Sinusitis is one of the most common reasons people go to the doctor, causing an estimated 20 million doctor visits in the U.S. each year. The illness also accounts for a vast number of antibiotic prescriptions—nearly 1 in 5 (Cochrane Database Syst Rev. 2008;2:CD000243).
The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) Foundation set the standard in developing a clinical practice guideline for sinusitis in 2007. At the time, the only materials available from otolaryngology were consensus documents and literature reviews, said Rich Rosenfeld, MD, MPH, professor and chair of otolaryngology at SUNY Downstate Medical Center in Brooklyn, N.Y., and lead author of the AAO guidelines. “There were not really any validated, trustworthy guidelines.”
Now, five years later, the Infectious Diseases Society of America (IDSA) has drawn up its own set of guidelines. “The IDSA has been putting out clinical practice guidelines for some time, but there had never been one on sinusitis,” said Tony Chow, MD, professor emeritus in the division of infectious diseases at the University of British Columbia and Vancouver Hospital and lead author of the IDSA guidelines. “It’s a controversial area and also an area for overuse of antibiotics.”
Both groups recruited multidisciplinary teams that followed established protocols for reviewing the literature systematically and developing actionable statements.
The main difference is the focus: The IDSA guidelines are for acute bacterial sinusitis in children and adults, whereas the AAO guidelines cover adult patients with either acute or chronic sinusitis. Other variations arise out of differing interpretations of randomized clinical trials.
The good news is that the two sets of guidelines are largely in agreement for acute adult sinusitis. Where they do diverge, the gap is not wide enough to be polarizing. In many cases, shared decision making by doctors and their patients may override the subtle differences in guideline advice.
Here’s a closer look at the two sets of guidelines, the evidence upon which they are based and the differing perspectives of infectious disease scientists versus ear, nose and throat doctors. With a better understanding of the whys behind the guidelines, practitioners will be in a better position to align their own practice in an informed way.
The first key to appropriate treatment is identifying the causes of sinusitis. Both sets of guidelines tackle how to diagnose bacterial sinusitis and differentiate it from the far more common viral cases. Basically, if symptoms of purulent nasal drainage, nasal obstruction and facial pain/pressure persist for at least 10 days, or if symptoms worsen after an initial improvement (double sickening), then doctors can presume bacterial involvement.
The evidence basis for this diagnostic, based on pattern and duration of illness, is that the vast majority of cases of sinusitis are viral in origin. Studies have shown that up to 2 percent of all viral sinusitis episodes are complicated by bacterial infection (J Allergy Clin Immunol. 1992;90:457-462). After 10 days of illness, about 60 percent of cases have a bacterial component (Clin Infec Dis. 2004;38:227-233).
According to Dr. Rosenfeld, the AAO-HNS guidelines were the first to present clear, actionable steps to distinguish viral and bacterial sinusitis. They do not recommend radiographic imaging, unless the physician suspects something beyond sinusitis. By basing the diagnosis on history and symptoms alone, Dr. Rosenfeld said, “even consumers could take this advice.”
For sinusitis that is suspected to be viral, physicians may offer symptomatic relief: analgesics, antipyretics and decongestants. The AAO-HNS says the evidence is too weak to recommend nasal steroids; the IDSA says they’re an option.
According to Dr. Chow, nasal steroids are a reasonable choice in patients with a history of allergy. “It’s weak evidence, but several studies showed a benefit and dose-dependent effects,” he said.
Once the pattern and duration of illness has led to a diagnosis of bacterial sinusitis, the AAO-HNS guidelines offer two options beyond symptomatic relief: watchful waiting or antibiotics prescription. The IDSA guidelines say that once bacteria are presumed to be involved, antibiotics should be prescribed.
This difference is based on differing interpretations of published clinical studies. Clinical trials have consistently shown that a large percentage of the trial participants who receive a placebo get better within the study window—usually a week or two later (Lancet. 2008;371(9616):908-914).
“The conclusion we came to, even in people with bacterial infections, was that those in the placebo group did pretty well,” Dr. Rosenfeld said of the AAO-HNS’s watchful waiting option. “Give it another seven days, and up to 70 percent of patients improve.”
Publishing this recommendation generated some controversy. Doctors couldn’t imagine telling patients who have already been ailing for 10 days to wait another seven days. But, according to Dr. Rosenfeld, “it’s a reasonable option.”
The infectious disease group guidelines, however, discuss the lack of stringent criteria used in the studies. Most of the clinical trials comparing
antibiotics to placebo enrolled patients with seven to 10 days of symptoms. Therefore, as the IDSA reasoning goes, it’s likely that a good proportion of participants in the clinical trials had viral sinusitis (even at 10 days, the percentage of viral illness in adults may be 40 percent), which would not respond to antibiotics, would resolve spontaneously and would muddy the data. Therefore, the IDSA guidelines state unequivocally that once bacterial involvement is diagnosed, withholding or delaying antibiotics is not recommended.
