Age-standardized Incidence Rate Ratios Research Articles

Educational and income inequalities across diseases in Denmark: a register-based cohort study

Educational attainment and income are often, but not always, associated with disease incidence. Existing research typically examines single diseases, resulting in disparate analyses with little comparability. In this study, we aimed to assess educational and income inequalities across diseases in Denmark. This register-based study included all Danish residents aged at least 30 years between Jan 1, 2013, and Dec 31, 2022, who were born after 1920, and with known educational attainment and income. We used a disease-wide approach to assess associations between education and income and the incidence of 751 diagnostic codes determined upon hospital admission. We estimated age-standardised incidence rates and incidence rate ratios (IRRs) using Poisson regression, adjusted for birth cohort and stratified by sex. Participants were followed up until time of diagnosis, death, emigration, or until Dec 31, 2022. 4 541 309 individuals aged 30 years and older were registered as living in Denmark between Jan 1, 2013, and Dec 31, 2022. 121 083 were excluded due to limited or missing information about educational attainment. 4 420 226 individuals were included in the analysis of educational inequalities (2 232 200 [50%] were female and 2 188 026 [50%] were male). 23 708 were excluded due to absence of income information, and 4 396 518 were included in the analysis of income inequalities (2 223 217 (51%) were female and 2 173 301 (49%) were male). Socioeconomic differences in incidence rates were observed across all disease groups; incidence rates of most diseases decreased with higher educational attainment and income. The magnitude of the socioeconomic inequalities varied substantially. Among non-communicable diseases, the strongest positive association with regard to education was observed in chronic obstructive pulmonary disease for female individuals (low education vs high education, IRR 2·7 [95% CI 2·4-3·0]) and schizophrenia for male inividuals (low education vs high education, IRR 4·4 [2·2-8·8]), and the strongest negative association was in melanoma and other skin cancers for females (low education vs high education, IRR 0·7 [0·7-0·8]) and melanoma and skin cancers for males (low education vs high education, 0·7 [0·6-0·8]). With regard to income, for females, the strongest positive association was observed in schizophrenia (quartile 1 [Q1] vs quartile 4 [Q4], IRR 10·1 [6·1-17·2]), whereas the strongest negative association was in melanoma and other skin cancers (Q1 vs Q4, IRR 0·5 [0·5-0·6]). For males, the strongest positive assocation was schizophrenia (Q1 vs Q4, IRR 18·4 [95% CI 8·5-39·9]) and the strongest negative association was also melanoma and other skin cancers (Q1 vs Q4, IRR 0·5 [0·5-0·6]). The most prevalent disease category, other digestive diseases, was also strongly positively associated with education (low education vs high education, IRR 1·6 [95% CI 1·6-1·6] for females; IRR 1·5 [1·4-1·5] for males) and income (Q1 vs Q4, IRR 1·5 [1·5-1·5] for females; IRR 1·3 [1·3-1·4] for males). Our study provides a detailed representation of the association between two socioeconomic indicators and disease incidence. A broad spectrum of diseases, and not only the most prevalent, show socioeconomic disparities. This finding highlights the need for not only policies that address specific diseases, but also universal policies addressing the root causes of socioeconomic disparities and their health consequences. The Novo Nordisk Foundation.

Impact of the COVID-19 Pandemic and Lockdown on Cancer Diagnoses Using Swiss Cantonal Cancer Registry Data

Background/Objectives: This study aims to investigate differences in cancer diagnosis based on absolute case numbers and age-standardized incidence rate ratios (IRRs) in the pre-Coronavirus disease 2019 (COVID-19) years (2018/19) and the first two years of the COVID-19 pandemic (2020, 2021) in two Swiss cantons. Methods: Data of the Swiss cantonal cancer registry of the cantons of Zurich (ZH) and Zug (ZG) were used to descriptively investigate differences in annual and monthly absolute numbers regarding all-cancer and the five most common cancer types. Directly age-standardized monthly incidence rates (IRs) were calculated. Multivariate Quasipoisson regression models were fitted to determine the IRRs with 95% confidence intervals (95% CI). Results: Annual absolute numbers of all investigated cancers were similar in 2018/19, 2020, and 2021, except for prostate cancer (increase of 20.8% in 2021 compared to 2018/19). In 2020, there were generally more cancer diagnoses in January and February followed by a decrease in April and May. Compared to the pre-COVID-19 period, lower IRs were observed in 2020 for all-cancer (IRR = 0.96 [95% CI 0.96, 0.97]) and female breast cancer (0.92 [0.89, 0.96]), whereas higher IRs were observed in 2021 for all-cancer (1.02 [1.02, 1.02]) and prostate cancer (1.23 [1.18, 1.28]). Conclusions: Cancer detection and diagnoses decreased during the first year of the pandemic, especially during the most stringent lockdown phase in April. The findings of this study may inform the decisions of policymakers and public health system during future pandemics.

