How to Prepare a Clinical Case Series for Publication

A clinical case series is an important form of medical research that describes the clinical characteristics, diagnostic findings, treatment approaches, and outcomes of multiple patients who share a disease, condition, exposure, procedure, or other clinically relevant feature. Case series can help clinicians recognise emerging patterns, describe uncommon conditions, evaluate preliminary treatment experiences, and identify questions that require further investigation.

Unlike a randomised controlled trial, a case series generally does not include a randomised comparison group. Its findings are therefore primarily descriptive and cannot usually establish whether a treatment caused a particular outcome. Nevertheless, a carefully prepared case series can contribute useful evidence to the medical literature when it addresses a clear clinical question and reports its methods transparently.

Preparing a clinical case series for journal publication involves more than collecting several patient histories and presenting them together. Authors must define the purpose of the series, establish eligibility criteria, obtain appropriate ethical permissions, organise clinical data, analyse the findings, and interpret the results cautiously.

This guide explains how to prepare a clinical case series, structure the manuscript, address ethical requirements, present clinical data, select a suitable journal, and improve the manuscript before submission. For related guidance, see How to Write a Case Report for a Medical Journal: Structure and Requirements.

What Is a Clinical Case Series?

A clinical case series is an observational descriptive study that reports information about a group of patients with a shared clinical characteristic. The patients may have received the same intervention, presented with a similar complication, developed a particular condition, or demonstrated an unusual pattern of symptoms or test results.

For example, a clinical case series might describe the outcomes of patients who developed a rare complication after a procedure, the clinical characteristics of patients diagnosed with an uncommon disease, or the treatment experiences of individuals with a condition that has limited published evidence.

Case series are used across medical specialties, including:

• Cardiology and cardiovascular surgery
• Neurology and neurosurgery
• Oncology and haematology
• Infectious diseases
• Dermatology
• Orthopaedics
• Paediatrics
• Radiology and diagnostic medicine
• Gastroenterology
• Pharmacology and clinical toxicology

The value of a case series depends on the relevance of the research question, the quality of the clinical information, the transparency of the methods, and the usefulness of the findings.

Clinical Case Report vs Clinical Case Series

A case report usually focuses on one patient, whereas a case series describes multiple patients who share a relevant clinical feature.

Number of patients: Usually one for a case report, multiple for a case series.

Main purpose: Describe an individual clinical experience for a case report, identify patterns across a group of cases for a case series.

Data presentation: Detailed individual narrative for a case report, individual details and group-level summaries for a case series.

Analysis: Primarily descriptive for a case report, descriptive analysis across cases for a case series.

Comparison group: Usually absent in both formats.

Main contribution: An unusual or educational observation for a case report, a broader description of clinical characteristics or outcomes for a case series.

The distinction is not determined by a universal minimum number of patients. Journal definitions and study conventions vary. Authors should choose the most accurate article type based on the study design and the target journal's requirements.

A case series should not be presented as a controlled study when no suitable comparison group or design supports that interpretation.

Why Publish a Clinical Case Series?

A clinical case series can be valuable when it addresses an important clinical problem that has not been adequately described in the existing literature.

1. Describe rare or emerging conditions

When a condition is uncommon, a series of patients may help clinicians understand its presentation, progression, diagnostic features, or potential complications.

2. Identify recurring clinical patterns

Reviewing several cases may reveal common symptoms, laboratory findings, imaging features, or management challenges that were not apparent from individual cases.

3. Report treatment experiences

A case series may describe how patients responded to a treatment or procedure in a real-world clinical setting. These findings can generate hypotheses for more rigorous studies, although they do not independently establish treatment effectiveness.

4. Examine complications and safety signals

A series describing unexpected complications or suspected adverse events may help clinicians recognise possible risks and identify areas requiring additional investigation.

5. Inform future research

Case series can provide preliminary information about patient characteristics, outcome definitions, recruitment feasibility, and clinical variability. These observations may help researchers plan subsequent observational studies or clinical trials.

Step 1: Identify a Clear Research Question

Before collecting or analysing patient information, define the purpose of the case series.

