Researchers gave 557 parents the Short Test of Functional Health Literacy. Then they asked them if they had a TV in the room where their child sleeps. Those who scored below the “adequate” range for health literacy were more likely to have a TV in the child’s room, and more likely to report their child slept less than the reported mean. So the child’s inadequate sleep and related behavioral problems, poor school performance and obesity s are attributed to parents “inadequate” or “marginal” health literacy.
This report reminds me of the classic example in statistics class: Research shows that men with hair in their ears are significantly more likely to have heart attacks. The quiz: Does hair in the ears cause heart attacks? Should we recommend removing hair from the ears to reduce risk? Should we test all men with hairy ears for atherosclerosis?
Of course not
You’re right. The lesson is that association does not equate to cause. Despite statistical significance, hair in the ears is not a reliable indicator of elevated risk of heart attack. You can imagine the disservice to men with hairy ears: anxiety, needless testing, unnecessary tweezing. I wondered then, and still, why was that study published?
Statistically significant, practically meaningless
The TOFHLA is a timed (7-minute maximum) reading comprehension test on instructions to prepare for a medical procedure. Despite it’s name, it is widely criticized as a test of health-related literacy and not a measure of the broader concept of health literacy. TOFHLA scores predicted the location of the TV, just as hairy ears predicted heart attack.
Publishing the association as if it matters suggests that if those parents could read better, they would know pediatricians recommend against a TV in the nursery; and knowing that, they would comply; and therefore the child would sleep more; and therefore, the child would be healthier.
That is a long line of assumptions that disrespects parents and offers little guidance for improving their reading ability or their health literacy, or for supporting unskilled readers to be good parents, or for communicating more clearly that location of the TV matters to the child’s heath. It should be noted that nearly half of parents who performed well on the test also reported a TV in the nursery; and a third of those who performed poorly on the test placed the TV elsewhere. More than half of infants with a TV in the room had normal sleep duration.
I have high respect for these researchers and their contributions to the field. Still, this study is one that should not have been published. It places way too much faith in a reading test that has long been criticized as an inadequate measure, and not nearly enough faith in parents.