Myelodysplastic syndrome/ Myeloproliferative disorder, Nos.

Background: Population-based research is limited for myelodysplastic syndrome/ myeloproliferative neoplasm, not otherwise specified (MDS/MPN-NOS) which comprises a heterogenous group of patients that do not fit into the other established MDS/MPN subgroups. Methods: We identified patients from the Surveillance, Epidemiology, and End Results (SEER) database with a diagnosis of MDS/MPN-U logged from 2010-2020. Age-standardized incidence rates (ASIR) and incidence rate ratios (IRR) were calculated using eight age subgroups. Subgroup analyses were performed for race and gender. Join point regression analyses were performed to model trends in ASIRs, and annual percent change (APC) was calculated. Results: A total of 2447 patients over age 50 were included in analysis. Incidence of MDS/MPN-U increased gradually between 2010-2016 (APC 12.90) then decreased between 2016-2020 (APC -19.56). ASIR was significantly higher in males compared to females in several age groups (age 65-69, 80-84, 85+). Conclusion: The underlying molecular complexity of these diseases remains a significant challenge. It is critical to identify MDS/MPN- specific therapeutic response criteria and suitable end points correlated with survival and AML risk for transformation to acute myeloid leukemia (AML) uniform assessment of treatment benefit.

A surveillance study of cancer incidence and mortality among young adults in Costa Rica

There has been an increase in certain cancers among young adults (YA) aged 20-39, particularly in LatinAmerica. This is the first study to examine cancer incidence and mortality in YA in Costa Rica, focusing on sex-specific patterns. Invasive cancer cases (excluding non-melanoma skin cancer) in YA from 2006 to 2015 were obtained from the Costa Rican National Registry of Tumors. Utilising SEER∗Stat software, age-standardized incidence rates (IRs) and incidence rate ratios (IRRs) were calculated. Trends and annual percent changes (APCs) in IRs were estimated using the Joinpoint regression analysis program. Cancer deaths from 2000 to 2021 were obtained from the Costa Rican National Institute of Statistics and Census. Age-standardised mortality rates were calculated using STATA®17. YA comprised 10.7% of all invasive cancer cases diagnosed from 2006 to 2015. The age-standardized incidence rate (ASIR) of invasive cancer in YA was 50.9/100,000 person-years. The ASIR was twofold higher for females compared to males (IRR=2.03, 95% CI:1.94, 2.13). This difference increased with age, peaking in the 35-39-year age group (IRR=2.84, 95% CI:2.62, 3.10). Thyroid, breast, and cervical cancer were the most common in females. Testicular cancer was the most common in males. Leading causes of cancer-related deaths included cervical and breast cancer in females and stomach and brain/nervous system cancer in males. The study highlights sex-specific patterns in cancer incidence and mortality among YA in Costa Rica to increase understanding and improve cancer outcomes in this age group. This study was funded by the Intramural Research Program of the National Cancer Institute.

Impact of the COVID-19 pandemic on international cutaneous squamous cell carcinoma incidence: A systematic review and meta-analysis.

Non-melanoma skin cancer (NMSC) is the most common cancer globally in white ethinicity populations, and cutaneous squamous cell carcinoma (cSCC) is the second most common subtype. The COVID-19 pandemic severely impacted public and private healthcare systems. Many studies have reported reduced cancer diagnoses during the pandemic. The impact of the COVID-19 pandemic on global cSCC and NMSC incidence is poorly reported. The aim was to conduct a systematic review and meta-analysis to assess the impact of the COVID-19 pandemic on global cSCC and NMSC incidence rates, compared with 2019 incidence rates. Two primary outcome measures were used: crude incidence rate ratios (CIRR) and age-standardised incidence rate ratios (ASIRR). A structured search was undertaken on 23 March 2023 using grey literature and four electronic databases: MEDLINE, CINAHL, EMBASE and Web of Science. Studies published before January 2020 were excluded. A quality assessment was undertaken using A. Lomas quality assessment tool. CIRR outcomes were synthesised in a meta-analysis, while ASIRR outcomes were narratively synthesised. Fourteen cancer registries were included, capturing data from 13 countries across Europe. Variation was observed in NMSC and cSCC incidence across the cancer registries. Pooled cSCC crude incidence rates in 2020 were equal to crude incidence rates in 2019 (cSCC-CIRR 1.00 (95% confidence interval (CI) 0.94-1.06). In 2021, the pooled result indicated a non-significant 8% increase in cSCC crude incidence rates, compared with 2019 (cSCC-CIRR 1.08 (95% CI 0.98-1.19). Significant reductions were reported in NMSC incidence across all meta-analyses in 2020 and 2021 compared with 2019. Heterogeneity was observed across most pooled estimates (I 2>75%). There was a lack of high quality data on cSCC incidence rates recorded during the pandemic outside of Europe. The COVID-19 pandemic resulted in no significant changes in cSCC incidence across Europe. By contrast, NMSC incidence fell across Europe following the pandemic. Significant reductions in pooled NMSC incidence rates may reflect a delay in basal cell carcinoma presentation, diagnosis and treatment. Although annual incidence rates for cSCC were not affected by the pandemic, delays in treatment may still have occurred, which may result in poorer outcomes yet to be fully understood.

