John P. DiBartolo Jr.: Finding shades of grey in a recent school late-start study

Last modified: Tuesday, April 15, 2014
NORTHAMPTON — I have been reluctant to publicly express my opinion on the late start issue given that so many friends whose opinions I respect seem to feel strongly that the start time at Northampton High School should be pushed back. People are entitled to differing views and I do not doubt that there are individual students who might benefit from a later start.

However, proponents of the late start often allude to scientific studies as providing support for their position. The findings of these studies are not always consistent with the positions advanced by supporters.

Most recently, late start advocates have been referencing the study conducted at the University of Minnesota that reviewed eight high schools and was covered in the New York Times on March 14.

It should go without saying that it would be inappropriate to use a study that found some benefit of an 8:35 a.m. start time to justify an 8 or 8:15 start time. However, given the media and social media accounts of this particular study, further comment seems warranted.

The Minnesota study showed that 33.6 percent of students were getting eight hours of sleep in two districts with a 7:30 start, as compared with 60 percent of students getting eight hours of sleep in four districts with 8:35 start times. Viewed in the light most favorable to late-start proponents, this study would suggest that moving the start back by 65 minutes might result in 26.7 percent of students getting at least eight hours of sleep.

It is worth noting that even 65 additional minutes would not be expected to affect another 40 percent of students who would still not manage to get eight hours.

Obviously, the Minnesota study should not be considered as evidence that moving to 8 or 8:15 would produce similar results as described above; in fact, the data in the study showed the contrary. In two districts with 7:35 start times, a higher percentage of students got eight hours of sleep than in two other districts where the start times 30 minutes later at 8:05 (44.2 percent at 7:35 vs. 42.5 percent at 8:05).

Although the “major findings” section of the University of Minnesota study touted a decrease in motor vehicle collisions by as much as 70 percent by using an 8:55 start time, the actual data in the report suggest such a finding is misleading.

Notwithstanding that local advocates are not suggesting such a late start for Northampton, it is misleading to even suggest the study conclusively demonstrated a causal relationship. The study reviewed data from four districts: one had a 65 percent decrease in collisions; one had a 70 percent decrease; another had a 6 percent decrease; and still another had a 9 percent increase in collisions. Most notably, the one school with the 70 percent decrease actually saw the percentage of early day collisions increase from 26 percent to 57 percent.

There are so many variables for which there were no controls in this part of the study that it seems inappropriate to suggest any causal relationship at all.

The Minnesota study also notes “significantly positive improvement” on “state and national achievement tests.” However, the table of “performance on standardized tests” illustrates that only three out of 25 comparisons were characterized as significant increases — two showed decreases and 20 showed “no significant” affect relative to start time. Furthermore, a quick look at the appendices containing the data reveals that each of the three increases was just one point or a fraction of a point.

Nevertheless, there is ample scientific evidence to show that students are better off, in a number of different measures, if they receive eight or more hours of sleep. The issue is not start time, but getting students the eight hours or more of sleep that they need.

The same Minnesota study expressly states that, “the reason adolescents tend to have insufficient sleep is not solely due to their body’s natural changes, but also due to an interaction with societal expectations and norms.”

The study cites among its biological factors that influence the amount of sleep that the “pressure to fall asleep tends to become lower as a child enters adolescence.” The study also points to the use of technology, light exposure from electronics and use of caffeine as all contributing to students getting fewer than eight hours of sleep.

All of these factors can be affected, at no cost, on an individual basis for any student who is interested in getting more sleep.

John P. DiBartolo Jr. is an attorney who practices in Northampton.