The evidence grades (A-D) and evidence-based statements (Strong Recommendation, Recommendation, Option, and No Recommendation) are defined at the end of the "Major Recommendations" field.
1a. Diagnosis of Acute Rhinosinusitis
Clinicians should distinguish presumed acute bacterial rhinosinusitis (ABRS) from acute rhinosinusitis caused by viral upper respiratory infections and noninfectious conditions. A clinician should diagnose ABRS when (a) symptoms or signs of acute rhinosinusitis are present 10 days or more beyond the onset of upper respiratory symptoms, or (b) symptoms or signs of acute rhinosinusitis worsen within 10 days after an initial improvement (double worsening).
Strong recommendation based on diagnostic studies with minor limitations and a preponderance of benefit over harm.
- Aggregate evidence quality: Grade B, diagnostic students with minor limitations regarding signs and symptoms associated with ABRS
- Value judgments: importance of avoiding inappropriate antibiotic treatment of viral or nonbacterial illness; emphasis on clinical signs and symptoms for initial diagnosis; importance of avoiding unnecessary diagnostic tests
- Policy level: strong recommendation
1b. Radiographic Imaging and Acute Rhinosinusitis
Clinicians should not obtain radiographic imaging for patients who meet diagnostic criteria for acute rhinosinusitis, unless a complication or alternative diagnosis is suspected.
Recommendation against based on diagnostic studies with minor limitations and a preponderance of benefit over harm.
- Aggregate evidence quality: Grade B, diagnostic studies with minor limitations
- Value judgments: importance of avoiding unnecessary radiation and cost in diagnosing acute rhinosinusitis
- Policy level: recommendation
2. Symptomatic Relief of Viral Rhinosinusitis (VRS)
Clinicians may prescribe symptomatic relief in managing VRS.
Option based on randomized trials with limitations and cohort studies with an unclear balance of benefits and harm that varies by patient.
- Aggregate evidence quality: Grade B and C, randomized controlled trials with limitations and cohort studies
- Value judgments: provide symptomatic relief, but avoid inappropriate use of antibiotics for viral illness
- Policy level: option
3a. Pain Assessment of Acute Bacterial Rhinosinusitis (ABRS)
The management of ABRS should include an assessment of pain. The clinician should recommend analgesic treatment based on the severity of pain.
Strong recommendation based on randomized controlled trials of general pain relief in non-ABRS populations with a preponderance of benefit over harm.
- Aggregate evidence quality: Grade B, randomized controlled trials demonstrating superiority of analgesics over placebo for general pain relief, but not trials specifically regarding patients with ABRS.
- Value judgments: pain relief is important
- Policy level: strong recommendation
3b. Symptomatic Relief of Acute Bacterial Rhinosinusitis (ABRS)
Clinicians may prescribe symptomatic relief in managing ABRS.
Option based on randomized trials with heterogeneous populations, diagnostic criteria, and outcome measures with a balance of benefit and harm.
- Aggregate evidence quality: Grade B, randomized controlled trials with heterogeneous populations, diagnostic criteria, and outcomes measures; Grade D, for antihistamines (in nonatopic patients) and guaifenesin
- Value judgments: provide symptomatic relief while minimizing adverse events and costs
- Policy level: option
4. Watchful Waiting for Acute Bacterial Rhinosinusitis (ABRS)
Observation without use of antibiotics is an option for selected adults with uncomplicated ABRS who have mild illness (mild pain and temperature <38.3°C or 101°F) and assurance of follow-up.
Option based on double-blind randomized controlled trials with heterogeneity in diagnostic criteria and illness severity, and a relative balance of benefit and risk.
- Aggregate evidence quality: Grade B, randomized controlled trials with heterogeneity in diagnostic criteria and illness severity
- Value judgments: minimize drug-related adverse events and induced bacterial resistance
- Policy level: option
5. Choice of Antibiotic for Acute Bacterial Rhinosinusitis (ABRS)
If a decision is made to treat ABRS with an antibiotic agent, the clinician should prescribe amoxicillin as first-line therapy for most adults.
Recommendation based on randomized controlled trials with heterogeneity and noninferiority design with a preponderance of benefit over harm.
- Aggregate evidence quality: Grade B, randomized controlled trials with heterogeneity and noninferiority design
- Value judgments: promote safe and cost-effective initial therapy
- Policy level: recommendation
6. Treatment Failure for Acute Bacterial Rhinosinusitis (ABRS)
If the patient worsens or fails to improve with the initial management option by 7 days after diagnosis, the clinician should reassess the patient to confirm ABRS, exclude other causes of illness, and detect complications. If ABRS is confirmed in the patient initially managed with observation, the clinician should begin antibiotic therapy. If the patient was initially managed with an antibiotic, the clinician should change the antibiotic.
Recommendation based on randomized controlled trials with limitations supporting a cut point of 7 days for lack of improvement and expert opinion and first principles for changing therapy with a preponderance of benefit over harm.
- Aggregate evidence quality: Grade B, randomized controlled trials with limitations supporting a cut point of 7 days for lack of improvement; Grade D, expert opinion and first principles for changing therapy
- Value judgments: avoid excessive classification as treatment failures because of a premature time point for assessing outcomes; emphasize importance of worsening illness in definition of treatment failure
- Policy level: recommendation
7a. Diagnosis of Chronic Rhinosinusitis or Recurrent Acute Rhinosinusitis
Clinicians should distinguish chronic rhinosinusitis and recurrent acute rhinosinusitis from isolated episodes of acute bacterial rhinosinusitis and other causes of sinonasal symptoms.
