Local economic inequality and mortality: Too little within-unit variation for fixed effects analysis?

This debate article discusses the use of fixed effects models for causal analysis, with reference to an article recently published in Scandinavian Journal of Public Health.

Nordic research on health inequalities: A scoping review of empirical studies published in Scandinavian Journal of Public Health 2000-2021.

AIMS: An important task for the Scandinavian Journal of Public Health is to address health inequality topics. This scoping review characterises Nordic empirical studies within this research field, published 2000-2021 by the Scandinavian Journal of Public Health. METHODS: Original empirical research studies using data from Denmark, Finland, Iceland, Norway and/or Sweden, which linked differences in health or health-related aspects to socioeconomic positions, immigrant status, family structures and/or residential areas, were included in the review. The initial search in the Web of Science article database resulted in 294 possibly relevant articles, and 171 were judged to comply with our criteria. RESULTS: Only one study was based on qualitative data, while all others used either surveys or register data, or both in combination. A wide variety of outcomes was addressed. Most studies had a social causation design, but 16 studies analysed health-related mobility processes and four reported intervention results. The most common statistical method was logistic regression. Poisson, Cox and ordinary least squares regression were less used. Few studies engaged explicitly with health inequality theories or with rigorous causality designs. CONCLUSIONS: The empirical health inequality studies published by the Scandinavian Journal of Public Health are rich sources for knowledge on a large array of health and health-related inequalities in Nordic countries. Drawbacks are underuse of qualitative data, few theoretical discussions and lack of studies assessing effects of interventions and policies.

Lack of recognition at the societal level heightens turnover considerations among Nordic eldercare workers: a quantitative analysis of survey data.

BACKGROUND: Recruiting and retaining staff are standing challenges in eldercare. Low pay, difficult working conditions, and social relations at the workplace impact on turnover intentions. Few studies have used quantitative data for estimating the role of recognition by the wider society for staff instability. This study examines how perceived lack of recognition at the societal level affects Nordic eldercare workers' considerations of leaving their jobs. METHODS: The 2015 Nordcare survey among frontline eldercare workers in Denmark, Finland, Norway, and Sweden (N = 3,677) is analysed. Issues such as working conditions, financial strain, work-life balance, and appreciation by care recipients and colleagues, were covered. Recognition at the societal level was measured by perceptions of being valued by top municipal leaders, mass media, and the general public. Analyses are made with cross-tabulations and multivariate linear probability regression models. RESULTS: In the total sample, 41.1 % had "seriously considered to quit during the last 12 months". About one third felt "not at all valued" by top municipal leaders, while one fourth felt "not at all valued" by mass media. In bivariate analyses, perceptions of recognition were strongly associated with considerations to quit. These associations were reduced, but remained sizeable and highly significant in multivariate analyses adjusted for age, gender, health, working conditions, financial stress, workplace relations, and other known turnover predictors. CONCLUSIONS: Lack of recognition by societal agents such as top municipal leaders, mass media, and the general public, is widely felt by Nordic eldercare workers. Feeling poorly valued by such sources is associated with frequent considerations to leave one's employment. Perceived lack of recognition by the wider society has a significant and independent impact on staff instability in the eldercare sector. Societies' recognition order is embedded in social structures which are resistant to change, but policies which succeed in raising the societal recognition of eldercare work may contribute to reduced retention difficulties in eldercare.

29 recommendations to combat social inequalities in health. The Norwegian Council on Social Inequalities in Health.

All political parties in Norway agree that social inequalities in health comprise a public health problem and should be reduced. Against this background, the Council on Social Inequalities in Health has taken action to provide specific advice to reduce social health differences. Our recommendations focus on the entire social gradient rather than just poverty and the socially disadvantaged. By proposing action on the social determinants of health such as affordable child-care, education, living environments and income structures, we aim to facilitate a possible re-orientation of policy away from redistribution to universalism. The striking challenges of the causes of health differences are complex, and the 29 recommendations to combat social inequality of health demand cross sectorial actions. The recommendations are listed thematically and have not been prioritized. Some are fundamental and require pronounced changes across sectors, whereas others are minor and sector-specific.

Educational inequalities in hospital care for mortally ill patients in Norway.

