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Biomedical subjects

F de Waard

Publications and source records attributed to F de Waard.

At least 55 records · Page 3Linked to original sources
PubMed1986

Analysis of the diagnostic performance in breast cancer screening by relative operating characteristics.

In medical usage, relative operating characteristics (ROC) refer to the symptoms, signs, and laboratory values used for making a diagnosis. Diagnosis analysis by ROC measures diagnosis performance independently of the diagnostic criteria used, thus revealing the arbitrary character of diagnosis. In order to carry out ROC analysis, the diagnosis has to be graded in levels of certainty of the presence of disease (or suspicion of a lesion). When both the graded diagnosis decisions and the ultimate proof of presence or absence of disease are available, ROC analysis can easily be carried out. Analysis of 50,102 successive examinations of 19,400 women in the Utrecht breast cancer screening projects presents a remarkably good fit of the observed data with the calculated values. In the medical context even small deviations of the actual sensitivity and specificity values from the ROC curve values must be considered as signs of differences in the diagnosis procedure and should lead to further analysis of the diagnostic criteria and the examined population. Consequently the separate effect of diagnosis impairment by the mammographic risk patterns (Wolfe) on diagnostic accuracy could be isolated. The effect of age on the detection capability of breast cancer by mammography appeared to operate in narrow age groups.

Aged↗
PubMed1986

VIP and prolactin release in response to meals.

To determine the role of vasoactive intestinal polypeptide (VIP) and prolactin (PRL) in digestion, plasma VIP and PRL levels were measured in healthy, non-obese and obese premenopausal women fed isocaloric breakfasts containing a high carbohydrate or a high fat-protein content. A significant increase in plasma VIP concentration occurred after a high fat-protein breakfast, the increase being independent of body mass index. Plasma PRL level was unaltered by breakfast. Results suggest that the release of VIP after a meal depends on a high fat concentration in the duodenum, which may then stimulate bicarbonate release and fat-stimulated release of cholecystokinin.

Adult↗
PubMed1985

[A round trip through epidemiology].

Descriptive and analytical epidemiology are reviewed. This discipline is to be considered to be a fundamental part of medicine. Many of its concepts and methods are applicable in veterinary medicine.

Animals↗
PubMed1984

Evaluation of screening for breast cancer in a non-randomised study (the DOM project) by means of a case-control study.

In 1974 a non-randomised study of the effect of mass screening by physical examination and xeromammography on mortality from breast cancer was started. Of the 20 555 eligible women in the city of Utrecht born between 1911 and 1925 (aged 50-64 at the start of the study), 14 796 attended for screening. Four rounds of screening were carried out. The relative risk of dying from breast cancer among women ever screened compared with women never screened was 0.30 (95% confidence interval 0.13-0.70).

Adult↗
PubMed1984

Hormonal factors in human carcinogenesis.

A synopsis is presented of hormone-cancer relationships as seen by an epidemiologist. Emphasis has been placed on reproductive risk factors and cancers of the endometrium, ovary and breast. Although there are definite parallelisms in this regard the aetiological mechanisms for these three sites may be different. Evidence is accumulating that the protective effect of an early first birth and of subsequent pregnancies on breast cancer risk can be understood biologically in terms of interference with the occurrence of preneoplastic lesions.

Breast Neoplasms↗
PubMed1984

The DOM project for the early detection of breast cancer, Utrecht, The Netherlands.

This report describes the short-term results of a population-based screening programme--the DOM project--during the years 1975-1980. Screening was offered to all women in the city of Utrecht (The Netherlands) and 11 neighbouring areas who were born between 1911 and 1925. Further evaluation will be reported in future publications. The programme was organised by the Department of Epidemiology, Institute of Social Medicine (now renamed The Institute of Public Health and Epidemiology), University of Utrecht, which established a screening centre--The Preventicon--in a new commercial and shopping centre with good public transport facilities. The study population was between 50 and 65 years old at intake, a decision based on results obtained in the H.I.P. study in New York. Women resident in the city of Utrecht (n = 14,697 at intake) were screened four times, with intervals of 12, 18 and 24 months respectively between the first and fourth examinations. Women resident in the other areas (n = 8814) were screened twice with an interval of 18 months. Screening consisted of a clinical examination (inspection, palpation) and xero-mammography. An important role was played by paramedical personnel, who performed the examination and had a degree of responsibility in reading the mammograms. Initially the radiation dose per breast was about 1 rad, but from 1977 onwards this was reduced to 0.4 rad per exposure; for women living in Utrecht (4 screenings) the total dose was less than 5 rad over the 5-year period. Referral policy was based on a set of three types of "signal" to general practitioners (who coordinated specialist services): 1. Recommendation for biopsy; 2. Suggested repeat examination after 6 months; 3. Brief note on palpable abnormalities, considered likely to be benign. In Section II the response of the invited population is analysed. The response rate for the first screening was 72% in the city of Utrecht and 68% in the other areas. Variation in response rates can only be explained to a minor degree by measured demographic and sociological variables, age being the most important determinant. Women were asked to contribute D.fl. 12.50 (approx. US $5) per screening cycle to meet part of the expenses, the rest being paid by public health research funds. A total number of 61,649 examinations was performed in 23,511 women. In Section III the immediate results of screening are presented. An analysis is made of the cancer yield of the 3 signals mentioned above.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1984

