Pan American Journal Investigación original / Original research of Public Health Health inequalities by gradients of access to water and sanitation between countries in the Americas, 1990 and 2010 Oscar J. Mújica,1 Mariana Haeberer,2 Jordan Teague,3 Carlos Santos-Burgoa,3 and Luiz Augusto Cassanha Galvão1 Suggested citation Mújica OJ, Haeberer M, Teague J, Santos-Burgoa C, Galvão LAC. Health inequalities by gradients of access to water and sanitation between countries in the Americas, 1990 and 2010. Rev Panam Salud Publica. 2015; 2015;38(5):347–54. ABSTRACT Objective. To explore distributional inequality of key health outcomes as determined by access coverage to water and sanitation (WS) between countries in the Region of the Americas. Methods. An ecological study was designed to explore the magnitude and change-over-time of standard gap and gradient metrics of environmental inequalities in health at the country level in 1990 and 2010 among the 35 countries of the Americas. Access to drinking water and access to improved sanitation facilities were selected as equity stratifiers. Five depen- dent variables were: total and healthy life expectancies at birth, and infant, under-5, and maternal mortality. Results. Access to WS correlated with survival and mortality, and strong gradients were seen in both 1990 and 2010. Higher WS access corresponded to higher life expectancy and healthy life expectancy and lower infant, under-5, and maternal mortality risks. Burden of life lost was unequally distributed, steadily concentrated among the most environmentally disad- vantaged, who carried up to twice the burden than they would if WS were fairly distributed. Population averages in life expectancy and specific mortality improved, but whereas absolute inequalities decreased, relative inequalities remained mostly invariant. Conclusions. Even with the Region on track to meet MDG 7 on water and sanitation, large environmental gradients and health inequities among countries remain hidden by Regional averages. As the post-2015 development agenda unfolds, policies and actions focused on health equity—mainly on the most socially and environmentally deprived—will be needed in order to secure the right for universal access to water and sanitation. Key words Health inequalities; water; sanitation; environmental health; social determinants of health; Millennium Development Goals; Sustainable Development Goals; Americas. The right to safe and clean drinking situation and trends in water, sanitation, 1 Special Program on Sustainable Development and Health Equity, Pan American Health Organization/ water and sanitation has been explicitly and hygiene (WS), declaring that the World Health Organization (PAHO/WHO), recognized by the United Nations (UN) as Region of the Americas has reached the Washington, DC, United States of America. Send correspondence to Oscar J. Mújica, email: a human right, essential for the full enjoy- Millennium Development Goal (MDG) [email protected] ment of life (1). In 2012, the World Health Target 7c for water and that it was on 2 Gender, Diversity, and Human Rights Unit, Organization (WHO)/UN Children’s Fund track to meet MDG Target 7c for sanita- PAHO/WHO, Washington, DC, United States. 3 Occupational and Environmental Risks Unit, (UNICEF) Joint Monitoring Programme tion by 2015 (2). That same year, the UN PAHO/WHO, Washington, DC, United States. released its global report on the current also released its Global Analysis and Rev Panam Salud Publica 38(5), 2015 347 Original research Mújica et al. • Water, sanitation, and health inequalities in the Americas Assessment of Sanitation and Drinking to drinking water and to sanitation facili- Venezuela. Collectively, these account Water Report (3) pointing to wide dispar- ties—between countries of the Americas for 99.5% of the current estimated popu- ities in access to water and sanitation as in 1990 and 2010, i.e., the study’s “MDG lation of the Region of the Americas (11). the main challenge to extending and sus- time window.” taining services in the Americas, particu- Data analysis larly in Latin America and the Caribbean MATERIALS AND METHODS (LAC). In fact, this Region is known by its This study followed Tukey’s principle for huge social and environmental disparities Study design exploratory data analysis: it aimed at pat- and health inequalities (4). tern extraction rather than causal associa- As reported in the Global Burden of An observational, ecological, country- tion (12). Standard inequality analyses (13) Disease Study (5), in 2010 LAC saw an level, secondary data-based study were performed using both abridged and aver age of 4 000 premature deaths (4.5 per was designed to explore both the unabridged distributions of each health mil lion) and 323.4 