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Annotated Bibliographies

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Definitions

A bibliography is a list of sources (books, journals, Web sites, periodicals, etc.) one has used for researching a topic. Bibliographies are sometimes called "References" or "Works Cited" depending on the style format you are using. A bibliography usually just includes the bibliographic information (i.e., the author, title, publisher, etc.).

An annotation is a summary and/or evaluation. Therefore, an annotated bibliography includes a summary and/or evaluation of each of the sources. Depending on your project or the assignment, your annotations may do one or more of the following.

For more help, see our handout on paraphrasing sources.

For more help, see our handouts on evaluating resources .

• Reflect : Once you've summarized and assessed a source, you need to ask how it fits into your research. Was this source helpful to you? How does it help you shape your argument? How can you use this source in your research project? Has it changed how you think about your topic?

Your annotated bibliography may include some of these, all of these, or even others. If you're doing this for a class, you should get specific guidelines from your instructor.

Why should I write an annotated bibliography?

To learn about your topic : Writing an annotated bibliography is excellent preparation for a research project. Just collecting sources for a bibliography is useful, but when you have to write annotations for each source, you're forced to read each source more carefully. You begin to read more critically instead of just collecting information. At the professional level, annotated bibliographies allow you to see what has been done in the literature and where your own research or scholarship can fit. To help you formulate a thesis: Every good research paper is an argument. The purpose of research is to state and support a thesis. So, a very important part of research is developing a thesis that is debatable, interesting, and current. Writing an annotated bibliography can help you gain a good perspective on what is being said about your topic. By reading and responding to a variety of sources on a topic, you'll start to see what the issues are, what people are arguing about, and you'll then be able to develop your own point of view.

To help other researchers : Extensive and scholarly annotated bibliographies are sometimes published. They provide a comprehensive overview of everything important that has been and is being said about that topic. You may not ever get your annotated bibliography published, but as a researcher, you might want to look for one that has been published about your topic.

The format of an annotated bibliography can vary, so if you're doing one for a class, it's important to ask for specific guidelines.

The bibliographic information : Generally, though, the bibliographic information of the source (the title, author, publisher, date, etc.) is written in either MLA or APA format. For more help with formatting, see our MLA handout . For APA, go here: APA handout .

The annotations: The annotations for each source are written in paragraph form. The lengths of the annotations can vary significantly from a couple of sentences to a couple of pages. The length will depend on the purpose. If you're just writing summaries of your sources, the annotations may not be very long. However, if you are writing an extensive analysis of each source, you'll need more space.

You can focus your annotations for your own needs. A few sentences of general summary followed by several sentences of how you can fit the work into your larger paper or project can serve you well when you go to draft.

How to Write an Annotated Bibliography - APA Style (7th Edition)

What is an annotation, how is an annotation different from an abstract, what is an annotated bibliography, types of annotated bibliographies, descriptive or informative, analytical or critical, to get started.

An annotation is more than just a brief summary of an article, book, website, or other type of publication. An annotation should give enough information to make a reader decide whether to read the complete work. In other words, if the reader were exploring the same topic as you, is this material useful and if so, why?

While an abstract also summarizes an article, book, website, or other type of publication, it is purely descriptive. Although annotations can be descriptive, they also include distinctive features about an item. Annotations can be evaluative and critical as we will see when we look at the two major types of annotations.

An annotated bibliography is an organized list of sources (like a reference list). It differs from a straightforward bibliography in that each reference is followed by a paragraph length annotation, usually 100–200 words in length.

Depending on the assignment, an annotated bibliography might have different purposes:

• Provide a literature review on a particular subject
• Help to formulate a thesis on a subject
• Demonstrate the research you have performed on a particular subject
• Provide examples of major sources of information available on a topic
• Describe items that other researchers may find of interest on a topic

There are two major types of annotated bibliographies:

A descriptive or informative annotated bibliography describes or summarizes a source as does an abstract; it describes why the source is useful for researching a particular topic or question and its distinctive features. In addition, it describes the author's main arguments and conclusions without evaluating what the author says or concludes.

