The validity of cancer information on death certificates in Norway and the impact of death certificate initiated cases on cancer incidence and survival

BackgroundDeath certificates are an important source of information for cancer registries. The aim of this study was to validate the cancer information on death certificates, and to investigate the effect of including death certificate initiated (DCI) cases in the Cancer Registry of Norway when estimating cancer incidence and survival.MethodsAll deaths in Norway in the period 2011–2015 with cancer mentioned on the death certificates were linked to the cancer registry. Notifications not registered from other sources were labelled death certificate notifications (DCNs), and considered as either cancer or not, based on available information in the registry or from trace-back to another source.ResultsFrom the total of 65 091 cancers mentioned on death certificates in the period 2011–2015, 58,425 (89.8%) were already in the registry. Of the remaining 6 666 notifications, 2 636 (2 129 with cancer as underlying cause) were not regarded to be new cancers, which constitutes 4.0% of all cancers mentioned on death certificates and 39.5% of the DCNs. Inclusion of the DCI cases increased the incidence of all cancers combined by 2.6%, with largest differences for cancers with poorer prognosis and for older age groups. Without validation, including the 2 129 disregarded death certificates would over-estimate the incidence by 1.3%. Including DCI cases decreased the five-year relative survival estimate for all cancer sites combined with 0.5% points.ConclusionIn this study, almost 40% of the DCNs were regarded not to be a new cancer case, indicating unreliability of death certificate information for cancers that are not already registered from other sources. The majority of the DCNs where, however, registered as new cases that would have been missed without death certificates. Both including and excluding the DCI cases will potentially bias the survival estimates, but in different directions. This biases were shown to be small in the Cancer Registry of Norway.     

Death certification in general practice: review of records.

The records of death that had been certified by general practitioners in one practice over 18 years were assessed in the light of the recent joint publications of the Royal College of Physicians and the Royal College of Pathologists. Over this period roughly 30% of the deaths in the practice population occurred outside hospital and a total of 262 certificates were issued. A review of 262 counterfoils of records of death certification showed that 12 counterfoils (4.6%) had no age and sex mentioned, and three counterfoils did not describe the place of death. The average age at death outside hospital was 71.6 years--the age of women being 75.1 years compared with that of men of 68.2 years. Only 2% of patients had had a necropsy. The common causes of death stated in the certificates were: cardiovascular 41%, carcinoma 35%, respiratory 15%, and stroke 8%. All contributory causes are also mentioned. Ninety seven per cent of the patients were seen after death by the doctors in the practice and 68% had been seen in the two days preceding death. We emphasise the importance of keeping accurate records of deaths in general practice for audit and research as well as for planning services for terminally ill and recently bereaved patients.     

Deaths from rhesus haemolytic disease in England and Wales in 1977: accuracy of records and assessment of anti-D prophylaxis.

All the death certificates for deaths in 1977 where haemolytic disease of the newborn (HDN) was the principal, an antecedent, or a contributory cause were obtained from the Office of Population Censuses and Surveys (OPCS). The hospital notes of all 54 of the live-born cases and all of the 101 stillbirths were also obtained. The cause of the death indicated by the notes was compared with the cause and coding on the death certificate. In about a quarter of the cases death was not due to haemolytic disease of any type. The commonest errors arose because the International Classification of Diseases (8th edition) stipulates that hydrops without mention of cause should be coded as HDN and because stillbirths to rhesus-negative mothers tend to be attributed to rhesus HDN automatically. Though deaths from HDN may be overestimated in this way, they are also underestimated because rhesus disease, although mentioned on the certificate, is not selected as the underlying cause, which it may be. These cases were found through multiple coding of all the contributory causes of death, which OPCS performs on a 25% sample of all death certificates for research purposes. These two sources of inaccuracy tend to cancel each other out, but statistics from death certificates give a misleading picture of the efficacy of anti-D prophylaxis because anti-D can never prevent cases which are not in fact due to rhesus HDN. Most of the mothers studied had become immunised before anti-D became available, but in those who could have been treated 75% had not received prophylaxis. As this was a sample of deaths, however, it would not be accurate to extrapolate this high figure to the population at risk. Nevertheless, the organisation of prophylaxis is clearly deficient and should be remedied before providing antenatal anti-D to supplement postnatal treatment.     

