A new study reveals that nearly all U.S. kids under the age of 4 use a mobile device such as a tablet or smartphone, Medical xpress reports.

The study was published in the Nov. 2 online edition of the journal Pediatrics.

The study was conducted on 350 children in a low-income, minority community. This also indicated that the income-based "digital divide" is getting narrower.

"Access to, familiarity with and skill using mobile devices are the first steps in achieving digital literacy," said one of the study's authors, Dr. Matilde Irigoyen, chair of pediatrics and adolescent medicine at Einstein Medical Center in Philadelphia.

However, one expert pointed out the trend as "disturbing," because it suggests that technology might be being used by parents as a surrogate babysitter.

"Parents in this study admitted to using mobile media for their children to keep them quiet or entertained in public places or in place of the interaction at bedtime," said Dr. Danelle Fisher, vice chair of pediatrics at Providence Saint John's Health Center in Santa Monica, Calif.

"Children need parental interaction for many reasons and this trend is, overall, worrisome."

For the study, researchers gave a questionnaire to parents of 350 children between 6 months and 4 years of age who visited a Philadelphia pediatric clinic in October and November of 2014.

The study found that the older the children were, the more likely they were to have their own technology. By age 4, about three-quarters of youngsters had their own mobile device, and half had their own TV.

The study found that 97 percent of the children in the study had used a smartphone or tablet.

The parents' education and the child's gender and ethnicity did not play any role in whether or not the child owned a mobile device.

Fisher pointed out that "some interactions can be beneficial and some detrimental."

She added that earlier studies had pointed a connection between mobile devices and disturbed sleep patterns.