For example:

McKinnon, A. (2019). Lessons learned in year one of business.  Journal of Legal Nurse Consulting ,  30 (4), 26–28. This article describes some of the difficulties many nurses experience when transitioning from nursing to a legal nurse consulting business. Pointing out issues of work-life balance, as well as the differences of working for someone else versus working for yourself, the author offers their personal experience as a learning tool. The process of becoming an entrepreneur is not often discussed in relation to nursing, and rarely delves into only the first year of starting a new business. Time management, maintaining an existing job, decision-making, and knowing yourself in order to market yourself are discussed with some detail. The author goes on to describe how important both the nursing professional community will be to a new business, and the importance of mentorship as both the mentee and mentor in individual success that can be found through professional connections. The article’s focus on practical advice for nurses seeking to start their own business does not detract from the advice about universal struggles of entrepreneurship makes this an article of interest to a wide-ranging audience.

An analytical or critical annotation not only summarizes the material, it analyzes what is being said. It examines the strengths and weaknesses of what is presented as well as describing the applicability of the author's conclusions to the research being conducted.

Analytical or critical annotations will most likely be required when writing for a college-level course.

McKinnon, A. (2019). Lessons learned in year one of business.  Journal of Legal Nurse Consulting ,  30 (4), 26–28. This article describes some of the difficulty many nurses experience when transitioning from nursing to a nurse consulting business. While the article focuses on issues of work-life balance, the differences of working for someone else versus working for yourself, marketing, and other business issues the author’s offer of only their personal experience is brief with few or no alternative solutions provided. There is no mention throughout the article of making use of other research about starting a new business and being successful. While relying on the anecdotal advice for their list of issues, the author does reference other business resources such as the Small Business Administration to help with business planning and professional organizations that can help with mentorships. The article is a good resource for those wanting to start their own legal nurse consulting business, a good first advice article even. However, entrepreneurs should also use more business research studies focused on starting a new business, with strategies against known or expected pitfalls and issues new businesses face, and for help on topics the author did not touch in this abbreviated list of lessons learned.

Now you are ready to begin writing your own annotated bibliography.

• Choose your sources - Before writing your annotated bibliography, you must choose your sources. This involves doing research much like for any other project. Locate records to materials that may apply to your topic.
• Review the items - Then review the actual items and choose those that provide a wide variety of perspectives on your topic. Article abstracts are helpful in this process.
• The purpose of the work
• A summary of its content
• Information about the author(s)
• For what type of audience the work is written
• Its relevance to the topic
• Any special or unique features about the material
• Research methodology
• The strengths, weaknesses or biases in the material

Annotated bibliographies may be arranged alphabetically or chronologically, check with your instructor to see what he or she prefers.

Please see the  APA Examples page  for more information on citing in APA style.

• Last Updated: Aug 8, 2023 11:27 AM
• URL: https://libguides.umgc.edu/annotated-bibliography-apa

Research Strategies

• Reference Resources
• News Articles
• Scholarly Sources
• Search Strategy
• OneSearch Tips
• Evaluating Information
• Revising & Polishing
• Presentations & Media
• MLA 9th Citation Style
• APA 7th Citation Style
• Other Citation Styles
• Citation Managers
• Annotated Bibliography
• Literature Review How to

What is An Annotated Bibliography?

An annotated bibliography is a list of sources (books, articles, websites, etc.) with short paragraph about each source. An annotated bibliography is sometimes a useful step before drafting a research paper, or it can stand alone as an overview of the research available on a topic.

Each source in the annotated bibliography has a citation - the information a reader needs to find the original source, in a consistent format to make that easier. These consistent formats are called citation styles.  The most common citation styles are MLA (Modern Language Association) for humanities, and APA (American Psychological Association) for social sciences.

Annotations are about 4 to 6 sentences long (roughly 150 words), and address:

•     Main focus or purpose of the work
•     Usefulness or relevance to your research topic 
•     Special features of the work that were unique or helpful
•     Background and credibility of the author
•     Conclusions or observations reached by the author
•     Conclusions or observations reached by you

Annotations versus Abstracts

Many scholarly articles start with an abstract, which is the author's summary of the article to help you decide whether you should read the entire article.  This abstract is not the same thing as an annotation.  The annotation needs to be in your own words, to explain the relevance of the source to your particular assignment or research question.

Annotated Bibliography video

MLA 9th Annotated Bibliography Examples

Ontiveros, Randy J.  In the Spirit of a New People: The Cultural Politics of the Chicano Movement . New York UP, 2014.

