We described the time trend of acute myocardial infarction (AMI) from 1999 to 2013 in Tianjin incidence rate with Cochran-Armitage trend (CAT) test and linear regression analysis, and the results were compared. Based on actual population, CAT test had much stronger statistical power than linear regression analysis for both overall incidence trend and age specific incidence trend (Cochran-Armitage trend P value<linear regression P value). The statistical power of CAT test decreased, while the result of linear regression analysis remained the same when population size was reduced by 100 times and AMI incidence rate remained unchanged. The two statistical methods have their advantages and disadvantages. It is necessary to choose statistical method according the fitting degree of data, or comprehensively analyze the results of two methods.
采用Cochran-Armitage趋势（CAT）检验和线性回归（LR）两种统计学方法，分析天津市居民1999－2013年急性心肌梗死（AMI）发病率的时间趋势，比较两种方法结果的差别。结果显示，以实际人口为基础，无论是总的发病率时间趋势，还是按年龄分亚组后的时间趋势，CAT检验的统计效能均大于LR（CAT P值<LR P值）。将实际人口缩小100倍，AMI发病率保持不变，CAT检验的P值呈明显升高，LR的P值保持不变。两种统计学方法在流行病学率的趋势分析中都有其各自的优势和缺点，研究者可以根据资料选择拟合度较好的模型，或者两种方法结合来分析，全面地描述统计结果。.
Keywords: Cochran-Armitage trend test; Linear regression analysis; Trend analysis.