Field of Pediatric

The Field of Pediatrics (Part 1)

Chapter 1 – Overview of Pediatrics
Bonita Stanton, Richard E. Behrman (Kliegman: Nelson Textbook of Pediatrics,18 ed)

Pediatrics is concerned with the health of infants, children, and adolescents; their growth and development; and their opportunity to achieve full potential as adults. Pediatricians must be concerned not only with particular organ systems and biologic processes, but also with environmental and social influences, which have a major impact on the physical, emotional, and mental health and social well-being of children and their families.

Pediatricians should also serve as advocates for all children, irrespective of culture, religion, gender, race, or ethnicity or of local, state, or national boundaries. Children cannot advocate for themselves. The more politically, economically, or socially disenfranchised a population or a nation, the greater the need for advocacy for children by the profession whose entire purpose is to advance the well-being of children. The young are often among the most vulnerable or disadvantaged in society and, thus, their needs require special attention. As artificial divides between nations blur through advanced transportation and communication, through globalization of the economy, and through modern means of warfare and as the categorization of countries into “developed” or “industrialized” and “developing” or “low income” break down due to uneven advances within and across countries, a global perspective for the field of pediatrics becomes both a reality and a necessity.

The number of births in the United States has been increasing since 1976 and is expected to continue to increase at 1–2% annually. Despite increases in the numbers of births, the proportion of children relative to the adult population is decreasing whereas the proportion of older adults relative to younger adults is increasing ( Fig. 1-1 ). Currently, children younger than age 18 constitute approximately ¼ of the U.S. population.

Worldwide, children represent a higher proportion of the population, with children younger than age 15 accounting for 1.8 billion (28%) of the world's 6.4 billion persons. In 2003, there were an estimated 133 million births worldwide, 120 million (90%) of which were in developing countries. Four million (3%) of these births were in the United States.

Figure 1-1 Percent of population in 4 age groups: United States, 1950, 2000, and 2050. (From Centers for Disease Control and Prevention, National Center for Health Statistics: Health, United States, 2004. DHSS Publication No. 2004–1232.)

SCOPE AND HISTORY OF PEDIATRICS AND VITAL STATISTICS

More than a century ago, pediatrics emerged as a medical specialty in response to increasing awareness that the health problems of children differ from those of adults and that a child's response to illness and stress varies with age. In 1959, the United Nations issued the Declaration of the Rights of the Child, articulating the universal presumption that children everywhere have fundamental needs and rights. Virtually all nations have practicing pediatricians and most medical schools across the globe have departments of pediatrics or child health.

The health problems of children and youth vary widely between and within populations in the nations of the world depending on a number of often interrelated factors. These factors include (1) economic considerations (economic disparities); (2) educational, social, and cultural considerations; (3) the prevalence and ecology of infectious agents and their hosts; (4) climate and geography; (5) agricultural resources and practices (nutritional resources); (6) stage of industrialization and urbanization; (7) the gene frequencies for some disorders; and (8) the health and social welfare infrastructure available within these countries. Health problems are not restricted to single nations and are not limited by country boundaries; the interrelation of health issues across the globe has achieved widespread recognition in the wake of the SARS (severe acute respiratory syndrome) and AIDS epidemics, expansions in the pandemics of cholera and West Nile virus, war and bioterrorism, and the tsunami of 2004.

Child health priorities must reflect local politics, resources, and needs. The state of health of any community must be defined by the incidence of illness and by data from studies that show the changes that occur with time and in response to programs of prevention, case finding, therapy, and surveillance. Accordingly, with time, the relative importance of the various causes of childhood morbidity and mortality may undergo major changes.

Resources also vary greatly by nation, with 78 nations enjoying a per capita income >$9,386/yr (27 >$20,000/yr) and 61 nations struggling with per capita incomes < $765/yr (20 <$300/yr). Likewise, nations expend differently; in the United States, >$5,000 is spent per citizen per year in health care compared to $3 per person in the world's 41 poorest countries, most of which are in sub-Saharan Africa. While there is a strong correlation between per capita income and child health outcomes (and between child health outcomes and expenditure for health), this relationship is not absolute. Singapore enjoys the lowest infant and child mortality rates in the world; the per capita income ranks ≈29th worldwide.

HISTORY OF INFANT AND CHILD HEALTH

INFANT HEALTH.