This book analyzes the journalism, visual arts, theater, and novels of the Chicano movement from 1960 to the present as articulations of personal and collective values. Chapter 3 grounds the theater of El Teatro Campesino in the labor and immigrant organizing of the period, while Chapter 4 situates Sandra Cisneros’s novel  Caramelo  in the struggles of Chicana feminists to be heard in the traditional and nationalist elements of the Chicano movement. Ontiveros provides a powerful and illuminating historical context for the literary and political texts of the movement.

Journal article

Alvarez, Nadia, and Jack Mearns. “The Benefits of Writing and Performing in the Spoken Word Poetry Community.”  The Arts in Psychotherapy , vol. 41, no. 3, July 2014, pp. 263-268.  ScienceDirect ,  https://doi.org/10.1016/j.aip.2014.03.004 .

Spoken word poetry is distinctive because it is written to be performed out loud, in person, by the poet. The ten poets interviewed by these authors describe “a reciprocal relationship between the audience and the poet” created by that practice of performance. To build community, spoken word poets keep metaphor and diction relatively simple and accessible. Richness is instead built through fragmented stories that coalesce into emotional narratives about personal and community concerns.  This understanding of poets’ intentions illuminates their recorded performances.

*Note, citations have a .5 hanging indent and the annotations have a 1 inch indent. 

• MLA 9th Sample Annotated Bibliography

APA 7th Annotated Bibliography Examples

Alvarez, N. & Mearns, J. (2014). The benefits of writing and performing in the spoken word poetry community.  The Arts in Psychotherapy, 41 (3), 263-268.  https://doi.org/10.1016/j.aip.2014.03.004 Prior research has shown narrative writing to help with making meaning out of trauma. This article uses grounded theory to analyze semi-structured interviews with ten spoken word poets.  Because spoken word poetry is performed live, it creates personal and community connections that enhance the emotional development and resolution offered by the practice of writing. The findings are limited by the small, nonrandom sample (all the participants were from the same community).

• APA 7th Sample Annotated Bibliography
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Annotated Bibliographies

What Is An Annotated Bibliography?

What is an annotated bibliography.

An annotated bibliography is a list of citations (references) to books, articles, and documents followed by a brief summary, analysis or evaluation, usually between 100-300 words, of the sources that are cited in the paper.  This summary provides a description of the contents of the source and may also include evaluative comments, such as the relevance, accuracy and quality of the source.  These summaries are known as annotations. 

• Annotated bibliographies are completed before a paper is written
• They can be stand-along assignments
• They can be used as a reference tool as a person works on their paper

Annotations vs. Abstracts

Abstracts are the descriptive summaries of article contents found at the beginning of scholarly journal articles that are written by the article author(s) or editor. Their purpose is to inform a reader about the topic, methodology, results and conclusion of the research of the article's author(s).  The summaries are provided so that a researcher can determine whether or not the article may have information of interest to them.  Abstracts do not serve an evaluative purpose.

Annotations found in bibliographies are evaluations of sources cited in a paper.  They describe a work, but also critique the source by examining the author’s point of view, the strengths and weakness of the research or article hypothesis or how well the author presented their research or findings.

How to write an annotated bibliography

The creation of an annotated bibliography is a three-step process. It starts with finding and evaluating sources for your paper. Next is choosing the type or category of annotation, then writing the annotation for each different source. The final step is to choose a citation style for the bibliography.

Types of Annotated Bibliographies

Types of Annotations

Annotations come in different types, the one to use depends on the instructor’s assignment.  Annotations can be descriptive, a summary, or an  evaluation or a combination of descriptive and evaluation.

Descriptive/Summarizing Annotations

There are two kinds of descriptive or summarizing annotations, informative or indicative, depending on what is most important for a reader to learn about a source.  Descriptive/summarizing annotations provide a brief overview or summary of the source. This can include a description of the contents and a statement of the main argument or position of the article as well as a summary of the main points.  It may also describe why the source would be useful for the paper’s topic or question. 

Indicative annotations provide a quick overview of the source, the kinds of questions/topics/issues or main points that are addressed by the source, but do not include information from the argument or position itself.

Informative annotations, like indicative annotations, provide a brief summary of the source.   In addition, an informative annotation identifies the hypothesis, results, and conclusions presented by the source.  When appropriate, they describe the author’s methodology or approach to the topic under discussion.  However, they do not provide information about the sources usefulness to the paper or contains analytical or critical information about the source’s quality. 

