Enhancing the accuracy of register-based metrics: Comparing methods for handling overlapping psychiatric register entries in Finnish healthcare registers.

OBJECTIVES: Healthcare registers are invaluable resources for research. Partly overlapping register entries and preliminary diagnoses may introduce bias. We compare various methods to address this issue and provide fully reproducible open-source R scripts. METHODS: We used all Finnish healthcare registers 1969-2020, including inpatient, outpatient and primary care. Four distinct models were formulated based on previous reports to identify actual admissions, discharges, and discharge diagnoses. We calculated the annual number of treatment events and patients, and the median length of hospital stay (LOS). We compared these metrics to non-processed data. Additionally, we analyzed the lifetime number of individuals with registered mental disorders. RESULTS: Overall, 2,130,468 individuals had a registered medical contact related to mental disorders. After processing, the annual number of inpatient episodes decreased by 5.85%-10.87% and LOS increased by up to 3 days (27.27%) in years 2011-2020. The number of individuals with lifetime diagnoses reduced by more than 1 percent point (pp) in two categories: schizophrenia spectrum (3.69-3.81pp) and organic mental disorders (1.2-1.27pp). CONCLUSIONS: The methods employed in pre-processing register data significantly impact the number of inpatient episodes and LOS. Regarding lifetime incidence of mental disorders, schizophrenia spectrum disorders require a particular focus on data pre-processing.

Socioeconomic position at the age of 30 and the later risk of a mental disorder: a nationwide population-based register study.

BACKGROUND: A study was undertaken to examine the association between multiple indicators of socioeconomic position (SEP) at the age of 30 and the subsequent risk of the most common mental disorders. METHODS: All persons born in Finland between 1966 and 1986 who were alive and living in Finland at the end of the year when they turned 30 were included. Educational attainment, employment status and personal total income were used as the alternative measures of SEP. Cox proportional hazards models were used to examine the association of SEP at the age of 30 with later risk of mental disorders. Additional analyses were conducted using a sibling design to account for otherwise unobserved shared family characteristics. Competing risks models were used to estimate absolute risks. RESULTS: The study population included 1 268 768 persons, 26% of whom were later diagnosed with a mental disorder. Lower SEP at age 30 was consistently associated with a higher risk of being later diagnosed with a mental disorder, even after accounting for shared family characteristics and prior history of a mental disorder. Diagnosis-specific analyses showed that the associations were considerably stronger when substance misuse or schizophrenia spectrum disorders were used as an outcome. Absolute risk analyses showed that, by the age of 52 years, 58% of persons who had low educational attainment at the age of 30 were later diagnosed with a mental disorder. CONCLUSIONS: Poor SEP at the age of 30 is associated with an increased risk of being later diagnosed with a mental disorder.

Living alone as a risk factor for cancer incidence, case-fatality and all-cause mortality: A nationwide registry study.

Lack of social contacts has been associated with an increased risk of cancer mortality, but it is not known whether living alone increases the risk of cancer incidence or case fatality. We examined the association between living alone with cancer incidence, case-fatality and all-cause mortality in eight most common cancers. All patients with their first cancer diagnosis in 2000-2017 were identified from the nationwide Finnish Cancer Registry. Information on living arrangements was derived from Statistics Finland. The incidence analyses were conducted using Poisson regression. The total Finnish population served as the population at risk. Fine-Gray model was used to estimate case-fatality and Cox proportional regression model all-cause mortality. In men, we found an association between history of living alone and excess lung cancer incidence but living alone seemed to be associated with lower incidence of prostate cancer and skin melanoma. In women, living alone was more consistently associated with higher incidence of all studied cancers. Cancer patients living alone had an 11%-80% statistically significantly increased case-fatality and all-cause mortality in all studied cancers in men and in breast, colorectal and lung cancer in women. Living alone is consistently associated with increased cancer incidence risk in women but only in some cancers in men. Both men and women living alone had an increased risk of all-cause mortality after cancer diagnosis.

