OBJECTIVES

: Conventionally, patients with chronic obstructive pulmonary disease (COPD) were informed about their 5-year survival rate, which might not be easily understood. This study intends to determine the life expectancy (LE) and loss of LE for patients with severe COPD.

METHODS

: 532 patients who were diagnosed with COPD according to the Global initiative of obstructive lung disease (GOLD) criteria at National Cheng Kung University Hospital between January 2006 and December 2016 were recruited. We verify the survival status and date of death of every patient by linkage with the Taiwan National Mortality Registry to estimate the survival by Kaplan-Meier method, which was extrapolated to lifetime by a semi-parametric method to obtain the LE. The loss of LE was quantified by subtracting the LE of COPD cohort from that of the age-, sex-, and calendar year of diagnosis-matched referents simulated from national life tables. Because the survival function of COPD at severe stage (FEV₁ < 50% of prediction) defined under GOLD in our cohort is almost the same as those hospitalized during preceding one year because of acute exacerbation (AE), we validated the results by analyzing national-wide cohort from the National Health Insurance (NHI) dataset with the same definition.

RESULTS

: The LE and loss-of-LE of severe COPD were 6.4 (standard error of mean 1.0) and 9.3(1.1) years, respectively, while those with AE in the preceding one year were 5.6 (1.1) and 9.4(1.3) years, respectively. The corresponding cohort established from the NHI showed a loss of LE of 8.3(0.1) years. There appeared no loss of LE for mild COPD patients.

CONCLUSIONS

: Patients with severe COPD or those with a history of one or more AE suffered from increased mortality, or about 8-9 years of life loss.