Telephone follow-up is one of the important ways to follow up patients. High-quality follow-up can benefit both doctors and patients. However, clinical research-related follow-up is often faced with problems such as time-consuming, laborious and poor patient compliance. The authors belong to a team that has been committed to the study of patient-reported outcomes for a long time. The team has carried out long-term follow-up of symptoms, daily function and postoperative complications of more than 1 000 patients after lung cancer surgery, and accumulated certain experience. In this paper, the experience of telephone follow-up was summarized and discussed with relevant literatures from the aspects of clarifying the purpose of clinical research follow-up, understanding the needs of patients in follow-up, and using follow-up skills.

Objective To analyze the pollution characteristics of 12 kinds of metals and metalloid elements in PM_2.5 in Xi'an city, and to assess the health risks. Methods In 2018, PM2.5 samples were collected regularly every month at two monitoring points in Lianhu District and Yanta District of Xi'an City. The content of twelve metal and metalloid elements (Sb, Al, As, Be, Cd, Cr, Hg, Pb, Mn, Ni, Se, and Ti) in the samples were determined. The test results were statistically analyzed and evaluated according to different regions and seasons. The health risk assessment model recommended by the US Environmental Protection Agency (EPA) was used to assess the health risks of the metal and metalloid elements. Results A total of 165 PM_2.5 samples were collected and analyzed. The qualified rates of As and Cd were 51.52% and 83.03%, respectively, and there was no significant difference between regions (P＞0.05). The qualified rate of As in each season from high to low was summer> autumn> winter> spring. The average concentration of As was 8.21 ng/m³, being 1.37 times higher than the standard. The average concentration of As in each season exceeded the standard, and the order from high to low was winter> spring> autumn> summer. The average concentrations of other elements did not exceed the standard. HQ value and HI value of As, Cd, Cr, Pb, Mn, Ni, Hg, Ti and Se were all less than 1. The ILCR value of carcinogenic elements As, Cd, Cr and Ni was between 3.63×10^-07 ~2.58×10^-05. The ILCR value was highest for As, followed by Cr. The ILCR value was highest in winter, followed by spring and autumn, and lowest in summer. The order of ILCR value was adult males> adult females> children and adolescents. Conclusion The pollution of metal and metalloid elements in the atmospheric PM_2.5 in Xi'an in the winter is most serious. Arsenic and chromium in PM_2.5 pose a higher potential health risk to the population through the respiratory route.