BACKGROUND: This study compared management of high-risk COPD patients in the UK to national and international management recommendations and quality standards, including the COllaboratioN on QUality improvement initiative for achieving Excellence in STandards of COPD care (CONQUEST). The primary comparison was in 2019, but trends from 2000 to 2019 were also examined. METHODS: Patients identified in the Optimum Patient Care Research Database were categorised as newly diagnosed (≤12 months after diagnosis), already diagnosed, and potential COPD (smokers having exacerbation-like events). High-risk patients had a history of ≥2 moderate or ≥1 severe exacerbations in the previous 12 months. FINDINGS: For diagnosed patients, the median time between diagnosis and first meeting the high-risk criteria was 617 days (Q1-Q3: 3246). The use of spirometry for diagnosis increased dramatically after 2004 before plateauing and falling in recent years. In 2019, 41% (95% CI 39-44%; n = 550/1343) of newly diagnosed patients had no record of spirometry in the previous year, and 45% (95% CI 43-48%; n = 352/783) had no record of a COPD medication review within 6 months of treatment initiation or change. In 2019, 39% (n = 6893/17,858) of already diagnosed patients had no consideration of exacerbation rates, 46% (95% CI 45-47%; n = 4942/10,725) were not offered or referred for pulmonary rehabilitation, and 41% (95% CI 40-42%; n = 3026/7361) had not had a COPD review within 6 weeks of respiratory hospitalization. INTERPRETATION: Opportunities for early diagnosis of COPD patients at high risk of exacerbations are being missed. Newly and already diagnosed patients at high-risk are not being assessed or treated promptly. There is substantial scope to improve the assessment and treatment optimisation of these patients. FUNDING: This study is conducted by the Observational & Pragmatic Research International Ltd and was co-funded by Optimum Patient Care and AstraZeneca. No funding was received by the Observational & Pragmatic Research Institute Pte Ltd (OPRI) for its contribution.