In the late 19th century in the United States, 200 of every 1,000 children born alive died before the age of 1 yr of conditions such as dysentery, pneumonia, diphtheria, and whooping cough. The efforts of pediatricians, scientists, and pioneers in public health have led to a better understanding of the origin and management of diseases of childhood such that, in the past half century, the infant mortality rate in the United States has decreased from around 75/1,000 live births in 1925 to ≈6.8/1,000 in 2001. Although this rate had held steady or improved every year since 1958, the 2003 rate was 6.85/1,000.

Both neonatal (<1>

TABLE 1-1 -- Death Rates^* for All Causes, According to Sex, Race, and Age: United States, Selected Years, 1960–1999 +

	1960		1970		1980		1990		2003
	White	Black	White	Black	White	Black	White	Black	White	Black
MALE
<1>	2,694	5,307	2,113	4,299	1,230	2,587	896	2,112	659	1,410
1–4 yr	105	209	84	151	66	111	46	86	32	54
5–14 yr	53	75	48	67	35	47	26	41	18	27
15–24 yr	144	212	171	321	167	209	131	252	109	171
FEMALE
<1>	2,008	4,162	1,615	3,369	963	2,124	690	1,736	521	1,132
1–4 yr	85	173	66	129	49	84	36	68	26	40
5–14 yr	35	54	30	44	23	31	18	28	13	19
15–24 yr	55	108	62	112	56	71	46	69	43	54

+Adapted from Statistical Abstract of United States 1993, 113th ed. Lanham, MD, Berman Press, 1993, table 119;

Death rates per 100,000 population. Hoyert DL, Arias E, Smith BL, et al: Deaths: Final data for 1999. Natl Vital Stat Rep 2001;49:1–113; National Center for Health Statistics: Health, United States 2005, DHSS Publication No. 2005–1232, table 35

TABLE 1-2 -- Deaths Rates for All Causes Among Children and Young Adults According to Sex, Race, Hispanic origin, and Age: 2002

	UNDER 1 YR	1–4 YR	5–14 YR	15–24 YR
DEATHS PER 100,000 RESIDENT POPULATION
All persons	695.0	31.2	17.4	81.4
Male	761.5	35.2	20.0	117.3
Female	625.3	27.0	14.7	43.7
MALES
White	650.9	31.5	18.4	109.7
Black male (African-American)	1,351.5	54.4	28.9	172.6
American Indian or Alaska Native	896.8	48.3	22.0	145.1
Asian or Pacific Islander	461.9	27.1	14.4	58.6
Hispanic or Latino	644.0	34.2	17.4	114.4
White not Hispanic or Latino	643.5	30.3	18.3	106.7
FEMALES
White	519.4	24.5	13.7	42.4
Black (African-American)	1,172.0	39.5	19.9	54.4
American Indian or Alaska Native	744.1	42.0	21.2	61.7
Asian or Pacific Islander	391.4	19.6	10.4	23.8
Hispanic or Latino	539.1	25.3	13.5	34.1
White not Hispanic or Latino	504.8	23.8	13.6	43.8

TABLE 1-3 -- Infant, Neonatal, and Postnatal Deaths and Mortality Rates by Specified Race or Origin of Mother: United States, 2002

	MORTALITY RATE PER 1,000 LIVEBIRTHS
RACE OF MOTHER	LIVEBIRTHS	INFANT	NEONATAL	POSTNATAL
All Races	4,021,726	7.0	4.7	2.3
White	3,174,760	5.8	3.9	1.9
Black or African-American	593,691	13.8	9.3	4.5
American Indian or Alaska Native	42,368	8.6	4.6	4.0
Asian or Pacific Islander	210,907	4.8	3.4	1.4
Chinese	33,673	3.0	2.4	0.7
Japanese	9,264	4.9	3.7
Filipino	33,016	5.7	4.1	1.7
Hawaiian	6,772	9.6	5.6	4.0
Other Asian or Pacific Islander	128,182	4.7	3.3	1.4
Hispanic or Latino	876,642	5.6	3.8	1.8
Mexican	627,505	5.4	3.6	1.8
Puerto Rican	57,465	8.2	5.8	2.4
Cuban	14,232	3.7	3.2
Central and South American	125,981	5.1	3.5	1.6
Other and unknown Hispanic or Latino	51,459	7.1	5.1	2.0
Not Hispanic or Latino
White	2,298,156	5.8	3.9	1.9
Black or African American	578,335	13.9	9.3	4.6

