What place do case reports have in the anesthesia literature? According to research, their impact is significant, being regularly cited in review articles and even clinical guidelines.
Even so, the quality of such reports needs improvement, and their worth can be gauged by implementation of the Case Report (CARE) guidelines (www.care-statement.org).
“Case reports have always been an important part of medical literature, particularly in anesthesia,” said Ekta Khemani, MD, assistant professor of anesthesia and perioperative medicine at Western University, in London, Ontario. “For example, lidocaine toxicity was first discussed in a case report. But with the paradigm shift toward evidence-based medicine, we’re seeing case reports being published less and less regularly, and one of the reasons they’ve been criticized is the lack of standardization.
“So to circumvent this issue, the CARE guidelines—which is a 30-item checklist—were introduced in 2013, and we wanted to see how published anesthesia case reports score on these guidelines, as well as their bibliometric impact, where they’re being cited and who’s citing them.”
High-Impact Journals Cite High-Impact Cases
To that end, Dr. Khemani and her colleagues performed a systematic review in which they identified and analyzed 261 case reports published in either Anesthesiology or Anesthesia & Analgesia between 2007 and 2012. Two reviewers independently scored each case, following the CARE guidelines.
Literary impact was defined as the total number of citations, average frequency of citation and type of publication making the citation. Untoward events were evaluated using the Anesthesia Quality Institute (AQI) anesthesia adverse events and near misses framework. The relationship between AQI scores and number of citations was also analyzed, with an eye toward scores with high citation rates (>10).
“What made you select the two journals that you included and how do you think the results would have differed had you picked lower-rated journals?” asked Alexander Villafranca, MS, a PhD candidate at the University of Manitoba, in Winnipeg.
“We picked Anesthesia & Analgesia and Anesthesiology because they’re high-impact journals,” Dr. Khemani replied. “Also, both of those journals have recently switched over to publishing separate, dedicated journals for case reports. In fact, Anesthesiology’s 100th-anniversary issue specifically mentioned that they’re no longer going to be publishing case reports because they lack the rigor of randomized controlled trials.”
As Dr. Khemani reported at the 2016 annual meeting of the Canadian Anesthesiologists’ Society (abstract 148825), the mean CARE score for analyzed case reports was 19.6±6.4 out of 30 (median, 20.0), which she described as “not too bad.” The 261 case reports in the study were cited a total of 2,054 times, with a median citation frequency of four times each. Furthermore, 21% of the case reports were cited at least 10 times. “Our interrater reliability was quite good, at 0.74.”
“Surprisingly,” Dr. Khemani continued, “review articles actually cited case reports the most, at 33% of the time, and guidelines even cite case reports [3%].” Factors found to be significant for high citation frequency included type of anesthetic (P=0.0092) and unanticipated difficult airway (P=0.0082). “Finally, 21% of case reports discuss adverse events, as per the AQI framework.”
Session moderator Jordan Tarshis, MD, questioned whether all journals use case reports in the same way. “Did you see if there’s a difference in the impact factor of the citing journals? In other words, do the higher-impact journals cite with the same frequency as lower-impact journals?” asked Dr. Tarshis, associate professor of anesthesia at the University of Toronto.
“Although we didn’t look at that as part of the study, I can tell you anecdotally that there was a tendency for higher-impact journals to cite higher-scoring case reports,” Dr. Khemani responded.
Ultimately, Dr. Khemani saw a clear place for the CARE guidelines in anesthesia research. “Given the trend toward standardization, we feel that the CARE guidelines represent a quality improvement opportunity for case reports,” she said, “and the bibliometric impact is still significant, especially since we see that so many review articles are citing them. So despite criticisms, case reports still make up an important part of our medical literature.”