subjects involved are needed to evaluate insomnia severity and its relation with health-related variables in Georgian population. Acknowledgements: Study supported by Swiss National Science Foundation, SCOPES, grant IZ74Z0_137415. http://dx.doi.org/10.1016/j.sleep.2013.11.136 The presence and the nature of dysfunctional cognitions and the focus of attention during pre-sleep period in shift workers E. Bastille-Denis, M. Roy, A. Vallières Université Laval, Centre de recherche de l’Institut universitaire en santé mentale de Québec, Canada Introduction: While research concentrates on biological aspects of shift work sleep disorder (SWSD), few studies addressed psychoso- cial variables. To date, no studies have investigated cognition in SWSD. However, cognitive variables could play a role in the develop- ment and maintenance of this disorder. The present study examines the presence and the nature of dysfunctional cognitions and the focus of attention during pre-sleep period in shift worker with and without SWSD. Materials and methods: The sample included 47 shift worker par- ticipants (mean age: 35.0%; 87.2% women), 25 with SWSD and 22 good sleepers. A semi-structured interview for sleep difficulties was administered to make the diagnosis. Participants wore an acti- graph and completed sleep diaries during 2 weeks. Self-report ques- tionnaires measuring pre-sleep content of thought were completed: Epworth sleepiness scale, Chronotype questionnaire, Thought con- trol questionnaire-insomnia revised (TCQ-IR), Pre-sleep activation scale (PSAS), Glasgow Content of Thoughts Inventory (GCTI) et le Dysfunctional Beliefs and Attitudes about Sleep (DBAS). Harvey semi-structured interview designed to assess pre-sleep cognition was administered by a qualified graduate student in psychology after the 2-week period. Results: Shift workers with SWSD scored significantly higher on GCTI (t = À2.05, p < .05) and on cognitive activation subscale of PSAS (t = À2.75, p < .01) compared to shift workers who were good sleep- ers. Harvey interview showed that SWSD group were significantly more likely than good sleepers to focus their attention on worries and preoccupations than good sleepers (F(1,45) = 6.07, p = .02). SWSD were significantly more likely to listen to noises than good sleepers (F(1,45) = 5.24, p = 0.3). SWSD group reported spending more time thinking or worrying about these topics compared with good sleepers (F(1,45) = 17.7, p = .00). Conclusion: This study is a first step in identifying cognitive vari- ables involved in SWSD. These results suggest that pre-sleep activa- tion and focus of attention are different depending of the presence or the absence of the disorder. It seems that cognitive variables could be a promising research avenue in a more multidimensional concep- tualization of this sleep disorder. The development of the cognitive activation in shift workers with SWSD could be studied. http://dx.doi.org/10.1016/j.sleep.2013.11.137 Catastrophization process and themes of worry in shift workers E. Bastille-Denis, M. Roy, A. Vallières Université Laval, Centre de recherche de l’Institut universitaire en santé mentale de Québec, Canada Introduction: This study constitutes the first step toward exploring the themes of worry related to sleep in shift workers. More specifi- cally, this study aimed to (1) examine the presence of catastrophiza- tion, (2) define the themes of worry, and (3) explore the relationship between catastrophization and sleep difficulties. Materials and methods: The sample included 47 participants shift workers (mean age: 35.0%; 87.2% women), 25 with shift work sleep disorder (SWSD) and 22 good sleepers. A semi-structured interview for sleep difficulties was administered. Participants wore an acti- graph and completed sleep diaries during two weeks. Self-report questionnaires measuring pre-sleep content of thought were com- pleted. The castastrophizing technique was conducted by a qualified graduate student in psychology. Data were entered and qualitative analysis was performed. Regression analyse was made to test the third objective. Results: Thirty-six participants (77%) reported two catastrophes or more. More frequently reported themes were concerning fatigue and level of energy (64%), mood issues (44%), work performance (44%) and errors (44%). The presence of sleep difficulties does not predict the number of catastrophizing steps (â = .215, t = 1.474, p = .147). The education level explained 22% of variance of the number of catastrophizing steps. Conclusion: These results suggest that shift workers tend to catas- trophize in pre-sleep period. While certain themes of worry resem- ble those find in studies on insomniacs, elderly and children populations, it appears that some themes are characteristics of shift workers. http://dx.doi.org/10.1016/j.sleep.2013.11.138 Analysis of mean transcutaneous carbon dioxide tension during polysomnographic extended monitoring in Sarah Network Hos- pital patients P. Bastos, G. Pinnola, S. De Oliveira Sarah Network Hospital, United States Introduction: Transcutaneous CO2 (PtcCO2) monitoring is a good non-invasive method of analysis to understand the PtcCO2 behav- ioral tendency during sleep in a great variety of respiratory sleep dis- orders (RDB). When a patient is under investigation for sleep disorders like Sleep Apnea or Obesity/Hypoventilation Syndrome, this method can help the physician both in the diagnostic criteria and in the follow up of therapeutic responses. Objective: To analyze the PtcCO2 in 179 consecutive patients submitted to a polysomno- graphic research at Sarah’s Neurophysiology Department and to identify the normal variety of mean PtcCO2 during the record of those patients that are considered normal (N = 53). The normality distribution trend was also studied. Materials and methods: 179 patients were submitted to a polysom- nographic record (PSGR) with concomitant measure of PtcCO2 using a TCM4 monitor (Radiometer, Switzerland). The group was classified into normal and non-normal patients. The normal group (N53) had an Apnea/hypopnea index <5 events/hour of sleep. The exclusion criteria were: existence of respiratory comorbidities, smoking his- tory, existence of neurologic diseases that could be responsible for dynamic respiratory commitment and/or central PCO2 deregulation. The age ranged from 7 to 76 years old. Results: The age ranged from 7 to 76 years old in the normal group (mean of 43.13 and SD of 16.46); 32 patients were female and 21 were male. The Shapiro-Wilk test with Liliefors correction was accomplished to analyze the tendency to normality of data (sig 0.379). The mean of mean PtcCO2 was 41.325 (confidence interval of 95% ranging from 40.122 to 42.325). The standard deviation was 4.363 and a 2jÒ reference was used for this appraisal. The normal values ranged from >33.0 to >50.0 mmHg of PtcCO2. e70 Abstracts / Sleep Medicine 14S (2013) e18–e92