History of Case Reports in Medicine
Case reports have been important throughout medical history in the recognition of new or rare diseases, evaluating the effects and costs of interventions, and supporting case-based medical education. The US National Library of Medicine in Washington, DC has on display one of the earliest written case reports — from 1500 BC from Egypt — an oncology case. High-quality case reports have the potential to provide evidence on effectiveness in real-life clinical settings, complementing the measurement of efficacy in the controlled settings of clinical trials.
Medical History: Dangers of Thalidomide
In 1961, The Lancet published a letter to the editor from Dr. McBride, a general practitioner in Australia, reporting an increased incidence of congenital abnormalities in babies delivered from women given thalidomide during pregnancy. In response to this global adverse event tragedy, the FDA was authorized to require proof of efficacy AND safety for all new drugs and medical devices. The randomized controlled trials became the accepted standard for efficacy determination.
Medical History: Case Reports Played a Role in Recognizing HIV/AIDS
Case reports continue to play a role in both our understanding of disease and the effectiveness of treatments. In the early 1980s, five cases reported in the CDC’s Morbidity and Mortality Weekly Report (MMWR); additional cases in the New England Journal of Medicine in 1981 and Science in 1983 have refined our understanding of AIDS.
Medical History: Case Reports Guide New Treatments, and Warn of New Dangers
More recently, cases reported in a letter to the editor of the New England Journal of Medicine in 2008 provided evidence for the effectiveness of treating infantile hemangioma with propranolol. And in 2016, also in the New England Journal of Medicine, a compelling case report was published within a brief report on Zika virus infection.
Recognizing the Value of Case Reports
The number of published case reports in indexed medical journals has increased by 45% from 2000 to 2010, and they continue to provide early evidence related to innovative treatments and emerging diseases.
The Need for Case Reporting Standards
When written without reporting guidelines, case reports are often inconsistent, incomplete and have a high risk of bias. Case reports are usually uncontrolled, retrospective evaluations of potential associations between interventions and outcomes, which can compromise the ability to draw causal conclusions.
The CARE guidelines have anticipated a long future for case reports and provide guidance for the writing of high quality case reports that benefit healthcare stakeholders around the world. “The growth of case reports in an era in which clinical trials and systematic reviews dominate the tables of content of medical journals indicates that case reports have value, particularly with the increasing importance of individualized care. Unlike randomized controlled trials, case reports are individual reports related to the care of individual patients where the sample size is one…. The analysis of systematically aggregated information from patient encounters (now mandated by some insurance plans) will provide scalable, data-driven insights into what works for which patients in real time, facilitating comparisons across medical systems and cultures.”
Case Report References
McBride WG. Thalidomide and congenital abnormalities. Lancet. 1961;278(7216):1358. doi:10.1016/S0140-6736(61)90927-8.
Gottlieb M, Schanker H, Fan P, Saxon A, Weisman J, Pozalski I. Pneumocystis pneumonia – Los Angeles. Morb Mortal Wkly Rep. 1981;30(21):1-3. http://www.cdc.gov/mmwr/preview/mmwrhtml/june_5.htm.
Gottlieb MS, Schroff R, Schanker HM, et al. Pneumocystis carinii pneumonia and mucosal candidiasis in previously health homosexual men: evidence of a new acquired cellular immunodeficiency. N Engl J Med. 1981;305(24):1425-1431. doi:10.1056/NEJM198112103052401.
Barré-Sinoussi F, Chermann J, Rey F, et al. Isolation of a t-lymphotropic retrovirus from a patient at risk for acquired immune deficiency syndrome (AIDS). Science. 1983;220(4599):868-871. doi:10.1017/CBO9781107415324.004.
Léauté-Labrèze C, de la Roque, ED, Hubiche T, Boralevi F, Thambo J-B, Taïeb A. Propranolol for severe hemangiomas of infancy. N Engl J Med. 2008;358(24):2649-2651. doi:10.1056/NEJMc0708819.
Driggers, RW, Ho C-Y, Korhonen EM, et al. Zika virus infection with prolonged maternal viremia and fetal brain abnormalities. N Engl J Med 2016;374(22):2142-2151. doi: 10.1056/NEJMoa1601824.
Sun GH, Aliu O, Hayward RA. Open-access electronic case report journals: the rationale for case report guidelines. J Clin Epidemiol. 2013;66(10):1065-1070. doi:10.1016/j.micinf.2011.07.011.
Vandenbroucke JP. In defense of case reports and case series. Ann Intern Med 2001;134(4):330-334. doi:10.1097/AOG.0b013e3181b0c0b8.
Kaszkin-Bettag M, Hildebrandt W. Case Reports on cancer therapies: The urgent need to improve the reporting quality. Global Adv Health Med. 2012;1(2):8-10. doi:10.7453/gahmj.2012.1.2.002.
Richason TP, Paulson SM, Lowenstein SR, Heard KJ. Case reports describing treatments in the emergency medicine literature: missing and misleading information. BMC Emerg Med. 2009;9(10). doi:10.1186/1471-227X-9-10.
Kiene H, Hamre H, Kienle G. In support of clinical case reports: a system of causality assessment. Global Adv Heal Med. 2013:2(2):64-75. doi:10.7453/gahmj.2012.061.
Gagnier JJ, Kienle G, Altman DG, et al. The CARE Guidelines: Consensus-based clinical case reporting guideline development. Global Adv Health Med. 2013;2(5):38-43. doi:10.7453/gahmj.2013.008.