Koplan J P, Azizullah M, Foster S O
Trop Geogr Med. 1978 Sep;30(3):355-8.
Smallpox mortality at Dacca, Bangladesh Infectious Diseases Hospital during 1972 and 1973 was 46 per cent. To determine if this was the actual rate within the population, data were compared to those collected from village populations in Noakhali District. Age/sex adjusted smallpox mortality for the rural population was 23 per 100 cases as compared to 52 per 100 for the hospital population. Analysis of the difference identified a selection bias of the hospital for severe disease.
1972年至1973年期间，孟加拉国达卡传染病医院的天花死亡率为46%。为了确定这是否为实际的人群死亡率，将该数据与从诺阿卡利地区农村人口收集的数据进行了比较。农村人口经年龄/性别调整后的天花死亡率为每100例中有23例，而医院人群则为每100例中有52例。对差异的分析确定了医院对重症疾病存在选择偏倚。
