Evidence-based medicine in otolaryngology journals

We set out to assess, within the context of evidence-based medicine, the levels of supporting evidence for therapeutic recommendations made in leading otolaryngology journals.

We used a cross-sectional survey of clinical research articles published in 1999 in 4 high-circulation otolaryngology journals.

We used study design methodology and level of evidence for clinical research articles with therapeutic recommendations. Outcomes were stratified by type of recommendation (positive vs negative) and by study focus (medical vs surgical therapy).

Of the 1019 articles identified, 737 (72%) were clinical research and 268 (36%) made therapeutic recommendations. Median sample size was modest (27 subjects), with only 38% of studies reflecting planned research and 22% including an internal control or comparison group. Positive studies were 20 times more prevalent than negative ones, but were 69% less likely to have an internal control group (P =.042) and 93% less likely to include confidence intervals (P =.020). Moreover, the level of evidence for positive studies was lower than for negative studies (P =.037), with twice as many negative recommendations supported by analytic research. Similarly, the level of evidence for operation was lower than for medical therapy (P <.001), with 3 times as many medical recommendations supported by analytic research.

Most therapeutic recommendations in otolaryngology journals are on the basis of descriptive case series (80%) and least often on randomized controlled trials (7%). A dual standard appears to exist for negative versus positive studies and for medical versus surgical recommendations. Greater scrutiny of the breadth and quality of evidence levels supporting therapeutic recommendations is likely to occur as the popularity of-and demand for-evidence-based medicine increases.

Evaluation of levels of evidence in otolaryngology decision making.