Cumulative social disadvantage and hospitalisations due to ambulatory care-sensitive conditions in Finland in 2011─2013: a register study.

OBJECTIVES: To study the interplay between several indicators of social disadvantage and hospitalisations due to ambulatory care-sensitive conditions (ACSC) in 2011─2013. To evaluate whether the accumulation of preceding social disadvantage in one point of time or prolongation of social disadvantage had an effect on hospitalisations due to ACSCs. Four common indicators of disadvantage are examined: living alone, low level of education, poverty and unemployment. DESIGN: A population-based register study. SETTING: Nationwide individual-level register data on hospitalisations due to ACSCs for the years 2011-2013 and preceding data on social and socioeconomic factors for the years 2006─2010. PARTICIPANTS: Finnish residents aged 45 or older on 1 January 2011. OUTCOME MEASURE: Hospitalisations due to ACSCs in 2011-2013. The effect of accumulation of preceding disadvantage in one point of time and its prolongation on ACSCs was studied using modified Poisson regression. RESULTS: People with preceding cumulative social disadvantage were more likely to be hospitalised due to ACSCs. The most hazardous combination was simultaneously living alone, low level of education and poverty among the middle-aged individuals (aged 45-64 years) and the elderly (over 64 years). Risk ratio (RR) of being hospitalised due to ACSC was 3.16 (95% CI 3.03-3.29) among middle-aged men and 3.54 (3.36-3.73) among middle-aged women compared with individuals without any of these risk factors when controlling for age and residential area. For the elderly, the RR was 1.61 (1.57-1.66) among men and 1.69 (1.64-1.74) among women. CONCLUSIONS: To improve social equity in healthcare, it is important to recognise not only patients with cumulative disadvantage but also-as this study shows-patients with particular combinations of disadvantage who may be more susceptible. The identification of these vulnerable patient groups is also necessary to reduce the use of more expensive treatment in specialised healthcare.

Excess mortality from breast cancer in female breast cancer patients with severe mental illness.

Women with a history of severe mental illness (SMI) have elevated breast cancer mortality. Few studies have compared cancer-specific mortality in women with breast cancer with or without SMI to reveal gaps in breast cancer treatment outcomes. We compared breast-cancer specific mortality in women with or without SMI and investigated effects of stage at presentation, comorbidity, and differences in cancer treatment. Women with their first breast cancer diagnosis in 1990-2013 (n = 80,671) were identified from the Finnish Cancer Registry, their preceding hospital admissions due to SMI (n = 4,837) from the Hospital Discharge Register and deaths from the Causes of Death Statistics. Competing risk models were used in statistical analysis. When controlling for age, year of cancer diagnosis, and comorbidity, breast cancer mortality was significantly elevated in patients with SMI. Relative mortality was highest in breast cancer patients with non-affective psychosis, partly explained by stage at presentation. Mortality was also significantly elevated in breast cancer patients with a substance use disorder and mood disorder. Patients with SMI received radiotherapy significantly less often than patients without SMI. Our findings emphasize the need to improve early detection of breast cancer in women with SMI and the collaboration between mental health care and oncological teams.

Employment Status and Personal Income Before and After Onset of a Severe Mental Disorder: A Case-Control Study.

OBJECTIVE: Individuals with severe mental disorders have an impaired ability to work and are likely to receive income transfer payments as their main source of income. However, the magnitude of this phenomenon remains unclear. Using longitudinal population cohort register data, the authors conducted a case-control study to examine the levels of employment and personal income before and after a first hospitalization for a serious mental disorder. METHODS: All individuals (N=50,551) who had been hospitalized for schizophrenia, other nonaffective psychosis, or bipolar disorder in Finland between 1988 and 2015 were identified and matched with five randomly selected participants who were the same sex and who had the same birth year and month. Employment status and earnings, income transfer payments, and total income in euros were measured annually from 1988 to 2015. RESULTS: Individuals with serious mental disorders had notably low levels of employment before, and especially after, the diagnosis of a severe mental disorder. Their total income was mostly constituted of transfer payments, and this was especially true for those diagnosed as having schizophrenia. More than half of all individuals with a serious mental disorder did not have any employment earnings after they received the diagnosis. CONCLUSIONS: The current study shows how most individuals in Finland depend solely on income transfer payments after an onset of a severe mental disorder.