Autopsy in California

From information complied from death certificates registered in 1952 and 1962 an examination was made of California''s autopsy performance and the characteristics of deaths in which autopsy was done. The data indicated that California had an overall autopsy rate of 37 per cent of total deaths in 1962, probably higher than any other state. In the decade reviewed, there was a 62 per cent absolute increase in autopsies and a 7 per cent increase relative to total deaths.Substantial increases in the proportion of deaths in which autopsy was done were found for physician-certified deaths in both metropolitan and nonmetropolitan counties and for coroner-certified deaths in nonmetropolitan counties. For all but two of forty-five selected natural causes of death there were increases in the proportion of deaths in which autopsy was done.Seventy per cent of deaths occurred in some type of facility. About one-half of all deaths occurred in general hospitals, and autopsy was done in 42 per cent of such cases.The dual factors of a high autopsy rate and overrepresentation of deaths brought to autopsy in white males, ages 35-64, support the validity of a reported decline in California''s death rate for arteriosclerotic heart disease.     

Deaths From Bites and Stings of Venomous Animals

Data abstracted from 34 death certificates indicate that the three venomous animal groups most often responsible for human deaths in California from 1960 through 1976 were Hymenoptera (bees, wasps, ants and the like) (56 percent), snakes (35 percent) and spiders (6 percent). An average incidence of 2.0 deaths per year occurred during these 17 years, or an average death rate of 0.01 per 100,000 population per year. Nearly three times more males than females died of venomous animal bites and stings. Half of the deaths from venomous snake bites occurred in children younger than 5 years of age. Susceptible persons 40 years or older appeared to be particularly vulnerable to hymenopterous insect stings and often quickly died of anaphylaxis. Fatal encounters with venomous animals occurred more often around the home than at places of employment or during recreational activities. Deaths resulting from spider bites are rare in California but many bites are reported. Medical practitioners are urged to seek professional assistance in identifying offending animals causing human discomfort and to use these animals'' scientific names on death certificates and in journal articles.     

Death certification and epidemiological research. Medical Services Study Group of the Royal College of Physicians of London.

The cause of death shown on 191 death certificates was compared with the cause indicated by the hospital case notes, the consultants'' opinions, and the necropsy findings. All 191 deaths occurred among medical hospital patients aged under 50. In 39 cases there was a major discrepancy between the two sources over the cause of death and in another 54 ther was a minor but epidemiologically important difference. Death certificates are not primarily intended for epidemiological research, but researchers often rely on them. This and other studies have shown, however, that death certificates are often inaccurate records of the cause of death--even coroner''s certificates issued after a coroner''s necropsy. The accuracy of death certificates might be improved if coroners consulted clinicians more closely and if senior hospital staff completed hospital death certificates.     

Reliability of recording uterine cancer in death certification in France and age-specific proportions of deaths from cervix and corpus uteri

French uterine cancer recordings in death certificates include 60% of "uterine cancer, Not Otherwise Specified (NOS)"; this hampers the estimation of mortalities from cervix and corpus uteri cancers. The aims of this work were to study the reliability of uterine cancer recordings in death certificates using a case matching with cancer registries and estimate age-specific proportions of deaths from cervix and corpus uteri cancers among all uterine cancer deaths by a statistical approach that uses incidence and survival data. Deaths from uterine cancer between 1989 and 2001 were extracted from the French National database of causes of death and case-to-case matched to women diagnosed with uterine cancer between 1989 and 1997 in 8 cancer registries. Registry data were considered as "gold-standard". Among the 1825 matched deaths, cancer registries recorded 830 cervix and 995 corpus uteri cancers. In death certificates, 5% and 40% of "true" cervix cancers were respectively coded "corpus" and "uterus, NOS" and 5% and 59% of "true" corpus cancers respectively coded "cervix" and "uterus, NOS". Miscoding cervix cancers was more frequent at advanced ages at death and in deaths at home or in small urban areas. Miscoding corpus cancers was more frequent in deaths at home or in small urban areas. From the statistical method, the estimated proportion of deaths from cervix cancer among all uterine cancer deaths was higher than 95% in women aged 30-40 years old but declined to 35% in women older than 70 years. The study clarifies the reason for poor encoding of uterus cancer mortality and refines the estimation of mortalities from cervix and corpus uteri cancers allowing future studies on the efficacy of cervical cancer screening.     

