社會經濟狀況與自殺死亡率的關係：台灣1981-2007年之趨勢分析

Socioeconomic Conditions and the Suicide Mortality Rate: A Trend Analysis in Taiwan, 1981-2007

研究目的：本研究主要目的在於透過瞭解台灣整體社會、經濟狀態與自殺死亡率變化趨勢之間的關聯性，來預測自殺死亡率。研究方法：蒐集1981-2007年期間台灣的自殺死亡資料（衛生署）、人口資料及各項經濟、社會指標資料（內政部社會指標統計資料），分別計算性別、年齡別及地區別之自殺死亡率，運用多元線性迴歸時間序列分析（multiple linear regression time series analysis）的方法，找出整體經濟、社會因素對於自殺死亡率的相對關聯程度，並據此建立自殺死亡率之預測模型。研究結果：預測模型（判別係數R²=0.8661）顯示，（1）若3年前的男性失業率愈高，當年的自殺死亡率愈高；（2）若1年前人均國民生產毛額比2年前高出新台幣1萬元以上，當年的自殺死亡率愈會下降；（3）若2年前的消費者物價指數≧80，當年的自殺死亡率會上升。依據此模型估算2008及2009年自殺死亡率，與本研究期間之後公布的官方統計數字相當接近。研究結論：相較於社會因素，台灣整體經濟環境與自殺死亡率變化趨勢之間的關聯性較高；上述三項經濟決定指標，對於台灣從1981到2007年的自殺死亡率，具有1至3年的延遲衝擊效應。根據預測結果，2007年到2009年期間，台灣自殺死亡率大幅降低的機率不高。

Purpose: This macro-epidemiologic study aimed to develop a statistical regression model for identifying important predictors of the crude annual suicide mortality rate in Taiwan. Methods: A time series analysis with seasonality was conducted to examine the associations between 33 socioeconomic variables and the crude annual suicide mortality rates using the male and female data of 4 age groups in 7 regions of Taiwan between 1981 and 2007. Results: A well-fitted multiple linear regression time series model (coefficient of determination, R2 = 0.8661) revealed that conditioning on the effects of the past crude annual suicide mortality rates and temporal oscillations, (1) the higher the male unemployment rate of the t - 3 year, the higher the crude annual suicide mortality rate of the current year t; (2) if the gross national product (GNP) per capita of the t - 1 year minus that of the t - 2 year was larger than NT $10,000, then the crude annual suicide mortality rate of the current year t would drop; and (3) if the consumer price index of the t - 2 years was greater than or equal to 80, then the crude annual suicide mortality rate of the current year t would go up. Based on this statistical regression model, the crude annual suicide mortality rates of 2008 and 2009 were predicted and found to be reasonably close to the actual values of the official death statistics released after the study period. Conclusions: The fluctuation of economic conditions had a much stronger and more direct impact on the suicide mortality than that of social conditions in Taiwan. In particular, 3 economic indices were identified as having 1- to 3-year short-term lagged effects on the crude annual suicide mortality rates from 1981 to 2007. Given the relatively poor economy from 2007 to 2009 in Taiwan, a remarkable decrease in the crude annual suicide mortality rate is not expected in the coming years.