Geophysical variables and behavior: LXVIII. Distal and lunar variables and traffic accidents in Saskatchewan 1984-1989

Effect of driver, roadway, collision, and vehicle characteristics on crash severity: a conditional logistic regression approach

The aim of the study is to examine the factors that appear to have a higher potential for serious injury or death of drivers in traffic accidents in Turkey, such as collision type, roadway surface, vehicle speed, alcohol/drug use, and restraint use. Driver crash severity is the dependent variable of this study with two categories, fatal and non-fatal. Due to the binary nature of the dependent variable, a conditional logistic regression analysis was found suitable. Of the 16 independent variables obtained from Turkish police accident reports, 11 variables were found most significantly associated with driver crash severity. They are age, education level, restraint use, roadway condition, roadway type, time of day, collision location, collision type, number and direction of vehicles, vehicle speed, and alcohol/drug use. This study found that belted drivers aged 18-25 years involving two vehicles travelling in the same direction, in an urban area, during the daytime, and on an avenue or a street have better chances of survival in traffic accidents.

The impact of the lunar cycle on the incidence of trauma

Over thousands of years it has been thought that the moon influences human behaviour and the world around us. We reviewed the literature for evidence of a relation of the lunar cycle with the incidence of trauma. We searched Pubmed for studies relating the moon and its phases to trauma. Nine studies were found, of which one suggested an inverse relation of full moon with the incidence of trauma. The lunar cycle might influence trauma incidence, but if any real effect exists, it is certainly small. Moreover such an effect does not require paranormal explanations.

Human responses to the geophysical daily, annual and lunar cycles

Collectively the daily, seasonal, lunar and tidal geophysical cycles regulate much of the temporal biology of life on Earth. The increasing isolation of human societies from these geophysical cycles, as a result of improved living conditions, high-quality nutrition and 24/7 working practices, have led many to believe that human biology functions independently of them. Yet recent studies have highlighted the dominant role that our circadian clock plays in the organisation of 24 hour patterns of behaviour and physiology. Preferred wake and sleep times are to a large extent driven by an endogenous temporal program that uses sunlight as an entraining cue. The alarm clock can drive human activity rhythms but has little direct effect on our endogenous 24 hour physiology. In many situations, our biology and our society appear to be in serious opposition, and the damaging consequences to our health under these circumstances are increasingly recognised. The seasons dominate the lives of non-equatorial species, and until recently, they also had a marked influence on much of human biology. Despite human isolation from seasonal changes in temperature, food and photoperiod in the industrialised nations, the seasons still appear to have a small, but significant, impact upon when individuals are born and many aspects of health. The seasonal changes that modulate our biology, and how these factors might interact with the social and metabolic status of the individual to drive seasonal effects, are still poorly understood. Lunar cycles had, and continue to have, an influence upon human culture, though despite a persistent belief that our mental health and other behaviours are modulated by the phase of the moon, there is no solid evidence that human biology is in any way regulated by the lunar cycle.

Application of hidden Markov models on residuals: an example using Canadian traffic accident data

Laverty, Kelly, Rotton, and Flynn conducted a regression analysis in 1992 on 9 years of automobile accidents in Saskatchewan (a total of 200,545 accidents) to find a small linear trend, season effects, holiday, and day of the week effects. The application of a hidden Markov model to the residuals of this analysis uncovered two states which are likely to be related to the weather. These states can be described as low volatility' and 'high volatility'. The 'low volatility' state involves low variability compared to the 'high volatility' state (occurring during the colder months) during which the largest numbers of accidents occur. It is suggested that hidden Markov models are a useful method for uncovering hidden, underlying states in social science and health-related data.

Lunar cycles and violent behaviour

OBJECTIVE

It is commonly believed that the full moon exerts an influence on violence and aggression in psychiatric settings. The literature to date is contentious. This study used a robust methodology to examine the hypothesis that there was an increased frequency of violent and aggressive behaviour among hospitalised psychiatric clients at the time of the full moon.

METHOD

Prospective data were collected in five inpatient psychiatric settings across the Northern Sydney Area Health Service. Morrison's hierarchy of violence and aggression was used to rate behaviour. Lunar phases were clearly defined and Poisson regression used to examine relationships between lunar phase and violence. Extraneous temporal variation was considered.

RESULTS

No significant relationship was found between total violence and aggression or level of violence and aggression and any phase of the moon.

CONCLUSION

Future research could profitably examine the implications of a belief in the lunar effect among health workers in the face of evidence that no relationship exists between violence, aggression and the lunar cycle.

