Harald Weedon-Fekjær

Bio: Harald Weedon-Fekjær is an academic researcher from Oslo University Hospital. The author has contributed to research in topics: Population & Breast cancer. The author has an hindex of 18, co-authored 45 publications receiving 1107 citations. Previous affiliations of Harald Weedon-Fekjær include University of Oslo.

The demographics of same-sex marriages in Norway and Sweden

Abstract: The present study investigates the demographics of same-sex marriages—that is, registered partnerships—in Norway and Sweden. We give an overview of the demographic characteristics of the spouses of these partnerships, study patterns of their divorce risks, and compare the dynamics of same-sex couples with those of heterosexual marriages. We use longitudinal information from the population registers of the two countries that cover all persons in partnerships. Our demographic analyses include information on characteristics such as age, sex, geographic background, experience of previous opposite-sex marriage, parenthood, and educational attainment of the partners involved. The results show that in many respects, the distributions of married populations on these characteristics differ by the sex composition of the couples. Patterns in divorce risks are rather similar in same-sex and opposite-sex marriages, but divorce-risk levels are considerably higher in same-sex marriages. The divorce risk for female partnerships is double that for male partnerships.

Breast cancer tumor growth estimated through mammography screening data

Abstract: Knowledge of tumor growth is important in the planning and evaluation of screening programs, clinical trials, and epidemiological studies. Studies of tumor growth rates in humans are usually based on small and selected samples. In the present study based on the Norwegian Breast Cancer Screening Program, tumor growth was estimated from a large population using a new estimating procedure/model. A likelihood-based estimating procedure was used, where both tumor growth and the screen test sensitivity were modeled as continuously increasing functions of tumor size. The method was applied to cancer incidence and tumor measurement data from 395,188 women aged 50 to 69 years. Tumor growth varied considerably between subjects, with 5% of tumors taking less than 1.2 months to grow from 10 mm to 20 mm in diameter, and another 5% taking more than 6.3 years. The mean time a tumor needed to grow from 10 mm to 20 mm in diameter was estimated as 1.7 years, increasing with age. The screen test sensitivity was estimated to increase sharply with tumor size, rising from 26% at 5 mm to 91% at 10 mm. Compared with previously used Markov models for tumor progression, the applied model gave considerably higher model fit (85% increased predictive power) and provided estimates directly linked to tumor size. Screening data with tumor measurements can provide population-based estimates of tumor growth and screen test sensitivity directly linked to tumor size. There is a large variation in breast cancer tumor growth, with faster growth among younger women.

The influence of mammographic screening on national trends in breast cancer incidence

Abstract: Introducing an organized mammographic screening programme affects the breast cancer incidence rate in a population. The diagnosis is advanced in time, and initially, an increase will occur in the number of cases, followed by a drop in the rate when women leave the programme. The aim of this study was to quantify the potential effects that mammographic screening programmes have on breast cancer incidence. In addition, we wanted to investigate how the incidence of breast cancer varies between different birth cohorts, age groups and time periods in the five Nordic countries Finland, Denmark, Iceland, Norway and Sweden, adjusting for the effects of the screening programmes. Time trends were analysed over the period 1978-1997, using age-period-cohort models. In Sweden, the rates more than doubled (relative risk (RR)=2.20, 95% confidence interval (CI) 1.8-2.6) in women offered screening for the first time compared with women not offered screening. The risk remained elevated (RR=1.34, 95% CI 1.2-1.6) for women who were continued to be offered screening, compared with women who were not offered screening. Finally, the rates dropped (RR=0.68, 95% CI 0.6-0.8) when the women left the programme. This indicates that screening advances the time of diagnosis, which is a prerequisite to subsequent reduction in mortality. Analysis of secular trends, corrected for the influence of screening, showed that the rates in Finland increased by 13% per 5-year period, with a more modest increase in the other countries. There were strong cohort effects in all Nordic countries, and the risk seemed to be flattening for the youngest cohorts in most of the countries.