Cancer incidence in immigrants by geographical area of origin: data from the Veneto Tumour Registry, Northeastern Italy.

We investigated whether there are differences in cancer incidence by geographical area of origin in North-eastern Italy. We selected all incident cases recorded in the Veneto Tumour Registry in the period 2015-2019. Subjects were classified, based on the country of birth, in six geographical areas of origin (Italy, Highly Developed Countries-HDC, Eastern Europe, Asia, Africa, South-central America). Age-standardized incidence rates and incidence rate ratio (IRR) were calculated, for all cancer sites and for colorectal, liver, breast and cervical cancer separately. We recorded 159,486 all-site cancer cases; 5.2% cases occurred in subjects born outside Italy, the majority from High Migratory Pressure Countries (HMPC) (74.3%). Incidence rates were significantly lower in subjects born in HMPC in both sexes. Immigrants, in particular born in Asia and Africa, showed lower rates of all site cancer incidence. The lowest IRR for colorectal cancer was observed in males from South-Central America (IRR 0.19, 95%CI 0.09-0.44) and in females from Asia (IRR 0.32, 95%CI 0.18-0.70). The IRR of breast cancer appeared significantly lower than Italian natives in all female populations, except for those coming from HDC. Females from Eastern Europe showed a higher IRR for cervical cancer (IRR 2.02, 95%CI 1.57-2.61). Cancer incidence was found lower in subjects born outside Italy, with differences in incidence patterns depending on geographical area of origin and the cancer type in question. Further studies, focused on the country of birth of the immigrant population, would help to identify specific risk factors influencing cancer incidence.

Cancer incidence, treatment, and survival in the prison population compared with the general population in England: a population-based, matched cohort study

The growing and ageing prison population in England makes accurate cancer data of increasing importance for prison health policies. This study aimed to compare cancer incidence, treatment, and survival between patients diagnosed in prison and the general population. In this population-based, matched cohort study, we used cancer registration data from the National Cancer Registration and Analysis Service in England to identify primary invasive cancers and cervical cancers in situ diagnosed in adults (aged ≥18 years) in the prison and general populations between Jan 1, 1998, and Dec 31, 2017. Ministry of Justice and Office for National Statistics population data for England were used to calculate age-standardised incidence rates (ASIR) per year and age-standardised incidence rate ratios (ASIRR) for the 20-year period. Patients diagnosed with primary invasive cancers (ie, excluding cervical cancers in situ) in prison between Jan 1, 2012, and Dec 31, 2017 were matched to individuals from the general population and linked to hospital and treatment datasets. Matching was done in a 1:5 ratio according to 5-year age group, gender, diagnosis year, cancer site, and disease stage. Our primary objectives were to compare the incidence of cancer (1998-2017); the receipt of treatment with curative intent (2012-17 matched cohort), using logistic regression adjusted for matching variables (excluding cancer site) and route to diagnosis; and overall survival following cancer diagnosis (2012-17 matched cohort), using a Cox proportional hazards model adjusted for matching variables (excluding cancer site) and route to diagnosis, with stratification for the receipt of any treatment with curative intent. We identified 2015 incident cancers among 1964 adults (1556 [77·2%] men and 459 [22·8%] women) in English prisons in the 20-year period up to Dec 31, 2017. The ASIR for cancer for men in prison was initially lower than for men in the general population (in 1998, ASIR 119·33 per 100 000 person-years [95% CI 48·59-219·16] vs 746·97 per 100 000 person-years [742·31-751·66]), but increased to a similar level towards the end of the study period (in 2017, 856·85 per 100 000 person-years [675·12-1060·44] vs 788·59 per 100 000 person-years [784·62-792·57]). For women, the invasive cancer incidence rate was low and so ASIR was not reported for this group. Over the 20-year period, the incidence of invasive cancer for men in prison increased (incidence rate ratio per year, 1·05 [95% CI 1·04-1·06], during 1999-2017 compared with 1998). ASIRRs showed that over the 20-year period, overall cancer incidence was lower in men in prison than in men in the general population (ASIRR 0·76 [95% CI 0·73-0·80]). The difference was not statistically significant for women (ASIRR 0·83 [0·68-1·00]). Between Jan 1, 2012, and Dec 31, 2017, patients diagnosed in prison were less likely to undergo curative treatment than matched patients in the general population (274 [32·3%] of 847 patients vs 1728 [41·5%] of 4165; adjusted odds ratio (OR) 0·72 [95% CI 0·60-0·85]). Being diagnosed in prison was associated with a significantly increased risk of death on adjustment for matching variables (347 deaths during 2021·9 person-years in the prison cohort vs 1626 deaths during 10 944·2 person-years in the general population; adjusted HR 1·16 [95% CI 1·03-1·30]); this association was partly explained by stratification by curative treatment and further adjustment for diagnosis route (adjusted HR 1·05 [0·93-1·18]). Cancer incidence increased in people in prisons in England between 1998 and 2017, with patients in prison less likely to receive curative treatments and having lower overall survival than the general population. The association with survival was partly explained by accounting for differences in receipt of curative treatment and adjustment for diagnosis route. Improved routine cancer surveillance is needed to inform prison cancer policies and decrease inequalities for this under-researched population. UK National Institute for Health and Care Research, King's College London, and Strategic Priorities Fund 2019/20 of Research England via the University of Surrey.