Other reviews of the clinical trial data have concluded that watchful waiting is warranted for most patients, even after 10 days of symptoms. An international team did a meta-analysis of nine clinical trials in which participants were randomly assigned to antibiotic treatment or placebo. Importantly, the team didn’t just average aggregate data but, rather, obtained individual subject data from the trials with the specific aim to identify particular clinical signs or symptoms that predicted a response to antibiotic treatment (Lancet. 2008;371(9616):908-914).
Not only did the group conclude that antibiotics offer little benefit for adults with acute sinusitis, but also, the meta-analysis authors wrote: “Antibiotics are not justified even if a patient reports symptoms for longer than seven to 10 days.”
It’s one thing to analyze the studies and make recommendations, however, and another thing entirely to be in the primary care office. “No one waits ten days—not the patients, not the doctors,” said Dan Merenstein, MD, coauthor of the Lancet study and assistant professor and director of research programs in the department of family medicine at Georgetown University School of Medicine in Washington, D.C. He quoted the statistic that more than 80 percent of people who seek treatment get antibiotics (Fam Med. 2006;38:349-354).
“It is hard to change behavior,” said Stephen Smith, MD, MPH, professor emeritus of family medicine at Brown University’s Alpert Medical School in Providence, R.I. Dr. Smith has led the National Physicians Alliance efforts to develop priorities in primary care settings for improving quality and reducing risks and costs of care. Treating mild to moderate sinusitis was number two on the family medicine list.
“I’m optimistic that we’ve reached a point where the culture is ready for change,” Dr. Smith said. Toward that end, Dr. Smith has worked at educating both patients and doctors that symptomatic relief, not antibiotics, is the standard of care.
Once a doctor and patient have decided to use antibiotics, the two sets of guidelines differ on which drug should be first-line treatment. The AAO-HNS guidelines call for amoxicillin (unless there’s a penicillin allergy), because it’s cheaper and carries a lower risk of side effects than other antibiotics. IDSA recommends amoxicillin and clavulanic acid (Augmentin), based on the latest microbiology evidence. The AAO-HNS was stricter in relying on clinical trial data, whereas the IDSA also incorporated microbiology trends.
“The microbiology has changed, resistance patterns have changed, and because of the pneumococcal vaccine, the types of pathogens associated with sinusitis have changed,” Dr. Chow said. Specifically, there’s more Haemophilus influenzae and less Streptococcus pneumoniae, particularly in children. And, Dr. Chow added, “with H. influenzae, the bacteria can break down amoxicillin, so we recommend amoxicillin plus clavulanate.”
The IDSA guidelines take an in-depth look at second-line and alternative antibiotic choices in children and adults. The AAO-HNS guidelines don’t go beyond the first-line treatment drug.
Peter Hwang, MD, professor and director of the Stanford Sinus Center at Stanford University School of Medicine in Stanford, Calif., said he has no problem with the IDSA’s broader interpretation of the data. In fact, he tends to choose amoxicillin-clavulanate in his practice based on knowledge of the local bacterial resistance patterns. At Stanford, a majority of H. influenzae types are beta lactamase producing, and almost all Moraxella catarrhalis are beta lactamase positive, he said. “As clinicians, we’re choosing antibiotics based on the antibiogram for our community or our hospital,” he said.
Drs. Merenstein and Rosenfeld argued for the conservative approach. Augmentin has never outperformed amoxicillin in a clinical trial; therefore, evidence-based guidelines cannot recommend its use as a first-line treatment, absent other considerations for an individual case. “The amoxicillin-clavulanate opinion is not based on trials; it’s just theoretical,” said Dr. Merenstein.
The AAO-HNS guidelines say to consider another therapy if symptoms haven’t improved after seven days of treatment. The IDSA says to look sooner than that if there’s no improvement after three to five days of antibiotics. (Both advise reassessment with worsening symptoms.)
Again, Dr. Rosenfeld cited clinical trial data for the AAO-HNS recommendation. “After the first few days, maybe 20 to 30 percent of patients will be better, but it took seven days before seeing many people improve,” he said.
Dr. Chow cited clinical observations of when patients get better. “If they’re not going to respond, we’ll know in three to five days,” he said. Indeed, the guidelines cite pediatric data in which 45 percent of patients were cured within three days, and ‘many others’ had improved.
When guidelines put out by different groups conflict, it can be confusing for doctors. In this case, the two documents have more in common than not, Dr. Hwang said. “And, of course, physicians are going to incorporate their own clinical judgments as well as take into account patient preferences,” he added.”