A broad topic such as "patients with a cardiovascular condition" may be too general to support a focused manuscript. A more specific question could examine the clinical characteristics and short-term outcomes of patients presenting with a particular complication in a defined setting.

A focused research question helps determine which patients belong in the series, what information should be collected, and how the results should be presented.

Define the clinical focus

The research question may centre on:

• A particular diagnosis or unusual clinical presentation
• A complication associated with a procedure
• The clinical course of a condition
• Diagnostic challenges and relevant investigations
• Treatment experiences or observed outcomes
• A group of patients with a shared exposure or characteristic

The objective should be descriptive and proportionate to the study design. If the series does not have an appropriate comparison group, avoid framing the question as though it can establish comparative treatment effectiveness.

Conduct a preliminary literature review

Search relevant medical literature to determine what is already known about the topic. Identify previous case series, individual case reports, observational studies, and relevant clinical reviews.

The literature review should help establish the contribution of the proposed series. Novelty may come from the patient population, clinical pattern, setting, diagnostic findings, complication, follow-up information, or the systematic description of cases.

A manuscript should not claim to be the first published series unless the search and supporting evidence justify that statement.

Step 2: Define Eligibility Criteria and Select Cases

A clear case-selection process is essential for producing a credible clinical case series.

Authors should specify which patients were eligible, the period covered by the study, and how cases were identified.

Inclusion criteria

Inclusion criteria describe the characteristics patients must have to be considered for the series. Depending on the research question, these may include:

• A confirmed or appropriately defined diagnosis
• A particular clinical presentation
• A specified treatment or procedure
• A defined clinical setting
• A relevant period of diagnosis or follow-up
• Availability of essential clinical information

Exclusion criteria

Exclusion criteria describe the circumstances under which otherwise potentially eligible cases are not included. Examples may involve insufficient diagnostic evidence, duplicate records, or missing information that makes the case unsuitable for the stated research question.

Exclusions should be scientifically justified and applied consistently. Researchers should not remove cases simply because their outcomes differ from the expected pattern.

Explain how cases were identified

Describe whether cases were identified prospectively or retrospectively, how the medical records or clinical registers were searched, and how eligibility was assessed.

For a retrospective series, explain which records were reviewed and how duplicate cases were handled. For a prospective series, describe the recruitment or enrolment process.

Where feasible, report the number of cases screened, excluded, and included, together with the relevant reasons for exclusion.

A transparent selection process helps readers understand the scope of the series and assess the potential for selection bias.

Step 3: Address Ethics Approval, Consent, and Confidentiality

Ethical considerations must be addressed before preparing a manuscript for submission. The requirements depend on the institution, jurisdiction, study design, and target journal.

Determine whether ethics review is required

Do not assume that a case series is automatically exempt from ethics review. Some institutions distinguish between individual case reports, descriptive case series, retrospective chart reviews, and formal research studies.

Consult the relevant institutional review board or ethics committee and follow the applicable procedures. If the institution determines that review is unnecessary or grants an exemption, document that determination when required.

Authors must report approval or exemption accurately. They should never imply that an ethics committee approved the study when no such approval was obtained.

Obtain consent where required

Patient consent for publication may be required, especially when the manuscript includes identifiable clinical details, photographs, imaging, or information about a rare condition.

Consent for clinical treatment is not automatically equivalent to consent for publication. Follow the journal's consent policy and institutional procedures. For children or patients unable to provide consent, the appropriate legally authorised representative may need to provide permission.

Protect patient confidentiality

Remove unnecessary identifying details from the manuscript, tables, images, and supplementary files. Names, initials, hospital numbers, and other direct identifiers should not appear in the manuscript unless a permitted and justified exception applies.

Even when names are removed, a combination of rare clinical details, dates, locations, and images may identify an individual. Use only the clinical information needed to communicate the scientific findings.

Do not alter important findings or fabricate details to protect privacy. Any necessary generalisation of dates or other information should preserve the clinical meaning and comply with journal policy.

Step 4: Develop a Standardised Data Collection Plan

A consistent data collection plan helps ensure that relevant information is gathered from every eligible case.

Before extracting information, define the variables required to answer the research question. A standardised data extraction form or spreadsheet can help reduce inconsistencies and missing data.