The preponderance of under-5 mortality (children dying before the age of 5 yr) occurring in the 1st year of life is also applicable to industrialized countries overall, with an infant mortality of 5/1,000 representing >80% of the under-5 mortality rate of 6/1,000 in 2004. In the least developed countries, the infant mortality rate of 98/1,000 accounts for 63% of the under-5 mortality rate of 155/1,000, indicating a somewhat greater proportion of deaths occurring among children after infancy in these very high risk countries ( Table 1-4 ). Worldwide, 3.9 million of the 10.8 million deaths of children younger than 5 yr occur in the 1st 28 days of life. In populations with the highest child mortality rates, however, just over 20% of all child deaths occurred in the neonatal period, but in countries with mortality rates <35/1,000>50% of child deaths were in neonates ( Fig. 1-2 ). Across the globe, there are significant variations in infant mortality rates by nation, by region, by economic status, and by level of industrial development, the categorizations employed by the World Bank and the United Nations (see Table 1-4 ). Among the nations categorized as industrialized, in 2004, the infant mortality rate was 5/1,000, whereas among nations categorized as developing, it was 59/1,000, with the poorest rate in sub-Saharan Africa (102/1,000 live births). The U.S. rate in 2004 of 7/1,000 compared unfavorably to that of 40 other nations (including developing countries such as Cuba with a rate of 6/1,000); Finland with a rate of 2/1,000, had the lowest infant mortality in the world.

TABLE 1-4 -- Child Health Indicators Worldwide by Region

	MORTALITY RATE BY YR PER 1,000 LIVEBIRTHS				Per CAPITA INCOME US$ 2004	LIFE EXPECTANCY AT BIRTH IN YR 2004	% PRIMARY SCHOOL ATTENDANCE 1996–2004
	UNDER-5		INFANT
YR	1960	2004	1960	2004
Sub-Saharan Africa	278	171	185	102	611	46	60
Middle East/North Africa	249	56	157	44	2,308	68	79
South Asia	244	92	148	67	600	63	74
East Asia/Pacific	208	36	137	29	1,686	71	96
Latin America/Caribbean	153	31	102	26	3,649	72	93
CEE/OS	112	38	83	32	2,667	67	88
Industrialized countries	39	6	32	5	32,232	79	95
Developing countries	224	87	142	59	1,524	65	80
Least developed countries	278	155	171	98	345	52	60
World	198	79	127	54	6,298	67	82

From UNICEF: The state of the world's children 2005, table 1, page 108.

Figure 1-2 Relationship between under-5 year mortality rate and percentage of deaths in neonatal period. (From Black E, Morris S, Bryce J: Where and why are 10 million children dying every year? Lancet 2003;361:2226–2234.)

Causes of death vary by developmental status of the nation. In the United States, the 3 leading causes of death among infants were congenital anomalies, disorders related to gestation and low birthweight, and sudden infant death ( Table 1-5 ). By contrast, in developing countries, the majority of infant deaths result from infectious diseases; even in the neonatal period, 24% of deaths are caused by severe infections and 7% by tetanus. In developing countries, 29% of neonatal deaths are due to birth asphyxia and 24% due to complications of prematurity.

TABLE 1-5 -- Leading Causes of Death and Numbers of Deaths, According to Age : United States, 2002

AGE AND RANK ORDER	CAUSE OF DEATH	DEATHS
Under 1 yr	All causes	28,034
	Congenital malformation, deformations, and chromosomal abnormalities	5,623
	Disorders related to short gestation and low birthweight, not elsewhere classified	4,637
	Sudden infant death syndrome	2,295
	Newborn affected by maternal complications of pregnancy	1,708
	Newborn affected by complications of placenta, cord, and membranes	1,028
	Unintentional injuries	946
	Respiratory distress of newborn	943
	Bacterial sepsis of newborn	749
	Diseases of circulatory system	667
	Intrauterine hypoxia and birth asphyxia	583
1–4 yr	All causes	4,858
	Unintentional injuries	1,641
	Congenital malformations, deformations, and chromosomal abnormalities	530
	Homicide	423
	Malignant neoplasms	402
	Diseases of heart	165
	Influenza and pneumonia	110
	Septicemia	79
	Chronic lower respiratory diseases	65
	Certain conditions originating in the perinatal period	65
	In situ neoplasms, benign neoplasms, and neoplasms of uncertain or unknown behavior	60
5–14 yr	All causes	7,150
	Unintentional injuries	2,718
	Malignant neoplasms	1,072
	Congenital malformations, deformations, and chromosomal abnormalities	417
	Homicide	356
	Suicide	264
	Diseases of the heart	255
	Chronic lower respiratory diseases	136
	Septicemia	95
	Cerebrovascular diseases	91
	Influenza and pneumonia	91
15–24 yr	All causes	33,046
	Unintentional injuries	15,412
	Homicide	5,219
	Suicide	4,010
	Malignant neoplasms	1,730
	Diseases of the heart	1,022
	Congenital malformations, deformations, and chromosomal abnormalities	492
	Chronic lower respiratory diseases	192
	HIV disease	178
	Diabetes mellitus	171
	Cerebrovascular diseases	171

Adapted from National Center for Health Statistics: Health, United States 2004, DHSS Publication No. 2004–1232, table 32, p 158.