Trends in mortality statistics in England and Wales with particular reference to AIDS from 1984 to April 1987

Death certification should be able to provide accurate data on the number of deaths due to AIDS as a basis for predicting future deaths from the syndrome. Trends in deaths from other causes may identify conditions that have not been recognised to be associated with HIV infection. Mortality statistics with reference to AIDS in England and Wales were completed from death certificates. Increases in deaths from selected causes likely to be associated with AIDS or HIV infection suggested that in some patients with HIV infection, AIDS was not stated on the death certificate or subsequently notified by the doctor who signed the certificate. From calculations of excess deaths between the beginning of 1985 and the end of April 1987, compared with 1984 at least 495 deaths possibly associated with HIV infection were estimated to have occurred among men aged 15-54 during that period. In 261 AIDS or HIV infection was stated on the original or amended death entry as the cause of death, and of these 198 were included in the estimated number of excess deaths.Accurate notification of the underlying cause of death and associated diseases is required for the precise monitoring of trends in mortality from AIDS and possible identification of unrecognised conditions associated with HIV infection.     

OPERATING ROOM DEATHS—An Analysis of Mortality in a Veterans Administration Hospital Over a Ten-Year Period

A study of operating room and recovery room deaths which occurred during a ten-year period from 1948 through 1957 at one hospital revealed that there were 59 deaths associated with 57,132 surgical procedures.Factors which directly influenced the rate of operating room and recovery room death were the age of the patient and the length of operating time. Seventy-five per cent of the deaths occurred in cases in which the operation took longer than one hour. Combined anesthesia techniques may have indirectly contributed to death in some cases.Complications of operation requiring another surgical procedure sometimes occur. In this series, reoperation proved to be more hazardous in terms of mortality rate than did single operations. This is not surprising for most complications occur in the poorer risk patients.The operating room death rate steadily increased during the ten-year period studied. This increasing death rate can largely be attributed to the more intricate operations which are being done on poorer risk patients. The use of the curariform drugs had no influence on the increasing death rate.     

Operating room deaths; an analysis of mortality in a Veterans Administration hospital over a ten-year period

A study of operating room and recovery room deaths which occurred during a ten-year period from 1948 through 1957 at one hospital revealed that there were 59 deaths associated with 57,132 surgical procedures. Factors which directly influenced the rate of operating room and recovery room death were the age of the patient and the length of operating time. Seventy-five per cent of the deaths occurred in cases in which the operation took longer than one hour. Combined anesthesia techniques may have indirectly contributed to death in some cases. Complications of operation requiring another surgical procedure sometimes occur. In this series, reoperation proved to be more hazardous in terms of mortality rate than did single operations. This is not surprising for most complications occur in the poorer risk patients. The operating room death rate steadily increased during the ten-year period studied. This increasing death rate can largely be attributed to the more intricate operations which are being done on poorer risk patients. The use of the curariform drugs had no influence on the increasing death rate.     

Unrecognised HIV related deaths.

OBJECTIVES--To establish whether follow up of deaths from selected HIV related causes could increase the number of cases of HIV infection reported to the Public Health Laboratory Service Communicable Disease Surveillance Centre (CDSC), and to estimate the proportion of deaths among HIV positive men that occurred in men who were not known to be HIV positive at the time of death by the person who signed the death certificate. DESIGN--Follow up of draft death entries received by the Office of Population Censuses and Surveys on which one of 11 medical or external causes likely to be related to HIV was stated; letters were sent to the people who signed the certificates. The respondents were invited to report men known to have been HIV positive who were not already on the CDSC register. SETTING--England and Wales. SUBJECTS--Men aged 15-54 who died in February 1989 to July 1989 with one of the 11 selected HIV related diseases as cause of death on their death certificates. MAIN OUTCOME MEASURES--Number of men reported to the CDSC as a result of this follow up; estimate of excess deaths due to an HIV related cause; estimate of the proportion of excess deaths that occurred in those who were not known to be HIV positive at the time of death. RESULTS--Replies were received for 473 deaths (86%). Forty were for men known to have been HIV positive, 31 of whom had been reported to CDSC by the time they died; six were subsequently reported. The respondent did not know that the decreased was HIV positive for 20 (35%) of the 57 excess deaths in men for whom one of the medical causes was stated and 41 (93%) of the 44 excess deaths in men for whom one of the external causes was stated. CONCLUSION--Follow up of death registrations is not an efficient way of increasing the number of cases of HIV infection reported to CDSC. Between 35% and 60% of HIV positive people for whom certain causes are stated may be dying without HIV positivity having been diagnosed. There may be implications for those caring for people with these conditions and those who carry out postmortem examinations.     

