A research study describes original scientific research and findings. In most cases, it is an article appearing in a peer-reviewed academic, scientific, or medical journal.
Research studies can be difficult to identify. Not every journal article you encounter in your searches will be a research study. For example, sometimes a title may sound like a study, but it may actually be a book review, editorial, letter, or commentary. This guide is intended to help you to identify which articles are studies and which ones are not.
A research study usually follows a common format and contains distinct parts. The best way to identify a study is by READING the abstract (which will almost always appear right after the title and will describe in a paragraph or two the main purpose and findings of the research.)
A research study typically follows this format:
- Technical & precise
- List of Authors
- Literature Review: Discussion of current and past research on the area of study, often under the subheading Literature Review or Background. The literature review cites primary research (journal articles) not secondary research (textbooks or news articles).
- Study Objectiove: This is usually a statement of goals, and explains why the study makes a new contribution to what is already known about a subject.
- Methodology/Materials and Methods
- How the test, experiment, or research was performed.
- Who participated in the study.
- How the results were measured.
- Visuals, such as charts or graphs.
- Analysis of Results/Discussion
- Summary of results.
- Interpretation of results.
- Problems or issues with data; sources of error.
- Future extension of the research or next steps.
- Listing of outside sources used in the research.
- Cites the journal articles described in the Literature Review portion of the Introduction.
Knisely, K. (2005). A Student Handbook for Writing in Biology (2nd ed.). Sunderland, MA: Sinauer Associates, Inc.
Examples of well-constructed studies and study components
Yarden, R. and Papa, M. (2006). BCRA1 at the crossroads of multiple cellular
pathways: approaches for therapeutic interventions.
Molecular Cancer Therapeutics, 5(6), 1394-1404.
Approximately 10% of the cases of breast cancer and invasive ovarian cancer are hereditary, occurring predominantly in women with germ-line mutations in the BRCA1 or BRCA2 genes. Low expression of these genes in sporadic tumors extends their significance to sporadic breast and ovarian cancers as well. For over a decade since its identification, extensive research has been directed toward understanding the function of the breast and ovarian tumor suppressor gene BRCA1. The long-term goal has been to identify the biochemical pathways reliant on BRCA1 that can be exploited for developing targeted therapies and benefit mutation carriers. To date, no one specific role has been identified, but rather it is clear that BRCA1 has significant roles in multiple fundamental cellular processes, including control of gene expression, chromatin remodeling, DNA repair, cell cycle checkpoint control, and ubiquitination, and overall is important for maintenance of genomic stability. Major findings and potential BRCA1-dependent therapies will be discussed.http://www.ncbi.nlm.nih.gov/pubmed/16818497?ordinalpos=1&itool=Entrez
Beenken, S., MD, Grizzle, W., MD, PhD, Crowe, D.R., MD, Conner M., MD et al. (20)
Molecular biomarkers for breast cancer prognosis: coexpression of c-erbB-2
and p53. Annals of Surgery, 233(5), 630-638.
Literature reviews summarize the research that has been done on a given topic. There are two types.
The first, short literature reviews, appear in the introductory portion of studies. They describe previous studies related to work on a topic and will be fully referenced at the end of the study. These literature reviews show the progression of the research.
The second type is a stand-alone article on a certain topic. Such articles are done periodically; often they are long, and they are referred to as overviews, literature overviews, or review articles. There are often subdivision categories in the online databases to search for these articles separately.
It is important to remember that literature reviews are not studies; this can sometimes prove confusing for students. It is an important distinction.
Example of the first type of literature review:
Liver cancer is among the deadliest of human malignancies, with an annual worldwide incidence of 600,000 cases and a mean survival time of 6 months from time of diagnosis (1). The principal causes of liver cancer are infection with hepatitis B or C virus, chronic alcoholism, aflatoxin exposure, or other circumstances that predispose to cirrhosis. These causes are believed to produce liver cancer by inducing repeated rounds of hepatocyte death and proliferation (2), creating a permissive environment in which genetic or epigenetic changes could occur that confer gain of function on protooncogenes or loss of function on tumor suppressor genes (3). Many such changes have been reported, but the combinations of these changes that operate to produce human hepatocellular carcinoma (HCC) remain largely uncharacterized. Frequent among the changes known to occur in human HCC are overexpression, amplification, or mutation of the protooncogene MET, which encodes the receptor protein tyrosine kinase Met (4–6) and activation of the Wnt signaling pathway by mutation of the genes encoding either ß-catenin (CTNNB1), axin (AXIN1), or axin 2 (AXIN2) (7). These changes provided points of departure for the present study.
