Mortality in individuals with severe deficiency of alpha1-antitrypsin: findings from the National Heart, Lung, and Blood Institute Registry

STUDY OBJECTIVE: To clarify the mortality rate and causes of death of individuals with alpha(1)-antitrypsin (AAT) deficiency, the Death Review Committee (DRC) of the National Heart, Lung, and Blood Institute Registry of Individuals with Severe AAT Deficiency reviewed all available medical records regarding the deaths of study subjects during Registry follow-up (up to 7.2 years). METHODS: Individual determinations by each member of the three-person DRC led to consensus judgments regarding the underlying cause and the immediate and contributing causes of death. RESULTS: Of the 1,129 Registry subjects, 204 died (18.1%) [approximately 3%/yr]. Record availability permitted detailed review in 120 decedents, and death certificates were available in 56 of the remaining 84 subjects (67%). Emphysema and cirrhosis were the most common underlying causes of death (72% and 10%, respectively), with malignancy and diverticulitis accounting for 3% of deaths each. To assess attributable mortality, standardized mortality ratio analysis was performed and indicated that excess mortality was ascribable entirely to lung and liver disease. CONCLUSIONS: We conclude that severe AAT deficiency poses a significant threat to health, that severe airflow obstruction is a major determinant of mortality, and that liver and lung disease account for the excess mortality in affected individuals. These findings support current efforts to enhance diagnostic recognition and treatment of AAT-deficient individuals.     

Immunization roulette: influenza occurrence in five nursing homes

Immunization with A/Bangkok 1/79 (H3N2) vaccine appeared to be protective for immunized nursing home residents during an influenza outbreak in 1983. All thirteen deaths during the 4-month period of the study were among residents of two of five nursing homes where influenza immunization was low or nonexistent. Death certificates included a diagnosis of I-ILI for only six of the 13 decedents, showing that I-ILI may be greatly underreported as a cause of death, and skewing statistical evaluation of the impact of influenza in nursing home populations. The cost of protection is only a small fraction of the cost to society of caring for seriously ill nursing home residents with I-ILI who must be admitted to a hospital.     

The British Diabetic Association Cohort Study, II: cause-specific mortality in patients with insulin-treated diabetes mellitus.

AIMS: To measure cause-specific mortality, by age, in patients with insulin-treated diabetes incident at a young age. METHODS: A cohort of 23 752 patients with insulin-treated diabetes diagnosed under the age of 30 years, from throughout the United Kingdom, was identified during 1972-93 and followed to February 1997. Death certificates have been obtained for deaths during the follow-up period and cause-specific mortality rates and standardized mortality ratios by age and sex are reported. RESULTS: During the follow-up period 949 deaths occurred and at all ages mortality rates were considerably higher than in the general population. Acute metabolic complications of diabetes were the greatest single cause of excess death under the age of 30 years. Cardiovascular disease was responsible for the greatest proportion of the deaths from the age of 30 years onwards. CONCLUSIONS: Deaths in patients with diabetes diagnosed under the age of 30 have been reported and comparisons drawn with mortality in the general population. To reduce these deaths attention must be paid both to the prevention of acute metabolic deaths and the early detection and treatment of cardiovascular disease and associated risk factors.     

Recent morbidity trends in myocardial infarction in Japan: investigation of death certificates and the survival rates at coronary care units

To elucidate recent trends in the mortality and morbidity of myocardial infarction (MI), we investigated death certificates and changes in the survival rate of MI patients at coronary care units (CCUs), which may affect the death rates. For all cases of MI, acute heart failure (AHF), heart failure (HF) as underlying cause, and hypertension as underlying cause with HF or AHF (categorized as hypertensive heart disease) on death certificates in two rural and two urban populations between 1981 and 1984, medical records were reviewed and case histories obtained from interviews with patients' families to validate the diagnosis. The number of MI deaths on the death certificates was not underestimated because some MI deaths were misdiagnosed as AHF, HF and hypertensive heart disease and some MI death certificates were misdiagnosed. Survival of MI patients at CCUs improved in several major cities, Tokyo, Osaka, Wakayama and Asahikawa between 1978 and 1984; a total of 4318 MI deaths were estimated to be averted by CCUs in 1984 compared with the number of deaths in 1978. Therefore, improvement of MI cases at CCUs may be one of the factors attenuating the rise in death rates in all of Japan.     

