Study Title and Description
Energy drink consumption and its association with sleep problems among U.S. service members on a combat deployment - Afghanistan, 2010.
Key Questions Addressed
|1||For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on behavior*?|
Primary Publication Information
|Title||Energy drink consumption and its association with sleep problems among U.S. service members on a combat deployment - Afghanistan, 2010.|
Secondary Publication Information
There are currently no secondary publications defined for this study.
Extraction Form: Behavior - Design Details - INCLUDED Studies
No arms have been defined in this extraction form.
|Question... Follow Up||Answer||Follow-up Answer|
|What outcome is being evaluated in this paper?||Behavior|
|What is the objective of the study (as reported by the authors)?||To determine the extent of energy drink use and the association with sleep problems and sleepiness during combat operations, Walter Reed Army Institute of Research analyzed data collected by Joint Mental Health Advisory Team 7 (J-MHAT 7) to Operation Enduring Freedom in Afghanistan in 2010.|
|Provide a general description of the methods as reported by the authors. Information should be extracted based on relevance to the SR (i.e., caffeine related methods)||In total, 1,249 service members were surveyed using a cluster sample of randomly selected U.S. Army and Marine combat platoons deployed to Afghanistan. All participants were male, because of the type of unit surveyed. Of those surveyed, 1,000 consented to have their data used for research purposes and 988 answered the following question: "How many energy drinks (e.g., Monster, Red Bull, 5-Hour Energy) do you use per day?" The six response options ranged from zero to five or more drinks per day. Service members also were asked about their use of sleep medication, average number of hours of sleep per day, concerns regarding lack of sleep, disruptions to sleep, and work impairment associated with sleepiness (Table 1). The number of sleep hours was dichotomized at ≤4 hours (reported by 24.2% of the persons sampled); in comparison, 50.2% of those sampled reported sleeping ≤5 hours. For comparison across sleep outcomes, energy drink use was divided into the following categories: no drinks, one to two drinks, and three or more drinks per day. These cutoffs were chosen because previous research demonstrated that 200 mg of caffeine, the equivalent of one to two energy drinks, improved cognitive performance in a military population (4). Prevalence rates of energy drink use are reported. Chi-square tests were used to determine significant differences between groups for sleep variables, using p<0.05 for significance. Post hoc analyses of the chi-square tests were conducted by examining discrepancies between observed and expected values for standardized residuals to produce z-scores and identify those cells contributing to the significant differences. The Sidak-Bonferroni correction was used to account for conducting multiple post hoc tests.|
|How many outcome-specific endpoints are evaluated?||1|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||sleep|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|Notes||sleep as measured by total sleep time, disruptions, and daytime sleepiness|
|What is the study design?||Cross-sectional|
|Randomized or Non-Randomized?|
|What were the diagnostics or methods used to measure the outcome?||Subjective|
|Optional: Name of Method or short description||survey|
|Energy drinks||Energy drinks|
|What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.)||0, 1-2, ≥3 energy drinks per day|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||N/A|
|Provide a general description of results (as reported by the authors).||Service members who drank three or more energy drinks per day were more likely to report ≤4 hours of sleep on average per night (38.2%) than service members who drank one to two (18.4%) or zero (23.9%) energy drinks per day (Table 3). The groups did not differ in their levels of concern regarding not getting enough sleep. Service members drinking three or more energy drinks per day were significantly more likely than the other groups to report sleep disruption on more than half the nights in the past 30 days because of stress related to combat, stress related to personal life, and illness. However, no differences were noted in sleep disruption because of the sleep environment, high operational tempo, nighttime duties, or leisure activities. Service members who drank three or more energy drinks per day also were significantly more likely to report sometimes or often falling asleep while sitting in briefings or while on guard duty, but not while riding in convoys.|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||No|
|What were the authors's observations re: trend analysis?|
|What were the author's conclusions?||Service members drinking three or more energy drinks a day were significantly more likely to report sleeping ≤4 hours a night on average than those consuming two drinks or fewer. Those who drank three or more drinks a day also were more likely to report sleep disruption related to stress and illness and were more likely to fall asleep during briefings or on guard duty.|
|What were the sources of funding?||none listed|
|What conflicts of interest were reported?||N/A|
|Does the exposure (dose) need to be standardized to the SR?||Yes|
|Provide calculations/conversions for the exposure based on the decision tree in the guide (for all endpoints/exposure levels of interest).||energy drink = 80 mg 2x energy drinks = 2 x 80 mg = 160 mg 3x energy drinks = 3 x 80 mg = 240 mg|
|List all the endpoint(s) followed by the dose (mg) which will be used in comparison to Nawrot. Characterize value as LOAEL/NOAEL, etc. if possible.||sleep - LOAEL = ≥ 240 mg/day; NOAEL = 80-160 mg (more sleep disruptions and were more likely to have reduced sleep and experience daytime sleepiness)|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||effects seen at levels below Nawrot.|
|What is the importance of the study with respect to the adverseness of the outcome?||Important|
No baseline characteristics have been defined for this extraction form.
Results & Comparisons
No Results found.
|Arm or Total||Title||Description||Comments|
No quality dimensions were specified.
No quality rating data was found.