Study Title and Description
Situational insomnia: consistency, predictors, and outcomes.
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||Situational insomnia: consistency, predictors, and outcomes.|
|Author||MH Bonnet,DL Arand,|
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)?||The purpose of this study was to determine the consistency of situational insomnia across several stressful conditions, including the first night in the sleep laboratory, phase advance of sleep time by 3 hours, phase advance of sleep time by 6 hours, and administration of 400 mg of caffeine. The impact of situational insomnia on alertness, metabolic rate, and cardiac measures on the following day was also measured.|
|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)||Subjects Subjects were required to be healthy men and women, aged 18 to 39 years. Potential subjects were solicited from research referrals and from advertisements in the local newspapers (including local university newspapers) for participants in sleep research. The majority of individuals applying to participate in the study were students from local universities. Individuals who were considered for participation completed a screening questionnaire that indicated that they had normal sleep (ie, no sleep problems and a sleep latency less than or equal to 30 minutes, wake time during the night less than or equal to 15 minutes, and 7 to 8 hours of reported sleep) with rare daytime naps and no current history of night work. Subjects who described problems with their sleep were not given further consideration for participation. Selected subjects did not consume excessive amounts of caffeine (more than 250 mg of caffeine per day) or more than 2 alcoholic drinks per day. Potential subjects who had histories strongly suggestive of circadian desynchrony (eg, shift workers), sleep apnea, or periodic leg movements were excluded. Subjects with a history of psychiatric care or use of psychoactive medication were excluded. Subjects who had previously slept in a sleep laboratory for any reason were also excluded. Subjects meeting the above criteria were invited to participate in the study after completing an informed consent and practicing on computer tests and questionnaires to be used in the study. Subjects were also screened with a routine complete blood cell count and urine drug screen. One potential subject was excluded from the study based upon a positive drug screen. All subjects were paid for their participation in the experiment. All subjects enrolled in the caffeine condition were individuals who had previously completed the other conditions. However, the caffeine condition was offered under a separate informed consent, and not all subjects wished to continue. This condition involved spending 2 nights and the following days in the laboratory. On 1 night, subjects received a placebo 30 minutes prior to going to bed. On the other night (counterbalanced across subjects), subjects received caffeine, 400 mg, 30 minutes prior to going to bed. Daytime testing was exactly the same as in the first experiment.|
|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||includes total sleep time, sleep stages, sleep latency and Multiple Sleep Latency Test|
|What is the study design?||Controlled Trial|
|Randomized or Non-Randomized?||RCT|
|What were the diagnostics or methods used to measure the outcome?||Objective|
|Optional: Name of Method or short description||Multiple Sleep Latency Test; polysomnograms|
|Caffeine (general)||Caffeine (general)|
|What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.)||counter-balanced with subjects alternately receiving either caffeine of placebo (no caffeine)|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||type of sleeper (e.g. good sleeper vs situational insomniac)|
|Provide a general description of results (as reported by the authors).||Seven subjects who were initially SI and 9 who were GS participated in the caffeine study. Sleep-efficiency data in these 2 groups for the caffeine-study nights are presented in Table 5. The Group by Condition interaction was not statistically significant (F = 2.34, P = .15). The ANOVA showed a significant main effect for group (F = 4.99, P < .05) and also for caffeine as compared to placebo (F1,14 = 16.0, P < .001). The data show that sleep efficiency decreased significantly after caffeine administration (from 96% to 82% in the GS and from 93% to 61% in the SI). However, based upon the specific hypothesis of the study, Neuman- Keuls pairwise comparisons showed that sleep efficiency after caffeine administration in the SI was significantly less than in the GS and significantly less than after the placebo condition in the SI. There was no significant difference between the groups after placebo administration. The change in the GS after caffeine administration was also not statistically significant. The MSLT data for the placebo and caffeine conditions are shown in Table 5. There was a significant main effect for caffeine (F = 14.23, P < .001). Both groups had longer latencies on their MSLT following administration of caffeine on the previous evening. This effect demonstrates the continuing action of the caffeine approximately 12 hours after administration. To compare caffeine effects with advanced sleep effects on the MSLT, an ANOVA including baseline, advanced sleep, and caffeine data was performed. The data are plotted in Figure 3. These MSLT data differ from those plotted in Figure 2 in that they are based on the reduced number of subjects who participated in all conditions. In the ANOVA, the 2-way interaction for Extreme Group was not statistically significant, but the Condition by Extreme Group interaction was significant (F = 3.87, P < .01). Neuman-Keuls pairwise comparisons indicated that sleep latency in the SI after the 6-hour advance was significantly shorter than their baseline sleep latency and significantly shorter than the latency for the GS after the 6-hour advance. After caffeine administration, the MSLT latency was significantly longer in the SI compared to all other latencies in the SI. Sleep latency in the GS did not vary significantly with condition.|
|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?||However, it was also shown that physiologic arousal, as produced by caffeine, was sufficient to reverse the daytime sleepiness produced in the SI. Specifically, despite the fact that the SI had poor sleep after administration of caffeine, the arousal associated with the caffeine was also effective in improving alertness during the day. Because these subjects appeared to be more sensitive to the effects of the caffeine, their improvement in daytime alertness also seemed greater after caffeine administration.|
|What were the sources of funding?||Financial Support was received from the Dayton Department of Veterans Affairs Medical Center, Wright State University School of Medicine, and the Sleep- Wake Disorders Research Institute.|
|What conflicts of interest were reported?||N/A|
|Does the exposure (dose) need to be standardized to the SR?||No|
|Provide calculations/conversions for the exposure based on the decision tree in the guide (for all endpoints/exposure levels of interest).|
|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 = 400 mg (decreased sleep efficiency; increased the mean sleep latency)|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||single dose Negative effects on sleep were found at doses similar to 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.