Analysis of comprehensive, individual level data demonstrated that amenable mortality in Finland varied systematically by income group between 1992 and 2003: the lower the income, the higher the risk of amenable mortality. During this period, the absolute and relative gap between the highest and lowest income groups widened with an excess of 28.74 amenable deaths per 100,000 among men in 2003 compared with 1992. Income related differences were particularly high for mortality amenable to improved treatment and medical care in primary healthcare. Towards the end of the study period, the risk ratio for amenable mortality for the lowest income quintile was 14 times that of the highest quintile for men and 21 times that for women. These large risk ratios reflect very few deaths from causes such as asthma, diabetes or epilepsy among the richest quintile.
The socio-economic gradient in amenable mortality increased, with limited reductions in the age-standardized death rates among the lowest income group. Widening inequalities in all cause and total disease mortality were more modest. While a detailed analysis of gender differences in amenable mortality is beyond the scope of this paper, amenable mortality rates remained higher in men than women except for the highest income quintile. In addition, the gender gap for amenable mortality was narrower than that for all-cause or total disease mortality and the reduction over time greater .
Since the initial studies of amenable mortality, the age limit for amenable death has increased from 65 to 75 years in Western Europe, reflecting increased life expectancy . The fall in premature deaths reflects lower exposure to several risk factors, notably smoking, and more effective medical care [34, 35]. Despite the overall decline in amenable mortality rates [36, 37] the differential reductions by income groups and the persistent socio-economic gradient illustrates the role of the health system in perpetuating health inequalities [15, 38]. Furthermore, the gap between the lowest and second lowest socio-economic group, or between those inside and outside of the workforce [16, 39] suggests that health services are not reaching the most disadvantaged. Although the rate is smaller in other countries, the pattern of excess amenable mortality due to chronic conditions such as diabetes is similar to that found among in lower income and minority ethnic groups elsewhere [7, 15–18]. More detailed analysis of the relationship between amenable mortality rates and inequities in access, quality and comprehensiveness of care is warranted.
Strengths and limitations
We applied current definitions of amenable mortality [2, 7] but our findings are based on comprehensive and reliable individually based linked register data. The level of confirmation of diagnosis at death by autopsy in Finland is high by international comparison .
Our data also enabled us to consider the impact of health service changes in the risk of amenable mortality by socioeconomic group. In many studies, it is difficult to determine the impact of changes in non-IHD mortality. We analysed IHD deaths separately for three reasons. Firstly, because of the continuing debate about the proportion of mortality from IHD that is amenable to health service intervention. Secondly, the large number of IHD deaths masks the pattern of amenable deaths from other causes, and thirdly, because we analysed individual level, not aggregate data, we could not exclude a proportion of deaths from one condition. We were, however, able to compare trends in IHD deaths with those for amenable mortality as a whole and with other causes of amenable mortality.
Data were incomplete in three areas. As with other register based studies, we had no behavioural data although alcohol and tobacco use clearly contribute to the socio-economic gradient in premature deaths [41, 42]. While the major contribution to reducing tobacco and alcohol related deaths results from policy interventions, smoking cessation  and alcohol brief interventions  are evidence based primary care treatments that could be used widely among lower income groups in Finland, but are not [45, 46]. We also omitted healthcare-associated deaths, as Statistics Finland does not identify these separately in the Causes of Death register.
While we have access to high quality linked data, and we checked the classification of deaths as amenable was appropriate, researchers and policy makers continue to debate the inclusion and exclusion of specific causes, the relationship between evidence for intervention and impact on amenable mortality rates and the boundary between health care and interventions excluded because they are classified as multi-agency or health promotion. All of these concerns are legitimate and are reflected in the final report of the AMIEHS project : Avoidable mortality in the European Union:
Towards better indicators for the effectiveness of health systems. (http://amiehs.lshtm.ac.uk/publications/reports/AMIEHS%20final%20report%20VOL%20I.pdf). We agree with the authors’ caution to avoid direct attribution of a causal relationship between deaths from amenable causes and health system effectiveness but consider that our findings are worrying and worthy of further investigation.
With this dataset, we were also unable to adjust for socio-economic differences in incidence, in the treatability of disease associated with co-morbidity, or delays in seeking medical care. In a universal healthcare system, differential changes in the incidence of treatable disease should not affect the socio-economic gradient in amenable mortality by virtue of being treatable. The extent of the socioeconomic gradient in multiple morbidity and its earlier onset in primary care patients living in areas of multiple deprivation has only recently been recognized . It seems plausible that the gradient in amenable mortality reflects the earlier onset and treatability of multiple morbidity in a less responsive health care environment rather than a rise in the incidence of a single specific cause. There is also evidence that lower socio-economic groups have more limited access to treatment known to reduce the risk of early death [48–50] even after adjustment for individual clinical characteristics. However, there is some evidence that attention to populations with higher incidence of disease in designing programmes of care can reduce some aspects of amenable mortality, for example survival after myocardial infraction in South Asian populations in Scotland . Attention to some of the previously identified socioeconomic inequities in access to secondary prevention and treatment of ischaemic heart disease, including revascularization, may explain the more modest increase in gradient in the lowest income group. Similarly, data from the UK indicate that investing in common, chronic conditions associated with amenable mortality can improve outcome  although further work is necessary to identify the optimal model of care to address the socioeconomic and age gradient in multiple morbidity.
Since this was a cross-sectional study relating mortality to current income, we were unable to infer the direction of causation. Changes over time in the selection of people with progressive illnesses and multiple morbidity into lower income quintiles could partly explain the gradients found.
Structural change in Finnish health services
Access to diagnosis and ongoing treatment regardless of socioeconomic status or geography characterises universal health systems. However gradients in amenable mortality, particularly for conditions such as hypertension and diabetes persist [7, 15, 16, 38, 50]. At the start of the study period, the 2-3 fold socioeconomic gradient in amenable mortality in Finland was similar to that reported by other comprehensive healthcare systems, despite differences in funding, generosity of the social welfare system, and study methodology. By the early 2000s in Finland, educational inequalities in amenable mortality were greater than in other Nordic countries  and income related differences were substantially larger.
Inequalities in amenable mortality in Finland widened during a period of structural and economic change. During the study period, municipal primary care received relatively less investment than specialist services. Since the late 1990s most people in stable employment receive primary healthcare from providers with which their employer contracts and GPs no longer provide comprehensive primary care. The expansion in private specialist ambulatory care services also provides more affluent groups with additional opportunities to access care and have the costs partially reimbursed by the social insurance system. The design of these newer services may have changed the help-seeking behaviour of men in higher income groups. Our findings may also reflect the differential impact of co-morbidity and complexity of need on the ability of people with lower income to access acute and chronic care in an increasingly complex Finnish healthcare system.
While most chronic conditions occur more frequently among lower income groups, rising co-payments and limited exemptions associated with the health service reforms increase the financial burden of healthcare . In addition, the Finnish health system has been slow to adopt active methods of improving access and treatment  for patients with chronic conditions in primary care. Disease registers, call-recall systems, outreach services, continuity of personal care, patient involvement in assessing need and designing services are not widespread in Finland.
Recent analysis of empirical and experimental research has identified some interventions that may reduce socio-economic inequalities in access to healthcare [55, 56]. These include abolition of user fees, strengthening primary care so that it is universally available, expert-based, and actively engages people from disadvantaged groups, particularly those with chronic conditions.