Causes of deaths in COPD patients in primary care setting--a 6-year follow-up

COPD is one of the most frequent respiratory diseases responsible for patients' disability and mortality. In 2005 a single primary care practice, COPD was diagnosed in 183 out of 1,960 eligible subjects ≥ 40 years (9.3%). The aim of this study was to assess mortality rate and causes of deaths in this group after 6 years.

In 2011 we invited all 183 patients with COPD recognised in 2005. We performed spirometry, physical examination, questionnaire of respiratory symptoms, smoking habits, concomitant diseases and treatment. Information about deaths was taken from primary care register, furthermore, family members were asked to deliver medical documentation or death certificate.

In 2011 we studied only 74 subjects (40.4%), 43 subjects died (23.5%) and 66 subjects were lost from the follow-up (36.1%). Cardiovascular diseases were the most frequent causes of deaths - 21 subjects (48.8%) (heart attack - 8 patients and stroke - 8 patients). Respiratory failure in the course of COPD exacerbation was the cause of 10 deaths (23.3%). Neoplastic diseases lead to 9 deaths (20.9%) (lung cancer 7 patients). Renal insufficiency was responsible for one death (2.325%), and the causes of 2 deaths remained unknown (4.65%). Subjects who died (predominantly males) were older, had higher MRC score and lower FEV₁.

Study performed six years after COPD diagnosis revealed that 23.5% of subjects died. The main causes of deaths were the following: cardiovascular diseases (mainly heart attack and stroke), COPD exacerbations and lung cancer (more than 75%). Death risk in COPD patients was associated with age, male sex, dyspnoea and severity of the disease.