Tracking progress towards equitable child survival in a Nicaraguan community: neonatal mortality challenges to meet the MDG 4

Nicaragua is one of the countries in Latin America where child survival has improved rapidly over the past few decades. Our group has previously reported a decline in infant mortality in León, Nicaragua, from the level of 120 to 40 infant deaths per 1 000 live births from the late 1960s to the beginning of the 1990s [14]. This improvement was seen during a time of severe political, economic and social turmoil that followed the revolution in 1979. Progress in child survival was most likely a result of pro-poor targeted and decentralized public health services, giving priority to mothers and children [15].

Nicaragua seems to be in progress towards the MDG-4 [6]. The U5MR declined from 65 to 30 per 1000 live births between 1990 and 2009 [16]. Even if Nicaragua is on track towards the MDG4 based on the overall level of U5MR, barriers as inequalities and newborn health could desacelerate this progress. The U5MR is higher in rural (55 per 1000) in comparison to urban (34 per 1000) areas; and among the poorest group the U5MR is 3.3 times higher than among the wealthiest group. On the other hand neonatal mortality has only shown a minor decline (from 20 to 16 deaths per 1 000 live births) from 1993 to 2006 [16]. Thus, this stagnation contrasts to the earlier rapid reduction in post-neonatal and child mortality.

During the late 1990s and early 2000s the Nicaraguan health care system underwent major change, resulting in an increase in private health services, also within reproductive and child health [15]. The country has a problematic economic situation with an estimated unemployment of 46% in 2005 [17].

This study aims at analysing trends and social differentials in neonatal and under-five mortality in the municipality of León, Nicaragua, and to relate the findings to the forth Millennium Development Goal as well as to a health equity perspective.

The study was carried out in León municipality, a city located in the Pacific part of Nicaragua 93 km from the capital. It has a population of 174 051 inhabitants (2005), where 80% live in urban areas, and 46% of the population is under 18 years of age [18]. León municipality is considered the second most important city in Nicaragua after the capital with a university hospital, which it is a referent hospital for the closest cities. According to the Human Development Report, in 2002 the human development index in Nicaragua ranked from 0.37 to 0.82 [19]. León municipality had a human development index of 0.74 a value shared for most cities located close to the capital. From 2002 and onwards a Health and Demographic Surveillance System (HDSS) has been running, updating demographic information every six to twelve months and providing prospective information on pregnancies, births and child survival until the end of the current study period December 31, 2005 [20]. This HDSS was based on a linkage on household and individual level to a cross sectional study data base. The data in this data base was collected from a 22% sample of the total population in León municipality selected in 1993, using a cluster-sampling technique described elsewhere [14]. The follow-up survey was performed in 2002, providing updated and linked information on demographic characteristics and selected health indicators. This 2002 HDSS data base included a total of 54 647 people residing in 10 994 households. Only eleven of the households (0.1%) declined to participate in the survey.

Female field workers performed the data collection and interviewed women of reproductive age in their homes. Quality control routines were realized during fieldwork and data entry.

Women of reproductive age (15-49) were interviewed with respect to their reproductive and birth histories including dates of births, outcome of each pregnancy and, when relevant, the date of the child's death. Data collection was supported by the use of a local events calendar. Data were also collected on educational level of the mother, age at delivery, parity, and domicile. However, for place and attendance at delivery data was collected only from the start of the surveillance (2003) and only for women resident in the study area.

Under-five mortality rate was defined as the number of deaths before five years of age per 1000 live births. The U5MR was disaggregated into neonatal (< 28 days), post neonatal (28 days-11.9 months) and child mortality (1-4.9 years). Mother's age and parity were calculated for the time of each childbirth. Parity was categorized into three levels; one, two to four, and more than four live births, respectively. Place of delivery was categorized as hospital, health centre, private clinic, home or other place. Attendant at delivery was classified into physician, nurse, midwife or other person. Women's educational levels were classified into no formal education (either illiterate or literate but had not completed primary school) or formal education (completed primary school or higher level of education). Domicile of the mother was defined as urban or rural.

Place of and attendance at delivery during the last 3-year period were analysed and differences between rural and urban areas were tested (Chi²). Data on births, deaths and neonatal, post-neonatal and child mortality rates were analysed for 3-year periods from 1970 to 2005. Mortality curves were prepared with 3-year moving averages in order to smooth random fluctuations in the material. The U5MRs for rural and urban areas were graphically represented. Comparisons of rates or proportions were supported by Chi² tests. Relative risk of neonatal death (Hazards ratios with 95% confidence intervals) and relative risk of under-five death were analysed by Cox proportional hazard analyses, considering educational level of the mother during three different time periods from 1970 to 2005. Adjustments were done for parity and domicile. Data entry and managing were done using Microsoft Access 2000 (Microsoft Corporation, Washington), while analyses were performed in Statistical Package for Social Sciences (Version 14.0; SPSS Inc, Chicago, USA).