Evaluative Annotations (also known as critical or analytical)

Evaluative annotations go beyond just summarizing the source and listing out it’s key points, but also analyzes the content. It looks at the strengths and weaknesses of the article’s argument, the reliability of the presented information as well as any biases of the author. It talks about how the source may be useful to a particular field of study or the person’s research project.

Combination Annotations

Combination annotations “combine” aspects from indicative/informative and evaluative annotations and are the most common category of annotated bibliography.  Combination annotations include one to two sentences summarizing or describing content, in addition to one or more sentences providing an critical evaluation.

Writing Style for Annotations

Annotations typically follow three specific formats depending on how long they are.

• Phrases – Short phrases providing the information in a quick, concise manner.
• Sentences – Complete sentences with proper punctuation and grammar, but are short and concise.
• Paragraphs – Longer annotations break the information out into different paragraphs. This format is very effective for combination annotations.

To sum it up:

An annotation may include the following information:

• A brief summary or overview of the source content
• The source’s strengths and weaknesses in presenting the argument or position
• Its conclusions
• Why the source is relevant in to field of study of the paper
• Its relationships to other studies in the field
• An evaluation of the research methodology (if applicable)
• Information about the author’s background and potential biases
• Conclusions about the usefulness of the source for the paper

Critically Analyzing Articles

In order to write an annotation for a paper source, you need to first read and then critically analyze it:

• Try to identify the topic of the source -- what is it about and is it clearly stated.
• See if you can identify the purpose of the author(s) in doing the research or writing about the topic. Is it to survey and summarize research on a topic?  Is the author(s) presenting an argument based on previous research, or refuting previously published research?
• Identify the research methods used and try to identify whether they appear to be suitable or not for the stated purpose of the research.  
• Was the research reported in a consistent or clear manner?  Or, was the author's argument/position presented in a consistent or convincing manner? Did the author(s) fail to acknowledge and explain any limitations?
• Was the logic of the research/argument claims properly supported with convincing evidence/analysis/data? Did you spot any fallacies?
• Check whether the author(s) refers to other research and if similar studies have been done. 
• If illustrations or charts are used, are they effective in presenting information?
• Analyze the sources that were used by the author(s). Did the author(s) miss any important studies they should have considered?
• Your opinion of the source -- do you agree with or are convinced of the findings?  
• Your estimation of the source’s contribution to knowledge and its implications or applications to the field of study.

Worksheet for Taking Notes for Critical Analysis of Sources/Articles

Additional Resources:

Hofmann, B., Magelssen, M. In pursuit of goodness in bioethics: analysis of an exemplary article. BMC Med Ethics 19, 60 (2018). https://doi.org/10.1186/s12910-018-0299-9

Jansen, M., & Ellerton, P. (2018). How to read an ethics paper. Journal of Medical Ethics, 44(12), 810-813.  http://dx.doi.org/10.1136/medethics-2018-104997

Research & Learning Services, Olin Library, Cornell University Library  Critically Analyzing Information Sources: Critical Appraisal and Analysis

Formatting An Annotated Bibliography

How do I format my annotated bibliography?

An annotated bibliography entry consists of two components: the Citation and the Annotation.

The citation should be formatted in the bibliographic style that your instructor has requested for the paper. Some common citation styles include APA, MLA, and Chicago. For more information on citation styles, see Writing Guides, Style Manuals and the Publication Process in the Biological & Health Sciences .

Many databases (e.g., PubMed, Academic Search Premier, Library Search on library homepage, and Google Scholar) offer the option of creating your references in various citation styles. 

Look for the "cite" link -- see examples for the following resources:

University of Minnesota Library Search

Google Scholar

Sample Annotated Bibliography Entries

An example of an Evaluative Annotation , APA style (7th ed). (sample from University Libraries, University of Nevada ).

APA does not have specific formatting rules for annotations, just for the citation and bibliography.

Maak, T. (2007). Responsible leadership, stakeholder engagement, and the emergence of social capital. Journal of Business Ethics, 74, 329-343.  https://doi.org/10.1007/s10551-007-9510-5

This article focuses on the role of social capital in responsible leadership. It looks at both the social networks that a leader builds within an organization, and the links that a leader creates with external stakeholders. Maak’s main aim with this article seems to be to persuade people of the importance of continued research into the abilities that a leader requires and how they can be acquired. The focus on the world of multinational business means that for readers outside this world many of the conclusions seem rather obvious (be part of the solution not part of the problem). In spite of this, the article provides useful background information on the topic of responsible leadership and definitions of social capital which are relevant to an analysis of a public servant.