Depending on the topic, the dataset may include the following categories.

Demographic and baseline characteristics

Collect relevant characteristics such as age, sex, medical history, comorbidities, and other clinical factors that may help readers understand the patient group.

Only include demographic details that are necessary for the research question. Avoid unnecessary precision when it could increase the risk of identification.

Clinical presentation

Record the relevant presenting symptoms, duration of illness, physical examination findings, severity indicators, and important clinical history.

Use consistent definitions across cases. If symptoms or clinical features were documented differently in the original records, explain how the information was interpreted or classified.

Diagnostic investigations

Include relevant laboratory tests, imaging findings, pathology results, microbiological results, and other diagnostic procedures.

Ensure that values, units, dates, and reference ranges are accurate where they are important to interpretation. If diagnostic confirmation differed between patients, explain the criteria used.

Treatment and management

Record relevant medications, procedures, supportive interventions, treatment duration, and important modifications to care.

If the series describes different treatment approaches, explain how the approaches were selected and whether the variation reflects clinical practice, disease severity, or another factor.

Outcomes and follow-up

Define the outcomes before analysis whenever possible. Depending on the clinical question, outcomes may include symptom improvement, disease progression, complications, recurrence, hospital discharge, mortality, or functional recovery.

Specify when outcomes were assessed and how follow-up information was obtained. If follow-up duration varies between patients, report that variation rather than implying that every patient was observed for the same period.

Missing data

Identify variables with incomplete information and describe how missing data were handled.

Do not assume that an undocumented finding was absent. Distinguish between a finding that was assessed and found to be negative and one that was simply not recorded.

Step 5: Organise and Analyse the Clinical Data

Most case series use descriptive analysis to summarise patient characteristics, clinical findings, management, and outcomes.

The analysis should match the study objectives and the amount and quality of available data.

Use descriptive statistics appropriately

For numerical variables, report suitable measures such as the mean and standard deviation or the median and interquartile range, depending on the distribution and clinical context.

For categorical variables, report counts and percentages. Clearly identify the denominator used for each percentage, particularly when information is missing for some patients.

For example, if a clinical feature was documented in only a subset of the cases, the manuscript should not calculate its percentage using the full series without explaining the missing information.

Present individual and group-level findings

A case series may benefit from both a summary table and selected individual case details.

Group-level summaries show recurring patterns, while individual descriptions can clarify clinically important differences. The amount of individual detail should be proportionate to the scientific purpose and should not unnecessarily expose patient information.

Avoid unsupported statistical comparisons

A case series without an appropriate comparison group generally cannot determine whether one treatment is superior to another or establish causal relationships.

Small sample sizes also limit the reliability of complex statistical analyses. Avoid presenting exploratory associations as definitive findings, and do not use statistical significance as a substitute for clinical interpretation.

If inferential analyses are performed, explain their purpose, assumptions, limitations, and relationship to the study design.

Explain the limitations of the data

Retrospective records may contain incomplete information, inconsistent documentation, or differences in clinical assessment. These issues should be acknowledged rather than concealed.

Transparent reporting of data limitations helps readers judge how much confidence to place in the results.

Step 6: Structure the Manuscript for Journal Publication

The exact manuscript format varies by journal. However, a clinical case series commonly includes a title, abstract, introduction, methods, results, discussion, conclusion, declarations, and any required tables or figures.

1. Title

The title should clearly identify the clinical topic and the fact that the manuscript reports a case series, where appropriate.

For example: Clinical Characteristics and Outcomes of Patients With [Condition]: A Case Series

This is a generic title structure. Replace the placeholder with the actual clinical topic and ensure that the wording accurately reflects the study.

Avoid exaggerated claims such as "breakthrough treatment" or "definitive cure" unless they are justified by an appropriate evidence base.

2. Abstract

The abstract should provide a concise summary of the objective, methods, principal findings, and conclusion.

Depending on journal requirements, use structured headings such as Background, Methods, Results, and Conclusion, or a single-paragraph format.

The abstract should report the number of patients, the study setting and period where relevant, the principal characteristics or outcomes, and the main limitations or implications.

