Child Growth Charts Often Difficult to Understand

< Sep. 30, 2009 > -- The growth charts widely used in pediatricians' offices are not easily understood or interpreted by many parents, a new survey finds. The results of the survey are reported in the medical journal Pediatrics.

About 85 percent of parents could look at a growth chart with one point plotted and correctly identify that the point corresponded to the child's age, according to an online survey of a nationally representative group of 1,000 moms and dads. About two-thirds of parents were able to identify both a child's weight and percentile on a chart with one plotted point.

But only 56 percent could correctly identify the meaning of "percentile" from a list of choices. In the context of a growth chart, a percentile measures how a child stacks up to his or her peers. A child who is in the 80th percentile for height, for example, is taller than 80 percent of other children his or her age, while a child in the 25th percentile, is shorter than 75 percent of his or her peers.

Only one-third of parents could identify a child's age, weight, and percentile on a chart, as well as the correct definition of percentile.

Monitoring a Child's Growth

Growth charts were developed in the 1960s to help physicians monitor a child's development, says study author Dr. Elana Pearl Ben-Joseph, consulting medical editor at Nemours Center for Children's Health Media. The latest versions, from the US Centers for Disease Control and Prevention (CDC), were updated in 2001.

The charts were meant for use by health-care providers. However, in practice, physicians often use the charts as visual aids for parents. About 31 percent of parents said they marked their child's growth on a chart at home.

Dr. Ben-Joseph says, "Growth charts can be helpful if used properly and if the parents understand them and they are explained properly. But they can be detrimental if not explained well or if parents aren't understanding them."

Parents Often Lack Understanding

The researchers found that many parents do not understand the growth charts. In the survey, about half of parents said a child in the 10th percentile for height and weight was underweight. To doctors, the child's height and weight is proportional and probably no cause for concern, Dr. Ben-Joseph notes.

Many parents expressed concern about a child in the 25th percentile for height and weight year after year. About 16 percent said they would encourage the child to eat more and 18 percent said they did not know what the information meant.

A child following a 25th percentile growth curve is smaller and lighter than average, but again, nothing to worry about, says Dr. Ben-Joseph.

When reading growth charts, doctors tend to look for abrupt changes, such as a child whose height or weight trend suddenly drops off, which could be a sign of a problem. They also look for proportionality in height and weight.

A child with a height in the 10th percentile and weight in the 90th percentile is overweight, though about half of parents in a survey did not realize this.

More Understanding Needed

The confusion over growth charts brings up the larger issue of "numeracy" - the numerical counterpart to literacy - or the ability of patients to understand risk, statistics, graphs, and charts used with increasing frequency in health care, says Dr. Goutham Rao, clinical director of the Weight Management and Wellness Center at Children's Hospital of Pittsburgh.

"When a patient comes to a doctor's office or a health-care facility, there are specific numeracy skills they need to understand their condition and what transpires in the health-care environment," Dr. Rao says. "It's not just patients that can have trouble with this: physicians can also have difficulty putting numbers into terms patients can understand."

Even so, growth charts remain a useful tool for broaching the delicate issue of a child's weight with parents, Dr. Rao points out. About 12.4 percent of children 2 to 5 years old are overweight, 17 percent of children ages 6 to 11 are overweight and 17.6 percent of teens ages 12 to 19 are overweight, according to the CDC.

"Many times parents don't recognize that their child is overweight," says Dr. Rao, whose clinic uses electronic charts so parents can take home printouts of the result. "We can show the parent where the child is on the growth chart, provide a very detailed explanation of the numbers and make sure the parents are able to understand it. Then we can ask the parents if it's something they would like to work on."

Further research should be done into developing growth charts that are easier for parents to understand, Dr. Ben-Joseph adds.

"There is a desire by the parents to see the growth chart and have doctors talk to them about it," says Dr. Ben-Joseph. "It's important for doctors to be aware that not all parents will understand these complicated mathematical concepts and to take that into account when they are doing the explaining."

Always consult your child's physician for more information.

Child Growth and Development

Understanding your child's changing and emerging growth and development is an important part of parenting. As infants and children progress through a series of growth stages, they may encounter physical and emotional challenges and some relatively common problems during these years.

Growth not only involves length and weight of a body, but also includes internal growth and development. A child's brain will grow the most during the first 5 years of life, reaching 90 percent of its final size.

Growth also affects different parts of the body at different rates; the head reaches almost its entire size by age 1. Throughout childhood, a child's body becomes more proportional to other parts of his/her body. Growth is complete between the ages of 16 and 18, at which time the growing ends of bones fuse.

Growth and development includes not only the physical changes that will occur from infancy to adolescence, but also some of the changes in emotions, personality, behavior, thinking, and speech that children develop as they begin to understand and interact with the world around them.

Keeping your child healthy with physical care and emotional support is a part of health maintenance. Topics in health maintenance include ways to promote healthy lifestyles in daily activities such as play and sleep, and also ensure your child receives proper dental care, immunizations, and discipline.

As a child grows from infancy through adolescence, it is important to promote good health throughout some of the common problems of development.

From diaper rash in babies, to toilet training in young children, health promotion topics also include learning disabilities and bedwetting for the school-aged child, and eating disorders and substance abuse for the adolescent.

Always consult your child's physician for more information.