In the majority of countries, the most robust predictor of infant mortality is a poor level of maternal education. Other maternal risk characteristics, such as unmarried status, adolescence, and high parity, correlate with increased risk of postneonatal mortality and morbidity and low birthweight.

HEALTH AMONG POSTINFANCY CHILDREN.

A profound improvement in child health occurred in the 20th century with the introduction of antibacterial disinfectants, antibiotic agents, and vaccines. Early in the 20th century in industrialized nations, efforts to control infectious diseases were complemented by better understanding of nutrition. In the United States, Canada, and parts of Europe, new and continuing discoveries in these areas led to establishment of public well child clinics for low-income families. Although the timing of control of infectious disease was uneven around the globe, this focus on control was accompanied by significant decreases in morbidity and mortality in all countries. The smallpox eradication program of the 1970s resulted in the global eradication of smallpox in 1977. The introduction in the 1970s of the Expanded Program of Immunizations (universal vaccination against polio, diphtheria, measles, tuberculosis, tetanus, and pertussis) by the World Health Organization (WHO) and United Nations' Children's Fund (UNICEF) has resulted in an estimated annual reduction of 2 million deaths per year globally. Recognizing the importance of prevention of infectious diseases to the health of children, several countries ranked by the World Bank as among the 61 poorest nations (per capita income < $766/yr) have invested heavily in infectious disease control through the development of internal vaccine production capability. Vietnam (per capita income $480/yr), the world's 3rd nation to produce polio vaccine, is now self-sufficient for vaccine production of 2 of the vaccines used in its vaccination program. As diarrheal diseases continued through the mid-1970s to account for ≈25% of infant and childhood deaths in the nonindustrialized countries (4.6 million deaths per year), attention turned to the development and utilization of oral resuscitation fluids to sustain children through potentially life-threatening episodes of acute diarrheal diseases. Oral rehydration solutions are largely credited with the current reduction of diarrheal deaths annually to 1.5 million. This simple medical treatment serves as an important example of “reverse technology” in which a major medical innovation was initially utilized in developing nations and subsequently introduced in the industrialized world.

In the later 20th century, with improved control of infectious diseases (including the elimination of polio in the Western hemisphere) through both prevention and treatment, pediatric medicine in industrialized nations increasingly turned its attention to a broad spectrum of conditions. These included both potentially lethal conditions and temporarily or permanently handicapping conditions; among these disorders were leukemia, cystic fibrosis, diseases of the newborn infant, congenital heart disease, mental retardation, genetic defects, rheumatic diseases, renal diseases, and metabolic and endocrine disorders. Thus, in industrialized nations, the last 2 decades of the 20th century were marked by accelerated understanding of new approaches to the management of many disorders as a consequence of advances in molecular biology, genetics, and immunology.

Increasing attention has also been given to behavioral and social aspects of child health, ranging from re-examination of child-rearing practices to creation of major programs aimed at prevention and management of abuse and neglect of infants and children. Developmental psychologists, child psychiatrists, neuroscientists, sociologists, anthropologists, ethnologists, and others have brought us new insights into human potential, including new views of the importance of the environmental circumstances during pregnancy, surrounding birth, and in the early years of child rearing. The later 20th century witnessed the beginning of nearly universal acceptance by pediatric professional societies of attention to normal development, child-rearing, and psychosocial disorders across the continents. In the last decade, irrespective of level of industrialization, nations have developed programs addressing not only causes of mortality and physical morbidity (such as infectious diseases and protein-calorie malnutrition), but also factors leading to decreased cognition and thwarted psychosocial development, including punitive child-rearing practices, child labor, undernutrition, war, and poor schooling. Obesity is recognized as a major health risk. Progress at the turn of the 21st century in unraveling the human genome offers for the 1st time the realization that significant genetic screening, individualized pharmacotherapy, and genetic manipulation will be a part of routine pediatric treatment and prevention practices in the future. The prevention implications of the genome project give rise to the possibility of reducing costs for the care of illness but increase privacy issues.