Recommendation based on cohort and observational studies with a preponderance of benefit over harm.
- Aggregate evidence quality: Grade C, cohort and observational studies
- Value judgments: importance of accurate diagnosis
- Policy level: recommendation
7b. Modifying Factors
Clinicians should assess the patient with chronic rhinosinusitis or recurrent acute rhinosinusitis for factors that modify management, such as allergic rhinitis, cystic fibrosis, immunocompromised state, ciliary dyskinesia, and anatomic variation.
Recommendation based on observational studies with a preponderance of benefit over harm.
- Aggregate evidence quality: Grade C, observational studies
- Value judgments: consensus that identifying and managing modifying factors will improve outcomes
- Policy level: recommendation
8a. Diagnostic Testing
The clinician should corroborate a diagnosis and/or investigate for underlying causes of chronic rhinosinusitis and recurrent acute rhinosinusitis.
Recommendation based on observational studies with a preponderance of benefit over harm.
- Aggregate evidence quality: Grade C, observational studies
- Value judgments: identifying and managing underlying conditions will improve outcomes
- Policy level: recommendation
8b. Nasal Endoscopy
The clinician may obtain nasal endoscopy in diagnosing or evaluating a patient with chronic rhinosinusitis or recurrent acute rhinosinusitis.
Option based on expert opinion and a preponderance of benefit over harm.
- Aggregate evidence quality: Grade D, expert opinion
- Value judgments: importance of a detailed, complete intranasal examination
- Policy level: option
8c. Radiographic Imaging
The clinician should obtain computed tomography (CT) of the paranasal sinuses in diagnosing or evaluating a patient with chronic rhinosinusitis or recurrent acute rhinosinusitis.
Recommendation based on diagnostic and observational studies and a preponderance of benefit over harm.
- Aggregate evidence quality: Grade C, diagnostic and observational studies
- Value judgments: minimize radiation exposure and avoid unnecessary intravenous contrast
- Policy level: recommendation
8d. Testing for Allergy and Immune Function
The clinician may obtain testing for allergy and immune function in evaluating a patient with chronic rhinosinusitis or recurrent acute rhinosinusitis.
Option based on observational studies with an unclear balance of benefit versus harm.
- Aggregate evidence quality: Grade C, observational studies
- Value judgments: need to balance detecting allergy in a population with high prevalence vs. limited evidence showing benefits of allergy management on rhinosinusitis outcomes
- Policy level: option
9. Prevention
Clinicians should educate/counsel patients with chronic rhinosinusitis or recurrent acute rhinosinusitis regarding control measures.
Recommendation based on randomized controlled trials and epidemiologic studies with limitations and a preponderance of benefit over harm.
- Aggregate evidence quality: Grade B, randomized controlled trials and epidemiologic studies with limitations
- Value judgments: importance of prevention in managing patients with CRS or recurrent acute rhinosinusitis
- Policy level: recommendation
Definitions:
Guideline Definitions for Evidence-Based Statements
Strong Recommendation: A strong recommendation means the benefits of the recommended approach clearly exceed the harms (or that the harms clearly exceed the benefits in the case of a strong negative recommendation) and that the quality of the supporting evidence is excellent (Grade A or B)*. In some clearly identified circumstances, strong recommendations may be made based on lesser evidence when high-quality evidence is impossible to obtain and the anticipated benefits strongly outweigh the harms. Implication: Clinicians should follow a strong recommendation unless a clear and compelling rationale for an alternative approach is present.
Recommendation: A recommendation means the benefits exceed the harms (or that the harms exceed the benefits in the case of a negative recommendation), but the quality of evidence is not as strong (Grade B or C)*. In some clearly identified circumstances, recommendations may be made based on lesser evidence when high-quality evidence is impossible to obtain and the anticipated benefits outweigh the harms. Implication: Clinicians also should generally follow a recommendation but should remain alert to new information and sensitive to patient preferences.
Option: An option means that either the quality of evidence that exists is suspect (Grade D)* or that well-done studies (Grade A, B, or C)* show little clear advantage to one approach versus another. Implication: Clinicians should be flexible in their decision-making regarding appropriate practice, although they may set bounds on alternatives; patient preference should have a substantial influencing role.
No Recommendation: No recommendation means that there is both a lack of pertinent evidence (Grade D)* and an unclear balance between benefits and harms. Implication: Clinicians should feel little constraint in their decision-making and be alert to new published evidence that clarifies the balance of benefit versus harm; patient preference should have a substantial influencing role.
Evidence Quality for Grades of Evidence
Grade A: Well-designed, randomized, controlled trials or diagnostic studies performed on a population similar to the guideline's target population
Grade B: Randomized, controlled trials or diagnostic studies with minor limitations; overwhelmingly consistent evidence from observational studies
Grade C: Observational studies (case-control and cohort design)
Grade D: Expert opinion, case reports, or reasoning from first principles (bench research or animal studies)
Grade X: Exceptional situations where validating studies cannot be performed and there is a clear preponderance of benefit over harm