Eeva-Liisa Røssell

To examine 4‐year changes in Body Mass Index z‐score (BMIz) among children and adolescents with overweight or obesity who participated in municipality‐based interventions, and to assess whether effects varied by age, sex or baseline weight category. This matched cohort study included children aged 5–15 years. The intervention group received a municipality‐based early treatment intervention. Controls (up to five) were matched on age, sex, baseline weight category and calendar year, and received school‐based surveillance consisting of mandatory school health examinations with repeated anthropometric assessments. BMIz trajectories were analysed using mixed effects models with linear splines, adjusting for socioeconomic factors derived from national registries. Among 1274 children and adolescents (216 intervention, 1058 control), 56.9%–58.0% in both groups were living with overweight at baseline. No significant differences in BMIz trajectories were observed over the 4‐year period. Both groups showed an initial decrease in BMIz during the first 6 months (intervention: −0.18; control: −0.28), followed by an increase from 6 to 12 months (intervention: 0.12; control: 0.21) and a plateau from 12 to 48 months (intervention: −0.01; control: −0.03). Municipality‐based interventions did not result in greater long‐term BMIz reductions than matched controls. Both groups had modest short‐term improvements, which may reflect beneficial effects of both the structured interventions and the active school‐based surveillance received by controls. The similar BMIz trajectories suggest system‐level equivalence within the Danish school health system. These findings underscore the need for understanding the mechanisms behind these early changes and how to support long‐term maintenance.

Background: The incidence of both melanoma and type 2 diabetes (T2D) is increasing. Recent studies suggest that T2D is associated with a more advanced melanoma stage at diagnosis, but its impact on melanoma prognosis remains unclear. Objectives: To examine the impact of T2D on sex- and stage-specific melanoma recurrence, melanoma-specific mortality, and overall mortality. Methods: This population-based cohort study included all Danish patients diagnosed with melanoma between 2004 and 2022, excluding those with prior cancer or type 1 diabetes. The impact of T2D on melanoma recurrence, melanoma-specific mortality, and overall mortality was assessed by stage (AJCC stage I-II [localised], stage III [locoregional], and stage IV [metastatic]) and stratified on sex. Cumulative incidence proportions and risk differences (RD) were estimated. Furthermore, regression analyses using competing risk models to estimate adjusted hazard ratios (aHR) were applied, adjusting for age, comorbidity, calendar year, and stage at diagnosis. Patients were from date of melanoma diagnosis and followed until death, emigration, or the end of the study period (December 31, 2024). Results: This study included 30,365 individuals diagnosed with melanoma; 14,343 were males (1,195 with T2D) and 16,022 were females (816 with T2D), with higher event frequencies in males than females. Among males with localised melanoma, T2D was associated with higher 5-year risks of recurrence (15.0% vs 8.3%, aHR 1.30, 95% CI 1.08–1.56) and melanoma-specific mortality (8.5% vs 4.2%, aHR 1.28, 1.00–1.64). Among women with localised melanoma, the T2D associated risk differences were less pronounced and no associations was observed after adjustment: Recurrence aHR: 1.04 (0.78–1.38), and Melanoma-specific mortality aHR: 1.10 (0.75–1.61). For both sexes with either locoregional or metastatic melanoma, T2D had no prognostic impact. Conclusion: T2D was associated with poorer prognosis among males with localised melanoma, whereas no prognostic impact was observed among females or patients with more advanced disease. These findings indicate the need for closer follow-up of males with early-stage melanoma and T2D, and for further studies to clarify underlying mechanisms and the potential benefits of optimised diabetes management.

