Search PubMed⌕ Search

Biomedical subjects

C W Looman

Publications and source records attributed to C W Looman.

At least 55 records · Page 3Linked to original sources
PubMed1992

Seasonal variation in mortality in The Netherlands.

STUDY OBJECTIVE: The aim was to describe the pattern of seasonal variation in all cause mortality in The Netherlands, and to analyse the contribution of specific causes of death to the winter excess of all cause mortality. DESIGN: Daily numbers of deaths in The Netherlands, by cause, were obtained for the period 1979-1987. Patterns of variation were analysed using Poisson regression. The model related the observed number of deaths to (1) the number expected for that day on the basis of person-days at risk by age and sex, (2) secular trend, and (3) first and higher order cosine terms where appropriate. MAIN RESULTS: All cause mortality has a bimodal peak in the first months of the year. After that it declines to reach a plateau in late spring. Mortality is lowest at the end of August, after which it rises steeply again. The winter excess of all cause mortality is primarily due to cardiovascular diseases (66%) and respiratory conditions (13%). Cardiovascular mortality peaks before respiratory mortality, suggesting different lag times in the effects of winter. There was an episode of exceptionally high mortality (above the normal winter excess) in early 1986, which was primarily due to cardiovascular diseases (39%) and respiratory conditions (25%). This episode was probably caused by a severe influenza epidemic, and was not followed by a compensatory lowering of mortality. CONCLUSIONS: The pattern of variation of mortality within the year suggests that it is not based on a simple relationship with climatological circumstances, because the latter fluctuate according to a less complex pattern. Cause specific data suggest an instantaneous effect of "winter" on the cardiovascular system, and a delayed effect mediated by respiratory infections.

Cause of Death↗
PubMed1991

Euthanasia and other medical decisions concerning the end of life.

This article presents the first results of the Dutch nationwide study on euthanasia and other medical decisions concerning the end of life (MDEL). The study was done at the request of the Dutch government in preparation for a discussion about legislation on euthanasia. Three studies were undertaken: detailed interviews with 405 physicians, the mailing of questionnaires to the physicians of a sample of 7000 deceased persons, and the collecting of information about 2250 deaths by a prospective survey among the respondents to the interviews. The alleviation of pain and symptoms with such high dosages of opioids that the patient's life might be shortened was the most important MDEL in 17.5% of all deaths. In another 17.5% a non-treatment decision was the most important MDEL. Euthanasia by administering lethal drugs at the patient's request seems to have been done in 1.8% of all deaths. Since MDEL were taken in 38% of all deaths (and in 54% of all non-acute deaths) we conclude that these decisions are common medical practice and should get more attention in research, teaching, and public debate.

Adolescent↗
PubMed1991

Delaying childbearing: effect of age on fecundity and outcome of pregnancy.

OBJECTIVES: To study the age of the start of the fall (critical age) in fecundity; the probability of a pregnancy leading to a healthy baby taking into account the age of the woman; and, combining these results, to determine the age dependent probability of getting a healthy baby. DESIGN: Cohort study of all women who had entered a donor insemination programme. SETTING: Two fertility clinics serving a large part of The Netherlands. SUBJECTS: Of 1637 women attending for artificial insemination 751 fulfilled the selection criteria, being married to an azoospermic husband and nulliparous and never having received donor insemination before. MAIN OUTCOME MEASURES: The number of cycles before pregnancy (a positive pregnancy test result) or stopping treatment; and result of the pregnancy (successful outcome). RESULTS: Of the 751 women, 555 became pregnant and 461 had healthy babies. The fall in fecundity was estimated to start at around 31 years (critical age); after 12 cycles the probability of pregnancy in a woman aged greater than 31 was 0.54 compared with 0.74 in a woman aged 20.31. After 24 cycles this difference had decreased (probability of conception 0.75 in women greater than 31 and 0.85 in women 20.31). The probability of having a healthy baby also decreased--by 3.5% a year after the age of 30. Combining both these age effects, the chance of a woman aged 35 having a healthy baby was about half that of a woman aged 25. CONCLUSION: After the age of 31 the probability of conception falls rapidly, but this can be partly compensated for by continuing insemination for more cycles. In addition, the probability of an adverse pregnancy outcome starts to increase at about the same age.

Adult↗
PubMed1991

Determinants of traffic accident mortality in The Netherlands: a geographical analysis.