Decrease in incidence of distal radius fractures in Oslo, Norway

SummaryThis study reported the incidence of validated adult distal radius fractures in Oslo, Norway, in 2019. The incidence has been reduced over the last 20 years. However, it is still high compared to other regions in Norway and some of the other Nordic countries.PurposeWe aimed to report the incidence of distal radius fractures in Oslo in 2019 and compare it to the incidence rates in 1998/1999.MethodsPatients aged ≥ 20 years resident in Oslo sustaining a distal radius fracture in 2019 were identified by electronic diagnosis registers, patient protocols, and/or radiology registers. The diagnosis was verified using medical records and/or radiology descriptions. We used the same method as the previous study from Oslo, making the comparison over time more accurate. The age-adjusted incidence rates and the age-standardized incidence rate ratio (IRR) were calculated.ResultsThe absolute number of fractures decreased from 1490 in 1998/1999 to 1395 in 2019. The IRR for women and men in the age group ≥ 20 years in 2019 compared to 1998/1999 was 0.77 (95% CI 0.71–0.84) and 0.77 (95% CI 0.66–0.90), respectively. The IRR for women and men in the age group ≥ 50 years in 2019 compared to 1998/1999 was 0.78 (95% CI 0.71–0.86) and 0.78 (95% CI 0.63–0.97), respectively. For the population in Oslo with Asian background compared to Norwegian background in the age group ≥ 50 years, the IRR in 2019 was 0.57 (95% CI 0.40–0.80) for women and 0.77 (95% CI 0.44–1.37) for men.ConclusionsThe incidence of distal radius fractures in Oslo has decreased over the last 20 years. It is still, however, higher than in other areas of Norway and in some of the other Nordic countries.

COVID-19 outcome trends by vaccination status in Canada, December 2020-January 2022.

The coronavirus disease 2019 (COVID-19) pandemic in Canada has evolved rapidly. Since late 2020, COVID-19 vaccines have been relied on to protect against severe outcomes in the presence of circulating variants of concern (VOC). This surveillance report provides a retrospective descriptive analysis of national trends in COVID-19 cases and severe outcomes by vaccination status, contextualizing trends against case demographics and circulating VOCs, from December 2020 to January 2022. Case and vaccination coverage surveillance data were obtained from the National COVID-19 Case Dataset and the Canadian COVID-19 Vaccination Coverage Surveillance System for 12 of 13 provinces and territories. Descriptive analyses were produced to describe trends over time among individuals aged 12 years and older by COVID-19 outcome, vaccination status, and demographics. Age-standardized and age-stratified incidence rates and incidence rate ratios were computed for cases, hospitalizations, and deaths. From mid to late-2021, incidence rates for cases and severe outcomes were consistently lowest among those with a completed primary series and highest among those who were unvaccinated. Unvaccinated individuals were much more likely to be hospitalized or to die compared to those with a completed primary series in all variant periods. Age-specific rates of severe outcomes were consistently highest among those aged 80 years and older across all vaccination statuses. Vaccination remains one of the most important public health interventions, particularly among older adults, to protect against COVID-19 severe outcomes as the pandemic evolves. Routine monitoring of COVID-19 outcomes by vaccination status can identify changes in COVID-19 epidemiology and inform public health action and policy.

