Authors:

Abstract

Learning and developmental disabilities (LDDs) include functional limitations that manifest in infancy or childhood as a result of disorders of or injuries to the developing nervous system (Institute of Medicine Committee on Nervous System Disorders in Developing Countries 2001). These limitations range from mild to severe and can affect cognition, mobility, hearing, vision, speech, and behavior. The known causes of LDD are numerous and include genetic factors, nutritional factors, infections, toxic exposures, trauma, perinatal factors, and multifactorial conditions.

Although information on the prevalence and impact of disabilities in low- and middle-income countries (LMICs) is scarce, five considerations support the conclusion that LDDs are a public health priority in LMICs today:

• Prevalence: Although each individual cause is relatively rare, taken together, LDD affects a large proportion of children. In high-income countries, 10 to 20 percent of children have an LDD (Benedict and Farel 2003). With improvements in child survival in LMICs, it is not known whether the prevalence of disabilities among children is increasing, as has been seen in wealthier countries (Winter and others 2002), but the few data available from LMICs suggest that the prevalence of specific causes and types of LDD may be even higher than in high-income countries. Examples include cognitive disabilities associated with prenatal iodine deficiency, brain infections, and blindness associated with vitamin A deficiency (Durkin 2002). The prevalence of childhood disabilities in LMICs is not well established, but it is likely higher than in high-income countries.
• Lifelong Duration: By definition, LDDs have an early onset, with the causes frequently occurring in the prenatal period. These effects are typically lifelong, affecting learning and other neurological functions, educational achievement, quality of life, earning potential, and productivity across the life span.
• Costs: The extensive costs include the direct costs of acute care, outpatient health care services, long-term care, rehabilitation, and special education, as well as the indirect costs of morbidity and increased mortality (Waitzman, Romano, and Scheffler 1994). Additionally, the costs and effects extend beyond the individuals affected to include entire families. Health, careers and employment of parents, family disposable income, health and adaptation of siblings, and family interaction are adversely affected when a family member has an LDD (Stein and Jessop 2003). It is difficult to comprehend the extent of these effects, just as it is difficult to measure them and develop economic models that account for them.
• Education and Work: As societies and economies become increasingly information-oriented and dependent on educated and literate workers, the impact of disabilities affecting cognition and learning becomes greater (Institute of Medicine Committee on Nervous System Disorders in Developing Countries 2001).
• Proven Interventions: The prospects for preventing LDD and for improving outcomes are considerable and can be achieved, to some extent, by implementing interventions that have been shown to be effective and cost-effective elsewhere but that are not being implemented in LMICs.

This chapter provides an overview of the range of interventions likely to improve child development and educational outcomes for children in LMICs. Evidence of cost-effectiveness is considered in some detail for three selected interventions. An overview of other key risk factors and conditions that result in LDD is provided. A research agenda is outlined for advancing knowledge of how to prioritize cost-effective interventions and how best to devote resources for the prevention of LDD in LMICs.

Full Article [PDF] from the Disease Control Priorities Project web site