Causes of Mortality for Indonesian Hajj Pilgrims: Comparison between Routine Death Certificate and Verbal Autopsy Findings

Background

Indonesia provides the largest single source of pilgrims for the Hajj (10%). In the last two decades, mortality rates for Indonesian pilgrims ranged between 200–380 deaths per 100,000 pilgrims over the 10-week Hajj period. Reasons for high mortality are not well understood. In 2008, verbal autopsy was introduced to complement routine death certificates to explore cause of death diagnoses. This study presents the patterns and causes of death for Indonesian pilgrims, and compares routine death certificates to verbal autopsy findings.

Methods

Public health surveillance was conducted by Indonesian public health authorities accompanying pilgrims to Saudi Arabia, with daily reporting of hospitalizations and deaths. Surveillance data from 2008 were analyzed for timing, geographic location and site of death. Percentages for each cause of death category from death certificates were compared to that from verbal autopsy.

Results

In 2008, 206,831 Indonesian undertook the Hajj. There were 446 deaths, equivalent to 1,968 deaths per 100,000 pilgrim years. Most pilgrims died in Mecca (68%) and Medinah (24%). There was no statistically discernible difference in the total mortality risk for the two pilgrimage routes (Mecca or Medinah first), but the number of deaths peaked earlier for those traveling to Mecca first (p=0.002). Most deaths were due to cardiovascular (66%) and respiratory (28%) diseases. A greater proportion of deaths were attributed to cardiovascular disease by death certificate compared to the verbal autopsy method (p<0.001). Significantly more deaths had ill-defined cause based on verbal autopsy method (p<0.001).

Conclusions

Despite pre-departure health screening and other medical services, Indonesian pilgrim mortality rates were very high. Correct classification of cause of death is critical for the development of risk mitigation strategies. Since verbal autopsy classified causes of death differently to death certificates, further studies are needed to assess the method’s utility in this setting.     

BCG vaccination and cancer mortality

Summary The mortality rate from leukemia and other neoplastic diseases for the years 1957–1969 was compared in 85,356 BCG-vaccinated newborns at Cook County Hospital, Chicago, and 534,870 nonvaccinated population in Chicago (all black). All cases of cancer deaths under 20 years of age in the black population of Chicago were obtained from death certificates at the Chicago Board of Health. The total black population 20 years of age and under was determined by demographic means from the Chicago Board of Health birth records, adjusted for deaths under the period of study. There were 13 deaths among the vaccinated for a rate of 1.17/100,000/year and 306 deaths among the nonvaccinated for a rate of 4.39/100,000/year. The difference was statistically highly significant (p<0.001). This was a reduction of 74% in the vaccinated group as compared to the nonvaccinated. There were no deaths from malignancies in the under 1 year of age group in the vaccinated, but a drop in the rates to 50% or less in the later age groups (except 10–14 years) in the vaccinated as compared to the nonvaccinated. Thus revaccination at given intervals (1–2 years) is recommended. The National Cancer Institute checked death reports due to cancer elsewhere in the country in our vaccinated population. To reduce the possibility of error, deaths due to trauma in the two groups were determined. No differences in the rates were found. The major categories of neoplasms for this age group were (1) leukemia, (2) central nervous system, (3) lymphoma, and (4) bone and connective tissue. This was a retrospective study. Statistically designed, controlled studies may provide definite conclusions.     

Impact of HIV infection on mortality in young men in a London health authority.