Association of Income With the Incidence Rates of First Psychiatric Hospital Admissions in Finland, 1996-2014.

Importance: The association between income and mental health has long been a question of interest. Nationwide register data provide means to examine trends and patterns of these associations. Objectives: To compare income-specific trends in the incidence rates of first psychiatric hospital admissions and to evaluate whether an income gradient exists in the incidence rates at all levels of household income. Design, Setting, and Participants: This population-based open cohort study used linked registry data from nationwide Finnish Hospital Discharge and Statistics Finland population registers to determine annual incidence rates of first psychiatric hospital admissions. All Finnish citizens (N = 6 258 033) living in the country at any time from January 1, 1996, through December 31, 2014, contributed to 96 184 614 person-years at risk of first inpatient treatment for mental disorders. The analyses were conducted from August 1, 2018, through September 30, 2019. Exposures: Equivalized disposable income, sex, age group, reduction in income decile in the previous 3 years, urbanicity, educational level, and living alone status. Main Outcomes and Measures: Annual percentage changes in the age-standardized incidence rates and incidence rate ratios (IRRs). Results: Altogether, 186 082 first psychiatric inpatient treatment episodes occurred (93 431 [50.2%] men), with overall age-standardized incidence rates per 1000 person-years varying from 1.59 (95% CI, 1.56-1.63) in 2014 to 2.11 (95% CI, 2.07-2.15) in 2008. In the highest income deciles, a continuous mean decrease per year of 3.71% (95% CI, 2.82%-4.59%) in men and 0.91% (95% CI, 0.01%-1.80%) in women occurred throughout the study period, in contrast to the lowest deciles, where the trends first increased (1.31% [95% CI, 0.62%-2.01%] increase in men from 1996 to 2007 and 5.61% [95% CI, 2.36%-8.96%] increase in women from 1996 to 2001). In the adult population, an income gradient was observed at all levels of household income: the lower the income decile, the higher the adjusted IRRs compared with the highest decile. The IRRs in the lowest decile varied from 2.94 (95% CI, 2.78-3.11) to 4.46 (95% CI, 4.17-4.76). In other age groups, the gradient did not persist at the highest income deciles. Diagnosis-specific income gradient was steepest in schizophrenia and related psychotic disorders, with estimated IRRs of the lowest income decile of 5.89 (95% CI, 5.77-6.02). Conclusions and Relevance: In this cohort study, clear negative income gradient in the incidence rates of first hospital-treated mental disorders was observed in the adult population of Finland. These findings suggest that reduction in the use of inpatient care has not taken place equally between different income groups.

Trajectory modelling of ambulatory care sensitive conditions in Finland in 1996-2013: assessing the development of equity in primary health care through clustering of geographic areas - an observational retrospective study.