There have been mixed findings on whether mortality is socially patterned among people with diabetes. We compared all-cause mortality trends by socioeconomic position (SEP) among people with and without diabetes for 2004–21 in four high-income countries. We conducted open cohort studies in Australia, Denmark, the Netherlands, and Scotland and included national or regional populations aged 35–69 years. We used the European standard population in 2013 to calculate age-standardized mortality rates (ASMRs) by calendar year, SEP quintile, diabetes status, and sex. SEP quintiles were defined using standardized disposable household income in Denmark and the Netherlands, and area-based indices in Australia and Scotland. We calculated the age-standardized slope index of inequality and age-adjusted relative index of inequality using Poisson regression as absolute and relative measures of socioeconomic inequality, respectively across the study populations stratified by calendar year, diabetes status, and sex. About 208 011 deaths occurred during 17 million person years (py) of follow-up among 35- to 69-year olds with diabetes, and 1.1 million deaths during 298 million py of follow-up among people without diabetes. ASMRs generally increased with increasing deprivation and varied between 1.3 (95% CI: 1.2–1.4) deaths per 1000 py to 29.4 (95% CI: 26.0–32.8) deaths per 1000 py. We found absolute and relative mortality inequality that increased during the follow-up period among adults without diabetes. Measures of absolute and relative inequality among adults with diabetes widened in some populations by country and sex. To conclude, disparities in mortality by SEP increased during follow-up in most countries. Strategies are needed to reduce excess mortality associated with low SEP and diabetes and related socioeconomic inequality.

Childhood obesity is associated with adverse health and psychosocial outcomes, often persisting into adulthood. Hospital‐based lifestyle interventions may provide intensive support, but evidence on long‐term effectiveness is limited. To evaluate changes in Body Mass Index z‐score (BMIz) among children and adolescents with overweight and obesity participating in a hospital‐based intervention compared to matched controls. This matched prospective cohort study includes children and adolescents aged 5–15 years. The intervention consisted of a family‐centered hospital‐based lifestyle program focusing on diet, physical activity, sleep and screen time management. Controls were matched on age, sex, weight category, and calendar year. BMI trajectories were analyzed using mixed effects models with linear splines, adjusting for socioeconomic factors from national registries. A total sample size of 1897 children and adolescents was included (325 intervention, 1572 controls). The intervention group achieved a higher reduction in BMIz during the first 6 months (−0.74 SD/years, 95% CI: −0.89; −0.60) and up to 12 months (−0.31 SD/years, −0.45; −0.16), compared to controls. From 12 to 36 months, a rebound in BMIz occurred (0.14, SD/years, 0.10; 0.17), and continued to rise through 72 months. The intervention was associated with improvements in BMIz up to 12 months after the intervention. However, the effects were not sustained at 6 years of follow‐up. Trial Registration: Clinicaltrials.Gov identifier: NCT05790174

Background. Observational studies are used to evaluate the effect of breast cancer screening programs, but their validity depends on use of different study designs. One of these is the evaluation model, which extends follow-up after screening only if women have been diagnosed with breast cancer during the screening program. However, to avoid lead-time bias, the inclusion of risk time should be based on screening invitation and not breast cancer diagnosis. The aim of this study is to investigate potential bias induced by the evaluation model. Methods. We used large-scale simulated datasets to investigate the evaluation model. Simulation model parameters for age-dependent breast cancer incidence, survival, breast cancer mortality, and all-cause mortality were obtained from Norwegian registries. Data were restricted to women aged 48 to 90 y and a period before screening implementation, 1986 to 1995. Simulation parameters were estimated for each of 2 periods (1986–1990 and 1991–1995). For the simulated datasets, 50% were randomly assigned to screening and 50% were not. Simulation scenarios depended on the magnitude of screening effect and level of overdiagnosis. For each scenario, we applied 2 study designs, the evaluation model and ordinary incidence-based mortality, to estimate breast cancer mortality rates for the screening and nonscreening groups. For each design, these rates were compared to assess potential bias. Results. In scenarios with no screening effect and no overdiagnosis, the evaluation model estimated 6% to 8% reductions in breast cancer mortality due to lead-time bias. Bias increased with overdiagnosis. Conclusions. The evaluation model was biased by lead time, especially in scenarios with overdiagnosis. Thus, the attempt to capture more of the screening effect using the evaluation model comes at the risk of introducing bias. Highlights: The validity of observational studies of breast cancer screening programs depends on their study design being able to eliminate lead-time bias. The evaluation model has been used to evaluate breast cancer screening in recent studies but introduces a study design based on breast cancer diagnosis that may introduce lead-time bias. We used large-scale simulated datasets to compare study designs used to evaluate screening. We found that the evaluation model was biased by lead time and estimated reductions in breast cancer mortality in scenarios with no screening effect.