Breast cancer risk associated with reproductive factors and breast parenchymal patterns.

In a population-based study of 23,511 women 50-67 years of age at the time of first screening, a striking relationship was found between parity and age at first childbirth, on the one hand, and two radiologic aspects of breast parenchymal pattern (dysplasia and prominent duct pattern), on the other. These relationships appeared to be causal.

Age Factors↗
PubMed1984

The Cordon study of weight reduction based on behaviour modification.

A behaviour modification programme for the treatment of obesity was offered to a population of obese women, aged 51-67, being screened for breast cancer. The programme was offered in two forms: (1) A series of ten small group sessions under the guidance of a non-medical leader, with three follow-up meetings after the course (10 S programme). (2). A series of ten mailed lessons with a pre- and post-course interview and three follow-up meetings after the course (10 L programme). The drop-out rate during the course was 12 per cent for the 10 S programme and 37 per cent for the 10 L programme. Follow-up in the 10 S programme revealed an average weight loss of 5.2 kg after 3 months, 4.1 kg after 17 months, and 3.0 kg after 36 months. Comparable figures in the 10 L programme were 3.0 kg, 3.0 kg and 1.6 kg, respectively. Percentile distributions of weight loss after these intervals are presented. Results are compared with those in other obese women in the cancer screening programme who either had no plans for weight reduction or said they had opted for other kinds of intervention. These comparisons clearly favour the behaviour treatment programme, but the picture may have been influenced by a possibly higher motivation of those who followed the course.

Aged↗
PubMed1983

Mortality pattern and life expectancy of Seventh-Day Adventists in the Netherlands.

The mortality pattern of Seventh-Day Adventists (SDAs) in the Netherlands was assessed during a ten-year study period, 1968-1977. Of 522 deceased SDAs the causes of death of 482 could be ascertained. Standardized Mortality Ratios (SMR) for total mortality (SMR = 0,45), cancer (SMR = 0,50) and cardiovascular diseases (SMR = 0,41) as well as for various subgroups differed significantly from the total Dutch population. Mean age at death as well as life-expectation at baptism were significantly higher in SDAs, both in males and females, as compared with Dutch males and females. A health survey among a sample of the total SDA population and a group of 'friend' controls' was done in order to try to explain the differences in mortality pattern and life expectancy. It is concluded that evidence was found for the thesis that abstinence from cigarette smoking is the main factor explaining the low mortality from ischaemic heart diseases among SDAs, while presumably an appropriate (prudent) diet confers additional benefit for example on colon cancer mortality.

Adolescent↗
PubMed1982

Weight reduction and oestrogen excretion in obese post-menopausal women.

The urinary excretion of oestrone (E1), oestradiol (E2) and oestriol (E2) was measured in 42 obese post-menopausal women before and 6-12 mth after their participation in a weight reduction programme. The method of inducing weight loss was based on modification of eating behaviour without specific changes in dietary composition. Urinary oestrogen, as a ratio to creatinine, were measured by a specific radioimmunoassay after purification of the specific oestrogen fraction. Before weight reduction efforts, there is a significant correlation among E1, weight and the Quetelet-index and between E3 and the Quetelet-index. These correlations have disappeared after weight reduction. There is a significant positive correlation between changes in body-weight and changes in the excretion of E1, E3 and total oestrogens. There was no significant change in the so-called oestrogen ratio (E1 + E2/E3) in relation to change in body weight. With respect to the statistical association between endometrial cancer, breast cancer and overweight, our data give support to the concept that intervention programmes on weight reduction may influence both the incidence and the prognosis of these two diseases.

Body Weight↗