OBJECTIVE--To determine the number of deaths attributable to HIV infection among men aged 15-64 in a geographically defined population in the United Kingdom. DESIGN--Retrospective review of death certificates and linkage with local and national HIV and AIDS surveillance data. SETTING--Riverside District Health Authority, London. MAIN OUTCOME MEASURES--Numbers of deaths attributed to HIV infection in male residents of Riverside aged 15-64 and 15-44 over a six month period. Proportion of attributed deaths were (i) identified from death certificates by the Office of Population Censuses and Surveys as being due to HIV infection and (ii) reported as cases of AIDS or HIV related deaths to the Public Health Laboratory Service Communicable Disease Surveillance Centre. RESULTS--34 of 213 (16%) deaths in men aged 15-64 and 27 of 69 (39%) deaths in men aged 15-44 were attributed to HIV infection. Six of 33 (18%) attributed deaths were identified by the Office of Population Censuses and Surveys and 32/34 (94%) were reported to the Communicable Disease Surveillance Centre. CONCLUSIONS--HIV infection was the leading cause of death in male residents of Riverside aged 15-44 and the third commonest cause of death in those aged 15-64. Most individuals dying of known HIV infection were reported to the Communicable Disease Surveillance Centre but identification of the true cause of death from the process of death certification was poor. Measures to improve the certification of HIV and AIDS or the use of AIDS surveillance information correctly to code the cause of death needs to be considered to ensure that the true impact of HIV infection is reflected in routine mortality statistics.     

Psychological Implications of Cystic Fibrosis

A psychological and psychiatric study of 11 children with cystic fibrosis revealed major psychological problems in all of them. Among the parents of the majority of these children, marked psychopathology and gross marital discord were noted. Popular literature concerning cystic fibrosis had a negative effect on the child''s attitude toward the disease. Virtually all of these patients showed a preoccupation with death. In this study, the necessity of psychiatric consultation as an integral part of current intensive treatment programs in cystic fibrosis clinics was demonstrated.     

Improving the reporting of cancer-specific mortality and survival in research using cancer registry data

Population-based registries are increasingly used in cancer research. In such studies, cancer-specific mortality or survival is frequently used as the primary outcome. To determine whether a putative cancer was part of the causal chain of events leading to death, cancer registries primarily rely on death certificates. Hence, they depend on the subjective interpretation of information available to medical examiners at the time of death. Misclassification may occur: studies report misclassification of cancer as a cause of death in 15%–35% of death certificates based on evaluation by expert panels and/or autopsy reports. Further misclassification may occur when coding death causes in the cancer registry. Researchers should be aware of potential misclassification bias when using cancer registry data. Differential misclassification may bias the results towards or away from the null hypothesis, depending on whether there is relative over- or under-reporting of cancer-related deaths in one group. Strategies to improve reporting of cancer-specific survival/mortality include (1) describing the procedure used to identify cancer-specific deaths; (2) considering the use of multiple definitions of cancer-related deaths (strict/liberal definitions of cancer-specific deaths, and/or addition of relative survival as an outcome); and (3) reporting cancer-specific survival/mortality together with the objectively measured parameters overall survival or all-cause mortality.     

Cancer mortality in Itapúa—A rural province of Paraguay 2003–2012

BackgroundItapúa is a rural department in Paraguay with a population of about 500,000 and a high degree of agro-mechanization for the production of soybean and other crops. So far, only basic health care is provided. Here we analyzed the cancer mortality in this region as a first step towards epidemiological data for cancer prevention.MethodsWe calculated the age-adjusted mortality rates according to world standard (AMRWs) for the major cancer sites in both males and females between 2003 and 2012, and estimated the differences between the capital and more central districts of Itapúa vs. remote districts.ResultsThere were about 2000 cancer deaths in the decade studied, with AMRWs for all malignancies of 90.9/100,000 in males from central vs. 49.1/100,000 in remote districts and 69.0/100,000 vs. 45.0/100,000 in women. Cancer was mentioned in 12.4% of all death certificates and outweighed mortality from certain infectious and parasitic diseases (3.6%). Cause of death was ill-defined in 19.6% of all death certificates, especially in remote regions and among the elderly. The part of cancer located in the uterus (47.8%) or cell type of neoplasm of the lymphatic or hematopoietic system (73.1%) were often not specified. The uterus (mainly the cervix) (C53–C55) was the leading cancer site in women with AMRWs of 17.2/100,000 in central and 14.0/100,000 in remote districts, followed by the breast. Lung and prostate were the leading cancer sites among men. The lung cancer mortality rate was 19.3/100,000 in the central region but 9.5/100,000 in remote districts. Although children comprised 36% of the population, only 24 death certificates listed cancer as cause of death in this decade.ConclusionsAnalysis of cancer mortality in this rural region of Paraguay, which lacks resources for diagnostics and care, revealed an already large number of cases, with higher rates in the central region than in remote districts. Lung and uterus (primarily the cervix) are common cancer sites and indicate the potential for prevention. However, the quality of the vital statistics needs to be improved. The true cancer burden is most likely underestimated, especially in remote regions and children.     

