Under the limitation of cross-sectional studies, more researchers are turning their attention to maternal and child cohort studies. However, some problems do exist in the traditional maternal and child cohort studies, if data is only gathered from the hospitals. The limitation would include the contents of research and the high rate of loss to follow-up. With the integration of different medical traits and the progress in big data, the development of maternal and child related cohorts, with characteristics of dynamic follow-up and data sharing, through combining the information and health service systems of different institutions, seem in urgent need. This paper aims to provide some basic achievements in conducting maternal and child cohorts that can serve the related health problems through full-life cycle, and provide new references on conducting cohort studies, aiming at special population or diseases.

Three healthcare revolutions and four medical paradigm shifts have had a profound impact on the development of healthcare system, which has greatly improved human health, however, the COVID-19 pandemic has exposed hidden dangers and problems in the construction of the healthcare system. In this paper, we made a brief introduction of population medicine and value-based healthcare for the purpose of suggesting new ideas and directions for the future development of healthcare system.

Objective:To investigate sleep quality in pregnant women during their first and second trimester and to identify risk factors.Methods:Data was from the Chinese Pregnant Women Cohort Study. A total of 3 618 pregnant women were included, with the exclusion 346 women who had missing information. Sociodemographic, health-related behavior, depression and sleep quality information were collected and analyzed. Logistic regression analysis were used to explore the influencing factors of sleep quality in pregnant women.Results:Among the 3 618 pregnant woman 28.2% had poor sleep quality in their first trimester and 28.7% in the second trimester. 15.2% pregnant women had progressively worse sleep and 13.0% had persistently poor sleep had pregnant women were generally suffered from poor sleep quality, difficulty falling asleep, sleep disorders and daily fatigue. Regular diet ( OR=0.75, 95% CI: 0.62-0.92) and work ( OR=0.84,95% CI: 0.71-0.99) in the first trimester were protective factors of sleep quality in pregnant women. Age ≥30 year old ( OR=1.19, 95% CI: 1.03-1.37), passive smoking ( OR=1.18, 95% CI: 1.02-1.36) and depression ( OR=2.25, 95% CI: 1.95-2.61) in the first trimester were risk factors. Conclusions:The rate of poor sleep quality are high among Chinese pregnant woman during their first and second trimester. The risk factors of sleep quality are multiple. Regular diet and work, reduction of tobacco exposure, alleviation of depression symptom may help improve sleep quality among pregnant women.

Objective:To investigate the effect of changes in physical activities on depressive symptoms in the second trimester of pregnancy.Methods:Data from the Chinese Pregnant Women Cohort Study, from July 25, 2017 to November 26, 2018, were used. Women who had effectively completed the survey of physical activity and depressive symptoms in the first and second trimesters of pregnancy, were recruited. Both International Physical Activity Questionnaire-short and Edinburgh Postnatal Depression Scale were used, respectively. Pregnant women who had completed two surveys were included in our study and were divided into two groups according to the depressive symptoms, measured at the baseline. Among the pregnant women without depressive symptoms at the baseline, logistic regression was used to analyze the effects of changes in physical activity on the prevention of depressive symptoms. Effect on the reduction of depressive symptoms was analyzed, using the same method.Results:The prevalence rates of depressive symptoms were 23.83 % and 20.57 % in the baseline and second trimester, respectively. After adjusting for age, education level, occupation, family annual income and pre-pregnancy BMI, data from the logistic regression showed that women without depressive symptoms and with increased and adequate physical activities in the baseline, were with lower risks to develop depressive symptoms in the second trimester ( OR=0.479, 95 %CI: 0.335-0.684; OR=0.566, 95 %CI: 0.394-0.815). Among women with depressive symptoms in the baseline survey, association between physical activity and depressive symptoms was not statistically significant ( P>0.05). Conclusions:Increased and adequate physical activities showed preventive effects on depressive symptoms during pregnancy, but the remission effect was not obvious in women with depressive symptoms. Pregnant women should be encouraged to increase their physical activities while screening programs should also be carried out to reduce the depressive symptoms during pregnancy.

