摘要：Objectives. We examined the impact of expanding health insurance coverage on socioeconomic disparities in total and cardiovascular disease mortality from 1998 to 2007 in Colombia. Methods. We used Poisson regression to analyze data from mortality registries (633 905 deaths) linked to population census data. We used the relative index of inequality to compare disparities in mortality by education between periods of moderate increase (1998–2002) and accelerated increase (2003–2007) in health insurance coverage. Results. Disparities in mortality by education widened over time. Among men, the relative index of inequality increased from 2.59 (95% confidence interval [CI] = 2.52, 2.67) in 1998–2002 to 3.07 (95% CI = 2.99, 3.15) in 2003–2007, and among women, from 2.86 (95% CI = 2.77, 2.95) to 3.12 (95% CI = 3.03, 3.21), respectively. Disparities increased yearly by 11% in men and 4% in women in 1998–2002, whereas they increased by 1% in men per year and remained stable among women in 2003–2007. Conclusions. Mortality disparities widened significantly less during the period of increased health insurance coverage than the period of no coverage change. Although expanding coverage did not eliminate disparities, it may contribute to curbing future widening of disparities. Recent health care reform in the United States has sparked debate on the potential impact of expanding health insurance coverage on access to care and disparities in health care. 1 People with lower socioeconomic status are at increased risk of many conditions and are therefore more likely to benefit from an expansion in health insurance coverage. 1 Previous observational studies in the United States have suggested that a lack of health insurance was associated with an increased risk of subsequent mortality in all socioeconomic groups. 2 However, little is known about the impact of health insurance coverage on socioeconomic disparities in mortality following a major expansion in insurance coverage. In 1993, the Colombian government implemented a major health care reform that introduced mandatory health insurance. 3 As a result, coverage increased from 47% in 1994 4 to 98% in 2010. 5 Although the social and economic context of Colombia differs substantially from that in the United States, lessons from the Colombian reform can shed light on the potential impact of increased health insurance coverage on health disparities in the United States and middle-income countries currently expanding insurance coverage. A desirable outcome of coverage expansion is that it will have a larger impact on the health of the poor and will contribute to a reduction in health disparities. 3,6 The reform in Colombia established a scheme of subsidies targeted to the poor, assigning citizens to 2 schemes on the basis of income: (1) the contributory scheme, which covers workers and their families with an income above the cut-off and is financed through payroll and employer’s contributions, and (2) the subsidized scheme, which covers the poor as identified through a proxy means test. 6 In the poorest income quartile, health insurance coverage increased from 6% in 1993 to more than 70% in 2007, 6 an increase attributable to the subsidized scheme. 5 Increased coverage among the poor is expected to improve health outcomes by ensuring timely care and bringing them into closer contact with the health care system. 7 However, the reform also increased the complexity of the system potentially leading to delays in some types of care 8 and reducing spending in prevention and public health. 9 Previous dynamic simulations for the United States have suggested that expanding health insurance coverage is cost-effective, but failing to also expand the primary care capacity for the disadvantaged could lead to increasing health disparities. 10 There have been no empirical studies examining these issues in the context of a major health care reform. Most previous studies have focused on the impact of health care reform on utilization and access to health care services, with only some studies examining the impact on population health. 7,11–13 A recent review of available evidence concluded that expanding health insurance coverage generally improves access to care and population health particularly for lower income groups, but health gains may be dependent on the institutional framework and governance arrangements. 14 On the other hand, the World Health Organization Commission on Social Determinants of Health concluded that, although inequity in health care is critical, the largest burden of illness arises in large part because of the conditions in which people are born, grow, live, work, and age. 15 We examined whether expanding health insurance coverage is associated with trends in socioeconomic disparities in mortality in the aftermath of the health care reform in Colombia. Findings from this study are of potential interest to the United States and middle-income countries that have recently implemented reforms to achieve universal access. We hypothesized that expanding health insurance coverage will contribute to curbing unfavorable trends in mortality disparities. To assess the impact of this expansion, we examined trends in mortality disparities by educational level separately for 2 divergent periods. In 2002, a process of decentralization led to a sharp increase in resource allocation to the subsided scheme in regional areas. 16 As a result, whereas in the period 1998–2002 there was a moderate increase in total health insurance coverage (coverage went from 59.8% in 1998 to 64.1% in 2002), thereafter total coverage increased rapidly from 65.9% (2003) to 92.5% (2007; Figure 1 ). This corresponds to a statistically significant increase of 5.1% per year ( P < .001) in the period 2003–2007. As illustrated in Figure 1 , this increase was driven by a particularly steep increase in affiliates to the subsidized scheme in 2003–2007 (15.1% per year; P < .001), as opposed to a much smaller increase in the period 1998–2002 (6.4% per year; P < .001), suggesting that it may have particularly reached the lower socioeconomic groups. The discrepancy in health insurance coverage trends between these 2 periods thus provides a natural experiment to examine the impact of health insurance coverage on socioeconomic disparities in mortality. Open in a separate window FIGURE 1— Percentage of population with health insurance coverage: Colombia, 1998–2007. Note . Other schemes include primarily members of the military and teacher and oil workers syndicate members. Source . Annual reports of the Ministry of Health and Social Protection. 5,17–19 Our specific aim was to evaluate to what extent increased health insurance coverage has contributed to diminishing socioeconomic inequalities in mortality in Colombia. If socioeconomic differences in mortality were responsive to increased health insurance coverage, we would expect a more favorable trend in socioeconomic differences in mortality during the second than the first period. If increased insurance coverage had no impact on socioeconomic disparities in mortality, we would expect similar trends in socioeconomic disparities in mortality between the 2 periods.