Changing patterns in causes of death in a cohort of injecting drug users, 1980-2001

BACKGROUND: High mortality among drug users has been widely recognized. This study investigates, in a large family practice of 10 000 patients in Edinburgh, Scotland, whether there has been a change in causes of mortality over time. Patients known to have ever injected drugs were recruited into a cohort study from 1980 until 2001. METHODS: Death certificates and clinical notes were scrutinized and data relating to demographic features, drug use, and causes of death were recorded. RESULTS: Of 667 patients, there were 153 deaths at follow-up (110 men and 43 women). Average annual mortality rate was 2.3%. Death rate peaked in the early to mid-1990s, reflecting the development of advanced human immunodeficiency virus (HIV) from the early epidemic in 1982-1984 and the onset of the effect of antiviral chemotherapy. Drug deaths and suicide were the same in both sexes but tended to occur in younger subjects. Principal cause of death was overdose in the early years and HIV/AIDS in later years. Toward the close of the study period, hepatitis C emerged as a cause of death. CONCLUSIONS: Injecting drug users have a very high risk of mortality. Infectious diseases from nonsterile injecting are the most obvious preventable cause of death. Use of death certificate information alone is inaccurate in analyzing drug-related deaths and greatly underestimates the full impact of the HIV epidemic. This study provides some of the most convincing evidence so far that harm minimization, in its broadest sense, is effective in reducing drug-related mortality.     

Risk factors for ARDS in the United States: analysis of the 1993 National Mortality Followback Study

OBJECTIVE: To identify specific comorbid factors that are present in US decedents with ARDS. DESIGN: We searched the 1993 National Mortality Followback Study for all decedents who had a code for ARDS mentioned on their death certificate. We also searched for comorbid conditions both on the death certificates (sepsis, medical or surgical misadventures, cirrhosis) and in the study database (current or former smoking, use of alcohol at least 3 d/wk, race, gender, and age). We calculated proportional mortality ratios (PMRs) for these risk factors. RESULTS: Of the 19,003 decedents for whom data were available, 252 decedents, representing an estimated 19,460 US decedents, had ARDS listed on their death certificate. PMRs among decedents with ARDS were significantly increased for medical or surgical misadventures (PMR, 11.8; 95% confidence interval [CI], 3.8 to 36.7), sepsis (PMR, 5.6; 95% CI, 2.0 to 16.0), nonwhite race (PMR, 2.6; 95% CI, 1.4 to 5.0), and cirrhosis (PMR, 2.2; 95% CI, 1.1 to 4.6). PMRs were increased but not statistically significant for current smokers (PMR, 1.2; 95% CI, 0.5 to 3.0) or former smokers (PMR, 1.8; 95% CI, 0.7 to 4.3) compared to never smokers, and drinking alcohol on > or = 3 d/wk in the year prior to death, when compared to drinking alcohol less than < 3 d/wk (PMR, 1.8; 95% CI, 0.6 to 4.9). CONCLUSIONS: The results of this study confirm the positive associations between ARDS mortality and the presence of sepsis and cirrhosis, and suggest possible new relationships between ARDS mortality and nonwhite individuals and patients with medical or surgical misadventures.     

Mortality from pulmonary fibrosis increased in the United States from 1992 to 2003

RATIONALE: From the late 1970s to the early 1990s, studies found that mortality rates for pulmonary fibrosis were increasing. Recent data for mortality from pulmonary fibrosis are unavailable. OBJECTIVES: We sought to determine mortality rates for pulmonary fibrosis in the United States from 1992 through 2003. METHODS: Using data from the National Center for Health Statistics, we calculated age-adjusted mortality rates from the deaths of persons with pulmonary fibrosis and stratified the data to determine differences in mortality rates by age, sex, race/ethnicity, and geography of the decedent. We developed a multivariable model to predict future mortality rates, and we determined the underlying cause of death in patients with pulmonary fibrosis. MEASUREMENTS AND MAIN RESULTS: From 1992 to 2003, there were 28,176,224 deaths in the United States and 175,088 decedents with pulmonary fibrosis. The average age- and sex-adjusted mortality rate was 50.8 per 1,000,000 people. The age-adjusted mortality rate increased 28.4% in men (from 40.2 deaths per 1,000,000 in 1992 to 61.9 deaths per 1,000,000 in 2003) and 41.3% in women (from 39.0 deaths per 1,000,000 in 1992 to 55.1 deaths per 1,000,000 in 2003). While increases were significant in both men and women (p < 0.0001), the rate of increase was higher in women (p < 0.0001). The most common cause of death in patients with pulmonary fibrosis was the disease itself. CONCLUSIONS: From 1992 to 2003, mortality rates for pulmonary fibrosis significantly increased. Further investigation is needed to determine the etiology of these trends, which are predicted to continue to increase.     