Objective:To prospectively explore the associations between total and different types of physical activities and gestational diabetes mellitus (GDM) in the first trimester of pregnant women, in Beijing.Methods:Data of 909 participants from the Chinese Pregnant Women Cohort study were extracted and studied. Four types of physical activities, including household/care-giving, occupational, sports/exercise and outdoor ways of transportation (walking/cycling/E-biking) in early pregnancy were studied by using the pregnancy physical activity questionnaire (PPAQ). All the participants were followed up and related data on GDM collected. Logistic regressions were conducted for data analysis on the associations of interests.Results:A total of 206 pregnant women (22.7 %) were diagnosed with GDM. After adjusting for age, pre-pregnancy BMI, family history of diabetes and other types of physical activities, results from the logistic regression showed that women with moderate level of household/care-giving activities were with the lower odds on GDM ( OR=0.654, 95 %CI: 0.436-0.980). Women who had met the guideline of exercise were less likely to have GDM ( OR=0.518, 95 %CI: 0.287-0.934). There was no significant association appeared between total physical, occupational and outdoor ways of transportation (walking/cycling/E-biking) activities with GDM. Conclusions:Sports/exercise and household/care-giving activities in early pregnancy appeared important on GDM prevention. Pregnant women are encouraged to wisely arranging their sports/exercise activities and engaging in moderate household/care-giving activities in the first trimester of pregnancy, to prevent GDM.

Objective:To understand the research progress and quality of lung cancer screening guidelines and consensus in China and abroad, and to provide reference for the formulation of high-quality lung cancer screening guidelines in China.Methods:Databases including PubMed, Medline, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, SinoMed, VIP and Wanfang Data were searched, websites and important references were also searched by hand retrieval. The Appraisal of Guidelines for Research & Evaluation Ⅱ(AGREE Ⅱ) and Reporting Items for Practice Guidelines in Healthcare (RIGHT) were used to assess the quality of newly published or updated guidelines and consensus.Results:A total of 9 guidelines and consensus published between 2015 and 2020 were included in this study, with countries including the United States, China, Canada, Saudi Arabia and South Africa. The field of scope and purpose and clarity of presentation scored relatively high but the rigor of development and applicability scored low. Five guidelines were judged to be A-level, all of which were published abroad, and the remaining four were B-level, including three guidelines and consensus issued by China and 1 guideline issued by South Africa. The report rate of RIGHT were higher in basic information and background, lower in review and quality assurance, funding and declaration and management of interests. There were 5 guidelines with a good level and 4 guidelines and consensus with a moderate level. The best overall quality guidelines were those published by the American College of Chest Physicians in 2018 and by the Canadian Task Force on Preventive Health Care in 2016.Conclusions:The number of countries and institutions that issue lung cancer screening guidelines and consensus had been increasing gradually, but the quality in China remained low. It is necessary to develop high-quality lung cancer screening guidelines suitable for China's national conditions in combination with evidence-based methods to guide practice.

Data standard plays an important role in the process of data collection, Integration and sharing in clinical cohort studies, and more attention have been paid to it. This paper summarizes the 5 international proven data standard model, analyze their characteristics and development status, and match their data modules with the general data set of the clinical cohorts to evaluate the international data standard models' applicability and provide reference for the development and improvement of the data standard model for clinical cohort studies in China.

High-quality clinical practice guidelines are of great significance for standardizing the clinical diagnosis and treatment process and improving the overall quality of health care. The Appraisal of Guidelines for Research & Evaluation InstrumentⅡ (AGREEⅡ) is one of the recognized tools for the evaluation of the quality of clinical practice guidelines. It has been translated into Chinese and is widely used in guideline formulation and quality evaluation. This article intends to take the comparatively high-quality clinical practice guidelines in the field of esophageal cancer screening in China, i.e. "Expert Consensus on Early Esophageal Cancer and Precancerous Lesion Screening in China (2019, Xinxiang)" as an example, to interpret the use of AGREEⅡ item by item, which might provide a reference for medical and health workers to better understand and use the assessment tool.

One of the most cost-effective measures in cancer prevention on cancer is to advocate to be aware of the disease, consciously changing negative behaviors, and taking the initiative to participate in regular physical checkup programs. Esophageal cancer is one of the malignant tumors accompanied by a heavy disease burden in China. Routine screening, early diagnosis, and treatment are the critical points of preventing and treating the disease. Cohort studies help understand the natural history and risk factors of esophageal cancer and identify high-risk groups of the disease. This paper intends to discuss the construction specifications of the multi-dimensional dynamic follow-up shared cohort for esophageal cancer by studying the risk factors, monitoring, and collecting biological sample information, providing references for developing a standardized and unified screening cohort research procedure, and necessary standards on esophageal cancer in the future.