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Cosmos Study

Adenoidectomies Associated with Increased Likelihood of Sinus and Ear Infections, Decreased Likelihood of Tonsilitis 

July 2, 2024
Dual-Team Study
Team A:Matthew Gracianette, MDBrendan Joyce
Team B:Steve Allen, MDEric Barkley

Key Findings

  • Patients with their adenoids removed have an 18% increased rate of sinusitis and a 6% increased rate of otitis media compared to those who have not had their adenoids removed.  
  • However, patients who have had their adenoids removed have a 13% lower rate of tonsillitis and pharyngitis, an 11% lower rate of upper respiratory infections, and a 7% lower rate of influenza compared to those who have not had their adenoids removed.  

We recently published a study correlating reduced ear, nose, and throat infection rates with having your tonsils removed.1 To investigate whether adenoid removal (adenoidectomy) has a similar relationship with infections, we compared 33,686 patients who had their adenoids removed, but kept their tonsils, to 33,686 patients who still had their adenoids and tonsils. All patients had a documented diagnosis of chronic adenoiditis, snoring, or adenoid hypertrophy. We matched the patients in each population based on diagnosis type, month of diagnosis, and age at diagnosis. We studied the rates of otitis media, upper respiratory infection (URI), sinusitis, laryngitis, influenza, pharyngitis, and tonsillitis severe enough that the patient sought care and received a diagnosis. We adjusted for patient sex, age, race, ethnicity, Rural-Urban Commuting Area (RUCA) score, Social Vulnerability Index (SVI) quartile, influenza vaccination, and a history of the studied infection. 

We found that patients who had their adenoids removed but kept their tonsils experienced an 18% increased rate of sinusitis diagnoses and a 6% increased rate of otitis media diagnoses compared to those who still had their adenoids and tonsils, as seen in Figure 1. However, these patients had a 7% lower rate of influenza diagnoses, an 11% lower rate of URIs, and a 13% lower rate of tonsilitis and pharyngitis. We did not find a statistically significant difference in rates of laryngitis diagnoses between the populations. 

Figure 1
Likelihood of Infection for Adenoidectomy Patients
Likelihood of Infection for Adenoidectomy Patients
Figure 1. Infection rates for patients who have had an adenoidectomy without evidence of a tonsillectomy.

These data come from Cosmos, a dataset created in collaboration with a community of Epic health systems representing more than 256 million patient records from 1,500 hospitals and more than 34,100 clinics from all 50 states and Lebanon. This study was completed by two teams that worked independently, each composed of a clinician and research scientists. The two teams came to similar conclusions. Graphics by Aishwarya Shettigar and Brian Olson. 

  1. Bartelt K, Joyce B, Gracianette M, Deckert J. Tonsillectomies Associated with Reduced Ear, Nose, and Throat Infections Among Tonsillitis Patients. Epic Research. https://epicresearch.org/articles/tonsillectomies-associated-with-reduced-ear-nose-and-throat-infections-among-tonsillitis-patients. Accessed on June 20, 2024.