Stroke Risk in Survivors of Head and Neck Cancer

Survivors of head and neck cancers (HNC) have increased risk of stroke. A comprehensive report using standardized methods is warranted to characterize the risk and to inform on survivorship strategy. To determine the stroke risk in subpopulations of survivors of HNC in Singapore. This national, registry-based, cross-sectional study aimed to estimate stroke risk in subgroups of the HNC population between January 2005 and December 2020. Participants were identified from the Singapore Cancer Registry, the Singapore Stroke Registry, and the Registry of Birth and Deaths using relevant International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) codes. HNC subgroups were defined based on patient demographic, disease, and treatment factors. Data were analyzed from September 2022 to September 2023. Diagnosis of HNC. Both ischemic and hemorrhagic stroke were studied. The age-standardized incidence rate ratio (SIRR) and age-standardized incidence rate difference (SIRD) were reported. The Singapore general population (approximately 4 million) served as the reference group for these estimations. A total of 9803 survivors of HNC (median [IQR] age at diagnosis, 58 [49-68] years; 7166 [73.1%] male) were identified. The most common HNC subsites were nasopharynx (4680 individuals [47.7%]), larynx (1228 individuals [12.5%]), and tongue (1059 individuals [10.8%]). A total of 337 individuals (3.4%) developed stroke over a median (IQR) follow-up of 42.5 (15.0-94.5) months. The overall SIRR was 2.46 (95% CI, 2.21-2.74), and the overall SIRD was 4.11 (95% CI, 3.37-4.85) strokes per 1000 person-years (PY). The cumulative incidence of stroke was 3% at 5 years and 7% at 10 years after HNC diagnosis. The SIRR was highest among individuals diagnosed at younger than 40 years (SIRR, 30.55 [95% CI, 16.24-52.35]). All population subsets defined by age, sex, race and ethnicity, HNC subsites (except tongue), stage, histology, and treatment modalities had increased risk of stroke compared with the general population. The SIRR and SIRD were significantly higher among individuals who had a primary radiation treatment approach (SIRR, 3.01 [95% CI, 2.64-3.43]; SIRD, 5.12 [95% CI, 4.18-6.29] strokes per 1000 PY) compared with a primary surgery approach (SIRR, 1.64 [95% CI, 1.31-2.05]; SIRD, 1.84 [95% CI, 0.923.67] strokes per 1000 PY). In this cross-sectional study of survivors of HNC, elevated stroke risks were observed across different age, subsites, and treatment modalities, underscoring the importance of early screening and intervention.

Femicide, intimate partner femicide, and non-intimate partner femicide in South Africa: An analysis of 3 national surveys, 1999-2017.

In most countries, reliable national statistics on femicide, intimate partner femicide (IPF), and non-intimate partner femicide (NIPF) are not available. Surveys are required to collect robust data on this most extreme consequence of intimate partner violence (IPV). We analysed 3 national surveys to compare femicide, IPF, and NIPF from 1999 to 2017 using age-standardised rates (ASRs) and incidence rate ratios (IRRs). We conducted 3 national mortuary-based retrospective surveys using weighted cluster designs from proportionate random samples of medicolegal laboratories. We included females 14 years and older who were identified as having been murdered in South Africa in 1999 (n = 3,793), 2009 (n = 2,363), and 2017 (n = 2,407). Further information on the murdered cases were collected from crime dockets during interviews with police investigating officers. Our findings show that South Africa had an IPF rate of 4.9/100,000 female population in 2017. All forms of femicide among women 14 years and older declined from 1999 to 2017. For IPF, the ASR was 9.5/100,000 in 1999. Between 1999 and 2009, the decline for NIPF was greater than for IPF (IRR for NIPF 0.47 (95% confidence interval (CI) 0.42 to 0.53) compared to IRR for IPF 0.69 (95% CI 0.63 to 0.77). Rates declined from 2009 to 2017 and did not differ by femicide type. The decline in IPF was initially larger for women aged 14 to 29, and after 2009, it was more pronounced for those aged 30 to 44 years. Study limitations include missing data from the police and having to use imputation to account for missing perpetrator data. In this study, we observed a reduction in femicide overall and different patterns of change in IPF compared to NIPF. The explanation for the reductions may be due to social and policy interventions aimed at reducing IPV overall, coupled with increased social and economic stability. Our study shows that gender-based violence is preventable even in high-prevalence settings, and evidence-based prevention efforts must be intensified globally. We also show the value of dedicated surveys in the absence of functional information systems.

Stroke Risk in Survivors of Head and Neck Cancer: A Descriptive Epidemiologic Cohort Study

