我們是否可用死亡率來推估盛行率?－嘗試找尋不同疾病冰山型狀

背景：一般而言，想獲得到盛行率的原始資料是需要耗費相當多的時間和金錢，因此許多學者試著嘗試使用花費較少而且有固定程序規則的死亡率資料來推估盛行率。儘管如此，利用死亡率推估盛行率這項作法仍然還是有其問題所在。 目的：本研究主要想探討有哪些疾病是非常適合使用死亡率推估盛行率。而對於一些不太適合使用死亡率推估盛行率的疾病，本研究也想嘗試利用1)最後一次出院主診斷；2)最後一次出院主次診斷；3)死亡證明書的原死因；4)死亡證明書的多重死因，這些變項之間的關係來探討各種疾病。 方法：本研究所收集的死亡證明書資料是從1998年1月到2000年12月，是由中山醫學大學附設醫院所提供。本研究將死因資料連結電子化出院診斷記錄，首先我們先計算出在最後一次出院主診斷有出現該疾病的人數，而該疾病又同時出現在死因統計的多重死因和原死因之人數，然後我們再計算出相互之間的百分比值。本研究使用相同的方法再將性別、年齡別分層來探討。 結果：有些疾病出現在死因統計原死因、多重死因的比率相當高，例如：血癌、胃癌、肺癌、乳癌、子宮頸癌、主動脈瘤、心肌梗塞。有些疾病出現在死因統計原死因、多重死因的比率相當低，例如：股骨頸骨折、胃潰瘍、顱內傷害、貧血、帕金森氏症、高血壓。有些疾病出現在死因統計原死因、多重死因的比率介於中間，例如：腎炎腎病和腎炎的症狀、肺炎、氣喘、肺結核、肝硬化、中風、糖尿病、缺血性心臟病。另外，經過性別、年齡別分層分析後，也呈現出相同的結果。? ? ?有些疾病出現在死因統計多重死因、疾病統計最後一次出院診斷的比值相當低，例如：血癌、胃癌、肺癌、主動脈瘤、心肌梗塞。有些疾病出現在死因統計多重死因、疾病統計最後一次出院診斷的比值相當高，例如：糖尿病、胃潰瘍、肺炎、高血壓、腎炎腎病和腎炎的症狀。有些疾病出現在死因統計多重死因、疾病統計最後一次出院診斷的比值介於中間，例如肺結核、肝硬化、缺血性心臟病、氣喘、中風。另外，經過性別、年齡別分層分析後，也呈現出相同的結果，並且呈現出疾病的冰山圖型。 結論：根據過去國際疾病分類標準與本研究的結果，我們建議：1)血癌、肺癌、子宮頸癌、胃癌、乳癌、心肌梗塞、主動脈瘤，這些疾病是適合使用死亡率推估盛行率；2)腎炎腎病和腎炎的症狀、肺炎、氣喘、肺結核、肝硬化、中風、糖尿病、缺血性心臟病；3)胃潰瘍、高血壓，這些疾病非常不適合使用死亡率來推估盛行率。

Background: To obtain original figures for prevalence data is very time and money consuming. Many scholars have attempted of using mortality data, which is less expensive and routine available, as an proxy of prevalence rate. Nevertheless, it was not without problem to use morality data as the proxy of prevalence rate. Objective: To determine what different kinds of diseases in which mortality data was more suitable as the proxy of prevalence rate. For those not a good proxy of prevalence rate we attempted to determine the relationships among number of cases with specific diagnosis according to 1) main discharge diagnosis (MD) in last hospitalization before death; 2) all discharge diagnoses (AD) in last hospitalization before death; 3) underlying cause of death (UCD) on death certificate; 4) multiple cause of death (MCD) on death certificate. Methods: All Death certificates issued in Chung Shan Medical University Hospital from January 1, 1998 through December 31, 2000 were extracted for this study. Using identification number we linked each death to the electronic hospitalization records. We first calculated the proportions in which the denominator was the number of MD with one specific diagnosis and the nominator was the number of MCD or UCD with one specific diagnosis in which it was appeared in the death certificate. We then calculated the ratios between number of MCD and AD with specific diagnosis with number of UCD with the specific diagnosis. The proportions and ratios were analysis by age and sex. Results: Diagnoses with high proportion between number of MCD and UCD with number of MD included: Leukemia, Stomach cancer, Lung cancer, Breast cancer, Cervical cancer, Aortic aneurysm, Myocardial disease. Diagnoses with low proportion were Fracture neck of femur, Peptic ulcer, Intracranial injury, Anemia, Parkinson’s disease, Hypertension. Diagnoses with intermediate proportions were Nephritis, nephrosis and nephrotic syndrome, Pneumonia, Asthma, Tuberculosis, Cirrhosis of liver, Stroke, Diabetes, Ischaemic heart disease. The results were similar if we stratified the analyses by sex and age. Diagnoses with high ratios between number of MCD and AD with number of UCD included: Diabetes, Peptic ulcer, Pneumonia, Hypertension, Nephritis, nephrosis and nephrotic syndrome. Diagnoses with ratios near one were Leukemia, Stomach cancer, Lung cancer, Aortic aneurysm, Myocardial disease. The ratios in the intermediate included Asthma, Tuberculosis, Cirrhosis of liver, Stroke, Ischaemic heart disease. The results were the same when stratified by sex and age. Conclusion: According to the above findings we concluded that 1) diagnoses like Leukemia, Stomach cancer, Lung cancer, Breast cancer, Cervical cancer, Aortic aneurysm, Myocardial infarction were highly appropriate to use number of UCD in the death certificate as the proxy of prevalence. 2) Diagnoses such as Diabetes, Pneumonia, Nephritis, nephrosis and nephrotic syndrome, Asthma, Tuberculosis, Cirrhosis of liver, Stroke, Ischaemic heart disease were moderate appropriate in using number of UCD in death certificate as the proxy of prevalence. 3) Diagnoses like Peptic ulcer and Hypertension were very inappropriate to use number of UCD in death certificate as the proxy of prevalence.