著者

Ichikawa Masao Inada Haruhiko Kumeji Minae

出版者

Elsevier

雑誌

Journal of affective disorders (ISSN:01650327)

巻号頁・発行日

vol.152, pp.183-185, 2014-01

被引用文献数

14

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BackgroundA recent preliminary communication suggested that the calming effect of blue lights installed at the ends of railway platforms in Japan reduced suicides by 84%. This estimate is potentially misleading from an epidemiological point of view and is reconsidered in the present study.MethodsGovernmental data listing all railway suicide attempts in Japan from April 2002 to March 2012 were used to investigate the proportion of suicide attempts within station premises, where blue lights are potentially installed, and at night, when they would be lit. For those suicide attempts within station premises, we also estimated the proportion that occurred at the ends of the platforms at night.ResultsOf 5841 total reported suicide attempts, 43% occurred within the station premises, 43% occurred at night (from 18:00 to 05:59), and 14% occurred both within the station premises and at night. Of the 2535 attempts within station premises, 32% occurred at night and 28% at most were at the end of a platform at night.LimitationsThe exact proportion of nighttime suicide attempts at the ends of railway platforms was not calculable. Nonetheless, the proportion of suicide attempts that is potentially preventable by blue lights should be less than our conservative estimate.ConclusionsThe installation of blue lights on platforms, even were they to have some effect in preventing railway suicides at night, would have a much smaller impact than previously estimated.

著者

Ichikawa Masao Inada Haruhiko Kumeji Minae

出版者

Elsevier

雑誌

Journal of affective disorders (ISSN:01650327)

巻号頁・発行日

vol.152-154, pp.183-185, 2014-01

被引用文献数

14 8

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BackgroundA recent preliminary communication suggested that the calming effect of blue lights installed at the ends of railway platforms in Japan reduced suicides by 84%. This estimate is potentially misleading from an epidemiological point of view and is reconsidered in the present study.MethodsGovernmental data listing all railway suicide attempts in Japan from April 2002 to March 2012 were used to investigate the proportion of suicide attempts within station premises, where blue lights are potentially installed, and at night, when they would be lit. For those suicide attempts within station premises, we also estimated the proportion that occurred at the ends of the platforms at night.ResultsOf 5841 total reported suicide attempts, 43% occurred within the station premises, 43% occurred at night (from 18:00 to 05:59), and 14% occurred both within the station premises and at night. Of the 2535 attempts within station premises, 32% occurred at night and 28% at most were at the end of a platform at night.LimitationsThe exact proportion of nighttime suicide attempts at the ends of railway platforms was not calculable. Nonetheless, the proportion of suicide attempts that is potentially preventable by blue lights should be less than our conservative estimate.ConclusionsThe installation of blue lights on platforms, even were they to have some effect in preventing railway suicides at night, would have a much smaller impact than previously estimated.

著者

Nakahara Shinji Katanoda Kota Ichikawa Masao

出版者

日本疫学会

雑誌

Journal of epidemiology (ISSN:09175040)

巻号頁・発行日

vol.23, no.3, pp.195-204, 2013-05

被引用文献数

20

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Background: In Japan, introduction of severe drunk-driving penalties and a lower blood alcohol concentration (BAC) limit in June 2002 was followed by a substantial reduction in fatal alcohol-related crashes. However, previous research suggests that this reduction started before the legal amendments. The causes of the decrease have not been studied in detail.Methods: Monthly police data on fatal road traffic crashes from January 1995 to August 2006 were analyzed using a joinpoint regression model to identify change-points in the trends of the proportion of drunk-driving among drivers primarily responsible for fatal crashes. We analyzed the data by BAC level (≥0.5 or <0.5 mg/ml), then conducted analyses stratified by vehicle type (car or motorcycle) and age group (<45 or ≥45 years) only for the proportion of those with a BAC of 0.5 mg/ml or higher.Results: Among all drivers, the proportion of those with a BAC of 0.5 mg/ml or higher and those with a BAC greater than 0 but less than 0.5 mg/ml showed a change-point from increase to decrease in February 2000 and in May 2002, respectively. The proportion of those with a BAC of 0.5 mg/ml or higher showed a change-point from increase to decrease in October 1999 among car drivers and in April 2000 among drivers younger than 45 years. There was no change-point among motorcyclists. A change-point from no trend to a decrease in January 2002 was observed among those 45 years or older.Conclusions: The change-point identified around the end of 1999 to the start of 2000 suggests that a high-profile fatal crash in November 1999, which drew media attention and provoked public debate, triggered subsequent changes in drunk-driving behavior.

著者

Nakahara Shinji Ichikawa Masao

出版者

日本疫学会

雑誌

Journal of epidemiology (ISSN:09175040)

巻号頁・発行日

vol.23, no.1, pp.70-73, 2013-01

被引用文献数

50

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Introduction: On 11 March 2011, a magnitude 9.0 earthquake caused a huge tsunami that struck Northeast Japan, resulting in nearly 20 000 deaths. We investigated mortality patterns by age, sex, and region in the 3 most severely affected prefectures.Methods: Using police data on earthquake victims in Iwate, Miyagi, and Fukushima prefectures, mortality rates by sex, age group, and region were calculated, and regional variability in mortality rates across age groups was compared using rate ratios (RRs), with the rates in Iwate as the reference.Results: In all regions, age-specific mortality showed a tendency to increase with age; there were no sex differences. Among residents of Iwate, mortality was markedly lower among school-aged children as compared with other age groups. In northern Miyagi and the southern part of the study area, RRs were higher among school-aged children than among other age groups.Conclusions: The present study could not address the reasons for the observed mortality patterns and regional differences. To improve preparedness policies, future research should investigate the reasons for regional differences.