求翻译：第二步，不同于以往研究，对非零医疗消费的城镇居民，我们进一步使用分位数回归（Quantile Regression）定量分析不同因素对医疗消费水平不同的城镇居民，其影响是否存在异质性。是什么意思？

The second step, unlike previous studies, the nonzero health care spending of urban residents, we further use quantile regression (Quantile Regression) quantitative analysis of different factors on different levels of health care spending of urban residents, the impact of the existence of heterogene

Step 2, different from that of the past research, the non-zero medical consumption of the urban population, we further use of sub-digit return) quantitative analysis (Quantile Regression different factors on different levels of health care spending, and its impact on urban residents heterogeneity of

Second step, was different with formerly studies, expends the cities inhabitant to the non-vanishing medical service, we further use the quantile return (Quantile Regression) the quantitative analysis different factor for the medical service consumption level different cities inhabitant, it affects

The second step, different from the previous studies on medical consumption of urban residents in non-zero, we further using quantile regression (Quantile Regression) quantitative analysis of different factors on medical consumption with different levels of urban residents, the effects of the existe

The second step, different from the previous studies on medical consumption of urban residents in non-zero, we further using quantile regression (Quantile Regression) quantitative analysis of different factors on medical consumption with different levels of urban residents, the effects of the existe