Background: There have been mixed findings on whether mortality is socially patterned among people with diabetes. We compared all-cause mortality trends by socioeconomic position (SEP) among people with and without diabetes for 2004-2021 in four high-income countries. Methods: We conducted open cohort studies in Australia, Denmark, the Netherlands, and Scotland and included national or regional populations aged 35-69 years. We used the European standard population in 2013 to calculate age-standardised mortality rates (ASMRs) by calendar year, SEP quintile, diabetes status, and sex. SEP quintiles were defined using standardised disposable household income in Denmark and the Netherlands, and area-based indices in Australia and Scotland. We calculated the age-standardised slope index of inequality (SII) and age-adjusted relative index of inequality (RII) using Poisson regression as absolute and relative measures of socioeconomic inequality respectively across the study populations stratified by calendar year, diabetes status, and sex. Results: 208,011 deaths occurred during 17 million person years (py) of follow-up among 35-69 year olds with diabetes, and 1.1 million deaths during 298 million py of follow-up among people without diabetes. ASMRs generally increased with increasing deprivation and varied between 1.3 (95% CI: 1.2-1.4) deaths per 1000 py to 29.4 (95% CI: 26.0-32.8) deaths per 1000 py. We found absolute and relative mortality inequality among those with and without diabetes, both generally increased during the follow-up period. Conclusion: Disparities in mortality by SEP increased during follow-up in most countries. Strategies are needed to reduce excess mortality associated with low SEP and diabetes and related socioeconomic inequality.

STUDY QUESTION: What is the association between endometriosis and working life (lost), workforce participation, and productivity? SUMMARY ANSWER: Women with endometriosis experienced more working years lost due to disability pension and to a smaller degree sick leave, they were less frequently working or enrolled in education, had more sick days, were less productive, and had lower work ability. WHAT IS KNOWN ALREADY: Endometriosis is associated with negative consequences on working life; however, previous studies are based on self-reported data or smaller samples of women. To the best of our knowledge, no previous studies have quantified the average reduction in working hours during the entire span of working life using population-based registers. STUDY DESIGN, SIZE, DURATION: This study included two Danish data sources. In the register-based cohort study (main analysis), a total of 2 650 554 women aged 18–65 years were followed for a total of 42.8 million person-years from 1992 to 2021. In the questionnaire-based cross-sectional study (Supplementary Analysis), 35 490 women aged 26–51 years were invited to participate and 7298 women completed the questionnaire. PARTICIPANTS/MATERIALS, SETTING, METHODS: For the main analysis, 42 741 (1.6%) were diagnosed with endometriosis. We estimated working years lost decomposed into disability pension, voluntary early retirement, or death for women with endometriosis and the general female population. For the supplementary analysis, 270 (4.0%) reported to have endometriosis. We analysed these recent questionnaire data on women’s health to further investigate working life and productivity among women with and without endometriosis. MAIN RESULTS AND THE ROLE OF CHANCE: Based on the main analysis, women with endometriosis lost on average an additional 0.26 years (95% CI: 0.17–0.37) of working life compared to the general female population. This was due to sick leave and especially disability pension. For the supplementary analysis, the participation rate was 20.6%. Women with endometriosis reported to be less frequently working or enrolled in education (74.1% (95% CI 68.4%–79.2%) with endometriosis, 82.7% (95% CI 81.8%–83.7%) without) and had more sick days (4–28 sick days last 4 weeks: 16.2% (95% CI 11.6%–21.8%) with endometriosis, 7.9% (95% CI 7.2%–8.7%) without). In addition, they reported lower productivity and work ability. LIMITATIONS, REASONS FOR CAUTION: Endometriosis is underdiagnosed in the register data as only hospital diagnoses are registered and diagnoses from private practicing gynaecologists and general practitioners are missing. In addition, sick leave might be underestimated as shorter periods of sick leave are not included in the registers. Questionnaire data were self-reported including endometriosis and participants might be a selected group of women. WIDER IMPLICATIONS OF THE FINDINGS: This study is in line with previous studies on endometriosis and its impact on working life. In addition, to the best of our knowledge, no previous study has quantified the average reduction in working years over the entire working life. However, the findings might only be generalizable to a Danish or Nordic context as these countries have welfare systems with economic security during unemployment, periods with illness, or reduced ability to work. STUDY FUNDING/COMPETING INTEREST(S): This study is supported by a grant from the project ‘Finding Endometriosis using Machine Learning’ (FEMaLe/101017562), which has received funding from The European Union’s Horizon 2020 research and innovation programme. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