BACKGROUND: Due to stagnating resources and an increase in staff workload, the quality of Finnish primary health care (PHC) is claimed to have deteriorated slowly. With a decentralised PHC organisation and lack of national stewardship, it is likely that municipalities have adopted different coping strategies, predisposing them to geographic disparities. To assess whether these disparities emerge, we analysed health centre area trajectories in hospitalisations due to ambulatory care sensitive conditions (ACSCs). METHODS: ACSCs, a proxy for PHC quality, comprises conditions in which hospitalisation could be avoided by timely care. We obtained ACSCs of the total Finnish population aged ≥20 for the years 1996-2013 from the Finnish Hospital Discharge Register, and divided them into subgroups of acute, chronic and vaccine-preventable causes, and calculated annual age-standardised ACSC rates by gender in health centre areas. Using these rates, we conducted trajectory analyses for identifying health centre area clusters using group-based trajectory modelling. Further, we applied area-level factors to describe the distribution of health centre areas on these trajectories. RESULTS: Three trajectories - and thus separate clusters of health centre areas - emerged with different levels and trends of ACSC rates. During the study period, chronic ACSC rates decreased (40-63%) within each of the clusters, acute ACSC rates remained stable and vaccine-preventable ACSC rates increased (1-41%). While disparities in rate differences in chronic ACSC rates between trajectories narrowed, in the two other ACSC subgroups they increased. Disparities in standardised rate ratios increased in vaccine-preventable and acute ACSC rates between northern cluster and the two other clusters. Compared to the south-western cluster, 13-16% of health centre areas, in rural northern cluster, had 47-92% higher ACSC rates - but also the highest level of morbidity, most limitations on activities of daily living and highest PHC inpatient ward usage as well as the lowest education levels and private health and dental care usage. CONCLUSIONS: We identified three differing trajectories of time trends for ACSC rates, suggesting that the quality of care, particularly in northern Finland health centre areas, may have lagged behind the general improvements. This calls for further investments to strengthen rural area PHC.

The impact of severe mental illness on lung cancer mortality of patients with lung cancer in Finland in 1990-2013: a register-based cohort study.

BACKGROUND: Although the link between severe mental illness (SMI) and elevated cancer mortality is well established, few studies have examined lung cancer survival and SMI in detail. Our study compared cancer-specific mortality in patients with lung cancer with and without a history of SMI and analysed whether mortality differences could be explained by cancer stage at presentation, comorbidity or differences in cancer treatment. METHODS: We identified patients with their first lung cancer diagnosis in 1990-2013 from the Finnish Cancer Registry, their preceding hospital admissions due to SMI from the Hospital Discharge Register and deaths from the Causes of Death statistics. Competing risk analyses were used to estimate hazard ratios (HRs) for the impact of SMI on mortality. RESULTS: Of the 37,852 lung cancer cases, 12% had a history of SMI. Cancer-specific mortality differences were found between patient groups in some cancer types after controlling for stage at representation and treatment. Men with a history of psychosis had excess mortality risk (HR = 1.24, 1.06-1.45) in squamous cell carcinoma. Similar excess risk was found among women with psychosis in small-cell carcinoma (HR = 1.76, 1.41-2.19) and in squamous cell carcinoma (HR = 1.67, 1.26-2.20) and among women with mood disorders in adenocarcinoma (HR = 1.37, 1.08-1.74). Patient group differences in HRs in five-year mortality did not markedly change from the 1990s. CONCLUSIONS: We found elevated cancer-specific mortality among persons with a history of SMI. Collaboration between patients, mental healthcare professionals and oncological teams is needed to reduce the mortality gap between patients with cancer with and without SMI.

Health information exchange in Finland: Usage of different access types and predictors of paper use.

INTRODUCTION: Timely, complete and accurate patient data is needed in care decisions along the continuum of care. To access patient data from other organizations, there are three types of regional health information exchange systems (RHIS) in use In Finland. Some regions use multiple RHISs while others do not have a RHIS available. The recently introduced National Patient Data Repository (Kanta) is increasingly used for health information exchange (HIE). OBJECTIVES: The purpose of this study was to assess usage of paper, RHISs and Kanta by context in 2017; evolution of paper use over the years; and predictors of paper use in 2017 among Finnish physicians for HIE system development. METHODS: Data from national electronic health record (EHR) usage and user experience surveys were taken from 2010 (prior to ePrescription system implementation), 2014 (prior to implementation of Kanta) and 2017 (Kanta was in full use in the public sector and in large private organizations). The web-based surveys were targeted to all physicians engaged in clinical work in Finland. RESULTS: Kanta was the most frequently used means of HIE in 2017. Paper use had reduced significantly from 2010 to 2014. The trend continued in 2017. Still, up to half of the physicians reported using paper daily or weekly in 2017. There were great variations in paper use by healthcare sector, available RHIS type and EHR system used. In multivariable analysis (with all other variables constant), predictors of more frequent use of paper than electronic means for HIE were: private sector or hospital, access to Master Patient Index RHIS (type 1), multiple RHIS (type 4) or no RHIS (type 5), two particular EHR systems, older age, less experience, operative, psychiatric or diagnostic specialties, and male gender. CONCLUSIONS: Usability of HIE systems including EHRs as access points to HIE need to be improved to facilitate usage of electronic HIE. Usage ensures more timely and complete patient data for safe, coordinated care. Specialty-specific needs and requirements call for more user participation in HIE design. Especially older professionals need training to better exploit HIS for HIE.