Although local famines and disasters, and regional and national wars have periodically disrupted the general trend for global improvement in child health indices, it was not until the advent of the AIDS epidemic in the later 20th century that the 1st substantial global erosion of progress in child health outcomes occurred. This erosion has resulted in ever-widening gaps between childhood health indices in sub-Saharan Africa compared to the rest of the world. From 1990 to 2002, life expectancy in sub-Saharan Africa decreased from 50 yr to 46 yr; 13 nations have experienced declining life expectancies. Until the WHO's global “3 by 5” campaign (three retroviral agents for 20% of global HIV victims by the year 2005), antiretroviral drugs were essentially unavailable to most developing countries, including all of those hardest hit by the HIV epidemic. Increasing rates of tuberculosis and continued problems with pandemics such as cholera further challenge many of these nations. Strains of drug-resistant malaria are also a major concern in isolated areas around the world, but 90% of malarial deaths (the majority among children) are occurring in sub-Saharan Africa. Diseases once confined to limited geographic niches, including West Nile virus, and diseases previously uncommon among humans, such as SARS and the avian flu virus, increased awareness of the interconnectedness of health around the world. Formerly perceived as a problem of industrialized nations, motor vehicle crashes are now a major cause of mortality in developing countries as well.

Enormous disparities exist in childhood mortality rates across the globe (see Table 1-4 ). Among the 10.8 million childhood deaths occurring worldwide each year, ≈41% occur in sub-Saharan Africa, home to <10% st="on">United States had an under-5 mortality rate of 8/1,000 livebirths. Thirty-five nations had under-5 mortality rates lower than that of the United States, with Singapore having the lowest rate at 3/1,000. The comparable child mortality rate in sub-Saharan Africa was 171/1,000 livebirths. Sierra Leone has the highest under-5 mortality rate at 283/1,000 livebirths, followed by Angola at 260, Afghanistan at 257, Liberia at 235, Somalia at 225, and Mali at 219. In 1990, Sierra Leone and Niger had rates in excess of 300/1,000 lives births; their current rates do represent progress. Of the 51 nations with under-5 mortality rates in excess of 200 in the year 1990, in 2003, 18 showed no improvement or a worsening, and 3 nations whose under-5 morality rate had been at <100/1,000>

Causes of under-5 mortality differ markedly between developed and developing nations. In developing countries, 66% of all deaths resulted from infectious and parasitic diseases. Among the 42 countries having 90% of childhood deaths, diarrheal disease accounted for 22% of deaths, pneumonia 21%, malaria 9%, AIDS 3%, and measles 1%. Neonatal causes contributed to 33%. The contribution for AIDS varies greatly by country, being responsible for a substantial proportion of deaths in some countries and negligible amounts in others. Likewise, there is substantial co-occurrence of infections; a child may die with HIV, malaria, measles, and pneumonia. Infectious diseases are still responsible for much of the mortality in developing countries. In the United States, pneumonia (and influenza) accounted for only 2% of under-5 deaths, with only negligible contributions from diarrhea and malaria. Unintentional injury is the most common cause of death among U.S. children ages 1–5 yr, accounting for about 33% of deaths, followed by congenital anomalies (11%), malignant neoplasms (8%), and homicides (7%). Other causes accounted for <5%>

MORBIDITIES AMONG CHILDREN.

It is important to examine morbidities as well as mortality. Adequately addressing special health care needs is important in all countries both to minimize loss of life and to maximize the potential of each individual.

In the United States, ≈70% of all pediatric hospital bed days are for chronic illnesses; 80% of pediatric health expenditures are for 20% of children. In 2004, an estimated 12.8% of children younger than age 18 yr in the United States (about 9.4 million children) have special health care needs. One fifth of U.S. households with children have 1 or more children with special health care needs. Significantly more poor children and minority children have special health care needs. Although there are multiple chronic conditions and the prevalence of these disorders vary by population, 2 of these morbidities—obesity and asthma—have a substantial and increasing presence worldwide and are associated with substantial health consequences and costs.

In the United States, ≈25% of children and adolescents are overweight, representing a 2.3- to 3.3-fold increase over the past 25 yr. Similar profiles have been reported from Australia and multiple countries in Europe. Also increasing in prevalence among industrialized nations and in middle- and low-income nations with substantial urbanization are rates of asthma. In the mid-1990s, the United States reported an annual prevalence rate of wheezing of 57.8/1,000 among children ages 0 to 4 yr and 74.4/1,000 among youth ages 5 to 15 yr, approximately twofold higher than comparable prevalence rates in 1980. The International Study of Asthma and Allergies has conducted a systematic review of asthma prevalence, with compelling evidence for a substantial global burden of childhood asthma, although rates vary substantially between and within countries. The highest annual prevalence rates are in the United Kingdom, Australia, New Zealand, and Ireland, with the lowest rates in Eastern European countries, Indonesia, China, Taiwan, India, and Ethiopia. Although there was a tendency for poorer countries to have lower asthma rates, this relationship was not absolute.

