Research report
Suicide rates in Shandong, China, 1991–2010: Rapid decrease in rural rates and steady increase in male–female ratio

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Abstract

Background

China has one of the highest suicide rates in the world; however, the recent trends in suicide have not been adequately studied. This study aimed to examine the potential changes in the rates and characteristics in a Chinese population.

Methods

Data on suicide deaths in 1991–2010 were extracted from the Shandong Disease Surveillance Point (DSP) mortality dataset based on ICD-10 codes. The temporal trend in age-adjusted suicide rates for each subpopulation was tested using log-linear Poisson regression analysis.

Results

From 1991 to 2010, there was a marked decrease in the overall suicide rate in Shandong, with an average reduction of 8% per year. The decrease trend was stronger in rural than in urban areas and more evident in females than in males. Similar decreases were observed for all age groups. Pesticide ingestion and hanging remained the top two methods for suicide.

Limitations

There are likely quality concerns in the morality data, such as underreporting and misclassification, as well as low accuracy in determining the underlying causes of deaths. The representativeness of the DSP system may also be problematic due to the rapid changes in economy and demography.

Conclusions

Completed suicides in Shandong have sharply declined over the past 20 years. Higher rates in females versus males and in rural versus urban areas, which were previously considered to be distinguishing features of suicide in China, are becoming less pronounced.

Introduction

Suicide is a major public health problem worldwide which claims approximately one million premature deaths each year, or one death every 30–40 s (WHO, 2002). Suicide in China has attracted increasing attention in recent years, especially since the publication of “Suicide rates in China, 1995–99” in The Lancet by Phillips and colleagues in 2002 (Phillips et al., 2002). Largely based on mortality data from late 1990s, China is widely recognized to have one of the highest suicide rates in the world (WHO, 2011). Many important features of suicide in China have also been identified (Phillips et al., 2002, Yang et al., 2005b), with perhaps the most distinguished one being the considerably higher female–male ratio of completed suicides, which contradicts the approximately 2:1 male–female ratio typically observed in the rest of the world (Gunnell, 2000, Hawton and van Heeringen, 2009, Phillips et al., 2002). In addition, China also has substantially higher rates of suicide in rural versus urban communities, and self-poisoning with pesticides is one of the most common suicide methods (Phillips et al., 2002, Yang et al., 2005b).

Unlike the increasing trend in suicide rates observed in many East Asian societies (Abe et al., 2007, Kwon et al., 2009, Lu and Lin, 2008, Tsai and Cho, 2011), mainland China has experienced a steady decline in the overall suicide rate since the early 1990s (Phillips, 2004, Yip et al., 2005). The national rates continued to decline into the 2000s. According to national data from the Disease Surveillance Point (DSP) system, the annual mortality rate due to suicide has been reduced to 9–12.5 per 100,000 persons in the years 2005–2009 (Chinese CDC, 2010a, Chinese CDC, 2010b, Chinese CDC, 2010c, Chinese CDC, 2010d, Chinese CDC, 2011), which is roughly half of the rate (23 per 100,000 persons) in late 1990s (Phillips et al., 2002). The decreasing trend in the overall suicide rate in China appears to be well-established in the literature. However, it is unclear whether certain distinguishing features of suicide in China, such as the higher female–male ratio and the large rural–urban gap, have remained constant over this time period. In examining the suicide rates in the 1990s, Yip et al. (2005) observed a significant increase in the male–female ratio and predicted that the male rates would soon surpass the female rates. However, this prediction has not been well justified by the most recent data.

There is considerable variation across provinces in terms of the rates and characteristics of suicide in China (Yang et al., 2004), and thus it is necessary to examine the trend of suicide rates at the regional level to implement locally-appropriate prevention strategies. Shandong is one of the most populous provinces in China, situated on the eastern coast of the country, with a population of 94.7 million in 2009 (Shandong Provincial Bureau of Statistics, 2010). Similar to findings from the national data, Shandong has also witnessed decreases in suicide rates in recent decades (Sun et al., 2011, Zhang et al., 2010). However, because none of the previous analyses have comprehensively examined the trends in suicide rates in relation to demographics (gender, age, and rural versus urban area) and suicide method, it is not clear whether the potential decreasing trend holds true when these factors are taken into account. Further, it is unknown whether the aforementioned important features in Chinese suicide remain valid at the provincial level.

This study examined the temporal trends in suicide rates over the past two decades in Shandong while taking into account demographic variations (gender, age and rural versus urban area) and methods of suicide. Based on previous research (Sun et al., 2011, Yip and Liu, 2006, Yip et al., 2005, Zhang et al., 2010), we hypothesised that the suicide rates in Shandong have decreased even after controlling for demographic characteristics and suicide method and that the features of suicide, such as the higher male–female ratio and rural–urban ratio have also changed since the 1990s.

Section snippets

Data source

Data on suicide deaths were extracted from the mortality database of the Shandong DSP system provided by the Shandong Provincial Center for Disease Control and Prevention (CDC). Official population data originally obtained from the Shandong Statistics Bureau were also provided by the Shandong CDC and were used in the calculation of suicide rates.

The Shandong DSP system was established in early 1980s and presently consists of 19 county-level data collection sites. The catchment population of

Overall trends

During the years 1991 to 2010, the age-adjusted suicide rate varied from 12.41 to 37.51 per 100,000 persons. There was a significant decline over this period, with an average annual decrease of 8% per year (IRR=0.921; 95%CI: 0.919–0.924, p<.001). The proportion of suicides among all deaths has also decreased from 7.4% in 1991 to 2.4% in 2009–2010 (B=−0.21, 95%CI: −0.26 to −0.17, p<.001).

Significant decreasing trends in suicide rates were also observed for males (IRR=0.927; 95%CI: 0.924–0.930, p

Discussion

As expected, suicide rates in Shandong have experienced sharp decreases in the past two decades, especially in rural communities. In addition, many important features of suicide rates have changed substantially over this time period, including the steady increase in the male–female ratio and the closing gap between rural and urban areas. Pesticide ingestion continues to be the leading method of suicide, but the proportion of hanging suicides is increasing.

Although previous analyses based on

Role of funding source

No fund was received for this study.

Conflict of interest

We declare that we have no conflict of interest.

Acknowledgements

Permission to use the mortality data in this analysis was given by the Chronic Disease Division of Shandong Provincial Center of Disease Control and Prevention (CDC). The authors thank Mr. Daniel Francis (Acting Director, Epidemiology Team, Central Regional Services, Queensland Health, Australia) for his assistance in the proof-reading of the manuscript. We would also like to thank the two anonymous reviewers for their comments that helped improve the manuscript significantly.

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