From the Guidelines
A case series study should be written by first selecting a group of patients with a similar condition, treatment, or outcome of interest, and following the guidelines outlined in the Preferred Reporting of CasE Series in Surgery guidelines, as recommended by 1. When writing a case series study, it is essential to begin with a clear introduction explaining the purpose of the study and its significance.
Key Considerations
- In the methods section, describe your patient selection criteria, data collection methods, and any ethical considerations or approvals obtained.
- The results section should present patient demographics, clinical characteristics, treatments administered, and outcomes observed, using tables or figures when appropriate to summarize data.
- Include detailed case descriptions for each patient, highlighting relevant clinical findings, diagnostic tests, interventions, and follow-up information. Some studies outlining tumor characteristics may follow a classical epidemiologic cohort or case-control design, and for these, authors should take into account the relevant Strengthening the Reporting of Observational Studies in Epidemiology (cohort studies or case-control) checklists, as suggested by 1.
Best Practices
- Maintain patient confidentiality by removing identifying information.
- Be consistent in your reporting format across cases.
- Focus on objective observations rather than speculation. The Case Report or CARE Guidelines, developed in 2013, provide a framework that supports transparency and accuracy in the publication of case reports and the reporting of information from patient encounters, as discussed in 1. However, for surgical case reports, the Surgical CAse REport (SCARE) Guidelines, developed through a Delphi consensus exercise among experienced case report reviewers and editors, should be used, as outlined in 1 and 1.
Additional Recommendations
- State the method of case selection, including whether prospective or retrospective and whether stratification or matching was used, as recommended by 1.
- Precisely define all clinical endpoints examined.
- List all candidate variables initially examined or considered for inclusion in models. By following these guidelines and best practices, a well-written case series study can provide valuable insights into rare conditions, novel treatments, or unusual disease presentations that might not be captured in larger studies, as noted in 1 and 1.
From the Research
Principles for Designing a Case Series Study
- A case series is a descriptive study that follows a group of patients who have a similar diagnosis or who are undergoing the same procedure over a certain period of time 2
- The clinical sample in a case series is representative of a common clinical population, as surgeons and patients decide on whether or not treatment is given 2
- Results of case series can generate hypotheses that are useful in designing further studies, including randomized controlled trials 2
Characteristics of High-Quality Case Series Studies
- Clearly defined study question 3
- Well-described study population 3
- Well-described intervention 3
- Use of validated outcome measures 3
- Appropriate statistical analyses 3
- Well-described results 3
- Discussion/conclusions supported by the data presented 3
- Funding sources acknowledged 3
Definition of a Case Series
- A case series should have more than four patients, while four patients or less should be reported individually as case reports 4
- The concept of "case series" is not well defined in the literature and does not reflect a specific research design 4