [snorts] at least in this. So Mr. while and Mr. Tang independently read the titles of the titles and abstracts of studies that were identified during their research and they excluded any study that did not refer to a randomized control trial of probiotics for eczema.

[00:07:30]So all those studies which did not employ the randomized control trial for the probiotics for eczema treatment they were rejected.

[00:07:45]So now we are observing Mr. Bole and Mr. Tang independently reading the titles and abstracts.

[00:07:55]Next, Bo and colleagues found the full text for each of the remaining studies.

[00:08:03]And again, Bo and Tang read through the articles to decide if any more studies needed to be excluded based on the selection criteria.

[00:08:18]And you you you must be observing that how regress is their is their work just to to ensure that the study remains totally unbiased.

[00:08:35]So when bo and tang disagreed about whether a study should be excluded there was difference between them. They discussed it with varos until the three researchers came to an agreement.

[00:08:52]So we are observing the regressness the type of regress with the three or with the three researchers that they are following to make the research to make the SLR totally 100% unbiased.

[00:09:12]Now after applying the selection criteria they were left with 12 studies involving the 781 participants.

[00:09:23]So this is it. Next was the step five that is to extract the data.

[00:09:35]Mr. Bo and Mr. trying independently extract the data using data collection forms.

[00:09:43]They collected data about the studies, population, methods and outcomes, but of course separately, independently.

[00:09:52]They also collected data about possible sources of bias such as how the study participants were randomized into the control and treatment groups.

[00:10:04]So the although they have taken only randomized control control studies but despite that they are in fact further further looking for possible sources of bias such as how the participant study participants were randomized into control and treatment groups.

[00:10:31]And if boil and tang disagreed on anything then varos broke the tie because then all the three will sit down and then they they would arrive at a common conclusion to extract the data.

[00:10:47]Then came the stage of synthesizing the data. Betal used a meta analysis approach to synthesize the data. Now we know what is meta analysis. H it is an statistical equivalent or mathematical equivalent of this lab. So BL used a meta analysis approach to synthesize the data. They combine data from different studies to calculate overall effect sizes and for and for the outcomes.

[00:11:25]They have combined data of different studies to calculate what is the effect, what is this, what is the volume of the effect, what is the degree of the effect or the outcome.

[00:11:41]They also calculated confidence intervals for these effect signs.

[00:11:48]Violet also divided their studies into subgroups such as studies about babies, children, adults analyze and analyzed the effect sizes within each group.

[00:12:05]While at all meta analysis found that there was no significant effect of probiotic treatment on eczema symptoms either for all or for any subgroup.

[00:12:19]That is the finding while it also boil and others his colleagues have found that there was no significant effect of probiotic treatment on eczema symptoms either for all or for any of the subgroup that they have studies about babies, children, adults.

[00:12:45]Then the seventh was to write and publish a report.

[00:12:56]In their report, Betal concluded that probiotics cannot be recommended for reducing eczema symptoms or improving health of eczema patients.

[00:13:08]That is the conclusion we have to see in their step six that that in their synthes when they synthesize the data they found that there was no significant effect of probiotic treatment on eczema symptoms either for any group or for all. So in their report when they wrote the report they concluded that probiotics cannot be recommended for reducing eczema symptoms or improving health of eczema patients.

[00:13:41]The and then while atal published their report in the querant database systematic reviews and a review general kitical and experimental energy in 2008.

[00:13:56]So this was an example from the medical science. Now we will have an example from the economic science.

[00:14:09]What is that?

[00:14:13]The second example concerns the systematic literature review. An example from microfers.

[00:14:24]This by Karina Van Ruan, Rat Start and The Devet.

[00:14:31]It has been published in African news volume 43, 2013.

[00:14:39]What is micro finance?

[00:14:42]Micro finance describes financial services for those without access to traditional formal banking.

[00:14:55]It provides loans to individuals, groups and small businesses that is micro credit.

[00:15:04]It has also been extended to include the provision of savings accounts, micro savings, micro insurance and money transfer services for the poor.

[00:15:16]Such interventions are done to increase the financial services to those without access to banking services.

[00:15:27]We know about the micro finance revolution in our neighboring country especially Bangladesh where marginalized groups such as women were brought into the economic arena into the economic activity by this micro finance.

[00:15:56]And it was so successful. The experiment was a very successful experiment and Mr. Muhammad Yunus who was the propounder of this he was given a Nobel prize. So such interventions are done to increase the financial in services or the quality of life to improve the quality of life or to improve the the income for those without access to banking services. In this paper here that we are going to study this paper reviews empirical research on the impact of micro finance on poor people in subsahar and Africa.