Pulmonary embolism mortality in the United States, 1979-1998: an analysis using multiple-cause mortality data

BACKGROUND: Pulmonary thromboembolism (PTE) is a common clinical problem that is associated with substantial morbidity and mortality. Estimates of PTE mortality and predictions of PTE trends have varied widely. These estimates play a role in the planning of national health strategies. The analysis of pulmonary embolism mortality trends and comorbidities may elucidate how well we treat and prevent the disease as well as identify additional risk factors. METHODS: We analyzed PTE (International Classification of Diseases, Ninth Revision code 415.1) as reported on death certificates in the Multiple-Cause Mortality Files compiled by the National Center for Health Statistics from 1979 to 1998. RESULTS: Of all the 42932973 decedents, 572773 (1.3%) had PTE listed on their death certificates and 194389 of these (33.9%) had PTE as the underlying cause of death. The age-adjusted rate of deaths with PTE decreased from 191 per million in 1979 to 94 per million in 1998 overall, decreasing 56% for men and 46% for women. During the study period, the age-adjusted mortality rates for blacks were consistently 50% higher than those for whites, and those for whites were 50% higher than those for people of other races (Asian, American Indian, etc). Within racial strata, mortality rates were consistently 20% to 30% higher among men than among women. Conditions that were of higher likelihood in persons who died with PTE included thrombophlebitis, fractures, trauma, postoperative complications, certain cancers, and the inflammatory bowel diseases. CONCLUSIONS: Mortality with PTE in the United States has decreased during the 20-year period. The mortality rates between men and women and between racial groups vary substantially. These findings may be useful in better directing preventive therapy efforts.     

Education level and mortality in systemic lupus erythematosus (SLE): evidence of underascertainment of deaths due to SLE in ethnic minorities with low education levels

OBJECTIVE: To determine if socioeconomic status, as measured by education level, is associated with mortality due to systemic lupus erythematosus (SLE), and to determine if these associations differ among ethnic groups. METHODS: Sex- and race-specific mortality rates due to SLE by education level were computed for persons age 25-64 years using US Multiple Causes of Death data from 1994 to 1997. SLE-specific mortality rates were compared with all-cause mortality rates in 1997 to determine if the association between education level and mortality in SLE was similar to that in other causes of death. RESULTS: Among whites, the risk of death due to SLE was significantly higher among those with lower levels of education, and the risk gradient closely paralleled the 1997 all-cause mortality risks by education level. However, in African American women and men and Asian/Pacific Islander women, the risk of death due to SLE was lower among those with lower education levels, contrary to the associations between education level and all-cause mortality in these groups. Comparing the distribution of education levels among deaths due to SLE and all deaths in 1997, persons with lower education levels were underrepresented among deaths due to SLE in African Americans and Asian/Pacific Islanders. CONCLUSION: Among whites, higher education levels are associated with lower mortality due to SLE. These associations were not present in ethnic minorities, likely due to underascertainment of deaths due to SLE in less-well educated persons. This underascertainment may be due to underreporting of SLE on death certificates, but may also represent underdiagnosis of SLE in ethnic minorities with low education levels.     

Tuberculosis and tuberculosis/HIV/AIDS-associated mortality in Africa: the urgent need to expand and invest in routine and research autopsies

Frequently quoted statistics that tuberculosis and human immunodeficiency virus (HIV)/AIDS are the most important infectious causes of death in high-burden countries are based on clinical records, death certificates, and verbal autopsy studies. Causes of death ascertained through these methods are known to be grossly inaccurate. Most data from Africa on mortality and causes of death currently used by international agencies have come from verbal autopsy studies, which only provide inaccurate estimates of causes of death. Autopsy rates in most sub-Saharan African countries have declined over the years, and actual causes of deaths in the community and in hospitals in most sub-Saharan African countries remain unknown. The quality of cause-specific mortality statistics remains poor. The effect of various interventions to reduce mortality rates can only be evaluated accurately if cause-specific mortality data are available. Autopsy studies could have particular relevance to direct public health interventions, such as vaccination programs or preventive therapy, and could also allow for study of background levels of subclinical tuberculosis disease, Mycobacterium tuberculosis-HIV coinfection, and other infectious and noncommunicable diseases not yet clinically manifest. Autopsies performed soon after death may represent a unique opportunity to understand the pathogenesis of M. tuberculosis and the pathogenesis of early deaths after initiation of antiretroviral therapy. The few autopsies performed so far for research purposes have yielded invaluable information and insights into tuberculosis, HIV/AIDS, and other opportunistic infections. Accurate cause-specific mortality data are essential for prioritization of governmental and donor investments into health services to reduce morbidity and mortality from deadly infectious diseases such as tuberculosis and HIV/AIDS. There is an urgent need for reviving routine and research autopsies in sub-Saharan African countries.     

