Incidence, prevalence and clinical management of achalasia since the introduction of high-resolution manometry in Western Australia.

BACKGROUND: Epidemiological studies in achalasia and its clinical management in Australia are limited. AIMS: To determine the prevalence and trends in incidence rates and describe the types of treatment stratified by subtypes of achalasia. METHODS: A retrospective observational study was conducted at a single site that offers a state-wide high-resolution manometry (HRM) service in Western Australia (WA). Patients (aged ≥ 18 years) newly diagnosed with achalasia based on HRM findings between 2012 and 2021 were extracted from the HRM database. The crude incidence rate and age-standardised incidence rate (ASIR) along with the 2021-point prevalence were calculated. Trends were assessed by the Kendall τb test. The patients' initial and subsequent treatment modalities were described. RESULTS: A total of 296 new cases were identified, and the median age at diagnosis was 56 years. The patient's median age, sex and year of the first treatment did not vary significantly with the subtypes. The lowest and highest ASIR (cases/100 000 person-years) were 0.8 in 2012 and 2.1 in 2021, respectively. Only type 2 achalasia showed a significant increasing trend (P = 0.009). The 2021-point prevalence was 16.9 cases/100 000 people and increased with age. Pneumatic balloon dilatation (PBD) was the most common treatment for types 1 and 2, while laparoscopic Heller myotomy was most common for type 3. Peroral endoscopic myotomy (POEM) has become common in the past 5 years. CONCLUSION: The ASIR of type 2 achalasia significantly increased in WA. PBD was most commonly performed, although peroral endoscopic myotomy has recently increased as a preferred treatment option.