[00:16:47]So this research would be through the SLR SLR. We have studied the impact of probiotics on the eczema patients. Now we are going to examine the impact of micro finance on poor people in subsaharan Africa.

[00:17:08]So what was the first step? First step was to formulate a research question in what they were interested. Roy Ital were interested in those who use micro finance services in subsaharan Africa.

[00:17:30]Those who provide micro finance services in subsaharan Africa.

[00:17:37]both the suppliers and the demanders, users and those who provide users provide the services. Then they were also interested in making policy decisions related to micro finance services in subsaharan Africa.

[00:17:58]They were also interested in those who research micro finance services in subsaran Africa.

[00:18:06]And finally poor people in subsaran Africa who were recipients of the services of micro finance question.

[00:18:17]So this is the this is the formulating a research question formul formulating the research question. Then came the stage of second stage of developing a protocol.

[00:18:34]So Royal set up a protocol that included region.

[00:18:42]They included research conducted in subsahar and African studies countries.

[00:18:49]This included, Moritania, Shad, Niger and Sudan and all African countries south of these and thus they excluded the North African countries researches rather researches or publications on the North African studies about the microfiber.

[00:19:19]However, all those researchers which included in a single study countries from both subsahar and a southern Africa and non-s subsahar and Africa they were included in the review.

[00:19:36]So this that was the protocol. Then the study designs although both quantitative and qualitative studies qualitative studies were included but comparative studies only those studies with only impact evaluations.

[00:19:56]They included randomized control trials which is the best way to measure the impact of micro finance. They also included other comparison studies intervention. They included only micro finance interventions concerning micro savings or microcurren services.

[00:20:19]However, micro insurance many transfers were not included. So they are very clear in what kind of intervention they have to study and the study is the the micro finance intervention considering only micro savings or micro credit services other services were not included population they focused on impacts on poor people those who were recipients of the services of the micro finance So those who were recipients of the of the micro finance services they were they were included they were focused for the impact of micro finance on poor people language roanal identified literature in English however they also access papers in Dutch, German, Portuguese Use French, French, Spanish, African, Zulu and Sutu languages.

[00:21:34]Then the third step they followed was to search for all relevant studies.

[00:21:41]Ruin ital search the following sources for relevant studies.

[00:21:47]Number one, African journals online.

[00:21:51]Number two, Arts and Humanities Citation Index Vapco.

[00:21:55]Number three, British Library for Development Studies. Four, Shimonics, Shimonics.com project final report.

[00:22:05]Fifth, conference proceedings citation index science yo. Sixth, econ base of economic literature. Seven L Eldis and online library of development literature provided by the Institute of Development Studies Sussex UK.

[00:22:26]Ideas Economics and Finance Research International Biblioraphy of Social Sciences.

[00:22:33]Jollis the databases of 14 World Bank International Monetary Fund libraries.

[00:22:39]Psych Info the Psychological Information Database.

[00:22:44]Research for development.

[00:22:47]Science citation index. Social science assistance in developing countries database.

[00:22:55]Social science citation index.

[00:22:58]Sociological abstracts. Who library database worldwide political science abstracts.

[00:23:07]So we we we we can have an idea of how wide and how detailed has been the search for the relevant studies by Mr. Royen Atal.

[00:23:26]Further key websites of organizations providing, coordinating and evaluating micro finance services across subsaharan Africa were searched.

[00:23:41]They conducted citation searches of key papers evaluating the impact of micro finance using randomized control trials.

[00:23:55]Searches of these sources were limited to studies conducted since 1990. As before that academic journals published very few articles on micro finance.

[00:24:08]It is not very very old subject. The such results were then filtered according to their inclusion and exclusion criteria.

[00:24:20]And we have numerous times pointed out that this inclusion and in exclusion inclusion criteria is very crucial crucial in maintaining the unbiasedness of the of the research of the systematic literature review and then they fourth step was applying the selection criteria.

[00:24:47]So the relevance of included studies to the review question was judged according to the following criteria. What is that?

[00:24:58]Whether they examined credit, loan, services and savings or only other financial services such as insurance or money transfers. Whether they measured impact on poverty levels or po poor people, their incomes, financial and non-financial wealth related outcomes, whether they examined services to and impacts on poor people specifically or only reported outcomes in terms of the general population. So we find here that the selection criteria are quite quite strong and quite rigorous.

[00:25:41]Then comes the step five. What is the step five? It is the extraction of the data.

[00:25:49]Once they coded all the included studies, they checked these for micro finance interventions. the participants the data collection and data analysis methods.

