An estimate of the number of mastoidectomy procedures performed annually in the United States

Ear, Nose & Throat Journal, May, 2008 by Lesley C. French, Mary S. Dietrich, Robert F. Labadie

Abstract

We conducted a study to estimate the number of mastoidectomy procedures performed annually in the United States. Our results are based on state-specific healthcare utilization data and Medicare-funded procedural data from 2002. The utilization data were obtained from the State Ambulatory Surgery Database, which is made available through the Healthcare Cost and Utilization Project. Statistical Package for the Social Sciences (SPSS) statistical software was used to quantify the number of mastoidectomy procedures performed during 2002 in Maryland, New Jersey, New York, and Florida. Information was also obtained from the Federated Ambulatory Surgery Association on the number of Medicare-funded mastoidectomy procedures performed in 2002. State and U.S. population statistics were obtained from the U.S. Census Bureau. These data were extrapolated to obtain a nationwide estimate of the number of mastoidectomies performed annually in the U.S. With 99% confidence, we determined that 0.73 to 0.94 mastoidectomy procedures were performed per 10,000 population in Maryland and 2.55 to 2.74/10,000 in New York. Estimates for both New Jersey and Florida fell in between. Medicare patients underwent between 1.68 and 1.79 procedures per 10,000 population. Based on these data, we estimate that between 30, 000 and 60,000 mastoidecto mies are performed each year in the U.S., although we suspect that our range may be an underestimation of the actual number because of some limitations inherent in the data collection process. Although mastoidectomy is a common outpatient procedure, to the best of our knowledge, no report on the annual frequency of mastoidectomy procedures in the U.S. has ever been published in the English-language literature. We hope that our report will serve to motivate further research into technological and surgical advancements surrounding this procedure.

Introduction

Mastoidectomy is the core surgical procedure in otology and neurotology. It is performed for the treatment of both chronic otitis media with effusion and cholesteatoma. Extensions of mastoidectomy are used to treat vertigo associated with Meniere disease (endolymphatic mastoid shunt, labyrinthectomy), hearing loss (cochlear implantation), and carcinoma (temporal bone resection).

Mastoidectomy is widely acknowledged to be a common procedure, but few reports in the literature offer any insight into how often they are performed. In the 1970s, Harker reported that the annual incidence of cholesteatoma in Iowa was 6.01/100,000 population. (1) In 2002, Shohet and de Jong estimated that the annual incidence of cholesteatomas among children in the United States was 3 to 6/100,000. (2) Two years earlier, Rakover et al reported that in Israel, the number of cholesteatoma operations per 10,000 population had decreased from 20 to 6.6 after the use of ventilation tubes for secretory otitis media had become routine. (3)

Each of these reports focused on the incidence of cholesteatoma and not on mastoidectomy. As far as we know, no estimate of the number of procedures involving a mastoidectomy performed annually in the U.S. has previously been reported. In this article, we describe our estimate of the number of mastoidectomies performed in the U.S., which we based on information reported to the federal government for 2002.

Materials and methods

Data were collected from the following sources:

* State-level healthcare utilization data were obtained from the State Ambulatory Surgery Database (SASD), which is available through the Healthcare Cost and Utilization Project (HCUP; Washington, D.C.). HCUP represents a federal-state-industry partnership sponsored by the Agency for Healthcare Research and Quality. When our study was initiated, seven states provided ambulatory surgery data to HCUP; we used data from four of these states, which are among the most heavily populated states in the U.S.: Maryland, New Jersey, New York, and Florida. The Maryland and New Jersey SASD data covered only hospital-based ambulatory surgery centers; data for New York and Florida were obtained from both hospital-based and freestanding ambulatory surgery centers. HCUP data were presented in Statistical Package for the Social Sciences format (SPSS statistical software; SPSS, Inc.; Chicago).

* The number of Medicare-funded procedures nationwide was obtained from the Federated Ambulatory Surgery Association (FASA; Washington, D.C.). FASA is a nonprofit association that represents the interests of ambulatory surgical centers throughout the nation.

* Population values for the states included in this study and the entire nation were obtained from the U.S. Census Bureau. (4) Number Cruncher Statistical System (NCSS) software was subsequently used to generate nationwide estimates of the number of mastoidectomy procedures. (5) NCSS provides both Wilson score estimation (recommended by Newcombe (6) for asymptotic interval estimations) and exact estimates. In every case, both methods generated identical 99% confidence intervals (to 6 decimal digits).