Chronic cognitive morbidities represent another substantial problem. Although different diagnostic criteria have been applied, attention-deficit/hyperactivity disorder (ADHD) is identified in >10% of children in many countries, including the United States, New Zealand, Australia, Spain, Italy, Colombia, and Great Britain. Variations in cultural tolerance and/or differences in screening approaches or tools may account for some of the differences in prevalence of the disorder by country, but genetic and gene-environmental interactions may also play a role. Despite variations in rate, the condition is universal. Beyond the personal and familial stress caused by the disorder, costs to the educational system are considerable. In the United States in 1995, an estimated $3 billion additional dollars were expended by public school systems on children with ADHD. In developing countries without resources for special education, these children are unlikely to fulfill their academic potential.

Mental retardation affects ≈1–3% of children in the United States, with 75% of these children having mild retardation. Rates are severalfold higher among very low birthweight infants, affecting between 20 and 40% of such children born in the mid-1990s. In the United States, there is substantial variation in rates of mild retardation by socioeconomic status (ninefold higher in the lowest compared to the highest socioeconomic stratum) but relatively equivalent rates of severe retardation. A similar income-related distribution is found in other countries, including some of the most impoverished countries such as Bangladesh. Lower overall rates have been reported in some countries, including countries ranging from Saudi Arabia to Sweden to China; the difference is primarily in the prevalence of mild retardation .

The prevalence of post-traumatic stress disorder (PTSD) varies considerably around the globe, but in children with substantial exposure to violence, the rates may be very high. After the attacks on the World Trade Center towers and the Pentagon in 2001, 33% of U.S. children had experienced one or more symptoms of PTSD. One half of Palestinian children experience at least 1 significant lifetime trauma and >33% (66% of those experiencing trauma) meet the criteria of PTSD. Natural disasters such as the tsunami of 2004; war, including those in Afghanistan, Sudan, and Iraq; and urban violence all leave their indelible marks on the minds of children. From 1990 to 2003, there were 59 major armed conflicts worldwide, only 4 of which were wars between nations; the majority of these internal conflicts are ethnically based. Approximately 90% of the deaths resulting from these conflicts have been among civilians, 80% among women and children. Sixteen of the world's poorest 20 countries have endured a civil war in the past 15 yr.

SPECIAL RISK POPULATIONS

In addition to the enormous differences in infant and child health between regions and nations, within countries there are substantial variations in morbidity and mortality rates by socioeconomic class and ethnicity. Most children at special risk need a nurturing environment but have had their futures compromised by actions or policies arising from their families, schools, communities, nations, or the international community. These problems have several causes, whether the end result is homeless children, runaway children, children in foster care, or children in other disadvantaged groups. The most effective preventive approach involves alleviation of poverty, inadequate parenting, discrimination, violence, poor housing, and poor education. Optimal care of these children requires reducing barriers to health care with organized programs, multidiscipline teams, and special financing.

CHILDREN IN POVERTY.

Family income is central to the health and well-being of children. Children living in poor families, especially those located in poor communities, are much more likely than children living in upper- or middle-class families to experience material deprivation and poor health, die during childhood, score lower on standardized tests, be retained in a grade or drop out of school, have out-of-wedlock births, experience violent crime, end up as poor adults, and suffer other undesirable outcomes. In 2003, 17% of U.S. children lived in poverty (defined as income < $18,400/yr for a family of four), a rate among the highest of developed countries. Seven percent lived in extreme poverty. The poverty rates are higher for children than adults and are highest for infants and toddlers. Children who are poor have higher than average rates of death and illness from almost all causes (exceptions being suicide and motor vehicle crashes, which are most common among white, non-poor children). Many factors associated with poverty are responsible for these illnesses; crowding, poor hygiene and health care, poor diet, environmental pollution, poor education, and stress.

Similar poverty-linked disparities may exist in countries with very high infant mortality rates (sub-Saharan Africa). In the low-income developing countries, the rate of infant mortality among the poorest quintile of the population is more than twice that of the wealthiest quintile ( Fig. 1-3 ).

Figure 1-3 Under-5 mortality rates by socioeconomic quintile of the household in selected countries. (From Victora CG, Wagstaff A, Schellenberg JA, et al: Applying an equity lens to child health and mortality: More of the same is not enough. Lancet 2003;362:233–241.)