In the Netherlands, a country with one of the lowest levels of traffic accident mortality in the world, large regional mortality differences can be observed. An analysis was performed of the contribution of regional differences in traffic mobility (kilometers travelled/person-years), injury rate (injured people/kilometre travelled) and case fatality (traffic deaths/injured people). Subsequently, possible determinants of regional differences in traffic accident mortality and its constituent parts were investigated. Both the influence of sociodemographic factors and of factors probably more directly related to traffic deaths (road infrastructure, medical care) was studied. Regional differences in traffic accident mortality in the Netherlands can only to a very limited extent be explained by regional differences in traffic mobility. Regional differences in case fatality seem to make the most important contribution. Of the sociodemographic factors that were used in the analysis, per capita income appears to be the strongest predictor of regional mortality differences. A higher income level is associated with lower mortality levels. Of the factors more directly related to traffic deaths, traffic density and the availability of advanced trauma care (neurosurgery and computerized tomography (CT-Scan)) in the region are the most important predictors of regional mortality differences. Both variables show an inverse relationship with case fatality. Probably a higher traffic density leads to a shift towards less severe injuries. The availability of advanced trauma care could be important in early diagnosis and treatment of head injuries. The results of this study, based on existing data sources, must be interpreted with care. Some potential sources of bias (omitted variables, regional differences in accident reporting) are discussed.

Accidents, Traffic↗
PubMed1991

The decline in winter excess mortality in The Netherlands.

In most countries, numbers of deaths rise considerably during the winter season. This winter excess in mortality has, however, been declining during recent decades. The causes of this decline are hardly known. This paper attempts to derive a number of hypotheses on the basis of a detailed description of trends in winter excess mortality in the Netherlands. Numbers of death by age, cause of death, and month of death for the period 1953-1988 were analysed by log-linear regression. There was a 50% reduction in winter excess mortality between the 1950s and 1970 followed by a much smaller reduction in later years. The decline in winter excess for total mortality can largely be attributed to parallel declines for a number of cardiovascular and respiratory diseases. Excess mortality decreased for winter months without influenza epidemics as well as for those with epidemics. The results suggest that the decline in winter excess mortality in the Netherlands can only partly be explained by decreases in influenza-associated mortality. It is argued that the role of the introduction of central heating is minimal and that a fundamental role is played by factors closely related to socioeconomic progress.

Adolescent↗
PubMed1991

Cultural and economic determinants of geographical mortality patterns in The Netherlands.

STUDY OBJECTIVE: The geographical pattern of mortality in The Netherlands is dominated by an area of relatively high mortality in the southern part of the country. The aim was to analyse the background of this geographical mortality pattern in the early 1980s, and its evolution over time since the early 1950s. DESIGN: Mortality data by district (n = 39), cause of death (13 large causes, "symptoms and ill defined conditions", all other causes), and time period (1950-54, 1960-64, 1970-74, 1980-84) were available from the Netherlands Central Bureau of Statistics. Standardised mortality ratios were calculated, and the logarithms of these were related to three sociodemographic characteristics using multiple, ordinary least squares regression analysis. SETTING: This study used data for the whole Dutch population. MAIN RESULTS: Although the geographical mortality pattern has been rather stable over the last decades, a clear tendency towards convergence is also apparent. Approximately 90% of the current excess mortality in the southern part of the country is due to cardiovascular diseases. The results of regression analysis show that the excess mortality is primarily related to the high percentage of Roman Catholics in this part of the country, and additionally to a slightly lower average income. In The Netherlands, a higher percentage of Roman Catholics in the population is linked with higher all cause mortality rates, as well as with higher mortality rates for lung cancer, ischaemic heart disease, cerebrovascular disease, arterial disease, and chronic non-specific lung disease. Survey data show that these associations are partly due to a higher prevalence of smoking among Roman Catholics. As in many other countries, a lower average income is linked with high all cause mortality rates in The Netherlands. Cause specific data show negative associations for stomach cancer, ischaemic heart disease, cerebrovascular disease, chronic non-specific lung disease, and traffic accidents. Since the early 1950s the association between geographical mortality patterns and the percentage of Roman Catholics in the population has gradually become less strongly positive. This suggests that the convergence of the mortality rates in the South towards the national average may be related to a gradual lessening of differences in lifestyle between population groups. CONCLUSIONS: Both cultural and economic factors are important in the explanation of geographical mortality patterns in The Netherlands.

Adolescent↗
PubMed1990

[Smoking behavior of family physicians, specialists and students in Rotterdam, 1989].

In a survey of smoking habits and attitudes among general practitioners of the Rotterdam area, consultants at the University Hospital of Rotterdam, medical students and students of the Department of Health Policy and Management (HPM) at the Erasmus University of Rotterdam, it was found that 30 percent of this population smoked. Among the male general practitioners and the male HPM students more smokers were found than in the general male population. Smoking prevalence among female doctors and students is lower than among their male counterparts and also lower than that among the general female population. Amongst doctors the knowledge of smoking cessation methods and the relationship between smoking and diseases was found to be suboptimal. Students of medicine are not inclined to start smoking. This will reinforce the present downward trend in the proportion of physicians who smoke.