Trends of socioeconomic equality in mortality amenable to healthcare and health policy in 1992-2013 in Finland: a population-based register study.

OBJECTIVE: To study trends in socioeconomic equality in mortality amenable to healthcare and health policy interventions. DESIGN: A population-based register study. SETTING: Nationwide data on mortality from the Causes of Death statistics for the years 1992-2013. PARTICIPANTS: All deaths of Finnish inhabitants aged 25-74. OUTCOME MEASURES: Yearly age-standardised rates of mortality amenable to healthcare interventions, alcohol-related mortality, ischaemic heart disease mortality and mortality due to all the other causes by income. Concentration index (C) was used to evaluate the magnitude and changes in income group differences. RESULTS: Significant socioeconomic inequalities favouring the better-off were observed in each mortality category among younger (25-64) and older (65-74) age groups. Inequality was highest in alcohol-related mortality, C was -0.58 (95% CI -0.62 to -0.54) among younger men in 2008 and -0.62 (-0.72 to -0.53) among younger women in 2013. Socioeconomic inequality increased significantly during the study period except for alcohol-related mortality among older women. CONCLUSIONS: The increase in socioeconomic inequality in mortality amenable to healthcare and health policy interventions between 1992 and 2013 suggests that either the means or the implementation of the health policies have been inadequate.

The effect of history of severe mental illness on mortality in colorectal cancer cases: a register-based cohort study.

BACKGROUND: While the link between mental illness and cancer survival is well established, few studies have focused on colorectal cancer. We examined outcomes of colorectal cancer among persons with a history of severe mental illness (SMI). MATERIAL AND METHODS: We identified patients with their first colorectal cancer diagnosis in 1990-2013 (n = 41,708) from the Finnish Cancer Registry, hospital admissions due to SMI preceding cancer diagnosis (n = 2382) from the Hospital Discharge Register and deaths from the Causes of Death statistics. Cox regression models were used to study the impact on SMI to mortality differences. RESULTS: We found excess colorectal cancer mortality among persons with a history of psychosis and with substance use disorder. When controlling for age, comorbidity, stage at presentation and treatment, excess mortality risk among men with a history of psychosis was 1.72 (1.46-2.04) and women 1.37 (1.20-1.57). Among men with substance use disorder, the excess risk was 1.22 (1.09-1.37). CONCLUSION: Understanding factors contributing to excess mortality among persons with a history of psychosis or substance use requires more detailed clinical studies and studies of care processes among these vulnerable patient groups. Collaboration between patients, mental health care and oncological teams is needed to improve outcomes of care.

Effect of stage, comorbidities and treatment on survival among cancer patients with or without mental illness.

BackgroundEarlier research suggests poorer outcome of cancer care among people with severe mental illness (SMI).AimsTo assess the effect of stage at presentation, comorbidities and treatment on differences in survival among cancer patients with and without a history of SMI in Finland.MethodThe total population with a first cancer diagnosis in 1990-2013 was drawn from the Finnish Cancer Registry. Hospital admissions because of SMI and deaths were obtained from administrative registers. We calculated Kaplan-Meier estimates and Cox regression models to examine survival differences.ResultsWe found excess mortality in people with a history of psychotic and substance use disorders. Cancer stage and comorbidity did not explain mortality differences. Controlling for cancer treatment decreased the differences. The mortality gap between patients with psychosis and cancer patients without SMI increased over time.ConclusionsIntegrated medical and psychiatric care is needed to improve outcomes of cancer care among patients with SMI.