An example of an Evaluative Annotation , MLA Style (10th ed), (sample from Columbia College, Vancouver, Canada )

MLA style requires double-spacing (not shown here) and paragraph indentations.

London, Herbert. “Five Myths of the Television Age.” Television Quarterly, vol. 10, no. 1, Mar. 1982, pp. 81-69.

     Herbert London, the Dean of Journalism at New York University and author of several books and articles, explains how television contradicts five commonly believed ideas. He uses specific examples of events seen on television, such as the assassination of John Kennedy, to illustrate his points. His examples have been selected to contradict such truisms as: “seeing is believing”; “a picture is worth a thousand words”; and “satisfaction is its own reward.” London uses logical arguments to support his ideas which are his personal opinion. He does not refer to any previous works on the topic. London’s style and vocabulary would make the article of interest to any reader. The article clearly illustrates London’s points, but does not explore their implications leaving the reader with many unanswered questions.

Additional Resources

University Libraries Tutorial --  Tutorial: What are citations?  Completing this tutorial you will:

• Understand what citations are
• Recognize why they are important
• Create and use citations in your papers and other scholarly work

University of Minnesota Resources

Beatty, L., & Cochran, C. (2020). Writing the annotated bibliography : A guide for students & researchers . New York, NY: Routledge. [ebook] 

Efron, S., Ravid, R., & ProQuest. (2019). Writing the literature review : A practical guide . New York: The Guilford Press. [ebook -- see Chapter 6 on Evaluating Research Articles] 

Center for Writing: Student Writing Support

• Critical reading strategies
• Common Writing Projects (includes resources for literature reviews & analyzing research articles)

Resources from Other Libraries

Annotated Bibliographies (The Writing Center, University of North Carolina at Chapel Hill)

Writing An Annotated Bibliography (University of Toronto)

Annotated Bibliographies (Purdue Writing Lab, Purdue University)

Annotated Bibliography (UNSW Sydney)

What is an annotated bibliography? (Santiago Canyon College Library): Oct 17, 2017. 3:47 min.

Writing an annotated bibliography (EasyBib.com) Oct 22, 2020. 4:53 min.

Creating an annotated bibliography (Laurier University Library, Waterloo, Ontario)/ Apr 3, 2019, 3:32 min.

How to create an annotated bibliography: MLA (JamesTheDLC) Oct 23, 2019. 3:03 min.

Citing Sources

Introduction

Citations are brief notations in the body of a research paper that point to a source in the bibliography or references cited section.

If your paper quotes, paraphrases, summarizes the work of someone else, you need to use citations.

Citation style guides such as APA, Chicago and MLA provide detailed instructions on how citations and bibliographies should be formatted.

Health Sciences Research Toolkit

Resources, tips, and guidelines to help you through the research process., finding information.

Library Research Checklist Helpful hints for starting a library research project.

Search Strategy Checklist and Tips Helpful tips on how to develop a literature search strategy.

Boolean Operators: A Cheat Sheet Boolean logic (named after mathematician George Boole) is a system of logic to designed to yield optimal search results. The Boolean operators, AND, OR, and NOT, help you construct a logical search. Boolean operators act on sets -- groups of records containing a particular word or concept.

Literature Searching Overview and tips on how to conduct a literature search.

Health Statistics and Data Sources Health related statistics and data sources are increasingly available on the Internet. They can be found already neatly packaged, or as raw data sets. The most reliable data comes from governmental sources or health-care professional organizations.

Evaluating Information

Primary, Secondary and Tertiary Sources in the Health Sciences Understand what are considered primary, secondary and tertiary sources.

Scholarly vs Popular Journals/Magazines How to determine what are scholarly journals vs trade or popular magazines.

Identifying Peer-Reviewed Journals A “peer-reviewed” or “refereed” journal is one in which the articles it contains have been examined by people with credentials in the article’s field of study before it is published.

Evaluating Web  Resources When searching for information on the Internet, it is important to be aware of the quality of the information being presented to you. Keep in mind that anyone can host a web site. To be sure that the information you are looking at is credible and of value.