AIMS: Health care should be allocated fairly, irrespective of patients' social standing. Previous research suggests that highly educated patients are prioritized in Norwegian hospitals. This study examines this contentious issue by a design which addresses two methodological challenges. Control for differences in medical needs is approximated by analysing patients who died from same causes of death. Area fixed effects are used for avoiding that observed educational inequalities are contaminated by geographical differences. METHODS: Men and women who died 2009-2011 at age 55-94 were examined ( N=103,000) with register data from Statistics Norway and the Norwegian Patient Registry. Educational differences in quantity of hospital-based medical care during the 12-24 months before death were analysed, separate for main causes of death. Multivariate negative binomial regression models were estimated, with fixed effects for residential areas. RESULTS: High-educated patients who died from cancers had significantly more outpatient consultations at somatic hospitals than low-educated patients during an average observation period of 18 months prior to death. Similar, but weaker, educational inequalities appeared for outpatient visits for patients whose deaths were due to other causes. Also, educational inequalities in number of hospital admissions were marked for those who died from cancers, but insignificant for patients who died from other causes. CONCLUSIONS: Even when medical needs are similar for mortally ill patients, those with high education tend to receive more medical services in Norwegian somatic hospitals than patients with low education. The roles played by physicians and patients in generating these patterns should be explored further.

Utilization of somatic specialist services among psychiatric immigrant patients: the Norwegian patient registry study.

BACKGROUND: Amongst psychiatric patients, the leading causes of reduced quality of life and premature death are chronic viral infections and cardiovascular diseases. In spite of this, there are extremely high levels of disparity in somatic healthcare amongst such populations. Little research has explored patterns of healthcare utilisation and, therefore, this study aims to examine the use of somatic specialist healthcare for infectious diseases and diseases of circulatory system among psychiatric patients from different immigrant groups and ethnic Norwegians. METHODS: Register data from the Norwegian Patient Registry and Statistics Norway were used. The sample (ages 0-90+) consisted of 276,890 native-born Norwegians and 52,473 immigrants from five world regions - Western countries, East Europe, Africa, Asia, and Latin America, all of whom had contacts with specialist mental healthcare during the period 2008-2011. Statistical analyses were applied using logistic regression models. RESULTS: Rates of outpatient consultation for circulatory system diseases were significantly lower amongst patients from Africa, Asia and Latin America compared with ethnic Norwegian psychiatric patients. Only patients from Eastern Europeans had a higher rate. With regard to hospital admission, all psychiatric patients had a lower rate than ethnic Norwegians with the exception of those from Africa where the finding was non-significant. In terms of infectious diseases, patients from African countries had significantly higher outpatient and admission rates than ethnic Norwegians. Outpatient consultation rates were lower amongst those from Western and Latin America and hospital admission rates were lower amongst those from Eastern Europe and Asia. CONCLUSIONS: The findings suggest that the majority of immigrant psychiatric patients have lower hospitalization rates for circulatory system diseases than Norwegian psychiatric patients. This may suggest that poor access for immigrants is a contributing factor, though the findings were less pronounced for infectious diseases.

Hospitalisations during the final three years of life. / Sykehusinnleggelser de tre siste leveårene.

BAKGRUNN: Kunnskap om sykehusbruk i livets sluttfase er nyttig for å forstå behovet for sykehustjenester. MATERIALE OG METODE: Registeropplysninger fra Statistisk sentralbyrå og Norsk pasientregister er brukt for å analysere tallet på innleggelser ved somatiske sykehus de siste tre leveårene blant individer som døde i alderen 56-95 år. RESULTATER: Analyseutvalget besto av 35 954 individer som hadde 136 484 innleggelser i observasjonsperioden. De som døde da de var 56-65 år hadde 5,2 innleggelser i gjennomsnitt de siste tre leveårene, mot 2,8 for dødsalder 86-95 år. 14,1 % hadde ingen innleggelser, mens 13,3 % hadde åtte eller flere. De som døde på grunn av ondartede svulster hadde 5,6 innleggelser i gjennomsnitt, mot 4,2 hvis dødsfallet skyldtes åndedrettslidelser, og 3,1 om årsaken var sirkulasjonssykdom. FORTOLKNING: Krevende behandlinger er antatt å ha mindre sjanse for å lykkes blant eldre pasienter. Dette kan være en grunn til færre sykehusinnleggelser i livets sluttfase blant 80- og 90-åringer enn blant de som døde i 60- og 70-årsalderen. Gjennomsnittsalder ved død vil øke etter hvert som levealderen stiger, og derfor vil aldersvariasjonen i sykehusinnleggelser de siste leveårene ha betydning for behovet for sykehusinnleggelser.

Immigrants' utilization of specialist mental healthcare according to age, country of origin, and migration history: a nation-wide register study in Norway.