Trends of relative and absolute socioeconomic equity in access to coronary revascularisations in 1995-2010 in Finland: a register study.

BACKGROUND: Resources for coronary revascularisations have increased substantially since the early 1990s in Finland. At the same time, ischaemic heart disease (IHD) mortality has decreased markedly. This study aims to examine how these changes have influenced trends in absolute and relative differences between socioeconomic groups in revascularisations and age group differences in them using IHD mortality as a proxy for need. METHODS: Hospital Discharge Register data on revascularisations among Finns aged 45-84 in 1995-2010 were individually linked to population registers to obtain socio-demographic data. We measured absolute and relative income group differences in revascularisation and IHD mortality with slope index of inequality (SII) and concentration index (C), and relative equity taking need for care into account with horizontal inequity index (HII). RESULTS: The supply of procedures doubled during the years. Socioeconomic distribution of revascularisations was in absolute and relative terms equal in 1995 (Men: SII = -12, C = -0.00; Women, SII = -30, C = -0.03), but differences favouring low-income groups emerged by 2010 (M: SII = -340, C = -0.08; W: SII = -195, C = -0.14). IHD mortality decreased markedly, but absolute and relative differences favouring the better-off existed throughout study years. Absolute differences decreased somewhat (M: SII = -760 in 1995, SII = -681 in 2010; W: SII = -318 in 1995, SII = -211 in 2010), but relative differences increased significantly (M: C = -0.14 in 1995, C = -0.26 in 2010; W: C = -0.15 in 1995, C = -0.25 in 2010). HII was greater than zero in each year indicating inequity favouring the better-off. HII increased from 0.15 to 0.18 among men and from 0.10 to 0.12 among women. We found significant and increasing age group differences in HII. CONCLUSIONS: Despite large increase in supply of revascularisations and decrease in IHD mortality, there is still marked socioeconomic inequity in revascularisations in Finland. However, since changes in absolute distributions of both supply and need for coronary care have favoured low-income groups, absolute inequity can be claimed to have decreased although it cannot be quantified numerically.

Regional trends in avoidable hospitalisations due to complications among population with diabetes in Finland in 1996-2011: a register-based cohort study.

OBJECTIVES: Diabetes requires continuous medical care including prevention of acute complications and risk reduction for long-term complications. Diabetic complications impose a substantial burden on public health and care delivery. We examined trends in regional differences in hospitalisations due to diabetes-related complications among the total diabetes population in Finland. RESEARCH DESIGN: A longitudinal register-based cohort study 1996-2011 among a total population with diabetes in Finland. PARTICIPANTS: All persons with diabetes identified from several administrative registers in Finland in 1964-2011 and alive on 1 January 1996. OUTCOME MEASURES: We examined hospitalisations due to diabetes-related short-term and long-term complications, uncomplicated diabetes, myocardial infarction, stroke, lower extremity amputation and end-stage renal disease (ESRD). We calculated annual age-adjusted rates per 10 000 person years and the systematic component of variation. Multilevel models were used for studying time trends in regional variation. RESULTS: There was a steep decline in complication-related hospitalisation rates during the study period. The decline was relatively small in ESRD (30%), whereas rates of hospitalisations for short-term and long-term complications as well as uncomplicated diabetes diminished by about 80%. The overall correlation between hospital district intercepts and slopes in time was -0.72 (p<0.001) among men and -0.99 (p<0.001) among women indicating diminishing variation. Diminishing variation was found in each of the complications studied. The variation was mainly distributed at the health centre level. CONCLUSIONS: Our study suggests that the prevention of complications among persons with diabetes has improved in Finland between 1996 and 2011. The results further suggest that the prevention of complications has become more uniform throughout the country.

