Summary and Critique by Claude Bingham
As part of his dissertation, Brett Litwiller conducted a meta-analysis of studies that examined sleep's effect on work quality. As this is a summary geared towards intelligence professionals, the findings will be limited to ideas that inform readers of this specific blog.
Litwiller starts by explaining that a recent study found 34% of American workers fell asleep unintentionally in the past 30 days. He defines sleep as a, "... state of immobility that consists of
greatly diminished physical responsiveness and is more rapidly reversible than
anesthesia or coma (Siegel, 2005)." Insufficient amounts of quality sleep, Litwiller says, leads directly to disease and workplace ineffectiveness. Sleep quality is obviously hard to quantify outside of hours of sleep completed.
Based on his literature review, he explains that supportive work environments actually reduce the effects of sleep deprivation but stressful environments will not only exacerbate their effects but also harm sleep quality in return. Analysis of source studies showed the following effects on effectiveness: increased accidents or mistakes, especially for monotonous tasks, increases in mental instability such as depression, mood changes, and burnout, and increases in work absences. Interestingly, sleep had no significant effect on how much people enjoyed their job, just how well they performed at it and connected with peers.
Meta-analyses are generally considered the most valid form of research as they have the benefit of testing already completed research results against each other. Litwiller was very keen to make sure results were compared only to like studies; only two studies examined actually used empirically validatable and testable definitions of sleep in their research. Likewise, most of the studies were based on self-reported results, something that can create incredibly drastic errors in data collection, considering the nature of sleep. These two factors make this meta-analysis slightly less credible than it would be otherwise, however, the sheer amount of data analysed showed that the results were mostly consistent, rarely contradictory, and showed a high correlation between more and better sleep, and better work production.