Poverty and economic loss diminish the capacity of parents to be supportive, consistent, and involved with their children. Clinicians need to be especially alert to the development and behavior of children whose parents have lost their jobs or who live in permanent poverty. Fathers who become unemployed frequently develop psychosomatic symptoms, and their children often develop similar symptoms. Young children who grew up in the Great Depression in the United States and whose parents were subject to acute poverty suffered more than older children, especially if the older ones were able to take on responsibilities for helping the family economically. Such responsibilities during adolescence seem to give purpose and direction to an adolescent's life. The younger children, faced with parental depression and unable to do anything to help, suffered a higher frequency of illness and a diminished capacity to lead productive lives even as adults.

Pediatricians and other child health workers have a responsibility both to mitigate the effects of poverty on their patients and to contribute to efforts to reduce the number of children living in poverty. Clinicians should ask parents about their economic resources, adverse changes in their financial situation, and the family's attempts to cope. Encouraging concrete methods of coping, suggesting ways to reduce stressful social circumstances while increasing social networks that are supportive, and referring patients and their families to appropriate welfare, job training, and family agencies can significantly improve the health and functioning of children at risk when their families live in poverty. In many cases, special services, especially social services, need to be added to the traditional medical services; outreach is required to find and encourage parents to use health services and bring their children into the health care system. Pediatricians also have the responsibility to contribute to and advocate for safety net services for impoverished children within and outside the boundaries of their own country. An increasing number of programs are available to help children of greatest need worldwide, such as Project Smile, CARE, Project Hope, and Doctors Without Borders.

CHILDREN OF IMMIGRANTS AND RACIAL MINORITY GROUPS INCLUDING U.S. NATIVE AMERICANS.

Eleven percent of the U.S. population is foreign-born; 1 of every 5 children lives in an immigrant family. The United States is experiencing a wave of immigration larger than that occurring in the early 20th century. There has been an increase in immigration from China, India, Southeast Asia, Mexico, the Dominican Republic, and the former Soviet Union nations. Until the mid-20th century, emigrants to the United States were primarily white and from Europe. Such individuals now represent only about 10% of immigrants; the remainder are overwhelmingly of color and from throughout the world. Although immigrants in the United States have faced discrimination and oppression throughout history, the potential for such discrimination is compounded by the racial differences represented in the current immigrant pool. In the United States, about 240,000 children legally immigrate each year, and an estimated 50,000/yr enter the country illegally. Immigrants now comprise >15% of the population in >50 countries, including many Western European countries.

The immigrant population constitutes a substantial proportion of the low-wage labor market. Immigrants represent 14% of all U.S. workers but 20% of low-wage workers. Immigrants are twice as likely as U.S.-born citizens to earn less than minimum wage. The poverty rate of children in immigrant families is 50% greater than in U.S.-born families, with 50% of immigrant children compared to 33% of children in U.S.-born families being below the 200% poverty level. Contributing to the lack of access to higher salaried jobs is the lack of proficiency in English (≈66% of immigrants) and the lack of education (40% have not completed high school). Immigrant fathers are as likely as U.S.-born fathers to work full-time (80%) but are 33–50% less likely to receive social welfare benefits. This gap exists for cultural reasons (many immigrants feeling it inappropriate to accept social support or fearing contact with governmental authorities), logistical complications (especially problematic given limited language skills), and reduced eligibility since the Welfare Reform Act of 1996. In the past decade, about 9 million immigrants attained permanent residency status. There may be 850,000–1,000,000 illegal immigrant children.

Families of different origins obviously bring different health problems and different cultural backgrounds, which influence health practices and use of medical care. To provide appropriate services, clinicians need to understand these influences. For example, the high prevalence of hepatitis among women from Southeast Asia makes use of hepatitis B vaccine essential for their newborns. Children from Southeast Asia and South America have growth patterns that are generally below the norms established for children of Western European origin, as well as high rates of hepatitis, parasitic diseases, and nutritional deficiencies and high degrees of psychosocial stress. Foreign-born children may surpass American-born children in many health outcomes, but their health deteriorates as they become acculturated.

Refugee children who escape from war or political violence and whose families have been subjected to extreme stress represent a subset of immigrant children who have faced severe trauma. These children have a particularly high incidence of mental and behavioral problems.

