Risk factors for COPD include genetic factors and environmental exposures. The major exposures are tobacco smoke, occupational dusts and chemicals, and pollution. The authors reported all-cause mortality relative risks RRs for COPD based on multivariable models that controlled for smoking status, pack-year history, years since last regularly smoked, body mass index BMI , and a number of demographic variables.
The RRs ranged from 1. Some other studies also reported RRs based on severity. Our primary goal was to compute life expectancy and the years of life lost due to COPD.
To do so we required quantification of the excess mortality associated with COPD. We thus sought to calculate the associated excess death rates EDRs and RRs, and to investigate whether these varied by age, sex, race, education, smoking status, the presence of concomitant medical conditions, and time since evaluation. We were particularly interested in how the RRs varied with age, as we have found in other chronic conditions that it declines with age.
As noted, these quantities have not been reported in the literature. Of these persons, 3, were smokers or former smokers and 3, had pack-year history. Pipe or cigar smokers were counted as current or former smokers as appropriate, but we did not have pack year history on these persons.
Examiners used either a dry rolling seal spirometer in the mobile examination center or a portable spirometer in the home examination to conduct pulmonary function testing. Testing procedures were based on the American Thoracic Society recommendation. Otherwise they were assumed to have no lung disease Normal or GOLD stage 0 if they reported respiratory symptoms.
Notes: Those who were diagnosed by a physician as having chronic bronchitis, emphysema, or asthma but did not have COPD or RLD according to the above criteria were classified as GOLD stage 0 if they reported symptoms or Normal if they reported no symptoms. Persons who had a positive response to a having a cough for three consecutive months out of the year, b phlegm first-thing in the morning three consecutive months out of the year, or c wheezing in the past 12 months, were considered as having GOLD stage 0 if their pulmonary function testing did not indicate COPD or RLD.
Analyses were performed using the statistical package SAS 9. These models provide hazard ratios or, equivalently, RRs for each potential mortality risk factor. The variables included in one or more of the multivariable regression models were: Age, sex, race, smoking status, pack-years of cigarette smoking, BMI, major medical conditions, and lung function COPD category.
The models were used to compute mortality rates for various groups, including 65 year-old males with the given severities of COPD.
The difference between a given rate and the corresponding general population or other baseline mortality rate is the EDR, which were computed for the various groups. Life expectancies were computed for the same groups by using the above mortality rates to construct a life table. When the EDR was positive increased risk compared with the general population , the assumption of proportional life expectancy PLE 18 , 29 was used to obtain the mortality rates at older ages. In brief, this method assumes that the proportion of normal life expectancy for a given medical condition is the same at every age.
When the EDR was negative, it was assumed to approach zero with age, much as persons in above-average health revert to the mean.
The mean duration of follow-up of the 6, persons studied was 7. Table 1 shows the baseline demographic characteristics of the cohort. Demographics and description of key variables. All figures are column percentages except for counts n, died and age. Figures 2 — 5 show the Kaplan—Meier survival curves based on severity of COPD, both for the entire population and stratified by smoking status. In all cases, any lung function impairment was associated with an increased risk of death.
The associated annual mortality rate over the year period for smokers with no lung disease is thus —ln 0. For stages 1, 2, and 3 or 4 COPD, the rates are 0. EDRs for all 24 groups are shown in Table 2. It is important to note that these are crude EDRs, unadjusted for any possible confounding factors.
Excess deaths rates from Figures 2 — 5 , relative to persons with no lung disease. The reason is that the EDR increases with age, and the Mannino and colleagues study population was significantly younger than the population used here: unlike the present study, half their population was under age 50 at the start of follow-up.
Additional analyses not shown indicated that persons with COPD, compared to those without lung disease, tended to be older and male, and of course were much more likely to be smokers. It is important to note that the survival curves in Figures 2 — 5 were not adjusted for any of the covariates.
Thus, the EDRs given in Table 2 may be confounded with the effects of these covariates. For this we required multivariate statistical methods, such as the Cox proportional hazards regression model. Cox models were used to adjust for age, sex, race, education, smoking status, smoking history, weight, and major medical conditions. The variables, their various levels, and the associated relative risks of mortality are shown in Table 3.
