Abstract
BACKGROUND:
A community-based prevalence survey performed in Cape Town in 2005, using the BOLD methodology reported a prevalence of COPD of 24% among adults aged >40 years.
AIMS:
To study the vital status and lung function in COPD subjects 5 years after their initial diagnosis in the BOLD survey.
METHODS:
Subjects identified with COPD in 2005 were invited to participate, and have spirometry repeated in 2010 using the same spirometers as in 2005.
RESULTS:
Forty-five (23%) of 196 eligible subjects had died since the 2005 survey: 8 of respiratory causes, 10 of cardiovascular and 6 of other known causes and in 21 the cause of death was not known. Only age and GOLD stage 4 disease (in 2005) were significantly associated with death on multivariate analysis. Of the survivors 11 (6%) had moved away; 33 (17%) declined or had medical exclusions (e.g. dementia); and 106 (54%) were included (median age 63y; 46% males).
Post-bronchodilator spirometry did not confirm airflow limitation (AFL) defined as FEV1:FVC ratio < 0.7 in 16 of 106 (15%) subjects, while 90 (85%) showed AFL. The median decline in FEV1 was 28.9ml/yr (IQR: -54.8: 0.00ml/yr), with no difference between GOLD stages. The median decline in FVC was -75ml, and was significantly greater in GOLD stage 1 (-350ml) compared with GOLD stages 2 or 3 (-80ml & +140ml respectively; p<0.01). Fifty-eight (64%) subjects with AFL remained in the same GOLD stage, while 21 (23%) had deteriorated and 11 (12%) improved by ≥1GOLD stage.
CONCLUSIONS:
Five-year follow-up of a BOLD COPD cohort revealed disease progression and high mortality. The BOLD definition and/or methodology was associated with overdiagnosis of COPD.
- © 2014 ERS