OBJECTIVES: Few large-scale studies document rates and impact of overweight/obesity across selected countries in Europe and Asia-Pacific.

METHODS: The EpIdeMiology Landscape and Patient Care pathways of Obesity (IMPACT-O) study was a multi-country retrospective cohort study that utilized electronic medical records and claims databases standardized to the Observed Medical Outcomes Partnership Common Data Model from Australia, China, France, Germany, Italy, Spain, the UK and Japan. The level of recording and the number of adults with overweight/obesity (based on diagnostic codes and/or body mass index [BMI]) between 2018-2022 were estimated. BMI thresholds and categories (according to the World Health Organization/Japan Society for the Study of Obesity), and presence of comorbidities were described for adults with ≥1 BMI record of ≥25.0kg/m²–overweight (Australia, Europe)/obesity (Japan)–and ≥12 months observation before the index date (highest BMI record) in the prevalent cohort. This analysis (April 2023 data cut) did not include data from China and Spain.

RESULTS: BMI was recorded for 4.8-38.9% of active patients across the databases. The number of adults identified with overweight or obesity (Japan) based on BMI and/or diagnostic codes was: Australia 41,533; France 880,815; Germany 1,194,272; Italy 248,256; UK 1,110,830; Japan 656,336. Of these, diagnostic codes were present in 2.9-49.7% of cases. The prevalent cohort consisted of 2,515,860 individuals (Australia 25,625; France 430,089; Germany 429,422; Italy 170,119; UK 893,246; Japan 567,359). The percentage of individuals by BMI threshold (non-Japan/Japan) was 74.8-81.4%/55.9% (≥27.0kg/m²); 44.1-54.8%/22.1% (≥30.0kg/m²); 15.8-24.4%/4.7% (≥35.0kg/m²); 5.0-10.1%/1.0% (≥40.0kg/m²). At least 1 weight-related comorbidity was reported in 59.6-85.0% of patients (≥25.0kg/m²), and 35.9-65.8% had multimorbidity (≥2); the proportion of patients with comorbidities generally increased with increasing BMI category. The main comorbidities for ≥25.0kg/m² were hypertension (28.9-62.3%), dyslipidemia (20.4-40.2%) and depression (4.1-27.5%).

CONCLUSIONS: A small proportion of people with overweight/obesity are formally diagnosed in healthcare databases. Generally, comorbidity burden increased with BMI.