A population-based study of motorcycle injury and costs.

STUDY OBJECTIVE: To provide a population-based injury and cost profile for motorcycle injury in Connecticut. DESIGN: Population-based retrospective epidemiologic review of Connecticut death certificates, hospital discharge data, and police accident reports. RESULTS: Connecticut death certificates identified 112 deaths from motorcycle injuries for an annual death rate of 1.2 per 100,000 persons. Death rates were highest among 20- to 24-year-old men. Nonhelmeted motorcyclists were 3.4-fold more likely to die than were helmeted riders (P less than .05). An estimated 2,361 motorcycle-related hospital discharges resulted in an annual hospitalization rate of 24.7 per 100,000 persons. Head, neck, and spinal injuries accounted for 22% of all injuries. Total costs exceeded $29 million; 29% of hospitalized patients were uninsured, and 42% of the cost was not reimbursed to the hospitals. CONCLUSION: Motorcycle injuries contribute significantly to Connecticut's mortality, morbidity, and medical costs. Our study suggests that a uniform helmet law would save an estimated ten lives and prevent more than 90 nonfatal injuries in Connecticut each year at a cost savings to the state of $5.1 million. These data are crucial in advocating re-enactment of motorcycle helmet laws.     

Declining hepatitis A mortality in the United States during the era of hepatitis A vaccination

BACKGROUND: Since the mid-1990s, hepatitis A vaccine has been recommended for US children living in historically high-incidence states and for persons with other risk factors or chronic liver disease (CLD). The incidence of hepatitis A has declined dramatically during the era of vaccination, but trends in mortality are largely unknown. METHODS: US death certificates from 1990 to 2004 for which hepatitis A was listed as the underlying cause of death were analyzed. Average annual age-adjusted mortality rates during the prevaccine (1990-1995) and post-vaccination recommendation (2000-2004) periods were compared using a Mantel-Haenszel test of association. The number of deaths for which CLD was listed as a contributing cause was determined. RESULTS: Overall, 1436 deaths due to hepatitis A occurred, averaging 96 annually (range, 142 in 1995 to 54 in 2003). CLD contributed to nearly half of these deaths. Mortality rates paralleled incidence rates, beginning to decline in the mid-1990s and achieving low points in 2003 and 2004. Average rates were 32% lower in the post-vaccination recommendation period than in the prevaccine period (P < .01). The decline was more dramatic for states with (45%; P < .001) than without (23%; P = .002) recommendations. CONCLUSIONS: Hepatitis A mortality rates have declined over the past decade. CLD remains an important and preventable contributing cause of death due to hepatitis A.     

Fatal asthma in Finnish children and adolescents 1976-1998: validity of death certificates and a clinical description

Several studies show that asthma mortality in children and adolescents increased until the mid-1990s, after which it has slightly decreased worldwide. The objective of this study was to describe the mortality rates of childhood asthma in Finland, and to analyze patient characteristics to identify predisposing factors for fatal asthma exacerbation among children and adolescents during 1976-1998 (2004). All death certificates where asthma or related respiratory tract disease was coded as the underlying cause of death were reviewed for those under 20 years of age. Health care records and autopsy reports were evaluated to validate the cause of death and to identify any predisposing factors. In all, there had been 28 asthma deaths. The validity of the death certificates proved to be good as only 7% were misclassified. Death occurred either in the very young children or adolescents: the median age in the group of <12 years (n = 15) was 3.3 years while the median age in the group of >12 years (n = 13) was 18.1 years. The fatal exacerbations occurred mostly during summer and early autumn. Clinical triggers, recorded for 14/22 patients with available patient records, included respiratory infection, (12) use of ibuprofen despite known allergy (1), and exercise after visiting a horse stable (1). The severity of the disease was discernible in 21 patients: severe in 15, moderate in 5, and mild in 1 patient. Inhaled corticosteroids were not used as maintenance or periodic therapy in 12/22 patients, of whom 4 had died during the 1990s. In conclusion, asthma mortality in Finnish children and adolescents was rare and its incidence remained stable. The validity of the death certificate diagnoses proved to be good. Poor asthma management and non or undertreatment with inhaled corticosteroids were risk factors for fatal asthma.     

