Background: The Insomnia Severity Index (ISI) is a short subjective questionnaire which helps physicians in making decisions about patients suffering from insomnia. The present study was an attempt to test the reliability and validity of the Iranian version of the ISI and to measure the correlation between ISI items and polysomnography results in chronic insomnia patients. Methods: Two groups responded to the Persian translation of four questionnaires; ISI, Pittsburg Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and General Health Questionnaire (GHQ). The first group consisted of 135 patients diagnosed with chronic insomnia, and the second group was comprised of 55 normal people. After completing the questionnaires, the insomniac patients underwent standard overnight polysomnography. Results: The internal consistency demonstrated by Cronbach’s alpha coefficient was above 0.8 for both groups. The Intra-class correlation coefficient was above 0.7 after two weeks for both groups. The correlations between ISI, PSQI, ESS, and GHQ were high. In addition, close correlations were found between scores obtained from the ISI questionnaire items in insomniac patients with corresponding polysomnographic variables. Conclusion: The Iranian version of the ISI is a reliable and valid instrument. It is a valuable short and first-line questionnaire for insomnia research and clinical work.

PURPOSEIran has a high rate of road traffic accidents. Poor quality of sleep brings about loss of attention, which is an important cause of road traffic accidents particularly in monotonous roads. The causes of poor quality of sleep in occupational drivers are multifactorial. The objective of the present study was to assess the prevalence of poor sleep quality among occupational drivers with rotating work schedules and analyze its different risk factors.

METHODS2200 professional long-haul truck drivers who had been referred to the Occupational Health Clinic for routine education course were invited. We obtained data from eight provinces from various parts of Iran during 2012-2013. Data were collected using a questionnaire including questions about demographic and job characteristics. Pittsburg Sleep Quality Index (PSQI) was used to assess drivers' sleep quality.

RESULTSMean working (driving) time was (9.3±2.5) hours daily and (55.5 ± 18.29) hours weekly. About 23.5% of the drivers reported history of smoking, 14.5% had low job satisfaction and 60% had irregular work schedule. 16.4% of drivers had an accidents leading to injury during the past five years. The mean PSQI score was 4.2 ± 2.7; 54% had a PSQI>5 (poor quality of sleep). Multivariate logistic regression showed that smoking, job satisfaction, history of accidents, shift work and work hours per day were the most important risk factors for poor sleep quality.

CONCLUSIONResults obtained from the current study showed a high prevalence of poor quality of sleep among professional drivers. It warrants more attention to this significant problem using some measures to improve working conditions in professional drivers, as well as health promotion interventions.

Accidents, Traffic ; statistics & numerical data ; Adult ; Aged ; Automobile Driving ; Educational Status ; Humans ; Iran ; Logistic Models ; Male ; Middle Aged ; Sleep ; Workload

PURPOSERoad traffic accidents are one of main problems in Iran. Multiple factors cause traffic accidents and the most important one is sleepiness. This factor, however, is given less attention in our country. Road traffic accidents relevant to sleepiness are studied.

METHODSIn this cross-sectional study, all road traffic accidents relevant to sleepiness, which were reported by police, were studied in Tehran province in 2009.

RESULTSThe risk of road traffic accidents due to sleepiness was increased by more than sevenfold (odds ratio = 7.33) in low alertness hours (0:00-6:00) compared to other time of day. The risk of road traffic accidents due to sleepiness was decreased by 0.15-fold (odds ratio = 0.15) in hours with maximum of alertness (18:00-22:00) of circadian rhythm compared to other time of day.

CONCLUSIONThe occurrence of road traffic accidents due to sleepiness has significant statistical relations with driving during lowest point of alertness of circadian rhythm.

Accidents, Traffic ; statistics & numerical data ; Circadian Rhythm ; physiology ; Cross-Sectional Studies ; Female ; Humans ; Iran ; Male ; Sleep