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F Bijlsma

Publications and source records attributed to F Bijlsma.

16 recordsLinked to original sources
PubMed1999

Gains in life expectancy after elimination of major causes of death: revised estimates taking into account the effect of competing causes.

BACKGROUND: It is generally acknowledged that conventional estimates of the potential number of life years to be gained by elimination of causes of death are too generous. This is because these estimates fail to take into account the fact that those who are saved from the cause are likely to have one or more other conditions ("competing" causes of death), which may increase their risks of dying. It is unknown to what extent this introduces bias in comparisons of life years to be gained between underlying causes of death. The purpose of the study was to assess this bias. DATA AND METHODS: A sample of 5975 death certificates from the Netherlands, 1990, was coded for the presence of diseases that, according to a set of explicit rules, could be regarded as potential causes of death "competing" with the underlying cause. Logistic regression analysis was used to quantify age and sex adjusted differences between four main underlying causes of death (neoplasms, cardiovascular diseases, respiratory diseases, all other diseases) in prevalence of the six most frequent competing causes of death (neoplasms, ischaemic heart disease, cerebrovascular disease, other cardiovascular diseases, chronic obstructive lung disease, all other diseases). These prevalence differences were then used to revise conventional calculations of gains in life expectancy, by taking them to indicate differences in risk of dying from these competing causes after the underlying cause has been eliminated. RESULTS: The prevalence of competing causes of death is relatively low among persons dying from neoplasms as the underlying cause, about average among persons dying from cardiovascular diseases, and relatively high among persons dying from respiratory diseases. Taking this into account results in substantial decreases of potential life years to be gained by elimination of cardiovascular diseases and respiratory diseases, relative to the number of years to be gained by elimination of neoplasms. Specifically, while according to the conventional calculations the gain in life expectancy by elimination of cardiovascular diseases exceeds that for neoplasms by more than one year, in the revised calculations the number of life years to be gained is approximately equal. CONCLUSIONS: Despite its limitations, mainly relating to reliance on death certificate data, this study suggests that conventional estimates of differences between underlying causes of death in life years to be gained by elimination are seriously biased by ignoring the effects of competing causes. Specifically, the relative impacts of eliminating cardiovascular diseases and respiratory diseases, as compared with eliminating neoplasms, seem to be overestimated. The implications are discussed.

Adolescent↗
PubMed1998

Analysis of the immunological cross reactivities of 213 well characterized monoclonal antibodies with specificities against various leucocyte surface antigens of human and 11 animal species.

213 Monoclonal antibodies (mAbs) raised against leucocyte surface antigens from human and 11 animal species were analyzed for reactivities against leucocytes from human and 15 different animal species. We found 77 mAbs (36%) to cross-react. Altogether, 217 cross reactions were registered out of 3195 possible combinations (7%). Most of the cross reacting mAbs had integrin or MHC class II specificities. This study defined cross reactions on the following markers: CD1a, 1c, 2, 4, 5, 8, 9, 11a, 11b, 14, 18, 20, 21, 23, 29, 31, 41, 43, 44, 45, 45R, 46, 49, 61, 62L, TCR gamma/delta, BCR, Thy-1, MHC class I and MHC class II, Swine-WC7 and Cattle-WC1. In order to characterize the molecular weight (MW) of the corresponding cross reacting antigens, selected mAbs were used to immunoprecipitate the antigens. The MW's of the analyzed precipitated antigens were in good agreement with the MWs of the homologous antigens. The followed strategy was found to be efficient and economical in defining new leucocyte antigen reactive mAbs.

Animals↗
PubMed1997

Competing causes of death: a death certificate study.

BACKGROUND: Despite the widespread interest in competing causes of death, empirical information on interrelationships between causes of death is scarce. We have used death certificate information to estimate the prevalence of competing causes of death at the moment of dying from specific underlying causes of death. MATERIALS AND METHODS: In a stratified sample of 5975 deaths occurring in The Netherlands in 1990, information contained in the death certificate was used to determine the presence of diseases which, in the hypothetical case of elimination of the underlying cause of death, could develop into a new underlying cause of death. Poisson regression analysis was used to describe variation in age- and sex-adjusted prevalence of competing causes of death between different underlying causes. RESULTS: Per 100 deaths, 46.2 competing causes were identified (52.0 after reweighting to take away the effects of stratification). The most frequent competing causes, all occurring in more than 2% of deaths, were: senile dementia, diabetes mellitus, ischemic heart disease, cerebrovascular disease, chronic obstructive lung disease, hypertensive disease, and arteriosclerosis. The overall prevalence of competing causes is relatively high among deaths from respiratory diseases (relative risk for respiratory diseases as compared with all underlying causes (RR) = 1.42 (95% CI, 1.25-1.62)), relatively low among deaths from neoplasms (RR = 0.54 (95% CI, 0.47-0.62)), and in between among deaths from cardiovascular diseases (RR = 1.08 (95% CI, 0.95-1.22)). CONCLUSION: Although it cannot be excluded that some of the variation in prevalence of competing causes by underlying cause is due to selective underregistration of coexisting diseases on death certificates, the results of this study suggest that conventional estimates of gains in life expectancy after elimination of neoplasms are much less biased by the effect of competing causes than the corresponding estimates for cardiovascular diseases and particularly respiratory diseases.