Ensure that every numerical statement agrees with the main manuscript. Follow the journal's word limit and rules concerning abbreviations and references.

3. Introduction

The introduction should establish the clinical background and explain why the case series is worth reporting.

A concise introduction generally:

• Describes the clinical condition or problem
• Summarises relevant existing knowledge
• Identifies the gap the series addresses
• States the study objective

Avoid including extensive background material that does not contribute to the research question.

4. Methods

The methods section should explain how the case series was assembled and how the information was analysed.

Include the following, as applicable:

• Study design and clinical setting
• Study period
• Inclusion and exclusion criteria
• Case identification and selection
• Definitions of relevant clinical variables and outcomes
• Data sources and extraction procedures
• Ethical approval or exemption and consent arrangements
• Statistical or descriptive analysis methods
• Procedures for handling missing data

The methods should provide enough detail for readers to understand how the findings were obtained. For related guidance, see How to Write the Materials and Methods Section of a Medical Research Paper.

5. Results

The results section should present the observed findings without excessive interpretation.

Start with the number of cases included and describe relevant baseline characteristics. Then report the clinical presentations, diagnostic findings, management approaches, and outcomes that address the research objective.

Use tables to summarise information across cases and figures to present relevant visual findings. Ensure that every table and figure is explained in the text.

Report important negative findings and variation between patients when they affect interpretation. Avoid highlighting only the most favourable or unusual outcomes.

6. Discussion

The discussion explains what the findings mean and how they relate to existing knowledge.

A useful discussion should:

• Summarise the principal findings
• Compare the observations with relevant published evidence
• Explain possible clinical implications
• Discuss alternative explanations where appropriate
• Acknowledge limitations and sources of bias
• Identify questions that future research should address

Avoid repeating the results section in full. Focus on interpretation and the contribution of the series.

The discussion should be especially careful when describing treatment outcomes. Improvement observed in a group of patients does not by itself prove that the treatment caused the improvement.

7. Conclusion

The conclusion should communicate the central clinical message in a concise and balanced manner.

State what the case series contributes, but do not claim that the results establish efficacy, safety, causation, or generalisability beyond what the study design supports.

A useful conclusion may identify a pattern worth recognising, a clinical issue requiring further evaluation, or a hypothesis that should be examined in larger studies.

8. Declarations and supplementary information

Follow the journal's requirements for funding statements, competing interests, author contributions, ethics declarations, consent, data availability, and other relevant disclosures.

If a reporting checklist is required, complete it and identify where each item is addressed in the manuscript. Ensure that any supplementary files follow the journal's technical and confidentiality requirements.

Step 7: Prepare Tables, Figures, and Clinical Timelines

Well-designed tables and figures can make a case series easier to interpret, particularly when the manuscript includes several patients with different clinical courses.

Patient characteristics table

A baseline table can summarise relevant demographic and clinical characteristics across the series.

Depending on the study, columns may include age group, presenting features, diagnostic findings, relevant comorbidities, and other variables that directly support the research question.

Avoid including identifying information or excessive details that do not help explain the results.

Clinical outcomes table

An outcomes table can show the management approach and follow-up status for each case or summarise outcomes across the group.

Use consistent definitions and clearly state the number of patients for whom each outcome was available. If outcomes were assessed at different time points, report this variation.

Figures and diagnostic images

Radiological images, pathology slides, photographs, and other clinical figures can be useful when they directly support the diagnosis or illustrate the clinical observation.

Every figure should have a clear caption. Label important findings where appropriate and explain abbreviations and symbols.

Confirm that patient consent covers publication of images where required, and remove embedded identifiers before submission.

Clinical timeline

A timeline may help readers understand how symptoms, investigations, diagnosis, treatment, and follow-up unfolded across the series.

If individual timelines differ substantially, report the differences accurately rather than combining them into a misleading single sequence.

Step 8: Use an Appropriate Reporting Guideline

Reporting guidelines help authors describe study methods and findings completely. The appropriate guideline depends on the study design and the nature of the case series.

The CARE guidelines are widely used for case reports. However, a multi-patient case series may require additional or different guidance depending on its design and specialty. Some clinical fields have specific reporting frameworks, and certain journals provide their own case-series checklists.

