Case reports/Case Series

A descriptive record of a single individual based on an unusual observation where there may have been an association between cause and effect

Definition of case reports

1. Disease identification

2. ADR (Adverse drug reaction reporting

3. New treatment report

4. Educational

5. Quality assurance

General Types of case reports

Retrospective or prospective

Case reports can be ___ or ____

• More common

• Reports occurrence observed AFTER Event

• Limited by information and outcome measures recorded during actual event

points about retrospective case reports

• Preplanning the proposed treatment approach

• Measurement of impact of the proposed treatment on patient outcomes 

points about prospective case reports

1. Makes unique/novel or NEW point (adds to literature)

2. provides sufficient background

3. Clearly states timeframe

4. Describes key patient characteristics

5. Details full clinical course

6. Lists all medications 

Characteristics of a good case report part 1

• Reports effects of dechallenge and rechallenge

• Includes patient outcomes, diagnostic workup, and lab results

• Provides convincing evidence within report itself

• Uses scientific evidence

• Applies accepted evaluation tools to strengthen causality assessment

• Ensures objectivity 

Characteristics of a good case report part 2

A descriptive record of multiple individuals based on observations where there may have been an association between cause and effect in multiple patients

Case series definition

1. Research question

2. Study population

3. Interventions

4. Outcome measures

5. Statistical analyses

6. Discussion/conclusion

Features of a case series report (in order)

• Describes new diseases/effects

• MAY identify rare disease/presentation

• MAY identify novel/new or rare side effect

• MAY identify new potential use or benefit of a drug(s)

• May generate hypithesis

• Educational

• Easy and cheap to do

Case reports/Series Advantages

• Limited generalizability

• Unable to establish causality

• No comparator group

• N = 1 or small sample size

• Limitations of documentation (usually retrieved post-hoc)

• Potential for recall bias/interviewer bias

• Data collection may be incomplete

Case reports/Series diadvantages