1971-2022年臺灣自殺地理空間模式之變化

Abstract

研究背景：自殺是導致過早死亡的主要原因。過去的研究指出，一個國家(包括臺灣)內部不同地區之間的自殺率存在顯著差異。目前對於自殺的地理空間變異及其地理模式是否會隨時間變化的了解仍然有限。因此，本研究主要探討臺灣過去五十年自殺的地理空間模式及其模式變化的潛在因素。 研究方法：本研究從臺灣死因資料檔中獲取1971年至2022年15歲及以上人口的自殺資料，依照性別、年齡組、自殺方法分層，來計算各鄉鎮市區（共354個）的自殺人數。使用貝氏階層模型(Bayesian hierarchical models)，依照性別、年齡組和自殺方法分層，來估計臺灣在六個時期（1971-1975、1978-1982、1988-1992、1998-2002、2008-2012、2018-2022）各鄉鎮市區的自殺平滑標準化死亡比（smoothed SMRs for suicide）。進一步分析在研究期間鄉村和城市的年齡標準化自殺率趨勢。最後使用2000、2010和2020年人口普查資料，來調查自殺與一系列地區層級的社會經濟特徵之間的關聯性。 研究結果：在1971至2022年間，臺灣的自殺地理空間模式保持一致，自殺率較高的地區主要集中在鄉村和山區，特別是臺灣東部地區，而主要城市的自殺率則較低或中等。然而，自1980年以後，臺灣自殺率的地理空間變異程度逐漸減少，特別是在女性之中。在各研究時期，鄉村地區的自殺率均高於城市地區，但這差距隨時間而減少，特別是在女性之中。鄉村和城市地區自殺率差距的減少主要歸因於鄉村和城市地區固體/液體中毒自殺率的顯著下降，而其他方法的自殺則沒有明顯或存在較小的城鄉差距。在2000至2020年間，自殺率與人口密度的負相關性減弱，而與家戶所得中位數的關聯性則保持穩定。 研究討論：過去五十年，台灣的自殺空間模式相對穩定，而固體/液體中毒自殺率的顯著下降減少了鄉村和城市地區自殺率的差距。然而，近年來自殺在地理和社會經濟方面仍存在顯著不平等。因此，需要持續監測自殺的地理變異趨勢，調查其潛在機制，並針對高風險地區和人群制定和實施預防策略。

Introduction: Suicide is a leading cause of premature mortality. Previous studies indicated marked variations in suicide rates across different areas within a country, including Taiwan. However, it is less known whether the geographic variations in suicide and their geographic patterns would change over time. This study aimed to investigate the geographic patterning of suicide in Taiwan over the last five decades and the potential reasons underlying the changes in the patterns. Methods: Suicide data (1971–2022) for people aged 15+ years were obtained from Taiwan’s national cause-of-death mortality data files. We calculated the number of suicides by sex, age, method, and township. We estimated smoothed standardized mortality ratios (SMRs) for suicide in each township (n=354), overall and by sex, age group, and suicide method, in six periods (1971-1975, 1978-1982, 1988-1992, 1998-2002, 2008-2012, and 2018-2022) using Bayesian hierarchical models. We also examined trends in rural and urban age-standardized rates of suicide over the study period. We investigated the association of suicide with a range of area socioeconomic characteristics using detailed census data for 2000, 2010, and 2020. Results: In 1971-2022, the geographic patterns of suicide rates remained relatively consistent in Taiwan, with higher suicide rates concentrated in rural and mountainous areas, particularly in East Taiwan and lower or average rates in major cities. However, the degree of geographic variations in suicide rates gradually decreased after 1980, particularly in females. Suicide rates were higher in rural than urban areas across years, while the difference decreased over time, particularly in females. The decrease in rural-urban difference in suicide rates was mainly attributable to the marked reduction in the rates of suicide by solids/liquids poisoning in both rural and urban areas, while there were smaller or no rural-urban differences in suicide for other methods. In 2000-2020, the negative association of area suicide rates with population density decreased, while that for median household income remained consistent. Discussion: There were relatively stable geographic patterns of suicide in Taiwan over the last five decades, while the marked reduction in suicide by solids/liquids poisoning contributed to a reduction in rural-urban difference in suicide. However, there were still marked geographic and socioeconomic inequalities in suicide in recent years. Continuous efforts were needed to monitor trends in geographic variations in suicide, investigate the underlying mechanisms, and develop and implement prevention strategies for high-risk areas and populations.