Humans also develop hepatocellular adenomas (HCAs), a relatively rare benign tumor of the liver found most frequently in women with a history of oral contraceptive use (8). In contrast to HCC, the most frequent genetic change that has been clearly implicated in HCA is mutation that inactivates the TCF1 gene, which encodes the transcription factor hepatocyte nuclear factor 1a (HNF1a). Biallelic inactivating mutations of TCF1 are found in 50% of sporadic HCAs, and some families with heterozygous germ-line mutations in TCF1 display an adenomatosis syndrome, in which individuals develop 10 or more HCAs that exhibit a loss of heterozygosity for TCF1. Although tcf1-/- mice develop hepatomegaly and die around the time of weaning, they have not been reported to show evidence of neoplasia (9). Hence, other events in addition to inactivation of TCF1 are likely to be necessary for HCA genesis.
We previously reported that overexpression of wild-type MET, as observed in a substantial fraction of human HCCs, can initiate HCC genesis in mice (10). We have now used those mice to reconstruct prospectively the genomic progression to both HCA and HCC. The results appear to replicate events that occur during the genesis of both benign and malignant tumors in the human liver. The mouse models described here should prove useful for the further study of tumorigenesis in the liver and for preclinical testing of new therapeutics.
Tward, A., Jones, K., Yant, S., Cheung, S., Fan, TS., et al. (2007). Distinct
pathways of genomic progression to benign and malignant tumors of the liver.
Proceedings of the National Academy of Sciences of the United States of
Example of the second type of literature review:
Lux, M., Fasching, P., and Beckmann, M. (2006). Hereditary breast and ovarian cancer:
review and future perspectives. (Disease/Disorder Overview.) Journal of
Molecular Medicine, 84 (1), 16-29. Downloaded January 30, 2008 from Health Reference Center Academic Database.
Types of Studies:
There are two main types of epidemiological research studies which you may find described in the articles you choose: observational studies and randomized controlled trials (RCTs).
Observational studies can be divided into two sub-types: prospective cohort studies and case-controlled studies. The main difference between the two types is that prospective cohort studies compare groups who differ in a particular way (smokes vs. does not smoke) to see which of them develop a specific outcome, such as a type of cancer. Case-controlled studies compare a group that already has a specific outcome, such as a type of cancer, with a group that does not, to see how the groups differ behaviorally and otherwise.
RCTs are just one type of clinical trial, and are considered “a gold standard for assessing certain factors, like cancer therapies” because they use a large sample group and follow them for a long time.
In addition, RCTs are what is called “double-blinded,” meaning that neither the patients nor the researchers know who is involved in either group, so the risk of bias is greatly reduced.
Clinical trials have many subtypes, which often relate to the stages that a new drug must go through to obtain FDA approval. Visit http://www.nextgenmd.org/vol1-5/clinicaltrialsv1i5.html for a discussion of different types of clinical trials.
The primary difference between observational studies and randomized controlled trials (RCTs) is that an observational study is concerned with what can be learned from the correlation between a subject(s) existing behavior, such as eating, drinking or exercise, with a given outcome, such as a type of cancer. A trial, on the other hand, changes the subject(s) behavior, such as modifying the diet or activity level, to see what can be learned from the intervention.
A meta-analysis is a type of study which itself takes a number of other studies on a topic and analyzes and combines their results statistically.
Visit the Susan G. Komen Breast Cancer Foundation website where you will find a comprehensive description of the types of studies used in breast cancer research. Click on the top navigation bar ‘”About Breast Cancer,” “Breast Cancer Research,” “Research Studies” and then select the link for “different types of studies” or click on the link below:
The Next Generation: An Introduction to Medicine, vol 1, no 5