Advantages and limitations
chronic disease
DISEASE, CHRONIC DISEASE
The design of this study had several advantages. First, unified standards and procedures were adopted and implemented by a respiratory professional attending physician with more than 5 years of working experience and skilled knowledge of how to operate the pulmonary function meter. Second, the data collection was jointly undertaken by two researchers to ensure that the observation forms were filled out in a detailed and objective manner. All the survey data and experimental data collected were input into the Epidata database. After data entry, consistency testing (comparison of differences after double entry of the questionnaire) and reliability testing (quality control of the input REC files) were carried out. Third, the researchers working on the study did not participate in the formulation of treatment plans. For follow‐up on the basis of chronic disease management, the participants had a high degree of fit, and the follow‐up intervals were designed to mitigate the risk of patients forgetting and thus control the rate of loss of follow‐up and improve the compliance of participants.In terms of limitations, the research was a single‐center study, so the disease severity distribution and treatment of the study population may not represent the general disease population. In addition, the follow‐up period was 6 months, which is relatively short, and it is difficult to decide on causal effects about the changes of the level of the cell types. Finally, in consideration of medical accessibility and the disease treatment burden, the effects of doxofylline on mild and moderate acute exacerbation were not quantified.