Trends in the mortality burden associated with diabetes mellitus: a population-based study in Rochester,Minn, 1970-1994

BACKGROUND: The prevalence of diabetes mellitus (DM) has increased markedly in recent decades, but trends in the mortality burden associated with DM are unclear. Therefore, we analyzed population-based longitudinal data to address this issue. METHODS: The community-based medical records of all Rochester residents 45 years and older who died between January 1, 1970, and December 31, 1994, were reviewed to identify those who met the standardized criteria for DM before death. Trends over successive quinquenniums were assessed for the proportion of all deaths in the community of persons with prevalent DM, for mortality rates for persons with and without DM, and for the distribution of causes of death among decedents with and without DM. RESULTS: Of 10 152 total deaths in 1970-1994, 1384 (13.6%) met the criteria for prevalent DM. Between 1970-1974 and 1990-1994, the proportion of decedents with DM increased by 48.2%. Mortality rates for persons with and without DM declined by 13.8% and 21.4%, respectively. This disparity in mortality trends was most apparent for older women and younger men. There were temporal declines in the proportion of all persons dying of cardiovascular disease, but temporal declines in persons dying of cerebrovascular disease were found only in decedents without DM. CONCLUSIONS: The mortality burden associated with DM increased significantly between 1970 and 1994, probably due to increases in DM incidence and smaller declines in mortality for persons with DM relative to those without DM. In the absence of improved DM prevention and treatment, the steady declines in mortality observed for the general population since the 1960s will likely begin to slow or even reverse.     

A prospective study of mortality among drug misusers during a 4-year period after seeking treatment

Aims The opportunity to study deaths as they occur within the framework of a prospective cohort study is relatively uncommon. This study investigates deaths among drug misusers over a 4‐year period, with specific attention to the circumstances and causes of death, and risk factors for mortality. The study also critically examines the recording of drug‐related deaths. Design, Setting, Participants Prospective cohort study of 1075 drug misusers recruited to 54 treatment programmes during 1995. Measurements Data derived from interviews conducted with clients at intake, death certificates and post‐mortem examinations. Findings The annual mortality rate was 1.2%, about six times higher than that for a general, age‐matched population. Fourteen per cent of the deaths were due to self‐inflicted injuries, accidents or violence and 18% were due to medical causes. The majority of deaths (68%) were associated with drug overdoses. Opiates were the drugs most commonly detected during post‐mortem examinations. In the majority of cases, more than one drug was detected. Polydrug use and, specifically, heavy drinking, and use of benzodiazepines and amphetamines, were identified as risk factors for mortality. Anxiety and homelessness were also predictive of increased mortality. Conclusions We suggest that drug misusers and those working with drug misusers need to be more alert to the risks of polydrug use, including the combined use of alcohol with illicit drugs. The study revealed inconsistencies in the recording of drug‐related deaths on death certificates. The routine recording of all substances detected during toxicological examination would improve the accuracy of death certification.     

Analysis of mortality in French diabetic patients from death certificates: a comparative study

This study was implemented in France to determine the causes of death in diabetic patients, whether diabetes was mentioned or not on the death certificate, and to assess the underestimation of the prevalence of diabetes at death. Two stratified random samples of death certificates were selected in the national mortality data base. The first included certificates mentioning diabetes as a cause of death (cases). The second, included certificates with no mention of diabetes (controls). For each certificate, a record form was sent to the certifying physician to ascertain diabetes in the first group and to trace unrecorded diabetes in the second group. In case of diabetes, the characteristics of the patient and his disease were collected (age at onset, treatment, complications ...). We obtained complete data for 325 cases and 959 controls. Among cases, 1% of the subjects were not confirmed as diabetic, while almost 10% of the controls were identified as having diabetes. The corresponding ratio of the corrected prevalence at death to that provided by the French statistics was estimated to 4.0 in men and 3.1 in women. Particular features are that 2% of the total diabetic decedents died from acute metabolic complications (diabetic or hyperosmolar coma, acidoketosis, or acute hypoglycemia), and that 33% of the unreported diabetic decedents under 45 died from trauma or poisoning. These results show that in France, the death rates published in the statistics for diabetes dramatically underestimate the impact of diabetes. A high risk of death is linked to this disease, particularly in people aged under 45, a problem that health deciders should address.     