PURPOSE: As the immigrant population rises in Norway, it becomes ever more important to consider the responsiveness of health services to the specific needs of these immigrants. It has been questioned whether access to mental healthcare is adequate among all groups of immigrants. This study aims to examine the use of specialist mental healthcare services among ethnic Norwegians and specific immigrants groups. METHODS: Register data were used from the Norwegian Patient Registry and Statistics Norway. The sample (age 0-59) consisted of 3.3 million ethnic Norwegians and 200,000 immigrants from 11 countries. Poisson regression models were applied to examine variations in the use of specialist mental healthcare during 2008-2011 according to country of origin, age group, reason for immigration, and length of stay. RESULTS: Immigrant children and adolescents had overall significantly lower use of specialist mental healthcare than ethnic Norwegians of the same age. A distinct exception was the high utilization rate among children and youth from Iran. Among adult immigrants, utilization rates were generally lower than among ethnic Norwegians, particularly those from Poland, Somalia, Sri Lanka, and Vietnam. Adult immigrants from Iraq and Iran, however, had high utilization rates. Refugees had high utilization rates of specialist mental healthcare, while labour immigrants had low use. CONCLUSION: Utilization rates of specialist mental healthcare are lower among immigrants than Norwegians. Immigrants from Poland, Somalia, Sri Lanka, and Vietnam, had generally quite low rates, while immigrants from Iran had high utilization rates. The findings suggest that specialist mental healthcare in Norway is underutilized among considerable parts of the immigrant population.

Income inequality and foregone medical care in Europe during The Great Recession: multilevel analyses of EU-SILC surveys 2008-2013.

BACKGROUND: The association between income inequality and societal performance has been intensely debated in recent decades. This paper reports how unmet need for medical care has changed in Europe during The Great Recession, and investigates whether countries with smaller income differences have been more successful than inegalitarian countries in protecting access to medical care during an economic crisis. METHODS: Six waves of EU-SILC surveys (2008-2013) from 30 European countries were analyzed. Foregone medical care, defined as self-reported unmet need for medical care due to costs, waiting lists, or travel difficulties, was examined among respondents aged 30-59 years (N = 1.24 million). Countries' macro-economic situation was measured by Real Gross Domestic Product (GDP) per capita. The S80/S20 ratio indicated the country's level of income inequality. Equity issues were highlighted by separate analyses of disadvantaged respondents with limited economic resources and relatively poor health. Cross-tabulations and multilevel linear probability regression models were utilized. RESULTS: Foregone medical care increased 2008-2013 in the majority of the 30 countries, especially among the disadvantaged parts of the population. For the disadvantaged, unmet need for medical care tended to be higher in countries with larger income inequalities, regardless of the average economic standard in terms of GDP per capita. Both for disadvantaged and for other parts of the samples, a decline in GDP had more severe effects on access in inegalitarian countries than in countries with less income inequality. CONCLUSIONS: During The Great Recession, unmet need for medical care increased in Europe, and social inequalities in foregone medical care widened. Overall, countries with a more egalitarian income distribution have been more able to protect their populations, and especially disadvantaged groups, against deteriorated access to medical care when the country is confronted with an economic crisis.

Register study of migrants' hospitalization in Norway: world region origin, reason for migration, and length of stay.

BACKGROUND: The proportion of migrants and refugees increase in many populations. Health planners have to consider how migration will influence demand for health care. This study explores how migrants' geographical origin, reason for migration, and duration of residence are associated with admission rates to somatic hospitals in Norway. METHODS: Sociodemographic information on all individuals residing in Norway at the start of 2008 was linked to data on all admissions to somatic hospitals during 2008-2011. Migrants, age 30-69, who had come to Norway during 1970-2007 (N = 217,907), were classified into seven world region origins and compared with native Norwegians of the same age (N = 2,181,948). Any somatic hospital stay 2008-2011 and number of hospital admissions 2008-2011 per 1000 personyears for a set of somatic diagnoses were analyzed by age and gender standardized rates, linear probability models, and Poisson regression. RESULTS: In the native Norwegian sample, 28.7 % had at least one admission 2008-2011, and there were 116 admissions per 1000 personyears. Corresponding age and gender adjusted figures for the migrant sample were 27.0 % and 103 admissions. Admission rates varied with migrants' geographical origin, with relatively many admissions among migrants from West and South Asia and relatively few admissions among migrants from Western, East European, and Other Asian countries. Hospitalization varied strongly with reason for migration, with low admission rates for recent work migrants and high admission rates for recent refugees. Admission rates tended to move towards the level among native Norwegians with increasing length of stay. Among longstanding migrants (arrival period 1970-1989), admission rates were close to the levels of native Norwegians for most analyzed migrant categories. CONCLUSION: Both world region origin, reason for migration, and duration of residence are important sources for variations in migrants' utilization of somatic hospitals. Forecasts about migrants' use of hospital services have to take into account how the migrant population is composed as to these three determinants. High admission rates among recently arrived refugees should be a health policy concern.