Survivors of head and neck cancer (HNC) have an increased risk of stroke. However, the evidence on the risk of stroke in various subpopulations of HNC defined by patient, disease and treatment factors remains unclear. This study aimed to determine whether age-standardized incidence rate ratios (SIRs) and risk differences (SIRDs) of stroke varied across different subpopulations of survivors of HNC. We used data from the national stroke and cancer registries to identify all cases of HNC who developed their first stroke after HNC diagnosis from January 2005 to December 2020. We estimated the SIRs and SIRDs of stroke in various subgroups of HNC defined by patient, disease and treatment factors using the Singapore general population as the reference group. A total of 8839 cases of HNC were identified and 308 cases (3.4%) developed stroke after HNC diagnosis at median follow up of 42.5 months (interquartile range 15.0 - 94.5 months). The overall SIR and SIRD were 2.46 (95% CI 2.21 - 2.74) and 4.11 cases per 1000 person-years (PY) (95% CI 3.37 - 4.85). The SIR and SIRD were higher among those post five years from HNC diagnosis compared to those with 5 or fewer years from HNC diagnosis (SIR: 3.92 (3.36 - 4.58) vs 1.84 (1.59 - 2.14), SIRD: 6.64 (5.26 - 8.03) vs 2.65 (1.80 - 3.50) cases per 1000 PY). The SIR was highest for those less than 40 years old (< 40 years: 30.55; 40 - 49 years: 5.84; 50 - 59 years: 3.13; 60 - 69 years: 2.38, 70 - 79 years: 1.53, > = 80 years: 1.41) while SIRD was highest for those with age 80 years and above (< 40 years: 2.16; 40 - 49 years: 3.44, 50 - 59 years: 4.25, 60 - 69 years: 5.55, 70 - 79 years: 4.16, > = 80 years: 6.14). Among those who had treatment within 6 months of HNC diagnosis, the SIR and SIRD were significantly higher among those who had primary radiation treatment approach (radiation only, radiation and chemotherapy) (SIR: 3.01 (2.64 - 3.43), SIRD: 5.12 (4.18 - 6.29) cases per 1000 PY) compared to primary surgery treatment approach (surgery only, surgery and radiation, surgery and chemotherapy and radiation) (SIR: 1.64 (1.31 - 2.05), SIRD: 1.84 (0.92 - 3.67)). The risk of stroke varied across different subpopulations of survivors of HNC with higher risk observed in those surviving five years post HNC diagnosis, less than 40 years old or received primary radiation treatment approach within 6 months from HNC diagnosis. A risk based prophylactic measures for stroke should be considered for different subpopulations of survivors of HNC.

Differences in site-specific cancer incidence by individual- and area-level income in Canada from 2006 to 2015.

Income, a component of socioeconomic status, influences cancer risk as a social determinant of health. We evaluated the independent associations between individual- and area-level income and site-specific cancer incidence in Canada. We used data from the 2006 and 2011 Canadian Census Health and Environment Cohorts, which are probabilistically linked datasets constituted by 5.9 million and 6.5 million respondents of the 2006 Canadian long-form census and 2011 National Household Survey, respectively. Individuals were linked to the Canadian Cancer Registry through 2015. Individual-level income was derived using after-tax household income adjusted for household size. Annual tax return postal codes were used to assign area-level income quintiles to individuals for each year of follow-up. We calculated age-standardized incidence rates (ASIR) and rate ratios for cancers overall and by site. We conducted multivariable negative binomial regression to adjust these rates for other demographic and socioeconomic variables. Individuals of lower individual- and area-level income had higher ASIRs compared to those in the wealthiest income quintile for head and neck, oropharyngeal, esophageal, stomach, colorectal, anal, liver, pancreas, lung, cervical and kidney and renal pelvis cancers. Conversely, individuals of wealthier individual- and area-level income had higher ASIRs for melanoma, leukemia, Hodgkin's lymphoma, non-Hodgkin's lymphoma, breast, uterine, prostate and testicular cancers. Most differences in site-specific incidence by income quintile remained after adjustment. Although Canada's publicly funded healthcare system provides universal coverage, inequalities in cancer incidence persist across individual- and area-level income gradients. Our estimates suggest that individual- and area-level income affect cancer incidence through independent mechanisms.

Ten-year trends in incidence and prevalence of atrial fibrillation and flutter in Denmark according to demographics, ethnicity, educational level, and area of residence (2009-2018).

Atrial fibrillation is the most common cardiac arrhythmia and a major global health burden. Updated trends in the epidemiology of atrial fibrillation or flutter (AF) are needed. Using the Danish Heart Statistics, we investigated nationwide trends 2009-2018 in incidence rate and prevalence of AF according to age as well as age-standardized incidence rate (ASIR) and prevalence (ASP) of AF according to sex, ethnicity, educational level, and area of residence. Comparing year 2018 to 2009, we calculated stratum-specific ASIR ratios (ASIRR) and changes in ASP. During 2009-2015 the ASIR for AF increased for both men and women, followed by a decline from 2015-2018. Overall, this resulted in a 9% increase among men (ASIRR: 1.09, 95% CI: 1.06-1.12), but no change among women (ASIRR: 1.00, 95% CI: 0.97-1.04). The ASP increased by 29% among men and 26% among women. An increase in ASIR was observed in all ethnic groups except men of Far Eastern ethnicity. Lower educational level was associated with greater increases in both ASIR and ASP. ASIR and ASP differed slightly between the Danish regions but increased in all of them. During 2009-2018 the incidence and prevalence of AF in Denmark increased although the increase in incidence was transient among women. Factors associated with higher incidence were male sex, higher age, Danish and Western ethnicity as well as Middle Eastern/North African ethnicity among women, and lower educational level. Within Denmark, we observed only minor regional differences in AF incidence and prevalence.

Site-Specific Cancer Incidence by Race and Immigration Status in Canada 2006-2015: A Population-Based Data Linkage Study.

