Table 3.
Prior Epidemiologic Studies of Achalasia, Sorted by Terminal Study Year
| Study | Location | Years Studied | Study Design | Case Definition Criteria* | Cases Reviewed or Claims Codes Validated | Number Achalasia Patients Reported | Incidence rates (per 100,000/year) | Prevalence rate (per 100,000) |
|---|---|---|---|---|---|---|---|---|
| Mayberry et al | Cardiff, Wales | 1926–1977 | Retrospective | (1) EGD and BE or (2) Manometry | Yes | 48 | 0.4 | Not Reported |
| Mayberry et al | Nottingham, England | 1966–1983 | Retrospective | (1) EGD and BE or (2) Manometry | Yes | 53 | 0.51 | 8 |
| Arber et al | Israel | 1973–1983 | Prospective | 2 of 3 studies: EGD, BE, Manometry | Yes | 162 | 0.8–1.1 | 7.9–12.6 |
| Howard et al | Edinburgh, Scotland | 1986–1991 | Prospective | Manometry | Yes | 36 | 0.81 | Not Reported |
| Ho et al | Singapore | 1989–1996 | Prospective | Manometry | Yes | 49 | 0.3 | 1.8 |
| Birgisson et al | Iceland | 1952–2002 | Retrospective | (1) Symptoms of achalasia and (2) exclusion of other esophageal disorders and either (3) BE or (4) Manometry | Yes | 62 | 0.55 | 8.7 |
| Farrukh et al | Leicester, England | 1986–2005 | Retrospective | (1) EGD and BE or (2) Manometry | Yes | 14 | 0.89 | Not Reported |
| Gennaro et al | Italy | 2001–2005 | Retrospective | Claims based – single ICD code for achalasia | No | 565 | 1.59 | Not Reported |
| Sadowski et al | Alberta, Canada | 1995–2008 | Retrospective | Claims based – single ICD code for achalasia + specialist note + CCP treatment code for balloon dilation or Heller myotomy | Yes (no specific criteria) | 463 | 1.63 | 10.82 |
| Enestvedt et al | United States | 2000–2008 | Retrospective | Claims based – EGD performed with ICD code for achalasia associated | No | 896 | Not Reported | Not Reported |
| Kim et al | Korea | 2007–2011 | Retrospective | Claims based – single ICD code for achalasia | No | 3,105 | 0.39 | 6.29 |
| Duffield et al | Australia | 2004–2013 | Retrospective | Manometry and EGD | Yes (gold standard – manometry) | 350 | 2.3–2.8 | Not Reported |
| Samo et al | Chicago, United States | 2004–2014 | Retrospective | Claims based – single ICD code for achalasia and free text search for EGJOO | Yes (gold standard – manometry) | 379 | 0.77–1.35 | 4.68–14.42 |
| Harvey et al | England | 2006–2016 | Retrospective | Claims based – single ICD code for achalasia | Hospital Episode Statistics (HES) – Yes; The Health Improvement Network (THIN) - No | HES – 10,509; THIN - 711 | HES – 1.99; THIN – 1.53 | THIN – 27.1 |
| Sato et al | Japan | 2005–2017 | Retrospective | Claims based – single ICD code for achalasia | No | 385 | 0.81–1.37 | 7 |
| Gaber et al | United States | MarketScan 2001–2018, Medicare 2007–2015 | Retrospective | Claims based – single inpatient or outpatient ICD code for achalasia | No | MarketScan – 2900 Medicare – 4907 |
MarketScan – 10.5 Medicare – 26.0 |
MarketScan – 18 Medicare – 162.1 |
EGD = esophagogastroduodenoscopy; BE = barium esophagram; ICD = International Classification of Diseases; EGJOO = esophagogastric junction outflow obstruction
*
Diagnostic studies or claims-based code criteria used in the study to identify achalasia cases