Acute myocardial infarction: period prevalence, case fatality, and comparison of black and white cases in urban and rural areas of South Carolina

Community surveillance revealed 1085 prevalent cases of acute myocardial infarction (AMI) during 1978 in urban metropolitan Columbia and rural Pee Dee areas of South Carolina. Six hundred fifty-eight hospitalized cases met our criteria and were classified as definite or probable. Death certificates identified 427 who died before admission to the hospital and who were classified as unvalidated. However, there is need to verify death certificate diagnosis in out-of-hospital deaths which account for approximately two thirds of total cases in blacks and about one third of white cases. Other findings were: White males had higher AMI rates in the rural Pee Dee area than in urban Columbia, while black males and black females had higher rates in Columbia than in the Pee Dee area and white females had similar rates in both areas. Rates for out-of-hospital AMI mortality were higher in blacks than in whites. Out-of-hospital AMI mortality rates in Columbia and the Pee Dee area were four times higher than in Minneapolis-St. Paul in 1978. For definite and all criteria AMI, white males had the highest rates, double the black male rate except for all criteria AMI in Columbia, where white male and black male rates were similar. Urban cases of both races experienced more anterior infarctions than rural cases.     

Out-of-hospital death: advance care planning, decedent symptoms, and caregiver burden

OBJECTIVES: To examine the end-of-life experiences of elderly decedents dying out of the hospital and their family caregivers in a state in which the vast majority of Medicare deaths occur in community settings. DESIGN: Telephone survey of family caregivers 2 to 5 months after decedents' deaths. SETTING: Statewide (Oregon) random sample of death certificates. PARTICIPANTS: One thousand one hundred eighty-nine family caregivers of decedents aged 65 and older who died of natural deaths in community settings between 2000 and 2002. MEASUREMENTS: A 69-item telephone questionnaire with single-item indicators and embedded scales that indexed advance directives, use of life-sustaining treatments, hospice enrollment, decedent symptom experience and perceived distress, family financial hardship, out-of-pocket expenses, and caregiver strain. RESULTS: Most decedents had advance directives (78.3%) and were enrolled in hospice (62.4%). Although perceived decedent symptom distress was low overall, certain symptoms (e.g., pain, dyspnea, constipation) were distressing for approximately half of decedents experiencing them. Financial hardship, out-of-pocket expenses, and caregiver strain were frequently reported. American Indian race and younger age were associated with decedent symptom distress. Greater perceived decedent symptom distress, hospice enrollment, more caregiver involvement, and more financial burden were associated with greater caregiver strain. CONCLUSION: Despite high rates of advance directives and hospice enrollment, perceived symptom distress was high for a subset of decedents, and caregiver strain was common. As location of death increasingly shifts nationwide from hospital to community, unmet decedent and family needs require new clinical skills and healthcare policies.     

Mortality Related to Chronic Obstructive Pulmonary Disease and Co-morbidities in the United States,A Multiple Causes of Death Analysis

ABSTRACT

Chronic obstructive pulmonary disease (COPD) mortality based on the underlying cause of death (UCOD) underestimates disease burden. We aimed to determine the current COPD mortality rate, trends and the distribution of co-morbidities using United States (US) multiple-cause of death (MCOD) records.

All 38,905,575 death certificates of decedents aged ≥45 years in the United States were analyzed for 1999–2015. COPD was defined by ICD–10 codes J40–J44 and J47 based either on the UCOD or up to 20 contributing causes coded. Annual age–standardized COPD death rates were computed by age, gender and race/ethnicity for those with any mention of COPD.

In 2015, COPD was mentioned in 11.59% (292,572 deaths) in MCOD, compared to 11.13% (243,617 deaths) in 1999, a 4% increase. However, it was reported as the UCOD for only 5.56% and 4.97% in 2015 and 1999 respectively, an 11% increase. The most common UCOD in subjects with any mention of COPD was respiratory disorders in 49% of males and 55% of females. The relative change in death rates differed between MCOD and UCOD. For example, among non-Hispanic white females aged 65–74 years the UCOD rate per 100,000 (95% CI) decreased from 163 (160–166) to 147 (145–150), average annual percent decrease (AAPD) –0.26, while the MCOD rate decreased from 308 (304–311) to 263 (260–267), AAPD –0.87.

Statistics based on UCOD understated the burden of COPD in the United States. MCOD rates were twice as high as UCOD rates. The relative change in death percent or rates differed between MCOD and UCOD. MCOD analysis should be repeated periodically to help evaluate the burden of COPD-related mortality.