Cyclical calendar and lunar patterns in automobile property accidents and injury accidents

Nine years of traffic accidents involving damage to property (n = 246,926 accidents) and involving nonfatal injury (n = 50,492) in Saskatchewan were examined by regression and spectral analyses. Both calendar and seasonal periodicities were found in both sets of data. After data were adjusted for calendar effects, no relationship was found with the total or half synodic and anomalistic lunar cycles or between the waxing and waning synodic cycle. No sudden change on the day of the full moon or surrounding days was found.

Seasonal variation and weather effects on road traffic accidents in Riyadh city

The monthly variation of Road Traffic Accidents (RTAs) in Riyadh city in the period 1989-1993 has been studied with reference to time of day, lighting conditions and prevalent weather conditions. Total RTA accidents were significantly more common, being directly correlated, with increased dry and wet bulb temperatures and significantly less common, being inversely correlated, with increased relative humidity and amount of precipitation of rain, snow, hail etc. However, RTAs recorded on rainy days only were significantly more common and directly correlated with precipitation (Note days of snow and hail are very rare in Riyadh city). Seasonal variation in RTAs was evident being maximal during the summer season particularly between 12 noon and 3 pm. This period is characterized by heavy traffic and intense sunlight. The role of hot weather prevalent in Saudi Arabia, where average temperatures of 34.4-34.7 degrees C with maximum of 40-42.7 degrees C are common in summer, have been suggested to be an important factor leading to increased stress and decreased performance of intellectual tasks which require considerable physical effort and motor skills. Increased heart rates, exacerbation of existing pathologic conditions such as heart disease and emphysema and loss of visual acuity have been reported. Consequently, prolonged exposure to heat must be considered as a hazard to the safety and health of drivers and a factor leading to an increased incidence of RTAs.

Lunar cycle and consultations for anxiety and depression in general practice

The influence of the moon on patient consultations for anxiety or depression in general practice was assessed through a retrospective survey based on general practice medical records and on lunar records detailing the dates and times of different phases of the moon. Seven-hundred-eighty-two patients continuously registered in a general practice in Beckenham, South London, between 1971 and 1988 were included in analyses. No statistically significant lunar effect was found by setting the expected surge in consultations one to three days after the full moon and the period of the sine-wave curve to 30 days. Similarly, no statistically significant lunar effect was found, when the period of the sine-wave curve was allowed to vary in order to best fit the data. The moon had little influence on when individuals consulted their general practitioner with anxiety or depression.

Aetiological factors contributing to road traffic accidents in Riyadh City, Saudi Arabia

The study analysed 13,390 police records of road traffic accidents (RTAs) covering a three and a half year period according to different suspected aetiological factors. The majority of the accidents were recorded for vehicles in good condition on well-paved straight roads with well-operating traffic light systems. Adverse weather conditions such as precipitation, fog and dust were of minimal importance, with most of the accidents being reported during sunny days during the rush period of 12 noon to 3 pm. Driver's error was identified as the main contributing factor in about two thirds of all RTAs mainly as reckless driving and excess speeding. About 27% of the drivers were professional drivers and 41% were in the age group 25-35 years in good health with no alcohol or drug intake. Hence, human errors may be attributed to carelessness, experience, lack of knowledge or attention, over-exhaustion or fatigue. The effects of physical stressors on performance of drivers need to be further explored and clarified but this need not underestimate the importance of vehicle and environment since most accidents are multifactoral and a slight change in them may effectively enhance perception and minimise personal error. Recommendations for remedial measures adopting an interdisciplinary approach are presented.

Speed limitation and motorway casualties: a time series count data regression approach

The paper deals with the effect of a lowered speed limit on the number of accidents in which there are fatalities, injuries and vehicle damage on Swedish motorways. Two models extending the Poisson and negative binomial count data models are used for estimation. The extended models account for both overdispersion and potential dependence between successive counts. The inferences of the parameters depend on the assumed form of overdispersion. It is found that the speed limit reduction has decreased the number of accidents involving minor injuries and vehicle damage. Furthermore, the models allowing for serial correlation are shown to have the best ex ante forecasting performance.

Geophysical variables and behavior: LXXII. Barometric pressure, lunar cycle, and traffic accidents

This study assessed relationships between traffic accidents and variables of the physical environment. Daily data on traffic accidents over a 4-year period were compared with daily records of barometric pressure and synodic lunar cycle. No significant variations in the number of accidents were found related to barometric height but a significant lunar periodicity was observed for one of the years considered. The number of accidents occurring during the full moon day was lowest; the highest occurred two days before the full moon. Accidents occurred more frequently during crescent moon than during waning moon, but no significant differences were noted when the lunar month was divided into four intervals of new moon, first quarter, full moon, and second quarter.