Prospective register-based study of the impact of immigration on educational inequalities in mortality in Norway.

BACKGROUND: Differences in mortality with regard to socioeconomic status have widened in recent decades in many European countries, including Norway. A rapid upsurge of immigration to Norway has occurred since the 1990s. The article investigates the impact of immigration on educational mortality differences among adults in Norway. METHODS: Two linked register-based data sets are analyzed; the first consists of all registered inhabitants aged 20-69 in Norway January 1, 1993 (2.6 millions), and the second of all registered inhabitants aged 20-69 as of January 1, 2008 (2.8 millions). Deaths 1993-1996 and 2008-2011, respectively, immigrant status, and other background information are available in the data. Mortality is examined by Cox regression analyses and by estimations of age-adjusted deaths per 100,000 personyears. RESULTS: Both relative and absolute educational inequality in mortality increased from the 1993-1996 period to 2008-2011, but overall mortality levels went down during these years. Immigrants in general, and almost all the analyzed immigrant subcategories, had lower mortality than the native majority. This was due to comparatively low mortality among lower educated immigrants, while mortality among higher educated immigrants was similar to the mortality level of highly educated natives. CONCLUSIONS: The widening of educational inequality in mortality during the 1990s and 2000s in Norway was not due to immigration. Immigration rather contributed to slightly lower overall mortality in the population and a less steep educational gradient in mortality.

Health-related exit from employment before and during the COVID-19 pandemic in Norway: Analysis of population-wide register data 2013-2021.

People with health problems experience various labor market disadvantages, such as hiring discrimination and heightened risk of firing, but the impact of deteriorating economic conditions on health-related labor market mobility remains poorly understood. The strength of the downturn/crisis will most likely make a difference. During minor downturns, when few employees are made redundant, health-related exit may occur frequently since employers prefer to keep those with good health on the payroll. However, during major economic crises, when large-scale downsizing and firm closures abound, there will be less discretionary room for employers. Thus, some mechanisms that usually are damaging for people with health problems (e.g., seniority rules and negative connotations), can be neutralized, ultimately leading to smaller health differentials in labor market outcomes. The current study used population-wide administrative register data, covering the years 2013-2021, to examine health-related exit from employment (to unemployment/social assistance) before and during the COVID-19 pandemic in Norway. The pandemic spurred a major crisis on the Norwegian labor market and led to a record-high unemployment rate of 10.6 percent in March 2020. Restricting the analytical samples to labor market insiders, linear probability models showed that previous recipients of health-related benefits had a higher unemployment likelihood in the pre-crisis year 2019. The relative importance of poor health changed non-negligibly, however, during the COVID-19 pandemic. When identical statistical analyses were run on the crisis year 2020, health-related exit from employment was dampened. Yet, this labor market equalization was not followed by smaller health differentials in work income in 2021, mainly because people with good health retained or regained decent-paying jobs when the economic conditions improved again. In conclusion, major economic crises can lead to an equalization of labor market disadvantages for people with health problems, but health-related inequalities may reemerge when the economy recovers.

Selection and mortality: a ten-year follow-up of income decile mortality in Norway.

BACKGROUND: There is universal agreement that higher mortality goes with lower income. Opinions differ on causality: the association may reflect the damaging effect of poverty on health and survival chances. Conversely, it may reflect selection/reverse causation: low income indicates health problems, and from health problems follow a higher risk of dying. METHODS: We studied all deaths in Norway (111,504) during the 10-year period 1994-2003 among persons aged 25-66 years in 1993 (2,261,076). For each year, age-standardized mortality rates were calculated for each 1993 income decile for men and women separately. Income was calculated as family size-adjusted income after taxes but including cash welfare transfers. If the selection theory was correct, one would expect to see the excess mortality in the lower income fractiles decline as the bad risks, over-represented among the poorer, died away. RESULTS: Large income decile variations in mortality remained at the end of the 10-year period: after 10 years, the age-standardized mortality rate for men and women was still much higher in the lower income deciles. CONCLUSION: As the excess mortality in the poorer income deciles was not much reduced during the 10-year period, excess mortality among persons in bad health in the lower income deciles does not explain the income inequality in mortality in our data set.