Nationwide quality assurance of rectal cancer treatment

Abstract: Objective The purpose of this prospective study was to examine the influence of the efforts for nationwide quality assurance of rectal cancer treatment. The study focuses on local recurrence and overall survival. Methods This study includes all 3388 Norwegian patients with a rectal cancer within 15 cm from the anal verge treated with curative intent in the period November 1993–December 1999. A comprehensive educational programme was established, and training courses were arranged in different Health Regions demonstrating the TME technique. A specific Rectal Cancer Registry enabled the monitoring of outcome of rectal cancer treatment for single hospitals. Radiotherapy was given to 10% of the patients. Results The risk of local recurrence has been significantly reduced, so that in 1999 the level was 50% below that observed in 1994 (Hazard ratio (HR)1999 = 0.5; 95% CI 0.4–0.8, P = 0.002). Similarly, during 1998, the mean national overall survival was significantly improved, compared to the rate in1994 (HR1998 = 0.8; 95% CI 0.6–1.0, P = 0.014). Conclusion The prognosis for rectal cancer can be improved by increased organizational focus on rectal cancer treatment and by establishing a rectal cancer registry monitoring treatment standards throughout the country.

Dynamic analysis of multivariate failure time data.

Abstract: We present an approach for analyzing internal dependencies in counting processes. This covers the case with repeated events on each of a number of individuals, and more generally, the situation where several processes are observed for each individual. We define dynamic covariates, i.e., covariates depending on the past of the processes. The statistical analysis is performed mainly by the nonparametric additive approach. This yields a method for analyzing multivariate survival data, which is an alternative to the frailty approach. We present cumulative regression plots, statistical tests, residual plots, and a hat matrix plot for studying outliers. A program in R and S-PLUS for analyzing survival data with the additive regression model is available on the web site http://www.med.uio.no/imb/stat/addreg. The program has been developed to fit the counting process framework.

Standards of Medical Care in Diabetes

Abstract: XI. STRATEGIES FOR IMPROVING DIABETES CARE D iabetes is a chronic illness that requires continuing medical care and patient self-management education to prevent acute complications and to reduce the risk of long-term complications. Diabetes care is complex and requires that many issues, beyond glycemic control, be addressed. A large body of evidence exists that supports a range of interventions to improve diabetes outcomes. These standards of care are intended to provide clinicians, patients, researchers, payors, and other interested individuals with the components of diabetes care, treatment goals, and tools to evaluate the quality of care. While individual preferences, comorbidities, and other patient factors may require modification of goals, targets that are desirable for most patients with diabetes are provided. These standards are not intended to preclude more extensive evaluation and management of the patient by other specialists as needed. For more detailed information, refer to Bode (Ed.): Medical Management of Type 1 Diabetes (1), Burant (Ed): Medical Management of Type 2 Diabetes (2), and Klingensmith (Ed): Intensive Diabetes Management (3). The recommendations included are diagnostic and therapeutic actions that are known or believed to favorably affect health outcomes of patients with diabetes. A grading system (Table 1), developed by the American Diabetes Association (ADA) and modeled after existing methods, was utilized to clarify and codify the evidence that forms the basis for the recommendations. The level of evidence that supports each recommendation is listed after each recommendation using the letters A, B, C, or E.

The Social Organization of Sexuality: Sexual Practices in the United States

Abstract: This survey of sexual practices in the United States has been combed by the media for items of interest to the public: monogamous sex is much more widespread in this country than has been thought; infidelity is less frequent than presumed; vaginal intercourse is the defining experience of heterosexual behavior; watching one's partner undress is stimulating to many people; married couples have more sex than single people (unmarried, cohabiting couples have the most sex of all); the majority of couples experience sex twice a week to several times a month; 2.8% of men identify themselves as homosexual and 1.4% of women do so, but a higher percentage of people consider a same-gender experience to have some appeal; 75% of men always experience orgasm compared with 28.6% of women, but more nearly equal numbers of men and women declare themselves satisfied with their sexual experiences. The book is, in fact, a

The Statistical Analysis of Recurrent Events

Abstract: Models and Frameworks for Analysis of Recurrent Events.- Methods Based on Counts and Rate Functions.- Analysis of Gap Times.- General Intensity-Based Models.- Multitype Recurrent Events.- Observation Schemes Giving Incomplete or Selective Data.- OtherTopics.