Chronic obstructive pulmonary disease (COPD): key points

• Chronic Obstructive Pulmonary Disease (COPD) refers to a group of lung conditions which restrict airflow to the lungs and cause breathing problems, including emphysema and chronic bronchitis. In addition to respiratory symptoms such as shortness of breath, persistent mucus-producing cough, and wheezing, sufferers can also experience fatigue and nutritional concerns which contribute to weight loss.
• The most significant risk factor for COPD is cigarette smoking. Despite a considerable decline in smoking rates over the past 25 years, morbidity and mortality due to COPD in Scotland remain high. There may be sex-based differences in the development of the disease, with females potentially having increased susceptibility to smoking-related morbidity such as COPD with comparable tobacco exposure to their male counterparts.
• The incidence of COPD in Scotland (measured using hospital admissions data and death records) dropped sharply during the COVID-19 pandemic. The latest figures indicate that the rise observed in 2021/22 has continued into 2022/23 for both females (112.4 cases per 100,000 population) and males (109.7 cases per 100,000 population); however, incidence across both sexes remains lower than prior to the pandemic.
• During 2022 the annual mortality rate from COPD for both males and females has increased after a marked reduction during the pandemic, with rises of 9.0% and 10.9% reported in males and females respectively.
• Whilst the burden of COPD has historically been greater in males, over the past 25 years females in Scotland have had:
  • virtually unchanged mortality rates compared to a large reduction in males. This is likely the result of smoking rates peaking later in females compared to males.
  • a slower rate of decline in smoking rates compared with males.
• The ageing of Scotland's population does not fully account for these trends, which may be explained by the fact that COPD rates fall many years after declines in smoking rates. Thus, the current burden of COPD in Scotland may, in part, be due to the high smoking rates seen 30 - 40 years ago. Increased awareness of COPD and its inclusion in the primary care quality and outcomes framework (QOF), which financially incentivised general practices to maximise COPD diagnosis rate, may also have contributed to increased reported prevalence.
• The burden of COPD is widely recognised to be underestimated with as many as two thirds of cases undiagnosed.