Table 1

Tool for evaluating the methodological quality of case reports and case series

DomainsLeading explanatory questions
Selection1. Does the patient(s) represent(s) the whole experience of the investigator (centre) or is the selection method unclear to the extent that other patients with similar presentation may not have been reported?
Ascertainment2. Was the exposure adequately ascertained?
3. Was the outcome adequately ascertained?
Causality4. Were other alternative causes that may explain the observation ruled out?
5. Was there a challenge/rechallenge phenomenon?
6. Was there a dose–response effect?
7. Was follow-up long enough for outcomes to occur?
Reporting8. Is the case(s) described with sufficient details to allow other investigators to replicate the research or to allow practitioners make inferences related to their own practice?
  • Questions 4, 5 and 6 are mostly relevant to cases of adverse drug events.