Adolescent↗
PubMed1995

Competing causes of death: an analysis using multiple-cause-of-death data from The Netherlands.

The standard methodology for cause-elimination life tables assumes that the various causes of death are statistically unrelated to one another, so that the mortality risks of those who are saved from an eliminated cause equal the risks of dying from other causes which are observed for the general population. In the analysis reported in this paper, data on multiple causes of death for the year 1990 in the Netherlands were used to investigate whether this is likely to be a valid assumption. For four groups of underlying causes of death (malignant neoplasms, cardiovascular diseases, and external causes), the age-standardized prevalence at death of other conditions was calculated. Two series of calculations were performed: one with all other coded conditions present at death and one with a selection of conditions that were eligible to become the new underlying cause of death after the present underlying cause had been eliminated. The results suggested that there are major differences between underlying causes of death in the prevalence at death of other conditions. According to the second series of calculations, the prevalence at death of other conditions. According to the second series of calculations, the prevalence of possible new underlying causes of death was relatively high among persons who died from cardiovascular diseases; about average for persons who died from respiratory diseases; and relatively low for persons who died from malignant neoplasms and external causes. Although studies validating the multiple-cause-of-death data as they appear in the official statistics are necessary, these results reconfirm that this is a potentially rich source of information and that the assumption made in conventional cause-elimination life tables is unlikely to be valid.

Adolescent↗
PubMed1994

[Mortality among young people: causes and background].

OBJECTIVE: To study the mortality pattern among adolescents and young adults (15-24 years of age) in the Netherlands, 1983- 1992. DESIGN: Retrospective study. SETTING: Centraal Bureau voor de Statistiek (Statistics Netherlands). METHOD: Based on central registration and coding of all cause of death certificates in the Netherlands, the results of 10 years for the age group of 15-24 years were arranged according to the Chapters of ICD-9 and subdivided where necessary. Changes during this period were also studied. The findings were compared with those obtained in other countries. RESULTS: Most young people (61.5% of the men, 45.2% of the women) died of external causes. Traffic accidents and suicide ranked first and second in this category. Among natural causes, (malignant) neoplasms were most important, followed by diseases of the nervous system and sensory organs, diseases of the circulatory system and congenital anomalies. There was a group of 8.8% classified as 'symptoms, signs and ill-defined conditions' of which over 90% were registered as 'cause unknown', mainly (65.8%) due to missing certificates of young people who died abroad. The course in time showed a slight decrease of all causes, particularly of external causes. Compared with other countries (Europe, USA) the results in the Netherlands stand out favourably. CONCLUSION: A further decline of mortality in young people could be achieved by unrelenting efforts to prevent traffic accidents and other accidental or suicidal deaths. Apart from this, life expectancy in the young will gain by prevention and/or early treatment of malignancies, infectious diseases and congenital conditions. A higher autopsy rate would solve some uncertainties.

Accidents, Traffic↗
PubMed1993

Cancer incidence differences between ethnic groups in Surinam.

Because of central registration, all new cases of malignant disease in Surinam confirmed by pathology could be studied over a twelve-year period (1979-1990). Patients were arranged by sex, age, racial or ethnic group, and primary localisation of the malignancy. A predominance of female patients could largely be ascribed to very frequent carcinoma of the uterine cervix. Apart from this, striking differences in proportional rate of general malignancy and of the four most frequent types were found among the various ethnic groups. Genetic differences in susceptibility to malignant disease are presumed to contribute substantially to the variations observed.

Adolescent↗
PubMed1981

Malignant tumours in Mozambican Africans with special reference to primary liver carcinoma.

The relative frequency of malignant disease as diagnosed by autopsy, biopsy or cytology in the Pathology Department, Central Hospital/Eduardo Mondlane University, Maputo, Mozambique, has been calculated for 1977 and compared with similar findings over the period 1956-70 (ICD codes 140-209). The figures relate to African patients mainly from the South Mozambican area. A decrease of relative frequency of primary liver carcinoma was observed in men (from over 50% to 35%) but not in women. Other malignancies tend to be constant over the years, in accordance with the general pattern of malignancies for most African countries south of the Sahara. No explanation for the decrease of primary liver carcinoma in men can be given, assuming an unchanging high incidence of viral hepatitis, liver cirrhosis and food contamination by aflatoxin. Curiously, the relative frequency figure for primary carcinoma of the liver in females shows no gross alterations in the 1956-77 period, fluctuating around 20%, which is about the same as the relative frequency of carcinoma of the uterine cervix.

Female↗
PubMed1979

Endomyocardial fibrosis and rheumatic heart disease in Mozambique.

The first five cases of endomyocardial fibrosis to be reported from Mozambique are described in an autopsy series over the years 1975-77, together with 85 cases of rheumatic heart disease in patients who died and were autopsied during the same period. Outside the central parts of the African continent, endomyocardial fibrosis does not seem as rare as previously thought. Observations on the age and sex of the patients correspond with what is already known about both diseases. The strikingly higher frequency of rheumatic heart disease discussed in this review is at variance with the findings of SHAPER et al. in Uganda over the years 1950-65 and poses problems as to the hypothesis of a common aetiological process in both diseases, i.e. a hypersensitivity mechanism acting on cardiac connective tissue.

Adolescent↗