退休男性礦工罹患塵肺症死亡率探討

Abstract

背景：國外很多研究對於礦工罹患塵肺症後其死亡率與特定疾病死亡率並沒有定論，針對導致塵肺症病人死亡的個別危險因子，國外並無相關研究，而塵肺症更是瑞芳鎮2001年男性十大死因之第五名，因此探討上述這些問題，對於瑞芳鎮退休男性礦工罹患塵肺症有其相當重要意義。 目的：本研究主要目的在於利用大樣本及貝氏分析求出塵肺症病人的標準化死亡比，並分析塵肺症會不會增加特定疾病的死亡率，另一目的為利用病例對照研究探討有哪些危險因子會造成塵肺症患者死亡。 方法：本研究一部份為回溯性世代研究，研究對象為548名曾至瑞芳鎮衛生所看診或打流感疫苗的塵肺症男性患者，資料收集期間為2000年7月1日至2004年6月30日，連結到死亡登記檔得到79名患者死亡，利用大樣本及貝氏分析方法計算出標準化死亡比，並求出各項死因有無統計上意義增加或減少，另外從未死亡名單隨機抽取死亡組兩倍人數當對照組，連結到疾病管制局的結核病防治網得到肺結核的罹病率，並利用電話問卷訪問獲得一些資料變項，以邏輯式迴歸分析尋找導致死亡率上升的危險因子。 結果：經貝氏統計分析後，塵肺症患者所有死因的標準化死亡比明顯比一般族群高(SMR:120, 95% CI: 116-124)，主要上升原因是呼吸道疾病死亡(SMR: 402, 95% CI: 320-506)，在所有癌症死亡率並沒有統計意義上升(SMR: 101, 95% CI: 95-107)，但胃癌死亡率卻有統計意義上升(SMR: 132, 95% CI: 100-175)。而在病例對照研究則顯示肺結核、抽菸習慣、年齡及礦坑內工作年數其死亡危險比分別為2.61(95% CI: 1.28-5.30)、2.00(95% CI: 1.04-3.85)、1.09(95% CI: 1.02-1.17)和1.08(95% CI: 1.03-1.14)。 結論：本研究發現塵肺症病人所有疾病、呼吸道疾病和胃癌標準化死亡比有顯著上升，另外肺結核、抽菸習慣、和礦坑內工作年數也是造成死亡的危險因子。

Introduction: Whether miners with pneumoconiosis were at increased risk for all-cause or specific-cause death is still controversial. Individual correlates in association with the risk for death among coal workers’pneumoconiosis (CWP) have not been fully addressed. To throw light on these points is of paramount importance to retired miners at Rueifang Township where the cause of pneumoconiosis has been the top five leading causes in 2001. Objectives: The aim of this study is to use SMR analysis with Bayesian approach to assess whether CWP cases lead to an increase in total mortality and specific cause mortality by combing information obtained from previous study with current data. A case-control study was also conducted to assess the effect of exposure to underground mining on the risk for death and to identify significant individual correlates and their effect modification with exposure to coal mine workers. Methods: We first identified a retrospective cohort with 548 retired male miners diagnosed as pneumoconiosis who sought medical consultation or seasonal flu vaccination at Rueifang Health Center. The time period for the collection of the data was from 1st of July, 2000 till 30th of June, 2004. We ascertained 79 deceased patients after linkage with mortality registry. Frequentist or Bayesian Method for Standard Mortality Ratio Analysis was used to calculate the SMR ratio to see if there was any increase in total mortality or a variety of causes of death. The ratio of 1:2 case-control study was designed with 79 deaths as the case and twice number of subjects randomly selected from the CWP cases still alive as the control group,. Information on tuberculosis (TB) was linked to the pulmonary TB prevention web site of the Center for Disease Control, Taiwan for the prevalence of TB. Other information was administered by a telephone-interview questionnaire with proxy subjects for the deceased. A logistic regression model was used to identify individual correlates associated with the risk for death.

Results: Using the Bayesian Method, all-cause death in patients with pneumoconiosis was significantly increased in comparison with general population (SMR:120, 95% CI: 116-124). The main causes for the increase was attributed to respiratory diseases (SMR: 402, 95% CI: 320-506). In all cancers’ mortality rate, there was no statistically significant increase (SMR: 101, 95% CI: 95-107), but stomach cancer rate had a remarkable increase in risk for death (SMR: 132, 95% CI: 100-175). In case-control study, the results show that TB, smoking habits, age and the number of year working in the mining pit were three independent significant factors and have respective adjusted odds ratios with the orders of 2.61 (95% CI: 1.28-5.30), 2.00(95% CI: 1.04-3.85), 1.09(95% CI: 1.02-1.17) and 1.08(95% CI: 1.03-1.14). Conclusion： The present study demonstrated that CWP cases have significantly higher risk for all-cause death, stomach cancer, and non-malignant respiratory disease. TB, smoking habit and number of years working in the mining pit were three principal factors responsible for death.