Excess Mortality in Patients with Severe Mental Disorders in 1996-2010 in Finland.

Unselected population-based nationwide studies on the excess mortality of individuals with severe mental disorders are scarce with regard to several important causes of death. Using comprehensive register data, we set out to examine excess mortality and its trends among patients with severe mental disorders compared to the total population. Patients aged 25-74 and hospitalised with severe mental disorders in 1990-2010 in Finland were identified using the national hospital discharge register and linked individually to population register data on mortality and demographics. We studied mortality in the period 1996-2010 among patients with psychotic disorders, psychoactive substance use disorders, and mood disorders by several causes of death. In addition to all-cause mortality, we examined mortality amenable to health care interventions, ischaemic heart disease mortality, disease mortality, and alcohol-related mortality. Patients with severe mental disorders had a clearly higher mortality rate than the total population throughout the study period regardless of cause of death, with the exception of alcohol-related mortality among male patients with psychotic disorders without comorbidity with substance use disorders. The all-cause mortality rate ratio of patients with psychotic disorders compared to the total population was 3.48 (95% confidence interval 2.98-4.06) among men and 3.75 (95% CI 3.08-4.55) among women in the period 2008-10. The corresponding rate ratio of patients with psychoactive substance use disorders was 5.33 (95% CI 4.87-5.82) among men and 7.54 (95% CI 6.30-9.03) among women. Overall, the mortality of the total population and patients with severe mental disorders decreased between 1996 and 2010. However, the mortality rate ratio of patients with psychotic disorders and patients with psychoactive substance use disorders compared to the total population increased in general during the study period. Exceptions were alcohol-related mortality among patients with psychoactive substance use disorders and female patients with psychotic disorders, as well as amenable mortality among male patients with psychotic disorders. The mortality rate ratio of persons with mood disorders compared to the total population decreased. The markedly high mortality amenable to health care intervention among patients with severe mental disorders found in our study suggests indirectly that they may receive poorer quality somatic care. The results highlight the challenges in co-ordinating mental and somatic health services.

Longitudinal biobanks-based study on the joint effects of infections, nutrition and hormones on risk of prostate cancer.

Background To evaluate the individual and combined effects of enterolactone, vitamin D, free testosterone, Chlamydia trachomatis and HPV-18 on the risk of prostate cancer in a large population-based biochemical material that combined three Nordic serum sample banks. Material and methods A joint cohort of 209 000 healthy men was followed using cancer registry linkages. From this cohort altogether 699 incident cases of prostate cancer were identified. Four controls were selected by incidence density sampling and matching for country, age and date of the blood sampling. Complete data for all investigated exposures was available for 483 eligible cases and 1055 eligible controls. Multivariate regression analyses were performed to investigate the solitary and combined effects. Results The solitary effects were small. Significantly increased risk [rate ratio 1.6 (95% CI 1.0-2.5)] was found in those seronegative for C. trachomatis infection. The joint effect in risk levels of enterolactone and vitamin D was antagonistic [observed rate ratio (RR) 1.4 (1.0-2.1), expected RR 2.0 (1.0-4.1)] as well as that of HPV-18 and C. trachomatis [observed RR 1.9 (0.8-4.5), expected RR 9.9 (1.1-87.0)]. Conclusion A large follow-up study combining data from several previously investigated exposures to investigate joint effects found no evidence that exposure to two risk factors would increase the risk of prostate cancer from that expected on basis of exposure to one risk factor. If anything, the results were consistent with antagonistic interactions.

Are there socioeconomic differences in outcomes of coronary revascularizations--a register-based cohort study.

