Chapter 8 Flashcards
A case series describes:
A group of patients who have the same disease condition or who have undergone the same procedure
What is the difference between a case reports and a case series?
A case report describes one patient, whereas a case series describes a group of individuals.
When can a case series be written?
1) When the researcher has access to an appropriate source of cases.
2) When there is a compelling reason to write about those cases.
A case series study approach can be useful for:
1) describing the characteristics and similarities among a group of individuals with the same signs and/or symptoms of a disease.
2) Identifying new syndromes and refining case definitions.
3)  Clarifying typical disease progression.
4) Describing atypical presentation of a disease or unusual complications from a treatment.
5) Developing hypotheses for future research.
How many participants do you need for case series studies?
A handful (rare conditions), a hundred, or a thousand.
What are the beginning steps of a case series study?
1) Selecting one disease of interest
2)  Determining what will be new and interesting about the study
3) Identifying an appropriate and available source of cases
What is the next step for case series studies?
Establishing a clear case definition that spells out inclusion and exclusion criteria.
How can we select participants for a case series study?
From clinical locations that use ICD codes (International Classification of Diseases).
What does the case definition include?
A disease description plus any relevant person, place, and time (PPT) characteristics. It may include the ICD number but a code alone is not sufficient.
Case defintions are essential for any:
Outbreak investigation regardless of the study approach used to investigate the epidemic.
When do we use the case series study approach?
When a source of cases is available, and no comparison group is required or available.
What should you watch out for in case series studies?
A lack of generalizability
What statistical measures are required for a case series study?
Only descriptive statistics are required
When medical Records will be consulted as part of the data collection process, it is often helpful to create what?
A questionnaire that guides the extraction of information from these files.
What is one of the limitations of relying on patient charts?
They usually contain only clinically relevant information.
What might the absense of a specific note about a symptom or history mean?
That the exposure was present, but not recorded.
What should a data extraction tool include?
A space to indicate the absence of a desired piece of information in the record.
What should the researcher carefully consider during the analysis and interpretation stage of the research project?
The amount and type of missing information.
What requirements protect patient privacy in case series studies?
1) Approval by a research ethics committee
2) Informed consent from participants and/or careful use of existing records
3) Removal of all potentially identifiable information prior to publication
If pictures will be used, what must the researcher have?
Informed consent and documentation of consent even when there are no identifying marks.
What kind of statistics do case series studies require?
1) Simple counts
2) Percentages
3) Morbidity
4) Mortality (Case fatality rate)
What is the case fatality rate?
The proportion of people with a particular disease who die as a result of that condition
What is the mortality rate?
The percentage of members of a population who die of any condition during a specified time period.
What is the proportionate mortality rate?
The proportion of deceased members of a population whose death was attributable to a particular cause
If a case series follows patients afterwards, what does this study become?
A cohort study in which all participants are defined by their disease status.