We have shown a rapid decline in under-five mortality from the middle of 1970s to the early 1980s. During that turbulent period in Nicaragua the new government prioritized the under-served part of the population [22], and the health budget increased from 3% to 11% of the Gross Domestic Product (GDP). Child deaths caused by infectious diseases were prevented in part by an increased coverage of immunizations, oral rehydratation treatment, management of infectious diseases and sanitation improvements [21, 22]. Emphasis was given to community participation, especially in rural regions and basic education and health promotion were implemented [22]. The war from 1983 to 1990 and the economic embargo imposed by the United States of America were some of the factors that led to a reduction of the health budget to 6.6% of the GDP in 1989 [23]. During that period under-five mortality increased, maybe as a result of lack of resources within the health system, lack of food, low economic resources in the family, high proportion of deliveries at home in those regions far from the health system, poor secondary preventions and tertiary preventions of child diseases and reduced access to clean water [24]. At the end of the war in 1990 there was a new political change, moving towards a decentralized health care system, with an increased private sector [15]. The under-five mortality decreased in spite of reduced public health expenditure. However, the potential benefits of the increasing private health sector services were only in urban areas, where 80% of the population is concentrated, the main university hospital is located and families of higher socioeconomic strata dominate.

Mother's education is frequently used as a social marker associated with child health and survival [25]. A wide gap in child survival between maternal education groups usually indicates a social variation in the uptake of preventive and curative services along the continuum of care for the pregnant woman and her offspring [26]. The remarkable reduction in mortality combined with a much smaller social gap in under-five and neonatal mortality that we have demonstrated in this Nicaraguan community (Table 3) suggests that the health system during the 1980s managed to scale up the essential services and to target those most in need [14]. This illustrates that improved child survival is not always associated with an increasing gap in mortality between social groups [27]. However, the last study period (1994-2005), the social divide in under-five and neonatal mortality has increased - in spite of being on track for the MGD-4. This reinforces the importance of adding an equity measure to the millennium development goal indicators [28]. The current health system is more complex with an increasing public-private mix in the available services for mothers and children. It is beyond the scope of this analysis to clearly identify the reasons to this increasing divide, but there are reasons to question whether mother and child health services are equitably distributed and maintain an adequate quality of care.

To live in rural settings is frequently described as a disadvantage for child health and survival [29]. However, in this Nicaraguan community big efforts were made during the 1980s to improve child health and survival in the rural areas and to reduce the rural-urban inequity. The government policy included community participation with community health workers called brigadistas to promote basic education and health promotion [30]. During the period of war 1983-1990 this community model was disintegrated and child mortality increased. When the war ended social programs and access to health services were re-established Private health services were only offered in urban areas, increasing their accessibility, although evidence of the quality of these services has not been assessed in connection to improve the child survival. However, a higher access to health services, better socio-economic status, good sanitation, access to clean water could have contributed to a more rapid reduction in under-five mortality in urban as compared to rural areas increasing the inequity in survival between the two areas. This pattern continued until 1997, when urban areas faced increasing under-five mortality. A rural-urban migration in part forced by the Hurricane Mitch in 1998 could explain this increase, and the mortality increase is most likely a reflection of the precarious conditions of the urban slums [31].

Many countries face a major obstacle to reach the MDG-4 - the persistent neonatal mortality. In this Nicaraguan community neonatal mortality was reduced, but at a lower speed than the reduction in post-neonatal and child mortality rates - a pattern found in many other societies in transition [32]. A successful audit-and-feedback process of change in perinatal services was initiated at the regional hospital in the early 1990s in order to improve the quality of care provided. That process resulted in 85% reduction of early neonatal mortality in the hospital [33], this was also reflected in the community-based data reported in this paper where NMR declined 50% during 1985-1993 (period of hospital intervention).There is usually an association between access to and utilisation of a continuum of good quality maternal and neonatal health care and neonatal survival [5, 9]. But efficacious services and interventions do not always reduce inequity in survival chances [9, 13, 27, 28, 34]. The recent development in neonatal mortality in this local Nicaraguan community raises questions of an equitable access to a continuum of perinatal services and about the quality of care that is provided. Further, these data illustrates the need for an equity stratification or adjustment in the MDG-4 monitoring and reporting of under-five mortality - otherwise, an increasing social divide in survival chances can be hidden in data showing a society on track to reach the child mortality goal.

Our study linked two retrospective reproductive life surveys (1993 and 2002) to a continuous health and demographic surveillance that followed (from 2002). The recording of retrospective data was performed in accordance with well-known and used methods in this type of surveillance. To minimize the recall bias of dates of birth and death a local events calendar was used in the interviews. In the Nicaraguan setting there is no reason to believe that women purposively should misreport births and/or deaths. The refusal rate was very small (< 0.1%) that minimizes the risk of selection bias [14, 20].The interviews with the included women were performed in privacy by trained female field workers in order to create confidence and reduce the risk of misreporting of childbirths and deaths.

Previous out-migration and maternal deaths could potentially distort our estimation of mortality in childhood during the past decades. However, it is unlikely that out-migration has had any major influence on trends and mortality differentials over time that are reported by the mothers who continue to live in the study area. This possible bias does not exist from 2002, when the surveillance system was initiated. Maternal mortality is - in spite of being a public health problem - not of the magnitude that influences aggregated child survival data.

Factors like educational level and rural/urban domicile were mainly used as stratifying variables when analyzing gaps between social groups. The mother's education was measured at time of interview as the number of years of schooling and this information was updated when the surveillance system was initiated.

The results shown in this study are not representative of Nicaragua as a whole. However, the municipality of León is relatively typical of the Pacific part of Nicaragua, and our findings are consistent with the corresponding results of national census and demographic surveys [16, 18].