Conducting Research Through An Anti-Racism Lens This guide is for students, staff, and faculty who are incorporating an anti-racist lens at all stages of the research life cycle.

Understanding Research Study Designs Covers case studies, randomized control trials, systematic reviews and meta-analysis.

Qualitative Studies Overview of what is a qualitative study and how to recognize, find and critically appraise.

Writing and Publishing

Citing Sources Citations are brief notations in the body of a research paper that point to a source in the bibliography or references cited section.

Structure of a Research Paper Reports of research studies usually follow the IMRAD format. IMRAD (Introduction, Methods, Results, [and] Discussion) is a mnemonic for the major components of a scientific paper. These elements are included in the overall structure of a research paper.

Top Reasons for Non-Acceptance of Scientific Articles Avoid these mistakes when preparing an article for publication.

Annotated Bibliographies Guide on how to create an annotated bibliography.

Writing guides, Style Manuals and the Publication Process in the Biological and Health Sciences Style manuals, citation guides as well as information on public access policies, copyright and plagiarism.

Annotated Bibliographies

• Definition and Purpose
• How to Make Annotated Bibliographies

Example Annotated Bibliography

•  Each reference in your bibliography follows the rules for your citation style, such as APA style.
•  Your notes for each reference come immediately after your reference. Your notes are indented so that each citation is easy to find.
•  The references in your bibliography appear in the same order they would in the reference list at the end of your paper. In APA style, that means that they are listed in alphabetical order by the first author’s last name.
•  Explain why each reference is useful for your paper.
•  Include specific data, facts, or other unique information you want to use in your paper.
•  Include limitations of each source.
•  You might notice some themes in what you are writing. Or, you might notice that different sources conflict. These themes and conflicts will be useful for organizing your literature review when you write your paper.

This study shows the complexity of identifying risk factors and, unlike other studies, closely examines the roles of obesity and birth weight. In this large cohort study of people in Britain, the researchers examined the roles of several demographic factors as well as a few different measures of weight and BMI changes. This study did not see a link between low birth weight and the risk of developing diabetes unless changes in BMI were also taken into account. The interplay between low birth weight and changes in BMI over time was a significant risk factor for developing diabetes. Other notable findings were that it mattered when people became obese; people who became obese as teenagers were at higher risk than people who became obese later in life. The study had several important limitations to note. First, the number of participants dropped drastically over time; they had an 82.4% drop-out rate over the 50 years of the study. Although they used statistical methods to estimate missing data and were careful to compare like timespans with like timespans, this lack of data could skew the results. The second major limitation is that the authors did not distinguish between different types of diabetes. Other limitations were more minor. Based on what the authors share about how they calculated another factor, which did not end up being significant, it is unclear if only people with married mothers were included in the study. The authors used the changes in BMI between the different data collection periods to estimate the average age of onset, but the data collection points were not evenly spaced and the authors did not explain why they collected data at those points in time instead of others. Again, that information could skew the data. In spite of its limitations, this article shows how no one factor alone can predict if a person will develop diabetes. It can be a caution in assigning too much importance to specific measures.

Ivarsdottir, E. V., Steinthorsdottir, V., Daneshpour, M. S., Thorleifsson, G., Sulem, P., Holm, H., Sigurdsson, S., Hreidarsson, A. B., Siggurdson, G., Bjarnason, R., Thorsson, A. V., Benediktsson, R., Eyjolfsson, G., Sigurdardottir, O., Zeinali, S., Azizi, F., Thorsteinsdottier, U., Gudbjartsson, D. F., & Stefansson, K. (2017). Effect of sequence variants on variance in glucose levels predicts type 2 diabetes risk and accounts for heritability. Nature Genetics , 49 (9), 1398-1402. https://doi.org/10.1038/ng.3928

In this study, the authors investigated the relationship between genetic variants that are known to affect blood glucose levels to see if they were also associated with type 2 diabetes. In addition to looking for differences between specific people, the authors also accounted for differences between samples taken from a single individual. The real value of this article is in the supplementary materials the authors shared. The authors included a copy of the code they used to calculate the differences between all of their samples. It can be modified to be used with other genetic traits. In addition, the authors also linked out to a set of open access genetic data sets for type 2 diabetes research. Both sets of information make this article super useful for additional genetic research.

