How many patients does case series should have In comparison to case reports - Pubrica
                     HOW MANY 
PATIENTS  DOES 
CASE SERIES  
SINH COOUMLPDA RHIASOVNE 
TO  CASE REPORTS
An Academic presentation by
Dr. Nancy Agnes, Head, Technical Operations, 
Pubrica  Group: www.pubrica.com
Email: [email protected]
Today's 
DisOcuutlsinsion In-Brief
e Introduction
When to Consider a Case Series
When High Acceptance Rate is 
Possible  Subjects in Case Series 
and Case Report  Merits and 
Demerits
Criteria
Conclusion
In-
Brief
The medical research field is continuously expanding, with more amount of data,  
being generated every day. In clinical research, several studies have been  
classified into descriptive and analytic studies. Descriptive studies include cross-  
sectional studies, ecological correlational studies, case reports writing, case 
series  report writing and surveillance studies. On the other hand, analytical 
studies  examine a hypothesis about a causal relationship between exposure and  
outcome. Since the objective of this article is on case report and case series, the  
analyses would be restricted only to those type of studies alone.
Introductio
n A case series and case reports consist of either of  
aggregate of individual cases in one publication on  
the diagnosis and treatment or a report of a single  
patient.
A high number of case reports been received for  
publication, but it seems the rejection rate of CRs is  
quite high across many journals.
This is because, according to the principle of  
evidence-based medicine, they provide a lower  
strength of evidence among clinical studies, as  
shown in Figure 1.
Contd...
Out of two different forms of clinical research studies
– (i) descriptive and (ii) analytic, case series (CS) 
 and case reports (CR) fall under descriptive one.
In specific, case reports/series are usually  
retrospective and occasionally be prospective, such  
as the Herrick’s first case report of sickle cell  
disease.
Contd...

When to  
Consider a 
If you intend to publish your case reports and case  Case 
series, remember your reports should be the first  
document medical breakthroughs i.e., reporting of rare  Series
diseases in identifying adverse or beneficial outcomes of  
intervention or novel diagnostic or therapeutic strategies.
Further, the primary purpose was to generate  
hypotheses that can be subsequently tested in studies of 
 greater methodological rigour.
Contd.
..
Therefore, case series can be applied to assess the treatment safety and  
diagnostic accuracy, and in fact, no control group is necessary with good long-term 
 follow-up.
In order to get your research to be funded, there is a need for preliminary evidence  
on which to base the belief that a treatment may be efficacious.
In this case, these reports often provide the first level of evidence.
A study published in the Journal of Clinical Epidemiology examined the case 
 reports and case series published in The Lancet Journal.
Contd...
The study demonstrated that case series that are carefully designed and, of  
course, similar to clinical trials are likely to minimize bias and maximize the  
information that can be deduced from a limited number of patients.
Besides, in order to publish your reports, need to ensure that both case series  
and reports have to follow a standard structure and methodological rigour with  
reference to selection, ascertainment, casualty and reporting.
The following section highlights the difference between these two reports and  
possible ways to get it published in High impact journals.
When 
High  Difference between a case series and a case report
Acceptan
A case series in general carries information acquired 
ce  Rate  from various sources containing one or more 
is  information  about the disease, treatment, diagnostic 
methods, etc.,  whereas a case report contains a very 
Possible less amount of  data and may contain in-depth 
demographical details.
It takes more time to accept the case series than
the  time taken to accept the case report by any 
publisher.
Contd...
Case reports are professional narratives that offer feedback on clinical practice  
guidelines and provides a framework for adverse events, initial signals of  
effectiveness, and cost.
They can be shared for medical, scientific, or educational purposes.
Subjects in 
 Case 
Many publishers strongly stick to the count of Series  and 
the  patients reported in the study. Case  
After the study reports, [1] suggested that a case report  Report
contain patients of less than five individuals, whereas a  
case series can contain four and more patients.
Few journals have no upper limit set for the case series; 
 other journals accept nearly 20 patients report as a  
single case series.
Contd...

Merits 
and  Both case series and casereportwriting have
their  merits and demerits.
Demerits
Case series is very useful in rare case scenarios where  
a new kind of disease or disorder harms the subject.
Also, the publishers may make few negotiations in  
considering a case series due to the biased contents  
based upon the editors' personal opinions.
Besides, case series has high external validity, no  
interference in treatment decision process, wide range  
of patients and finally inexpensive.
Contd...
In terms of limitations, the study lack of comparison 
 groups, data collection often be incomplete, 
susceptible  to bias, selection and measurement bias.
On the other hand, case reports help healthcare  
professionals easily understand the cases and take less 
 time to be prepared.
But case reports may not possess all the relevant and  
minute details to treat the subjects.
No randomisation is followed in a case series;  
therefore, it becomes more efficient and affordable.
Criteria
Whenever a case series is getting developed,
few  criteria need to be followed.
(i) Title – Remember to include the words “case series” and 
 the area of focus in the title
(ii) Abstract’ – Introduction - Unifying theme of the case 
 series should be emphasized
a. Methods – what was done, how and when.
b. Results – what was found.
c. Conclusion – what we have learned.
Contd...
(iii) Introduction – emphasize the scientific background 
 and rationale.
(iv) Design –the research registry number  
(ResearchRegistry.com or ClinicalTrials.gov or 
 ISRCTN), list the intended population, 
process  manner, and end outcome.
There must be a proper method to acquire the data 
 like regular telephone calls, clinical observation, and  
more.
Study design should be sated including prospective,  
retrospective in design.
Contd...
Also, enough time should be given between continuous 
 follow-ups.
Not a case series would be attractive when taking the  
subject cases that last more than a year because  
increasing the period may lead to disruption of study in  
the middle due to any unexpected situations like the  
patient would die or relocate his/her place or change 
 the hospital.
(ii) Analysis – Descriptive statistics and methodologies  
must be used while analysing and no comparative tests 
 yielding p values should be carried out.
Contd...
(iii) Reporting – A case series must report the subject  
details and progress, complete details, and analyse 
 every follow-up.
There must be no declared conclusions at the end  
because once a valid conclusion is declared, it makes  
the investigators keep on updating the results by  
comparing with other results, which develops a need 
 for hypothesis testing.
Contd...
The researcher must understand the limitations before  
getting engaged and possess awareness about the  
conclusions.
Pubrica has extensive experience in developing a  
detailed clinical case report Writing Services that assist 
 in highlighting the scientific documentation.
Contd...

Conclusion
Both case series and case reports in the clinical  
research field are meant to be utilized by healthcare  
professionals.
Except for the distinguishing features between a case  
series and a case report, they both tend to give valid  
information with timely intervention.
Contd...
If both are well prepared from the initial stages, they  
can even be alternatives to another level of studies  
employed more confidently than the former.
Reporting case series in a standardized and  
statistically appropriate manner would allow for proper  
interpretation at the same time enable to conduct of  
future meta-analyses to produce estimates for the  
long-term outcomes.
Contact Us
UNITED KINGDOM
+44- 7424810299
INDIA
+91-9884350006
EMAIL
[email protected]