Smartphone screentime is associated with poor sleep, according to research published in PLoS One.1

Researchers performed a cross-sectional analysis in a subset of more than 650 adults, measuring smartphone screentime on participants’ phones via an app. Researchers calculated total and average screentime per participant during a 30-day period and calculated screentime during self-reported bedtime hours and sleeping period.

Median total screentime for 30 days was 38 hours and median average screentime for 30 days was 3.7 minutes per hour. Younger age and self-reported race/ethnicity of “black” or “other” were associated with longer average screentime after adjustment for potential confounders.

Longer average screentime was associated with shorter sleep duration and worse sleep efficiency. Longer average screentimes during bedtime and sleeping period were associated with poor sleep quality, decreased sleep efficiency, and longer sleep onset latency.

Researchers made clear that causation could not be established—poor sleep may lead to increased screentime, they offered as an example—but concluded that exposure to smartphone screens may have adverse effects on sleep, particularly if exposure occurs during bedtime.

 

1. Christensen MA, Bettencourt L, Kaye L, et al. Direct measurements of smartphone screen-time relationships with demographics and sleep. PLoS One. 2016;11(11):e0165331.

Study: Preterm Birthrate Fell Between 2007 and 2014, Teen Births Also Down

The percentage of preterm births decreased by 8.4% from 2007 to 2014, according to a study published in the Morbidity and Mortality Weekly Report.1 There were approximately 450,000 preterm births in 2007 (10.4% of all births) and 380,000 preterm births in 2014 (9.5% of all births).

Maternal age increased from mean 27.4 years to 28.3 years during the study period. The number of births to women under 20 years fell from 450,000 to 250,000, a nearly 40% decrease; women between 20 and 24 years also saw decreased birthrates, from 1 million to 900,000 births.

The number of preterm births for women under 20 years was cut in half: 49,000 women under 20 delivered prematurely in 2007 and 24,500 delivered prematurely in 2014. The only age group to see an increase in preterm births was women between 30 and 34 years. There were 98,000 preterm births in that age group in 2007, and 101,000 preterm births in 2014 (1% increase).

Researchers partially credited the decline in preterm birthrates to success of teen pregnancy prevention programs and declines in unintended pregnancy. n

1. Ferré C, Callaghan W, Olson C, et al. Effects of maternal age and age-specific preterm birth rates on overall preterm birth rates—United States, 2007 to 2014. MMWR Morb Mortal Wkly Rep. 2016;65(43):1181-1184.

 

Section Editor David S. Boyer, MD
• clinical professor of ophthalmology at the University of Southern
California Keck School of Medicine, department of ophthalmology,
in Los Angeles, Calif.
• member of the Retina Today editorial advisory board
• +1-310-854-6201; vitdoc@LARetina.com