For example, surgical case series may be expected to follow a specialty-specific reporting framework. A retrospective clinical series based on medical records may also need to address the reporting requirements relevant to observational research.

Authors should:

• Identify the study design accurately
• Check whether a guideline applies to that design or specialty
• Review the journal's instructions for reporting checklists
• Ensure that the checklist reflects the actual methods used
• Avoid treating checklist completion as proof of methodological quality

A reporting guideline supports transparent communication; it does not replace appropriate study design, ethical review, or critical appraisal. For related guidance, see STROBE Checklist for Observational Studies: Medical Research Guide.

Step 9: Select a Suitable Journal

Choosing the right journal is an important part of the publication process. A clinically useful series may be unsuitable for a journal that does not accept case series or prioritises other study designs.

Check the journal's scope

Look for journals that publish research in the relevant specialty and accept the article type. Review recent publications to understand the journal's preferred topics, manuscript formats, and expected level of clinical contribution.

Read the author guidelines

Check the journal's word limits, abstract structure, reference style, figure requirements, consent forms, ethics declarations, and reporting checklist requirements.

Some journals may impose limits on the number of patients or require a case series to meet a particular definition. Confirm these details before drafting the final version.

Evaluate publication credibility

Review the publisher, editorial board, peer-review procedures, publication ethics policies, and indexing claims.

Be cautious of journals that guarantee acceptance, offer implausibly short peer-review periods, or make misleading claims about their reputation.

Consider publication costs

Check whether the journal charges submission fees, publication fees, or article processing charges. Review the available access options and any waiver policies before submitting.

Do not choose a journal solely because it promises rapid publication or has a low fee. The journal should be suitable, credible, and transparent about its procedures.

Step 10: Common Reasons Clinical Case Series Are Rejected

A case series may be rejected even when the clinical topic is relevant. Common issues include:

• Unclear research objective: The manuscript describes several patients but does not establish a focused clinical question.
• Insufficient justification: The authors fail to explain what the series adds to the existing literature.
• Poorly defined selection criteria: It is unclear why certain cases were included or excluded.
• Incomplete data: Important diagnostic findings, outcome information, or follow-up details are missing.
• Weak analysis: The manuscript presents numbers without explaining their relevance to the research question.
• Overstated conclusions: The authors claim treatment effectiveness or causation without an appropriate design.
• Ethical deficiencies: Consent, confidentiality, or institutional review requirements are not adequately addressed.
• Poor presentation: Tables are difficult to interpret, the clinical timeline is unclear, or the discussion repeats the results.
• Journal mismatch: The selected journal does not accept case series or does not consider the topic suitable for its readership.

Addressing these issues before submission can improve clarity and reduce avoidable editorial concerns.

Final Checklist Before Submission

Before submitting a clinical case series, verify that:

• The title accurately identifies the clinical topic and article type
• The research objective is clearly stated
• Eligibility criteria and case-selection methods are explained
• The data collection process is described
• Relevant clinical variables and outcomes are defined
• Descriptive statistics and denominators are reported accurately
• Missing data and limitations are acknowledged
• Tables and figures are clear and appropriately de-identified
• Ethical review, consent, and confidentiality requirements have been addressed
• The discussion is supported by relevant literature
• Conclusions are proportionate to the findings
• Funding and competing interests are disclosed
• The selected journal accepts the article type
• All journal-specific formatting and reporting requirements have been followed

A clinical case series can make a valuable contribution to medical literature when it is carefully designed, ethically prepared, and clearly reported. The strongest series combine a focused research question with transparent methods, appropriate descriptive analysis, and cautious interpretation of the findings.

Authors should remember that a case series without a comparison group cannot establish treatment effectiveness or prove causation. Its value lies in describing clinical patterns, generating hypotheses, sharing management experiences, and informing future research.

By following a structured approach, addressing ethical requirements, and selecting a suitable journal, researchers can improve the quality and publication readiness of their case series manuscripts. For those considering doctoral research in this area, Top 10 Pharmaceutical Research Topics for PhD offers guidance on selecting impactful research directions.

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