Reading and Assessing the Clinical Research Literature

Maureen Hannley, PhD, is currently Chief of the Research Division of the Department of Otolaryngology and Communication Sciences at Medical College of Wisconsin and Research Consultant for the Triological Society. She formerly served as the Chief Research Officer of the American Academy of Otolaryngology-Head and Neck Surgery Foundation and has held positions at the National Institutes of Health, Stanford University Medical School, and Arizona State University.

Do you cringe when another journal comes in, only to join the growing stack of still-unread back issues? Every clinician is familiar with the losing battle faced with the information overload regularly imposed by the monthly arrival of the latest issues of journals: Laryngoscope; Otolaryngology-Head and Neck Surgery; Otology and Neurotology; International Journal of Pediatric Otorhinolaryngology; American Journal of Rhinology; Archives of Otolaryngology; American Journal of Otolaryngology-Head and Neck Surgery…the list goes on and on, depending on practice specialty and/or membership in senior societies. This problem is not limited to otolaryngology: Some 20,000 biomedical periodicals publish around six million articles annually; this is supplemented by 17,000 biomedical books published each year-many of which are out of date before they even make it into print.1

It is not difficult to understand why most practitioners of medicine or science find that keeping current falls into the someday category-and stays there. A quick search of PubMed recovered 47,000 references to head and neck cancer and more than 90,000 articles related to ear, nose, or throat surgery. Most clinicians will scan through a journal’s table of contents searching for papers relevant to their interests or practice focus.

Selecting carefully, then keeping a few key principles and features in mind as you read, will help you become a more critical reader, decide which papers have information reliable and valid enough to apply to your practice, and make better use of your valuable time.

Types of Studies

Clinical research papers can first be viewed as falling into a hierarchy of value, anchored on the low side by expert opinion and retrospective chart reviews or case series, and on the high side by randomized clinical trials or meta-analyses/systematic reviews of clinical trials. In between those two extremes, ranging from the highest value to the lowest, are: (1) cohort studies; (2) case-control studies; (3) cross-sectional studies; (4) practice patterns and demographic surveys; and (5) retrospective database analyses. Whereas randomized controlled clinical trials are an experimental study design, the cohort, case-control, and cross-sectional studies are examples of observational or analytical designs. Demographic surveys and database analyses would be categorized as descriptive studies.