BACKGROUND: Earlier studies have reported socioeconomic differences in coronary heart disease incidence and mortality and in coronary treatment, but less is known about outcomes of care. We examined trends in income group differences in outcomes of coronary revascularizations among Finnish residents in 1998-2010. METHODS: First revascularizations for 45-84-year-old Finns were extracted from the Hospital Discharge Register in 1998-2009 and followed until 31 December 2010. Income was individually linked to them and adjusted for family size. We examined the risk of major adverse cardiac events (MACEs), coronary mortality and re-revascularization. We calculated age-standardized rates with direct method and Cox regression models. RESULTS: Altogether 69 076 men and 27 498 women underwent revascularization during the study period. Among men [women] in the 1998 cohort, 41% [35%] suffered MACE during 29 days after the operation and 30% [28%] in the 2009 cohort. Myocardial infarction mortality within 1 year was 2% among both genders in both cohorts. Among men [women] 9% [14%] underwent revascularization within 1 year after the operation in 1998 and 12% [12%] in 2009. Controlling for age, co-morbidities, year, previous infarction and disease severity, an inverse income gradient was found in MACE incidence within 29 days and in coronary mortality. The excess MACE risk was 1.39 and excess mortality risk over 1.70 among both genders in the lowest income quintile. All income group differences remained stable from 1998 to 2010. CONCLUSIONS: In health care, more attention should be paid to prevention of adverse outcomes among persons with low socioeconomic position undergoing revascularization.

A Monte Carlo method to estimate the confidence intervals for the concentration index using aggregated population register data.

In this paper, we introduce several statistical methods to evaluate the uncertainty in the concentration index (C) for measuring socioeconomic equality in health and health care using aggregated total population register data. The C is a widely used index when measuring socioeconomic inequality, but previous studies have mainly focused on developing statistical inference for sampled data from population surveys. While data from large population-based or national registers provide complete coverage, registration comprises several sources of error. We simulate confidence intervals for the C with different Monte Carlo approaches, which take into account the nature of the population data. As an empirical example, we have an extensive dataset from the Finnish cause-of-death register on mortality amenable to health care interventions between 1996 and 2008. Amenable mortality has been often used as a tool to capture the effectiveness of health care. Thus, inequality in amenable mortality provides evidence on weaknesses in health care performance between socioeconomic groups. Our study shows using several approaches with different parametric assumptions that previously introduced methods to estimate the uncertainty of the C for sampled data are too conservative for aggregated population register data. Consequently, we recommend that inequality indices based on the register data should be presented together with an approximation of the uncertainty and suggest using a simulation approach we propose. The approach can also be adapted to other measures of equality in health.

The contribution of health policy and care to income differences in life expectancy--a register based cohort study.

BACKGROUND: Growing mortality differences between socioeconomic groups have been reported in both Finland and elsewhere. While health behaviours and other lifestyle factors are important in contributing to health differences, some researchers have suggested that some of the mortality differences attributable to lifestyle factors could be preventable by health policy measures and that health care may play a role. It has also been suggested that its role is increasing due to better results in disease prevention, improved diagnostic tools and treatment methods. This study aimed to assess the impact of mortality amenable to health policy and health care on increasing income disparities in life expectancy in 1996-2007 in Finland. METHODS: The study data were based on an 11% random sample of Finnish residents in 1988-2007 obtained from individually linked cause of death and population registries and an oversample of deaths. We examined differences in life expectancy at age 35 (e35) in Finland. We calculated e35 for periods 1996-97 and 2006-07 by income decile and gender. Differences in life expectancies and change in them between the richest and the poorest deciles were decomposed by cause of death group. RESULTS: Overall, the difference in e35 between the extreme income deciles was 11.6 years among men and 4.2 years among women in 2006-07. Together, mortality amenable to health policy and care and ischaemic heart disease mortality contributed up to two thirds to socioeconomic differences. Socioeconomic differences increased from 1996-97 by 3.4 years among men and 1.7 years among women. The main contributor to changes was mortality amenable through health policy measures, mainly alcohol related mortality, but also conditions amenable through health care, ischaemic heart disease among men and other diseases contributed to the increase of the differences. CONCLUSIONS: The results underline the importance of active health policy and health care measures in tackling socioeconomic health inequalities.