Adult↗
PubMed1990

[Regional differences in mortality from ischemic heart disease].

The geographical distribution of mortality from ischaemic heart disease in the Netherlands has changed dramatically since 1950. In 1950-1954 mortality was highest in high-income, urbanized areas, in 1980-1984 the reverse was true. This development resembles the one observed in the United States of America. The changes in geographical distribution cannot be attributed to differences in cause-of-death certification. The change in the association with income and the association between mortality and a number of ischaemic heart disease risk factors found in 1970-1974, suggest that at least part of the explanation is a change in the geographical distribution of risk factors.

Adult↗
PubMed1990

Socio-economic mortality differences in The Netherlands in 1950-1984: a regional study of cause-specific mortality.

The finding that mortality differences between occupational classes in England and Wales have widened during the postwar period raises the question whether a similar development has occurred in other industrialised countries. In this paper, a comparison is made with results from a geographical study on the Netherlands. This study compares four periods between 1950 and 1984 by means of a standard regional division, a single socio-economic index, uniform cause-of-death groups and a standard regression procedure. During the postwar period, the relationship between socio-economic level and all-cause mortality has become (more) negative. This development can to a large extent be attributed to 'negative' trends for lung cancer, diabetes mellitus, ischaemic heart disease, cerebrovascular disease and traffic accidents. High-level regions have fared better partly because favourable changes in national mortality trends seem to have begun first in these regions. The findings from this regional study agree to a large extent with evidence from Dutch studies at the individual level. It is concluded that socio-economic mortality differences in England and Wales and the Netherlands have probably developed similarly in various respects.

Cause of Death↗
PubMed1990

Factors influencing success or failure after reversal of sterilization: a multivariate approach.

Reversal of sterilization was performed in 215 patients after unipolar coagulation, Fallope ring or clip sterilization, or bipolar coagulation or a Pomeroy sterilization. All patients had a follow-up of at least 1 year. Prognostic variables were derived from the previous history, the preoperative fertility assessment, and the actual operation. Some variables were combined into a fertility reducing factor. A first selection was performed by comparing the preoperative and perioperative variable scores of the successes (defined as all intrauterine pregnancies within 1 year after surgery) with those of the failures (no intrauterine pregnancy within 1 year). Eight variables appeared to have prognostic potential. Taking account of the inter-relations of those variables by using logistic regression analysis, the localization of the anastomosis, the number of anastomosed tubes, and the presence of a fertility reducing factor were selected as the most predictive ones. Using this logistic model, an estimate of the pregnancy outcome could be calculated for each individual patient.

Adult↗
PubMed1989

Geographic variation in the onset of decline of male ischemic heart disease mortality in The Netherlands.

We studied variation in the year of onset of ischemic heart disease mortality decline among regions (n = 39) in the Netherlands. Using loglinear regression methods, a quadratic regression model was fitted to the observed numbers of male deaths in each region in the period 1950-84, controlling for changes in age-structure of populations. The quadratic regression model proved inadequate to describe the mortality experience of females. For the country as a whole, the estimated year of onset of male ischemic heart disease mortality decline is 1973.9. The difference between the earliest and the latest region is almost nine years (1970.0 and 1978.9, respectively). An early onset of decline (less than or equal to 1972) is only found in the urbanized, western part of the country. A later (greater than or equal to 1975) onset of decline is characteristically found in more peripheral regions in the South-West and South-East, as well as in the North. Exploratory correlation and regression analyses show that both average income and percent of population living in larger cities have independent, negative associations with the year of onset of male ischemic heart disease mortality decline. We argue that regional variation in the timing of lifestyle changes is a more plausible explanation of these observations than regional variation in the timing of medical care improvements.

Age Factors↗
PubMed1988

Medical care and regional mortality differences within the countries of the European community.

"This paper addresses the question whether regional mortality differences within developed countries reflect differences in characteristics of medical care service. It adds two new elements to previous studies on this subject: it concentrates on selected 'avoidable' causes of death, and it makes parallel analyses for ten [European Community] countries. The results show that levels of medical care supply contribute little to the explanation of regional differences in mortality from the selected conditions. It is concluded that if regional mortality differences are related to health care, factors other than the level of supply are probably involved." (SUMMARY IN FRE)

Cause of Death↗
PubMed1988

Post-1950 mortality trends and medical care: gains in life expectancy due to declines in mortality from conditions amenable to medical intervention in The Netherlands.

