In the first national study of children's use of eye care services in 30 years, the researchers find that about a quarter of all children wear glasses or other corrective lenses, and that about the same proportion had seen an eye care specialist in the last year.
But when the researchers looked further, they found some clear disparities in level of vision care and correction among school-aged children according to gender, race, insurance status and family income. They will outline their results in a pair of presentations on May 5 at the Pediatric Academic Societies annual meeting here.
"Even though vision problems are some of the most common chronic health conditions affecting children, there's been very little research on their prevalence, diagnosis and treatment," says Alex Kemper, M.D., M.P.H., M.S., an assistant professor and member of the U-M Health System's Child Health Evaluation and Research team. "These data show that while a large number of children are getting vision care, there are clear differences in care along racial and economic lines."
The results, he notes, mean doctors, parents and schools need to do better at screening all children for vision problems, making sure they get referred for eye care, and finding ways to overcome economic, social and cultural barriers to good vision.
Kemper and his colleagues performed their research using two federal databases containing the answers of thousands of parents to in-depth, in-person interviews -- allowing extrapolation to the national population. The data included information on children's age, gender race, insurance status, family income, health status, and recent medical care. The study focused on children between the ages of 6 and 17.
In all, the researchers estimate from the results, 24.8 percent of the nation's children have had some eye care in the past year, and 25.4 percent wear corrective lenses. Girls are 29 percent more likely than boys to have seen an eye specialist recently, and are 41 percent more likely to wear glasses or lenses.
But the bigger differences between groups emerged when the researchers looked at vision care and use of corrective lenses by race, income and insurance status.
In all, non-Hispanic and non-black children were 47 percent more likely than Hispanic children -- and 59 percent more likely than black children -- to have received eye care in the last year.
Insurance status and income also mattered when it came to seeing an eye specialist, but Kemper notes that there seems to be a clear positive effect from Medicaid's coverage of vision services. "Medicaid covers more eye care than many commercial insurance plans, including glasses and even replacement glasses," he notes.
Among children whose family income was less than twice the federal poverty level, children with public health insurance such as Medicaid were actually more likely to have seen a vision specialist than children with private health insurance or children with no insurance. The effect was less pronounced in families living on more than twice the poverty-level income, but uninsured children in these families were still the least likely to have seen an eye specialist.
When it came to which children were actually wearing corrective lenses -- eyeglasses or contact lenses -- the effects of insurance status, income and race mingled:
- Uninsured black or Hispanic children were much less likely than uninsured children of other races or ethnicities to have corrective lenses.
- Uninsured black or Hispanic children were less likely to have corrective lenses than black or Hispanic children with public or private insurance.
- Higher family income was associated with an increase in the likelihood of having corrective lenses among children aged 12 and over, regardless of insurance, race or ethnicity.
Nearsightedness (myopia) and farsightedness (hyperopia) are the most common causes of vision problems in children. Most cases can be corrected almost completely through the use of eyeglasses or contact lenses, but many cases can go undiagnosed until children are screened for vision problems in school, or until alert parents ask their child's doctor to conduct a vision test or take their child directly to an eye doctor.
Vision screening tests using eye charts are often part of regular well-child physician visits. In the study, children 12 to 14 years old who received regular well-child care were more likely to receive eye care.
Overall, Kemper notes that many factors may be contributing to the disparities in eye care and corrective lens use between children of different genders, racial and ethnic backgrounds, incomes and insurance statuses. There may be differences in the actual rate of vision problems in these groups, he says -- though there is not enough data on incidence to know for sure.
But because much of the disparity found in the study was economic in nature, the researchers think it's unlikely that physical differences are solely to blame. They suspect that uninsured families may be unable to pay for appointments with eye specialists and corrective lenses, and that many privately insured families lack specific coverage for basic eye care, making it an out-of-pocket health expense. This is supported by the finding that private insurance only increased the likelihood of eye care among children in families living at more than twice the poverty level.
Cultural and social barriers may also be at work, such as parents' and teachers' perceptions of the differences between how boys and girls function with poor vision. Just as gender differences in behavior have led to a disparity between boys and girls in diagnosis of attention deficit hyperactivity disorder, similar factors may be at work in suspicion and diagnosis of poor vision.
In all, Kemper says, more studies of children's eye health are needed in order to understand the prevalence of eye disorders, the influence of insurance coverage, and the impact of uncorrected poor vision on school performance.
"If early detection of visual impairment is important for long-term educational performance, which we think it may be, then it's possible that disparities in eye care and corrective lens use may lead to an 'education gap' by gender, race, ethnicity, income and insurance status," Kemper concludes. "Our study is a first step in understanding this entire issue."
The study of eye care patterns used data from the National Health Interview Survey conducted in the year 2000 by the National Center for Health Statistics, part of the Centers for Disease Control and Prevention. The study of corrective lens use was based on data from the 1998 Medical Expenditure Panel Survey, sponsored by the Agency for Healthcare Research and Quality. Both surveys are conducted using statistical methods to provide data representative of the nation's health care and health care spending and coverage.
In addition to Kemper, the study was performed by programmer-analyst David Bruckman, M.S., and by Gary Freed, M.D., M.P.H, the Percy and Mary Murphy Professor of Pediatrics and Child Health Delivery, and Director of the Division of General Pediatrics, in the U-M Medical School. It was carried out using Kemper's Pfizer Scholar Grant for faculty development in pediatric health.