Mortality rates in subjects with fetal alcohol spectrum disorders and their siblings

BACKGROUND: Our objective was to estimate the mortality rate in subjects with fetal alcohol spectrum disorders (FASD) and their siblings whose FASD status was unknown. METHODS: We used the state FASD Registry to link subjects with FASD to a North Dakota birth certificate. We were able to link 304 of 486 cases (63%). We used the birth certificates to identify the mother and children born to the mother (siblings). We then searched for death certificates for both the FASD cases and their siblings. We then calculated the annual and age‐adjusted mortality rates for the siblings of the Registry cases and compared them with mortality rates from North Dakota. RESULTS: The FASD case mortality rate was 2.4%, with a 4.5% mortality rate for their sibings, accounting for 14% of all deaths when compared to the North Dakota residents matched by age and year of death. The sibling deaths accounted for 21.5% of all cause mortality matched by age and year of death. The age‐standardized mortality ratios were 4.9 for the FASD cases and 2.6 for their siblings whose FASD status was unknown. CONCLUSIONS: Mortality rates for FASD cases and their siblings were increased and represent a substantial proportion of all cause mortality in North Dakota. Prevention of FASD may be a useful strategy to decrease mortality. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.     

Maternal Mortality in California

During the period August 1957 to December 1966, the Committee on Maternal and Child Care of the California Medical Association and the State Department of Public Health studied 1,219 deaths of women who died during or within 90 days of termination of pregnancy. Twenty-two percent of the deaths reviewed were considered unavoidable. Seventy percent had one or more avoidable factors; of these, 46 percent were attributed to errors in professional judgment, and 16 percent to inadequate prenatal care by the patient herself.Nearly one-third (383) of the 1,219 cases reviewed were deaths from non-obstetric causes. Of the 836 deaths from obstetric causes, 260 were attributed to abortion. Preliminary figures suggest a reduction in criminal abortion deaths corresponding to the increase in therapeutic abortions since 1968.Over one-third of the deaths occurred in Mexican and Negro mothers. Death rate for Negro was triple that for white mothers. Despite the presence of four medical schools in District II (Los Angeles County), maternal death rates were 30 to 50 percent higher than in other districts due to the large urban black and Chicano population. One rural district with a large migratory agricultural population also had high rates.     

Using death certificates to estimate the completeness of AIDS case reporting in Ontario in 1985-87.

The completeness of AIDS (acquired immune deficiency syndrome) case reporting in Ontario was assessed by reviewing all AIDS death certificates compiled by the Registrar General between Jan. 1, 1985, and Dec. 31, 1987. Several demographic variables were used to match death certificates with cases reported to the provincial AIDS registry. The completeness of case reporting was then estimated by examining the ratio of reported deaths of patients with AIDS to the total number of deaths reviewed. The estimated completeness of case reporting was 81.1% in 1985, 71.5% in 1986 and 75.4% in 1987; the overall rate for 1985-87 was 75.2%. The difference in the completeness of case reporting from year to year was not statistically significant. There was a significant increase from 1985 to 1986 in the proportion of unreported cases in people who had never been married (p less than 0.02). Reporting was not associated with the patient''s age, sex, occupation or place of residence. The deficiency in AIDS case reporting could adversely affect the long-term planning of health care resources and the development of programs to prevent and control the spread of AIDS.