The health and nutrition survey databases of China, the United States, and Korea are all focused on national health and nutrition surveillance, which have become important public resources for data mining in recent years. The construction status, brief histories, sampling methods, and survey contents of the three health and nutrition survey databases were compared and analyzed, it was found that the main difference lies in the types of study design, with cohort study used in China, cross-sectional survey used in both the United States and Korea. Then, the database-based publication volume and research hotspots were visually analyzed and found that the upward trend is more prominent in the United States, the research hotspots of the three databases were consistent with the themes of the health and nutrition survey. Finally, the construction and application of the databases were discussed and recommendations were made, which was expected to provide a path for relevant researches and better encourage the generation of scientific evidence.
Spirometry is the most common and extensively used pulmonary function test method, whose quality control is the cornerstone for its promotion and application. The report format is a key factor associated with the quality control of spirometry, but it is generally various in China, which is not conducive to the popularization and application of spirometry.
To assess the current status of report formats for spirometry in Chinese mainland.
The reports of spirometry were collected from some hospitals in China between April 2016 and December 2018, which are composed of four parts, including the general demographic information, test indicators, graphs, and results evaluation. The key and/or essential information for each part is as follows: (1) the general demographicinformation part: sex, height, BMI, age and the reference source; (2) test indicators part: forced vital capacity (FVC) , forced expiratory volume in 1 second (FEV1) , the ratio of FEV1/FVC or FEV1/VCmax, maximal mid-expiratory flow〔FEF25%-75%, forced expiratory flow at 50% (FEF50%) , forced expiratory flow at 75% (FEF75%) 〕, peak inspiratory flow (PIF) and forced expiratory time (FET) ; (3) graphs part: flow-volume curve (F-V curve) and volume-time curve (V-T curve) ; (4) results evaluation part: subjects cooperation, test quality control level, and physician interpretation. The differences in the report format of spirometry were compared by region and hospital level in this study.
In total, 1 562 spirometry reports from 1 562 hospitals (one from each hospital) across China were enrolled, but only 0.4% provided all key indicators. (1) For the general demographic information part, only 27.7% reports provided complete key indicators, which differed significantly by regions and the level of hospitals (P<0.05) . Moreover, the part showed the reference source only accounted for 28.2%. (2) Furthermore, in the test indicators part, 91.9% of the total reports provided all key indicators. More than 90.0% reports listed FEF25%-75%, FEF50% and/or FEF75%, while the PIF and FET was reported in 36.4%, 46.0%, respectively. (3) In terms of the graphs part, 73.4% reports provided key indicators, but 26.6% did not report the important information like V-T curve. (4) Finally, in the results evaluation part, the report without lacking key indicators were only accounted for 1.6%, and there were great differences between hospitals of different levels (P<0.05) . What's more, only 14.9% clearly showed the quality control of spirometry.
There were great differences of the report formats for spirometry analyzed and the 2019 Standard for pulmonary function examination report. Lack of the key information such as the reference resource, inspiratory phase indicators, the indicators about quality control and quality control of test would seriously affect the clinical value of spirometry. Therefore, it is suggested to add the program of report format standards during the standardized trainings of pulmonary function testing, and strengthen the understanding and application of various indicators of spirometry among pulmonary function practitioners.