In all cases the relative ordering of severity was preserved in the resulting RRs. However, as can be seen, the stage 1 group had a relative risk that, in 3 of the 4 cases, was actually less than that of the reference group stage 0 , though the differences were neither practically nor statistically significant.
We return to this issue in the discussion. Those with restrictive lung disease RLD or symptoms of COPD, but no formal diagnosis, both had uniformly increased risk of death compared with those with no lung disease. Other analyses not shown , using models that a accounted for only age, sex, and COPD, and b were based on different subsets of data, yielded similar results. Further analyses not shown revealed that the effect of COPD did not appear to vary by sex, race, or college education.
That is, there were no significant interactions. But it did vary by age, as we hypothesized, with older persons having a lower RR than younger persons results not shown.
This was true for those with stage 2 and 3 or 4 COPD, and amongst current, former, and never smokers, with one exception it did not hold for the former smokers with moderate COPD.
We comment further on this issue in the discussion. The last row of Table 3 shows the mortality rate for the composite baseline group: female, age 50—59, non-Caucasian, college education, no lung disease, never smoker first model only , low pack-years of smoking models 1—3 only , normal weight, and no other medical conditions. By comparison, we note that the corresponding annual mortality rates at age 55 for the United States female general population 28 and the insured population at time of underwriting 31 are 0.
That is, the best group contemplated by the models is slightly better than the general population, but does not have mortality as low as the recently insured who have additionally demonstrated normal blood work, urinalysis, and electrocardiogram. The RRs from Table 3 can also be used to compute the mortality rate for any combination of levels of the covariates in the model.
These rates are shown in Table 4. COPD is actually the umbrella term for chronic bronchitis and emphysema , both lung diseases. A recent study published in Thorax: An International Journal of Respiratory Medicine found that not only does COPD reduce your quality of life in the present, but it can also shorten your overall life expectancy by causing excess wear and tear on the cells in your body.
As you age your cells divide. Each time they divide, a piece of the telomeres is cut off until there is nothing left. Once the protective tips have disappeared, the cells stop functioning, ultimately leading to organs shutting down and death. This process occurs naturally over time, but the study demonstrated an accelerated rate in people with COPD.
Smoking is the most common source of COPD , but the disease can also be caused by genetics or long-term exposure to other lung irritants such as pollution, dust, or chemical fumes. As COPD progresses, damage to the lungs makes it more difficult to breathe.
There is no single life expectancy for people with COPD. The FEV1 test measures how much air a person can expel from their lungs in 1 second. Its results show as a percentage of the airflow that doctors would predict for that person, according to their weight, height, and race. Its most recent guidelines involve the FEV1 test results as an indicator of severity. A doctor will use these results to decide the disease grade. GOLD has four grades, each more severe than the previous one:.
GOLD also takes into account symptoms such as breathing difficulties and the number of exacerbations, or flare-ups, that occur. People with a higher GOLD grade have a lower life expectancy than those whose grade is a lower number. BODE scores range from 0— People with a score of 10 have the most impaired function and the worst outlook.
People can click here to find an automated calculator to determine their BODE score. Many people live longer, while others may have shorter expectancies. Another system that doctors commonly use is the ADO scale, which stands for age, dyspnea, and obstruction. Doctors will consider the symptoms each individual is experiencing, along with their other medical conditions, to prescribe the best medication regime.
Pulmonary rehabilitation involves sessions with a respiratory therapist or lung specialist who teaches techniques for better breathing. Rehabilitation options may also include nutrition counseling and education about COPD. Life expectancy LE and loss-of-LE for patients with chronic obstructive pulmonary disease. Respir Med. Epub Aug PMID: Curtis JR.
Palliative and end-of-life care for patients with severe COPD. European Respiratory Journal. Heart failure and chronic obstructive airway disease as combined comorbidities. Meta-analysis and Review. Arch Pulmonol Respir Care 5 1 : DOI: What do chronic obstructive pulmonary disease patients die from? A multiple cause coding analysis. International journal of chronic obstructive pulmonary disease, 4, — Eur Respir J.
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