The Canadian Cancer Registry (CCR) does not collect demographic data beyond age and sex, making it difficult to monitor health inequalities. Using data linkage, we compared site-specific cancer incidence rates by race. The 2006 and 2011 Canadian Census Health and Environment Cohorts are population-based probabilistically linked datasets of 5.9 million respondents of the 2006 long-form census and 6.5 million respondents of the 2011 National Household Survey. Race was self-reported. Respondent data were linked with the CCR up to 2015. We calculated age-standardized incidence rate ratios (ASIRR), comparing group-specific rates to the overall population rate with bootstrapped 95% confidence intervals (CI). We used negative binomial regressions to adjust for socioeconomic variables and assess interactions with immigration status. The age-standardized overall cancer incidence rate was lower in almost all non-White racial groups than in the overall population, except for White and Indigenous peoples who had higher incidence rates than the overall population (ASIRRs, 1.03-1.04). Immigrants had substantially lower age-standardized overall cancer incidence rates than nonimmigrants (ASIRR, 0.83; 95% CI, 0.82-0.84). Stomach, liver, and thyroid cancers and multiple myelomas were the sites where non-White racial groups had consistently higher site-specific cancer incidence rates than the overall population. Immigration status was an important modifier of cancer risk in the interaction model. Differences in cancer incidence between racial groups are likely influenced by differences in lifestyles, early life exposures, and selection factors for immigration. Data linkage can help monitor health inequalities and assess progress in preventive interventions against cancer. See related commentary by Withrow and Gomez, p. 876.

Epidemiology and trends in stroke mortality in the USA, 1975-2019.

Whether changes in stroke mortality are affected by age distribution and birth cohorts, and if the decline in stroke mortality exhibits heterogeneity by stroke type, remains uncertain. We undertook a sequential time series analysis to examine stroke mortality trends in the USA among people aged 18-84 years between 1975 and 2019 (n = 4 332 220). Trends were examined for overall stroke and by ischaemic and haemorrhagic subtypes. Mortality data were extracted from the US death files, and age-sex population data were extracted from US census. Age-standardized stroke mortality rates and incidence rate ratio (IRR) with 95% confidence interval [CI] were derived from Poisson regression models. Age-standardized stroke mortality declined for females from 87.5 in 1975 to 30.9 per 100 000 in 2019 (IRR 0.27, 95% CI 0.26, 0.27; average annual decline -2.78%, 95% CI -2.79, -2.78). Among males, age-standardized mortality rate declined from 112.1 in 1975 to 38.7 per 100 000 in 2019 (RR 0.26, 95% CI 0.26, 0.27; average annual decline -2.80%, 95% CI -2.81, -2.79). Stroke mortality increased sharply with advancing age. Decline in stroke mortality was steeper for ischaemic than haemorrhagic strokes. Stroke mortality rates have substantially declined, more so for ischaemic than haemorrhagic strokes.

Incidence of childhood leukemia before and after shut down of nuclear power plants in Germany in 2011: A population-based register study during 2004 to 2019.

The association between leukemia and proximity to nuclear-power-plants (NPPs) has been assessed in several countries with inconsistent results. A case-control study from Germany had shown an increased risk for childhood leukemia (diagnoses 1980-2003) near NPPs. Germany began shutting down nuclear reactors in 2011, following the Fukushima disaster. We tested whether the previously observed association between leukemia and proximity to NPP persisted despite the shutdown. We used an ecological study design to investigate the incidence of leukemia during 2004 to 2019 in children aged 0 to 14 years living near NPPs where at least one reactor was shut down in 2011. We defined study and control areas as municipalities whose surface area was at least 75% within 10km or between 10 and 50 km of NPPs, respectively. We calculated age-standardized rates and incidence rate ratios (IRR) using control-areas as the reference. We also computed standardized incidence ratios (SIR) separately for each NPP using incidence rates of the German population as a reference. IRR decreased from 1.20 (95% confidence interval: 0.81-1.77) in 2004 to 2011 to 1.12 (0.75-1.68) in 2012 to 2019. Analyses of single plants showed an excess of childhood leukemia during 2004 to 2019 for the Unterweser-NPP, based only on three cases, and the Krümmel-NPP (n=14; SIR: 1.98, 1.17-3.35). We found slightly decreasing of leukemia incidence rate ratios after the shutdown of nuclear reactors in 2011. Due to the small number of cases, risk estimates have large uncertainty. Further research including a longer follow-up is warranted. The consistent excess of incidence cases around Krümmel may require analytical epidemiological analysis.

