Incidence and Prevalence of Achalasia in Central Chicago, 2004–2014, Since the Widespread Use of High-Resolution Manometry

Background & Aims Reported global incidence and prevalence values for achalasia vary widely, from 0.03 to 1.63 per 100,000 persons per year and from 1.8 to 12.6 per 100,000 persons per year, respectively. This study aimed to reconcile these low values with findings from a major referral center, in central Chicago (which began using high-resolution manometry in 2004 and used it in all clinical studies since 2005), and has determined the incidence and prevalence of achalasia to be much greater. Methods We collected data from the Northwestern Medicine Enterprise Data Warehouse database (tertiary care setting) of adults residing in Chicago with an encounter diagnosis of achalasia from 2004 through 2014. Patient files were reviewed to confirm diagnosis and residential address. US Census Bureau population data were used as the population denominator. We assumed that we encountered every incident case in the city to calculate incidence and prevalence estimates. Data were analyzed for the city at large and for the 13 zip codes surrounding the Northwestern Memorial Hospital (NMH), the NMH neighborhood. Results We identified 379 cases (50.9% female) that met the full inclusion criteria; of these, 246 were incident cases. Among these, 132 patients resided in the NMH neighborhood, 89 of which were incident cases. Estimated yearly incidences were stable over the study period, ranging from 0.77 to 1.35 per 100,000 citywide (average, 1.07 per 100,000) and from 1.41 to 4.60 per 100,000 in the NMH neighborhood (average, 2.92 per 100,000). The corresponding prevalence values increased progressively, from 4.68 to 14.42 per 100,000 citywide and from 15.64 to 32.58 per 100,000 in the NMH neighborhood. Conclusions The incidence and prevalence of achalasia in central Chicago diagnosed using state-of-the-art technology and diagnostic criteria are at least 2- to 3-fold greater than previous estimates. Additional studies are needed to determine the generalizability of these data to other regions.