Min, D., & Cho, E. (2018). Associations among health behaviors, body mass index, hypertension, and diabetes mellitus: A path analysis. Medicine , 97 (22), Article e10981. https://doi.org/10.1097/md.0000000000010981

Using existing data from a study of aging in Korea, this study identified specific risk factors for developing type 2 diabetes for people who have lower-than-normal weight levels or higher-than-normal weight levels. They looked at correlations between several dietary behaviors, exercise, demographic factors, and changes in body-mass index (BMI). Overall, they found a 2.4% incidence rate for diabetes in their study population, which consisted of middle-aged and older people in Korea who had not previously been diagnosed with diabetes. Regardless of weight, increases in a person’s BMI correlated with higher risk of developing diabetes. For people who were underweight, eating regular meals played a complex role; it was associated with a lower chance of developing type 2 diabetes, but also with increasing the person’s BMI. The study is helpful because it shows the complexity of identifying risk factors for developing type 2 diabetes and deciding what factors might be appropriate targets for public health programs. Rather than focusing on a single potential risk factor, this study looked at the interplay between several possible risk factors, which means the results reflect reality more closely. The study is limited in that the number of people studied was relatively small (a few thousand) and only a small portion of that group were underweight (about 130 people.) It is unclear if the results would hold for the larger population or for a different population.

Muller, N., Heller, T., Freitag, M. H., Gerste, B., Haupt, C. M., Wolf, G., & Muller, U. A. (2015). Healthcare utilization of people with type 2 diabetes in Germany: An analysis based on health insurance data. Diabetic Medicine , 32 (7), 951-957. https://doi.org/10.1111/dme.12747

This study demonstrates the high costs associated with having type 2 diabetes for both the individual and for insurance companies. It helps establish the argument that diabetes should be a public health priority and a priority for policy-makers and insurance companies. In addition, this study clearly showed that age correlates with both diabetes incidence and prevalence. This study looked at health-care related costs in insurance data for people in Germany who used the most common German insurance provider at the time. Based on that data, the researchers found that nearly 34% of people who had type 2 diabetes had secondary diabetes-related conditions. In addition, people with type 2 diabetes were more likely to use healthcare services on both outpatient and in-patient bases. People with type 2 diabetes were twice as likely to be admitted to the hospital and, when taking both outpatient and inpatient information into account, stayed at the hospital three times as long as people without any form of diabetes. (The researchers had excluded people with type 1 diabetes and gestational diabetes from their sample.) The researchers did not include standard deviations or confidence intervals; the data may not be fully representative. The data used in this study was collected in 2010; newer data might show different trends. The study’s findings may not be generalizable to other areas of the world due to differences in diabetes’ prevalence and incidence, the health care structures in place, and environmental factors. It still indicates that diabetes can be an expensive disease. In spite of some limitations, the information in this article suggests that targeting diabetes could have wide benefits.

Wang, T., Huang, T., Li, Y., Zheng, Y., Manson, J. E., Hu, F. B., & Qi, L. (2016). Low birthweight and risk of type 2 diabetes: A Mendelian randomisation study. Diabetologia , 59 (9), 1920-1927. https://doi.org/10.1007/s00125-016-4019-z

In this meta-analysis, the researchers pooled longitudinal data about two studies of healthcare workers in the United States to evaluate the connection between genetic differences and risk of developing diabetes. Building on a study that showed certain genetic variants increased the likelihood that a person would have a low birth weight, this study examined participant’s genetic make-up to determine their likelihood of having a low birth weight and then investigated how many people with each variation had diabetes at the end of the study. Overall, these calculated risk factors did correlate with increased risk of developing diabetes; having a higher risk factor increased the chances that the person would develop diabetes. However, only two of the five variants the authors considered correlated with increased risk of developing diabetes and they did not include the variant that had the strongest correlation to having a low birth weight. Even when taking into account other behavioral and demographic factors, genetic makeup was a significant risk factor for diabetes. This reinforces the idea that diabetes has several interacting causes. That said, the authors were only looking at people in the U.S. with European heritage; different populations might have different results. This study is important because it shows that social and behavioral factors are not the sole causes for diabetes; traditional public health programs cannot completely eliminate diabetes. In addition, the study’s results might explain some of why people with similar outward appearances or behaviors have different outcomes.

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