Colorectal cancer incidence and survival inequalities among labour immigrants in Belgium during 2004–2013

Colorectal cancer (CRC) is one of the leading causes of cancer-related morbidity and mortality. We aim to map out differences in CRC incidence and survival between first-generation traditional labour immigrants of Italian, Turkish and Moroccan descent and native Belgians; and assess the contribution of socioeconomic position (SEP) to these differences. Individually-linked data of the 2001 Belgian Census, the Crossroads Bank for Social Security and the Belgian Cancer Registry are used. Age-standardized incidence rates and incidence rate ratios are calculated by country of origin, with and without adjusting for SEP. For CRC patients, 5-year relative survival rates and the relative excess risk for dying within five years after diagnosis are calculated by migrant origin. Lower CRC incidence was observed among immigrants compared to native Belgians, in particular among non-Western immigrants, which could not be explained by SEP. Survival inequalities were less clear, yet, after adjusting for age and stage at diagnosis and educational attainment, we observed a survival advantage among Turkish and Italian immigrant men. Health gains can be made for the native population by adapting lifestyle. The later stage at diagnosis for immigrants is of concern. Barriers regarding screening as perceived by the vulnerable groups should be identified.

Stage-Specific Risk of Breast Cancer among Canadian Immigrant and Non-Immigrant Women.

Breast cancer screening utilization varies across immigrant and non-immigrant populations. Recent studies have also suggested that some immigrant populations in Canada present with a higher frequency of later-stage breast cancer compared to non-immigrants. Our study aimed to augment prior research by presenting breast cancer stage distributions and stage-specific breast cancer incidence rates for immigrant and non-immigrants in British Columbia, Canada. We utilized a population-based cohort of more than 1.3million women built from linked administrative health and immigration data sets. Age-standardized incidence rate ratios were generated to compare immigrant and non-immigrant groups. Poisson regression was used to assess the relative frequency of later stage diagnosis among immigrant groups compared to non-immigrants. Indian and Chinese immigrants both showed significantly lower stage I and stage II-IV incidence rates compared to non-immigrants. However, Indian immigrants showed a higher frequency of later stage tumours at diagnosis compared to non-immigrants, while in contrast Chinese immigrants showed a lower frequency of later stage tumours. Filipino immigrants showed similar stage-specific rates and stage at diagnosis compared to non-immigrants. Our findings highlight a need for continued surveillance of cancer among immigrant and non-immigrant populations and inquiry into reasons for differences in stage at diagnosis across groups.

Abstract 2234: Incidence of clinically significant prostate cancer after negative prostate MRI - comparison to general population

Abstract Prostate MRI has high NPV (around 90%) for clinically significant prostate cancer (csPCa, ISUP grade group ≥ 2)1. However, clinicians are still faced with significant uncertainty when considering whether to avoid or to proceed to systematic biopsies in a man with negative MRI (nMRI). When making such an informed decision, information on the risk of subsequent csPCa diagnosis after nMRI in respect to risk of csPCa in general population may be beneficial. Hence, our objective was to compare incidence rate (IR) of csPCa and overdiagnosis rate (diagnosis of ISUP grade group 1 cancer, isPCa) after nMRI (PI-RADS 1-2) to outcomes in general population, and to assess the value of age and PSA-density in stratification. We utilized institutional and national registries to retrospectively identify 1,685 50-79-year-old PCa-free men who underwent a primary nMRI at our institution, of whom 906 men had PSA-D &amp;lt; 0.15 ng/ml/cm3. We compared the IR of csPCa and overdiagnosis rate in relation to general population (n=230,246) during follow-up (up to four years) under clinical routine since December 2015 (PIRADS v2 era). We calculated age-standardized IR ratios (IRR) of csPCa and odds ratios (OR) of overdiagnosis with 95% confidence intervals (95% CI) as age-pooled and among 10-year interval groups (50-59, 60-69 and 70-79 years). Follow-up times in general population cohort, nMRI cohort, and nMRI and low PSA-D cohort were 885,792, 3,363, and 1,821 years and IRs of csPCa were 406, 2,201, and 989 per 100,000 person years. In reference to general population, IRR of csPCa in nMRI cohort was 4.2 (95% CI 3.3-5.4) which reduced to 1.8 (95% CI 1.1-2.9) if PSA-D was &amp;lt; 0.15 ng/ml/cm3. ORs of isPCa were 3.0 (95% CI 2.0-4.6) and 4.6 (95% CI 2.2-9.5), respectively. IRRs of csPCa of 50-59, 60-69 and 70-79-year-old men were 14.1 (95% CI 10.5-25.4), 3.2 (95% CI 2.1-4.6) and 3.4 (95% CI 1.6-3.9). Limitations of this study include retrospective and registry-based design. In conclusion, the risk of subsequent csPCa after nMRI in young men is significant, when compared to population risk. However, with advancing age, these risks converge. For a subgroup of men with PSA-D &amp;lt; 0.15 ng/ml/cm3, the relative risk of csPCa is low in all age groups and comparable to population risk. At the same time, the risk of overdiagnosis after nMRI is substantially higher than in general population. In light of our results, elderly men with nMRI and men at all age groups with nMRI and PSA-D &amp;lt; 0.15 ng/ml/cm3 could be considered candidates for follow-up instead of systematic biopsy.