disability-adjusted life magnitude of and change-over-time outcome. The former was used to explore years lost per million attributable to the in core environmentally-determined absolute and relative gap inequality, cap- lack of access to improved WS sources. health inequal ities in the Region of the tured in range-based, Kuznets-like metrics Inadequate WS practices and services lead Americas in 1990, and in 2010. by subtracting and dividing, respectively, to a higher prevalence of waterborne dis- the unbiased ( population weighted) health eases, such as acute diarrhea (mostly Data acquisition outcome estimators of the bottom (least among infants and children), hepatitis, advantaged) from the top (most advan- typhoid and paratyphoid enteric fevers, Country data were obtained from taged) WS country quartiles. The absolute and intestinal parasites and other parasitic a number of institution-based, internally- gap inequality index retains the units of the diseases (6). Furthermore, the lack of access consistent, publicly-available data sour- health variable and has zero as its equity to improved sources of sanitation may ces, including the WHO/UNICEF Joint reference; the relative gap inequality index force individuals to defecate in the open— Monitoring Programme (2), PAHO is dimensionless and has the unity as its described by WHO as “the riskiest sanita- Re gional Core Health Data Initiative (11) equity reference. tion practice of all”—generating a major (which, in turn, contains several The unabridged distribution of each cause of ground water pollution, agricul- interagency- derived, MDG-related indi- health outcome was used to generate tural produce contamination, and disease cators, as well as UN population esti- more robust summary measures of gra- transmission (7, 8). This context creates mates), the World Bank databank, and dient inequality. Absolute gradient in- severe detrimental effects on the health of from the Global Burden of Disease 2010 equality was captured by the slope index individuals and societies, leading to impover- Study (5), available at the Institute for of inequality (SII), which corresponds ishment and destitution due to decreasing Health Metrics and Evaluation’s Global to the slope of the regression line obtai- economic and educational opportunities. Health Data Exchange. ned by regressing country-level health Access to water and sanitation can be The study variables selected for the outcome rates on a relative scale of considered the very epitome of an envi- study were survival and mortality WS-related social position (ridit), as defi- ronmental determinant of health. The de- indicators of public health relevance ned by the cumulative class interval mid- terminants of health—that is, the general with high quality data available. The point of the population ranked by the conditions and circumstances in which indepen dent variables were two envi- equity stratifier. To account for intrinsic people are born, grow, live, work, and ronmental determinants/social strati- heteroskedasticity of aggregated data, age—play a central role in establishing fiers: access to drinking water and access the Maddala’s weighted least-squares and maintaining social position, thus de- to improved sanitation, according to the regression model was applied, as des- termining the distribution of health and standard definitions of WHO/UNICEF cribed elsewhere (14). Logarithmic data well-being (9). Under the eco-epidemiolo- (2). The dependent variables were five transformation was also tested to ac- gic paradigm (10), social inequalities are public health outcomes: life expectancy count for equity stratifier-health status considered “the causes of the causes” of at birth, healthy (disability-free) life ex- relationship skewness or non- linearity, poor health outcomes; therefore, inequa l- pectancy at birth, infant mortality rate, when indicated. As an absolute measure- ities in access to WS must drive inequali- under-5 mortality rate, and maternal ment of inequality, the SII retains the ties in avoidable morbidity, mortality, mortality ratio. units of the health variable and has zero and survival. Evidence on the magnitude The units of analysis (n = 35) were ag- as its equity reference. and trends of those environmentally- gregated at the country level and corre- Relative gradient inequality was cap- determined inequalities in health is yet sponded to: Antigua and Barbuda, tured by the health concentration index lacking for the Region of the Americas. Argentina, Bahamas, Barbados, Belize, (HCI), a summary measure of dispropor- To help fill this gap, this study aimed to Bolivia, Brazil, Canada, Chile, Colombia, tionality between population and health explore the magnitude and change-over- Costa Rica, Cuba, Dominica, Dominican