Trends in educational inequalities in mortality, seven types of cancers, Norway 1971-2002.

BACKGROUND: Knowledge about educational disparities in deaths from specific cancer sites is incomplete. Even more scant is information about time trends in educational patterns in specific cancer mortality. This study examines educational inequalities in Norway 1971-2002 for mortality in lung and larynx, colorectal, stomach, melanoma, prostate, breast and cervix uteri cancer. METHODS: A data file encompassing all Norwegian inhabitants registered some time during 1971-2002 while aged 45-74 was constructed with linked information from administrative registers. During an exposure of more than 40 millions person-years, about 87,000 deaths in the analysed cancer types were registered. Absolute and relative inequalities during three periods were analysed by age-standardized deaths rates, hazard regression odds ratios and Relative Index of Inequality. RESULTS: Educational inequalities in lung and related cancer mortality widened considerably from the 1970s to the 1990s for both sexes. The moderate educational gradient for stomach and cervix uteri cancer persisted, as did the weak gradient for colorectal cancer. No educational differences in prostate cancer were observed in any of the time periods. The modest inverse educational gradients in deaths from breast cancer and melanoma remained at the same level. CONCLUSION: Among the seven cancer types examined in this study, only lung cancer mortality showed a clear widening in educational disparities. As lung cancer mortality constitutes a large proportion of all cancer deaths, this increase may result in larger disparities for overall cancer mortality. Some explanations for the observed patterns in cancer mortality are suggested.

Does the socioeconomic context explain both mortality and income inequality? Prospective register-based study of Norwegian regions.

BACKGROUND: Studies from various countries have observed worse population health in geographical areas with more income inequality. The psychosocial interpretation of this association is that large income disparities are harmful to health because they generate relative deprivation and undermine social cohesion. An alternative explanation contends that the association between income inequality and ill health arises because the underlying social and economic structures will influence both the level of illness and disease and the size of income differences. This paper examines whether the observed association between mortality and income inequality in Norwegian regions can be accounted for by the socioeconomic characteristics of the regions. METHODS: Norwegian register data covering the entire population were utilised. An extensive set of contextual and individual predictors were included in multilevel Poisson regression analyses of mortality 1994-2003 among 1.6 millions individuals born 1929-63, distributed across 35 residential regions. RESULTS: Mean income, composition of economic branches, and percentage highly educated in the regions were clearly connected to the level of income inequality. These social and economic characteristics of the regions were also markedly related to regional mortality levels, after adjustment for population composition, i.e., the individual-level variables. Moreover, regional mortality was significantly higher in regions with larger income disparities. The regions' social and economic structure did not, however, account for the association between regional income inequality and mortality. A distinct independent effect of income inequality on mortality remained after adjustment for regional-level social and economic characteristics. CONCLUSIONS: The results indicate that the broader socioeconomic context in Norwegian regions has a substantial impact both on mortality and on the level of income disparities. However, the results also suggest, in a way compatible with the psychosocial interpretation, that on top of the general socioeconomic influences, a higher level of income inequality adds independently to higher mortality levels. PREVIOUS PUBLICATION: This article is a reworked version of the study 'Er inntektsforskjeller dødelige?' [Are income inequalities lethal?] which was published in Norwegian in Tidsskrift for velferdsforskning [Journal for welfare research], Vol. 13 (4), 2010.

The role of welfare state principles and generosity in social policy programmes for public health: an international comparative study.

BACKGROUND: Many important social determinants of health are also the focus for social policies. Welfare states contribute to the resources available for their citizens through cash transfer programmes and subsidised services. Although all rich nations have welfare programmes, there are clear cross-national differences with respect to their design and generosity. These differences are evident in national variations in poverty rates, especially among children and elderly people. We investigated to what extent variations in family and pension policies are linked to infant mortality and old-age excess mortality. METHODS: Infant mortality rates and old-age excess mortality rates were analysed in relation to social policy characteristics and generosity. We did pooled cross-sectional time-series analyses of 18 OECD (Organisation for Economic Co-operation and Development) countries during the period 1970-2000 for family policies and 1950-2000 for pension policies. FINDINGS: Increased generosity in family policies that support dual-earner families is linked with lower infant mortality rates, whereas the generosity in family policies that support more traditional families with gainfully employed men and homemaking women is not. An increase by one percentage point in dual-earner support lowers infant mortality by 0.04 deaths per 1000 births. Generosity in basic security type of pensions is linked to lower old-age excess mortality, whereas the generosity of earnings-related income security pensions is not. An increase by one percentage point in basic security pensions is associated with a decrease in the old age excess mortality by 0.02 for men as well as for women. INTERPRETATION: The ways in which social policies are designed, as well as their generosity, are important for health because of the increase in resources that social policies entail. Hence, social policies are of major importance for how we can tackle the social determinants of health.

