Mental Health Disorder Trends in Denmark According to Age, Calendar Period, and Birth Cohort.

Importance: Research suggests an increase in mental disorder incidence in recent years, but this trend remains unexplained, and there is a lack of large studies based on a representative sample that investigate mental disorders over the full spectrum.

Objective: To explore sex- and age-specific incidence of any mental disorder and 19 specific disorders according to birth cohort and calendar period.

Design, Setting, And Participants: This was a population-based cohort study among 5 936 202 individuals aged 1 to 80 years living in Denmark at some point between January 1, 2004, and December 31, 2021.

Evaluating mammography screening in observational cohort designs: the importance of avoiding lead time bias.

Aims: To investigate the potential lead time bias of the evaluation model (extended follow-up for women diagnosed with breast cancer) used to evaluate mammography screening in a recent Danish study. This model was compared with two traditional models.

Methods: We retrieved data on women diagnosed with breast cancer in each county of Norway from 1986 to 2016.

Predicting difference in mean survival time from cause-specific hazard ratios for women diagnosed with breast cancer.

Background: Relative reduction in breast cancer mortality is the preferred outcome measure for evaluation of mammography screening. However, mean survival time has been advocated as a better and more intuitive outcome for risk communication. We have previously introduced a method to predict difference in mean survival time from empirical hazard ratios for all-cause mortality.

Negative controls to detect uncontrolled confounding in observational studies of mammographic screening comparing participants and non-participants.

Background: When comparing mammography-screening participants and non-participants, estimates of reduction in breast-cancer mortality may be biased by poor baseline comparability. We used negative controls to detect uncontrolled confounding.

Methods: We designed a closed cohort of Danish women invited to a mammography-screening programme at age 50-52 years in Copenhagen or Funen from 1991 through 2001.

Predicting Difference in Mean Survival Time from Reported Hazard Ratios for Cancer Patients.

Background: Gain in mean survival time from new cancer treatments is a core component of cost-effectiveness analyses frequently used by payers for reimbursement decisions. Due to limited follow-up time, clinical trials rarely report this measure, whereas they often report hazard ratios comparing treatment groups.

Aim: We aimed to explore the empirical relationship between gain in mean survival time and the hazard ratio for cancer patients.

Effect of organized mammography screening on breast cancer mortality: A population-based cohort study in Norway.

We aimed to estimate the effect of organized mammography screening on incidence-based breast cancer mortality by comparing changes in mortality among women eligible for screening to concurrent changes in younger and older ineligible women. In a county-wise balanced, open-cohort study, we used birth cohorts (1896-1982) to construct three age groups in both the historical and screening period: women eligible for screening, and younger or older women ineligible for screening. We included women diagnosed with breast cancer who died within the same age-period group during 1987-2010 (n = 4,903).

An introduction to instrumental variable assumptions, validation and estimation.

The instrumental variable method has been employed within economics to infer causality in the presence of unmeasured confounding. Emphasising the parallels to randomisation may increase understanding of the underlying assumptions within epidemiology. An instrument is a variable that predicts exposure, but conditional on exposure shows no independent association with the outcome.

Benefits and harms of mammography screening.

Mammography screening for breast cancer is widely available in many countries. Initially praised as a universal achievement to improve women's health and to reduce the burden of breast cancer, the benefits and harms of mammography screening have been debated heatedly in the past years. This review discusses the benefits and harms of mammography screening in light of findings from randomized trials and from more recent observational studies performed in the era of modern diagnostics and treatment.