“Linguistically isolated households,” in which no one older than 14 yr of age speaks English, often present significant obstacles to providing quality health care to children because of difficulties in understanding and communicating basic concerns and instructions, avoiding compromising privacy and confidentiality interests, and obtaining informed consent

The United States is home to multiple minority populations, including the 2 largest groups, Latinos and African Americans. The nonwhite minority groups will constitute >50% of the U.S. population by 2050. Nonwhite children in the United States disproportionately experience adverse child health outcomes (see Tables 1-1, 1-2, and 1-3 [1] [2] [3]). Infants born to African-American mothers experience low-birthweight and infant mortality rates twice those with white mothers. Rates of these 2 adverse health outcomes are also substantially higher among Hispanic infants and children, although there is great variation by country of origin. The rates are particularly high among those of Puerto Rican descent (≈1.5 times the rates for white infants). In 2002, the infant mortality rate for white infants was 5.8/1,000, whereas that for African-America infants was 12.5; for Native Americans, 8.1; and for Hispanics, 5.9 ( Table 1-6 ). Latino, Native American, and African-American children are substantially more likely to live in poverty than are white children.

TABLE 1-6 -- Incidence of Low Birthweight and Infant Mortality Among Selected Groups of Native-Born vs Foreign-Born Mothers

	LOW BIRTHWEIGHT (PERCENT)		INFANT MORTALITY (RATE PER 1,000 BIRTHS)
Racial/Ethnic/Immigrant Group	Native-Born Mother	Foreign-Born Mother	Native-Born Mother	Foreign-Born Mother
White	4.5	3.9	5.8	4.6
African American	11.8	8.0	12.9	10.5
Mexican	5.4	4.1	6.6	5.3
Puerto Rican	7.9	7.5	7.8	7.0
Cuban	4.7	4.4	5.3	4.7
Central/South American	5.2	4.8	5.2	5.0
Chinese	4.8	3.8	4.6	4.3
Filipino	6.9	6.1	6.8	4.8
Japanese	5.0	5.0	3.7	3.7
Other Asian	5.3	5.7	6.2	5.3

In Hernandez DJ (ed): Children of Immigrants: Health, Adjustment, and Public Assistance. Washington, DC, National Academy Press, 1999, pp 244–285. From Landale NS, Oropesa RS, Gorman BK: Immigrants and infant health: Birth outcomes of immigrant and native-born women.

There are ≈2.5 million Native Americans (4.1 in combination with other races/ethnicities) and 558 federally recognized tribes. With 840,000 children (1.4 million in combination), the Native American population has a much higher proportion of children (34%) than does the remainder of the U.S. population (26%). About 60% of Native Americans live in urban areas, not on or near native lands. Like their minority immigrant counterparts, they have faced social and economic discrimination. The unemployment and poverty levels of Native Americans are, respectively, threefold and fourfold that of the white population, and far fewer Native Americans graduate from high school or go to college. The rate of low birthweight among Native Americans is more than the white rate but less than the black rate. The neonatal and the postneonatal mortality rates are higher for Native Americans living in urban areas than for urban white Americans. Deaths in the 1st yr of life due to sudden infant death syndrome, pneumonia, and influenza are higher than the average in the United States, whereas deaths due to congenital anomalies, respiratory distress syndrome, and disorders relating to short gestation and low birthweight are similar.

Unintended injury deaths among Native Americans occur at twice the rate for other U.S. populations; deaths due to malignant neoplasms are lower. During adolescence and young adulthood, suicide and homicide are the 2nd and 3rd causes of death in this population and occur at about twice the rates of the rest of the population. There may be significant underreporting of deaths of Native American children.

As many as 75% of Native American children have recurrent otitis media and high rates of hearing loss, resulting in learning problems. Tuberculosis and gastroenteritis, formerly much more common among Native Americans, now occur at about the national average. Psychosocial problems are more prevalent in these populations than in the general population: depression, alcoholism, drug abuse, out-of-wedlock teenage pregnancy, school failure and dropout, and child abuse and neglect.

Most other nations have indigenous populations who are subjected to discrimination, social and economic sanctions, and/or physical maltreatment and who demonstrate the poorest child health outcomes. An estimated 300 million indigenous persons live in 70 countries (50% in Asia) and speak ≈4,000 languages. Such children endure lower vaccination rates, lower school entry and higher dropout rates, higher rates of poverty, and lower access to justice. Indigenous children in Latin America account for 66% of the deaths of children younger than age 2 yr.

In the United States, existing programs for meeting child health problems are not available to all families in need, with gaps between eligibility for public support and parents' ability to pay for services. Needed services for immigrants are often either nonexistent or fragmented among programs, agencies, or policies. Programs are often poorly coordinated, and the data collection is inadequate.