[00:26:00]They identified three broad categories for quality high, medium, poor.

[00:26:07]This weighing for what is good evidence and what not is the very crucial and difficult part of the systematic review process.

[00:26:18]As systematic reviews have to be transparent, replicable and free from bias. More than one researcher conducted the key tasks and peer review of this work.

[00:26:32]The review process is including the electronic search. A string inclusion and exclusion criteria, [snorts] coding sheets and synthesis were piloted initially on a small sample of papers and discussed among the team members to finalize these tools.

[00:26:55]They also tried to reduce researcher bias and ensure that all the relevant literature were included in the review.

[00:27:06]One reviewer initially applied the inclusion and exclusion criteria to identify titles and abstracts and two reviewers then independently screened for potential inclusion and any disagreement will resolve through discussion.

[00:27:28]So we have the three persons here.

[00:27:32]Then coding of included papers was also conducted by two members of the review group working initially independently and then compared their decisions and coming to a consensus.

[00:27:47]Once inter researcher coding was consistent and definitions established, all remaining papers were coded by one of the two researchers working simultaneously in the same place to allow for queries to be raised and discussed. Lastly, both the protocol and draft report were independently reviewed.

[00:28:10]Now came the stage of the synthesizing of the data.

[00:28:16]As we are aware, the systematic reviews involve more than just describing the findings of the new studies. It involves a specific process of synthesis to combine the available evidence.

[00:28:32]These range from statistical meta analysis of quantity data to narrative and thematic analysis and metaethography of the quality data to realist synthesis of mixed methods.

[00:28:48]They did not conduct any meta statistical meta analysis as they required conditions were not met.

[00:28:57]Instead and others set at all they synthesized findings using the framework analysis.

[00:29:06]So they applied predetermined categories to the data and enabled a structural comparison and synthesis through the use of a structured qualitative matrices.

[00:29:24]They synthesized the findings of comparative outcome evaluations which measured the impact of micro finance on the incomes and on the material poverty wealth of the poor. They also synthesized the findings of comparative outcome evaluations which measured the impact of micro finance on other non-financial outcomes for the poor and then the the next stage is the writing and publishing a report.

[00:30:05]Everything has been done. So finally ruin met to arrive at conclusions and discuss policy implications.

[00:30:14]Initial conclusions and implications were circulated to the network of review users for their input.

[00:30:22]Then amendments were made in light of feedback from them. Their research indicates that micro finance has both positive and negative impacts on poor people in subsahar and Africa. So we find that this is a new kind of because up till now we were of the impression that all the micro finance results in only positive impact. But here ruin ital is finding that it has both positive and negative impacts on poor people in sapsar and Africa. Micro finance provides access to credit and savings accounts facilitating poor people to save money and invest it in it like assets it in assets like business, education or healthcare.

[00:31:23]Access to micro finance enables for people to improve their health and nutrition by accessing better health care and nutritious food.

[00:31:34]Micro finance help people to start or expand businesses leading to increased income and greater income economic stability in subsaharan Africa. Micro finance helped to reduce income inequality by providing financial opportunities to marginalized groups. Further, micro finance empowered women by providing them with financial independence and decision making power.

[00:32:09]However, they found that micro finance had some negative aspects also.

[00:32:17]Micro finance sometimes led to the debt traps if borrow borrowers cannot repay could not repay their loans.

[00:32:28]So borrowers might have used micro finance loans for purposes other than intended potentially exervating exervating existing problems.

[00:32:42]At times very high interest rates and fees can lead to the explanation exploitation of vulnerable populations.

[00:32:54]Thus overall impact of micro finance on poor people is complex which is clear from the study on sabsar and Africa.

[00:33:05]While micro finance did provide significant benefits to the poor, there were potential risks and the program had to be designed and implemented in such a way that minimized negative impacts and maximizes the positive outcomes. So the it is against the general impression that micro finance is 100% or always beneficial. the ruan at all. They arrived at the conclusion that it is a mixed benefit both benefit and the losses and however they agree to it that the benefits are far are far more than the than the than the risk for the poor people. How?

[00:34:10]So they recommend that the it has to be designed and implemented in such a way to minimize negative impacts and maximize the positive outcomes for the poor and then they publish their findings in this referred as this referred article. So dear ladies and gentlemen, we have discussed examples of the medical science also and we have discussed the examples of the the the economic science also and we find that systematic literature review has been a very important a very crucial analysis tool for the researchers.

[00:35:03]And this has to be increasingly adopted. I wish I have been able to clear these concepts by giving these examples.

[00:35:15]Thank you very much. [music]