To case report or not to case report, that is the question

The Canadian Journal of Respiratory, Critical Care and Sleep Medicine (aka as the Red and White Journal) has decided to publish case reports. Controversy continues to surround the much maligned case report and its place in scientific publications. Most case reports are rarely cited, generally tend to decrease impact factors, and have thus generally fallen out of favor with many editors and publishers.¹

However, they continue to be popular with readers. In addition, entire medical curricula have been built around case-based learning approaches (problem-based learning programs), and they are highly popular with both students and faculty.² Why is this? Well, for one, I have rarely seen a randomized controlled study walk into my office with a referral for a thoracoscopic probe of the statistics section, but I do continue to see a lot of patients referred for confounding lung lesions. In other words, the case report puts the disease process in a relevant context that clinicians can readily identify with in terms of their daily work. In addition, cases are used in medical pedagogy and continuing professional development (CPD) because they are a powerful learning tool which, in my opinion, has been under-recognized by scientific journals.

Tell me and I forget; Teach me and I remember; Involve me and I learn

-Attributed to Benjamin Franklin… or some ancient Chinese sage³

An in-depth discussion of learning theory is beyond the scope of this article. However, a basic understanding of relevant cognitive psychology will be useful here.⁴ Memory is divided conceptually into long- and short-term memory. Short-term memory is short-lived; and long-term memory is, well… long-lived. Learning happens in the space defined as short-term memory. For learning to happen, new information has to meet prior knowledge within the space defined as short-term memory. This requires the reception of new information, and activation of prior knowledge that otherwise resides in long-term memory. In many ways then, short-term memory is like the RAM on your computer, and long-term memory like the ROM. There are two additional things to know: new information is very difficult for the mind to handle; according to experts even the smartest people may manipulate only a maximum of 7 such « units of information » at any one time (try memorizing the following 7 units of information: « o r t p s r e »; now try memorizing one unit: « r e p o r t s »). Once the meeting between new and old information has taken place, in order for true in-depth learning to occur, this new information must be organized and integrated with prior knowledge and transferred back into long-term memory, where it will exist indefinitely.

Case-based learning is advantageous because it allows all of these elements to function. Focused learning objectives and pre-test questions, such as the Red and White journal has incorporated into our case reports, activate prior knowledge of the subject. A well-structured case presentation and discussion present the reader with a limited amount of new information in an organized way and contextualize that information in a relevant clinical setting, which makes it easier for the mind to understand and to handle. Images illustrating various features of the case (radiological, surgical and pathological) help build on and organize that new information and the post-test helps consolidate and integrate learning.

Singularity is almost invariably a clue.

-Sir Arthur Conan Doyle⁵

Now let us for a moment break away from all this pedagogical theory and plunge into the hidden recesses of the history of medicine to illustrate how case reports can influence medical practice. Some may have heard that Jacobaeus described the technique of thoracoscopy as early as 1910.⁶ But in fact, thoracoscopy had been performed some 50 years earlier by Sir Francis Richard Cruise of Dublin (who would nowadays be described as an urologist); he used a cystoscope to perform a thoracoscopy in an 11yo patient with empyema! This index case was published… as a case report.⁷ In 1898 John Murphy of Chicago described his technique for inducing an artificial pneumothorax as a form of treatment in cavitary tuberculosis; 5 patients were included in this seminal report;⁸ Forlanini in Italy later independently described a similar technique.⁹ The impact of these case reports were such that artificial pneumothorax and medical thoracoscopy for diagnostic assessment and lysis of adhesions in collapsotherapy became mainstays in the treatment of tuberculosis for almost half a century until effective antibiotics were introduced.

Another more recent example: While still an intern at McGill, Myer Kryger had as a patient an obese taxi driver who complained of falling asleep at red lights! He studied this patient well and found that he obstructed his upper airway during sleep, leading to sleep deprivation and daytime somnolence. This was one of the first recognitions that sleep-related upper airways obstruction and sleep deprivation were components of what was known as the Pickwickian syndrome.¹⁰ This case report was an important step in the recognition of the entity of Obstructive Sleep Apnea and has been cited 94 times according to Google Scholar. There are many other such examples; pulmonary embolectomy and caval interruption, reports of pneumocystis pneumonia in the initial descriptions of AIDS, etc. And I refer the reader to the upcoming issues of the Red and White Journal!

This background explains why we have chosen to recognize the potential contribution of case reports to the scientific literature and to the advancement of medical knowledge. The journal will publish rare and scientifically relevant cases with the aim of increasing educational content and meeting the CPD needs of the respirology community, in a feature called « Clinico-Pathologic Conferences. We will also be looking to actively collaborate with Post Graduate Training programs in affiliated specialties throughout Canada in order to create a platform allowing trainees sponsored by their mentors to submit interesting and educational cases. Prospective authors are encouraged to consult the « Clinico-Pathologic Conferences » feature in the « instructions for authors » section on the Journal's website to insure proper formatting of their manuscripts.

It will also be our objective to work with accreditation bodies with the goal of allowing readers to automatically earn CPD points via the Journal's website once they have finished reviewing a case and completing the post-test.