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. In a population-based open cohort study, the change in incidence-based mortality (IBM) was estimated by relative rate ratios comparing a screening period with a historical period for each of three age groups: women eligible for screening and younger and older ineligible women. We applied the evaluation model, and for comparison two traditional IBM models from a recent Norwegian study: one without extended follow-up and no possibility of lead time bias and one with extended follow-up irrespective of diagnosis, possibly diluting any screening effect. Results: The evaluation model estimated an extra 11% reduction in breast cancer mortality among the screening eligible relative to ineligible women. However, this result could largely be ascribed to lead time bias inflated by overdiagnosis and a decreasing mortality from other causes among eligible women. A reduction in breast cancer mortality was observed for both eligible and younger and older ineligible women across models, and relative rate ratios close to 1 were obtained using the two traditional IBM models, indicating no effect of screening on breast cancer mortality. Conclusions: Two models without lead time bias found no reduction in breast cancer mortality, whereas the evaluation model estimated a reduction attributable to lead time bias .

Introduction: At mammography screening invitation, the Danish Health Authority recommends women aged 50 to 69 y make an informed decision about whether to be screened. Previous studies have shown that women have very positive attitudes about screening participation. Therefore, we hypothesized that Danish women may already have decided to participate in breast cancer screening prior to receiving their screening invitation at age 50 y. Methods: We invited a random sample of 2,952 Danish women aged 44 to 49 y (prescreening age) to complete an online questionnaire about barriers to informed screening decision making using the official digital mailbox system in Denmark. We asked participants about their screening intentions using 3 different questions to which women were randomized: screening presented 1) as an opportunity, 2) as a choice, and 3) as an opportunity plus a question about women’s stage of decision making. All women completed questions about background characteristics, intended participation in the screening program, use and impact of screening information, and preferences for the decision-making process. Data were linked to sociodemographic register data. Results: A total of 790 (26.8%) women participated in the study. Herein, 97% (95% confidence interval: 96%–98%) reported that they wanted to participate in breast cancer screening when invited at age 50 y. When presented with the choice compared with the opportunity framing, more women rejected screening. When asked about their stage of decision making, most (87%) had already made a decision about screening participation and were unlikely to change their mind. Conclusion: In our study, almost all women of prescreening age wanted to participate in breast cancer screening, suggesting that providing information at the time of screening invitation may be too late to support informed decision making. Highlights: Almost all women of prescreening age (44–49 y) in our study wanted to participate in the Danish national mammography screening program starting at age 50 y. Early decision making represents a barrier for informed decision making as women in this study had intentions to participate in breast cancer screening prior to receiving an official screening invitation, and therefore, providing information at the time of screening invitation may be too late to support informed decision making. Very few women rejected screening participation; however, more women rejected screening when the information was framed as an active choice between having or declining breast cancer screening (continue with usual care) compared with presenting only the option of screening with no description of the alternative. Two-thirds of women reading the screening information in this study had unchanged attitudes toward screening after reading the presented information.