Contribution of smoking and alcohol consumption to income differences in life expectancy: evidence using Danish, Finnish, Norwegian and Swedish register data.

BACKGROUND: Despite being comparatively egalitarian welfare states, the Nordic countries have not been successful in reducing health inequalities. Previous studies have suggested that smoking and alcohol contribute to this pattern. Few studies have focused on variations in alcohol-related and smoking-related mortality within the Nordic countries. We assess the contribution of smoking and alcohol to differences in life expectancy between countries and between income quintiles within countries. METHODS: We collected data from registers in Denmark, Finland, Norway and Sweden comprising men and women aged 25-79 years during 1995-2007. Estimations of alcohol-related mortality were based on underlying and contributory causes of death on individual death certificates, and smoking-related mortality was based on an indirect method that used lung cancer mortality as an indicator for the population-level impact of smoking on mortality. RESULTS: About 40%-70% of the between-country differences in life expectancy in the Nordic countries can be attributed to smoking and alcohol. Alcohol-related and smoking-related mortality also made substantial contributions to income differences in life expectancy within countries. The magnitude of the contributions were about 30% in Norway, Sweden and among Finnish women to around 50% among Finnish men and in Denmark. CONCLUSIONS: Smoking and alcohol consumption make substantial contributions to both between-country differences in mortality among the Nordic countries and within-country differences in mortality by income. The size of these contributions vary by country and sex.

Dental care coverage and income-related inequalities in foregone dental care in Europe during the great recession.

OBJECTIVES: This study examines income inequalities in foregone dental care in 23 European countries during the years with global economic crisis. Associations between dental care coverage from public health budgets or social insurance, and income-related inequalities in perceived access to dental care, are analysed. METHODS: Survey data 2008-2013 from 23 countries were combined with country data on macro-economic conditions and coverage for dental care. Foregone dental care was defined as self-reported abstentions from needed dental care because of costs or other crisis-related reasons. Age-standardized percentages reporting foregone dental care were estimated for respondents, age 20-74, in the lowest and highest income quartile. Associations between dental care coverage and income inequalities in foregone dental care, adjusted for macro-economic indicators, were examined by country-level regression models. RESULTS: In all 23 countries, respondents in the lowest income quartile reported significantly higher levels of foregone dental care than respondents in the highest quartile. During 2008-2013, income inequalities in foregone dental care widened significantly in 13 of 23 countries, but decreased in only three countries. Adjusted for countries' macro-economic situation and severity of the economic crisis, higher dental care coverage was significantly associated with smaller income inequalities in foregone dental care and less widening of these inequalities. CONCLUSIONS: Income-related inequalities in dental care have widened in Europe during the years with global economic crisis. Higher dental care coverage corresponded to less income-related inequalities in foregone dental care and less widening of these inequalities.

Shape of the association between income and mortality: a cohort study of Denmark, Finland, Norway and Sweden in 1995 and 2003.

OBJECTIVES: Prior work has examined the shape of the income-mortality association, but work has not compared gradients between countries. In this study, we focus on changes over time in the shape of income-mortality gradients for 4 Nordic countries during a period of rising income inequality. Context and time differentials in shape imply that the relationship between income and mortality is not fixed. SETTING: Population-based cohort study of Denmark, Finland, Norway and Sweden. PARTICIPANTS: We collected data on individuals aged 25 or more in 1995 (n=12.98 million individuals, 0.84 million deaths) and 2003 (n=13.08 million individuals, 0.90 million deaths). We then examined the household size equivalised disposable income at the baseline year in relation to the rate of mortality in the following 5 years. RESULTS: A steep income gradient in mortality in men and women across all age groups except the oldest old in Denmark, Finland, Norway and Sweden. From the 1990s to 2000s mortality dropped, but generally more so in the upper part of the income distribution than in the lower part. As a consequence, the shape of the income gradient in mortality changed. The shift in the shape of the association was similar in all 4 countries. CONCLUSIONS: A non-linear gradient exists between income and mortality in most cases and because of a more rapid mortality decline among those with high income the income gradient has become steeper over time.