In order to assess the impact of medical care innovations on post-1950 mortality in The Netherlands, we analysed trends in mortality from a selection of conditions suggested by Rutstein et al.'s lists of "unnecessary untimely mortality". This selection covers 11 types of innovation, and includes 35 conditions which have become amenable to medical care. Loglinear regression analysis shows that for most of these conditions mortality declined during each of two subperiods (1950-1968; 1969-1984). Mortality decline accelerated in the second subperiod for many conditions. Reductions in mortality from these conditions between 1950/54 and 1980/84 added 2.96 and 3.95 years to life expectancy at birth of Dutch males and Dutch females respectively. A priori evidence indicates that these mortality reductions are due to some extent to 'spontaneous' incidence declines. Although the exact contribution of medical care innovations to these changes in mortality thus cannot be determined, the impact of medical care on post-1950 mortality in The Netherlands could well have been substantial.

Cause of Death↗
PubMed1988

Secular trends of infectious disease mortality in The Netherlands, 1911-1978: quantitative estimates of changes coinciding with the introduction of antibiotics.

Secular trends of mortality from 21 infectious diseases in the Netherlands were studied by inspection of age/sex-standardized mortality curves and by log-linear regression analysis. An attempt was made to obtain quantitative estimates for changes coinciding with the introduction of antibiotics. Two possible types of effect were considered: a sharp reduction of mortality at the moment of the introduction of antibiotics, and a longer lasting (acceleration of) mortality decline after the introduction. Changes resembling the first type of effect were possibly present for many infectious diseases, but were difficult to measure exactly, due to late effects on mortality of World War II. Changes resembling the second type of effect were present in 16 infectious diseases and were sometimes quite large. For example, estimated differences in per cent per annum mortality change were 10% or larger for puerperal fever, scarlet fever, rheumatic fever, erysipelas, otitis media, tuberculosis, and bacillary dysentery. No acceleration of mortality decline after the introduction of antibiotics was present in mortality from 'all other diseases'. Although the exact contribution of antibiotics to the observed changes cannot be inferred from this time trend analysis, the quantitative estimates of the changes show that even a partial contribution would represent a substantial effect of antibiotics on mortality from infectious diseases in the Netherlands.

Adolescent↗
PubMed1988

Regional differences in decline of mortality from selected conditions: The Netherlands, 1969-1984.

In The Netherlands, as in many other industrialized countries, recent mortality developments have been characterized by rapid declines for a number of important causes of death. The results of an analysis of regional variation in mortality decline within The Netherlands are reported, covering the period 1969-1984. The causes of death included in this analysis are Perinatal mortality, Cerebrovascular disease, a more global 'Amenable' selection (formed by aggregating a number of causes of death considered to be amenable to medical intervention), Cancer of the stomach, Ischaemic heart disease and Traffic accidents. For Perinatal mortality, Cerebrovascular disease, the 'Amenable' selection, and Ischaemic heart disease, as well as for Total mortality, declines have not been geographically homogeneous. Perinatal mortality had a tendency to decline faster in regions where starting levels were higher, suggesting a certain convergence. For Cerebrovascular disease and the 'Amenable' selection, but especially for Ischaemic heart disease, the reverse was true. A simple correlation analysis shows that for Perinatal mortality, as well as for the 'Amenable' selection, mortality declined faster in less urbanized, more peripherally located, lower income areas. There is no association with the presence of a university hospital. This pattern suggests that faster mortality decline for these conditions is due to factors other than faster diffusion of new medical technologies. For Ischaemic heart disease, mortality declined faster in more urbanized, more centrally located, higher income areas. Although this pattern is what one would expect as a result of regional differences in the diffusion of new medical technologies, it may also be due to differences in the diffusion of new lifestyles.(ABSTRACT TRUNCATED AT 250 WORDS)

Cause of Death↗
PubMed1988

Regional differences in mortality from conditions amenable to medical intervention in The Netherlands: a comparison of four time periods.

In The Netherlands, as in many other countries, important geographical variation in mortality from conditions amenable to medical intervention exists. Associations with a number of simple medical care supply characteristics (general practitioner density, hospital bed density, and percentage of regional hospital beds located in university and small hospitals) are generally weak and inconsistent, both before and after controlling for possible confounding factors. We explored one of the possible reasons for this lack of consistency, which is the time dependency of the relationship between medical care supply and avoidable mortality. A comparison of associations in four time periods (1950-54, 1960-64, 1970-74 and 1980-84) shows that the percentage of variance in regional mortality levels which can be "explained" by the medical care supply variables has changed over time. Although the patterns of change differ little from what one would expect on the basis of the time of introduction of medical care innovations, the exact nature of the associations is puzzling. Apart from some expected negative associations between mortality and the presence of university hospitals, we also found a few unexpected positive associations with general practitioner density. Possible explanations for these findings are discussed, and it is concluded that further study is necessary to reveal the causes of a higher or lower mortality level for conditions considered to be amenable to medical intervention.

Catchment Area, Health↗