Qualitative study - Primary research

Qualitative studies are primary research that explores peoples' experiences, perceptions and viewpoints. The researcher collects data about what people say and may interview or survey people. 

In a qualitative study abstract you might see: 

• Who the researcher spoke to
• How they spoke to them
• What the perception, viewpoint or experience of people was

Calma, K. R. B., Halcomb, E., Williams, A., & McInnes, S. (2021). Final‐year undergraduate nursing students’ perceptions of general practice nursing: A qualitative study. Journal of Clinical Nursing, 30(7-8), 1144–1153. https://doi.org/10.1111/jocn.15662

Meta-analysis - Secondary research

A meta-analysis is a very high level of evidence. It is secondary research in which authors collect data from a number of primary studies and analyse it all together. Because this gives a larger collection of data than a single study, the results are considered to be highly reliable.

Things you might see in the abstract of a meta-analysis are:

• How the studies analysed were found
• How the data was analysed
• Terms such as pooling or combining results 

Hamley, S. (2017). The effect of replacing saturated fat with mostly n-6 polyunsaturated fat of coronary heart disease: A meta-analysis of randomised controlled trials. Nutrition Journal, 16, Article 30. https://doi.org/10.1186/s12937-017-0254-5

Systematic review - Secondary research

A systematic review is also a high level of evidence, and is secondary research. They ask a specific clinical question, identify all the research available and eliminate poorly done studies to make practice recommendations.

In a systematic review abstract, you are likely to see:

• How the authors found the studies
• What databases they searched
• How they decided whether to include the studies they found
• How they evaluated the studies to assess the quality and risk of bias

Brooke, J., & Ojo, O. (2015). Enteral nutrition in dementia: A systematic review. Nutrients, 7(4), 2456–2468. https://doi.org/10.3390/nu7042456

Scoping review - Secondary research

A scoping review is also secondary evidence, but is not considered as high a level of evidence as systematic reviews. It is done to see what literature is available on a particular topic, or if there is a gap in what has been studied. The authors identify all the research available and summarise it, or identify themes in it. 

In a scoping review abstract, you are likely to see: 

• What they are trying to find out
• Where the authors searched
• How they chose the studies
• What the chosen studies were like, including any themes found

Glasdam, S., Sandberg, H., Stjernswärd, S., Jacobsen, F. F., Grønning, A. H., & Hybholt, L. (2022). Nurses' use of social media during the COVID-19 pandemic: A scoping review. PloS One, 17(2), e0263502. https://doi.org/10.1371/journal.pone.0263502

Narrative review - Secondary research

While a narrative review, sometimes called a literature review, is secondary research, it is not considered a high level of evidence. This is because the authors usually don't say how they chose the articles they reviewed, so it is not reproducible. Narrative reviews aim to identify and discuss previous relevant research on a topic to summarise, identify a gap, or build on or critique previous work. 

In a narrative review abstract, you are likely to see:

• Some background information that explains why the authors are writing about the issue or topic
• A brief description of what previous research has found
• What the review does, eg summarise or critique the literature
• A recommendation of some kind, such as a need for more research on a topic, or a new way of doing something

Crnich, C. J., Jump, R., Trautner, B., Sloane, P. D., & Mody, L. (2015). Optimizing antibiotic stewardship in nursing homes: A narrative review and recommendations for improvement. Drugs & Aging, 32(9), 699–716. https://doi.org/10.1007/s40266-015-0292-7

Editorial or expert opinion - Secondary research

An editorial or expert opinion is secondary research, but are considered a low level of evidence. This is because editorials can be based on one person's experience or opinion, and expert opinions on a group's opinion. They may not be transferable to other situations. 

In an editorial, you can expect to see:

•  The author using the first person, eg. I wish to continue.....
• No references or abstract
• A description of the author's personal experiences

Watson, R. (2009). Editorial: Nursing innovations: The Joey. Journal of Clinical Nursing, 18(17), 2393. https://doi.org/10.1111/j.1365-2702.2009.02823.x

Randomised controlled trial - Primary research

Randomised controlled trials are primary research. The researchers conduct experiments to find out how effective a particular intervention or treatment is. Participants are randomly assigned to an intervention group or a control group that does not receive the intervention, and then the results are compared to see if the treatment had an effect.

In the abstract of a randomised controlled trial, you are likely to see: 

• A description of the patient characteristics
• How they were divided into a control or treatment group
• What the treatment was
• Some statistical analyses of the results, comparing the control and treatment group

Wilson, P. H., Rogers, J. M., Vogel, K., Steenbergen, B., McGuckian, T. B., & Duckworth, J. (2021). Home-based (virtual) rehabilitation improves motor and cognitive function for stroke patients: A randomized controlled trial of the Elements (EDNA-22) system. Journal of NeuroEngineering and Rehabilitiation, 18, 165. https://doi.org/10.1186/s12984-021-00956-7

Cohort study - Primary research

A cohort study is primary research and examines links between potential risk factors and health outcomes. Health outcomes for people who have been exposed to the risk and those who have not been compared.

In the abstract of a cohort study, you are likely to see: 

• The characteristics of the people studied
• The risk factors and health outcome or condition
• The time frame the study was conducted in
• Some statistical analyses showing changes over time in the population and risk factors

Soriano, L. C., Soriano-Gabarro, M., & Rodriguez, L. A. G. (2018). Trends in the contemporary incidence of colorectal cancer and patient characteristics in the United Kingdom: A population-based cohort study using The Health Improvement Network. BMC Cancer, 18, Article 402. https://doi.org/10.1186/s12885-018-4265-1

Case control study - Primary research

Case control studies are primary research comparing people who already have a specific health condition or outcome with those who don't in order to try and find factors that may be linked to the outcome. The researcher may look at medical records or what the patient remembers, and there is no treatment given to the participants.

• The health condition or outcome
• The patients with the condition that were studied, and the group they were compared to
• Statistics on factors such as co-morbidities or medication 

Russom, M., Tesfaselassie, H., Goitom, R., Ghirmai, T., Weldedhawariat, F., Berhe, A., Tedfai, D., Debesai, M., Berhane, T., & Woldu, H. G. (2019). Risk factors of gout in MDR-TB patients in Eritrea: A case-control study. Tuberculosis Research and Treatment, 2019, Article ID 9429213. https://doi.org/10.1155/2019/9429213

Case reports and series - Primary research

Case series and reports are primary research and describe individual cases, focused on areas such as a particular disease, symptom, outcome, or intervention. They may not be generalisable to the wider population and are considered a low level of evidence. 

In a case report abstract you might see: 

• A description of the patient studied and their symptoms, condition or outcome
• How they were treated
• The outcome of the treatment
• Sometimes an explanation of why the patient was considered unusual

Huang, S., Li, R., & Yuan, Y. (2021). Severe neuropathic attack in a woman with acute intermittent porphyria: A case report. Journal of International Medical Research, 49(1). https://doi.org/10.1177/0300060520983143