Objective:To systematically search and evaluate risk prediction models for ventilator-associated pneumonia (VAP) of ICU in order to provide references for developing higher-quality VAP risk prediction models.Methods:Relevant literature was retrieved from databases including China Biology Medicine disc, WanFang data, China National Knowledge Infrastructure, Embase, PubMed, CINAHL, Web of Science, and Cochrane Library. The search timeframe was from the establishment of the databases to September 30, 2023, limited to English and Chinese languages. Two researchers independently screened the literature and extracted data, and the PROBAST tool was used to evaluate the risk of bias and applicability of the included studies.Results:A total of 15 studies on VAP risk prediction models were included. The area under the receiver operating characteristic curve for the 15 models ranged from 0.722 to 0.982. The most frequently involved predictors were age, duration of mechanical ventilation, ICU length of stay, and comorbid chronic obstructive pulmonary disease. The overall adaptability was good, but the risk of bias was high. The main sources of bias included insufficient sample size, inappropriate data sources, lack of model performance evaluation, and inadequate attention to missing data.Conclusions:The risk of bias in studies on VAP risk prediction models is high, indicating that the field is still developing. Future research should focus on the effectiveness of different risk assessment methods to construct models with low bias, excellent predictive performance, and suitability for clinical practice in China.

Clopidogrel was believed to be superior to aspirin by the well-known CAPRIE trial. However, no other large clinical trials demonstrated the same results, but all focused on the combination use of clopidogrel with aspirin, and combination therapy in CREDO was called the "Emperor's New Clothes". However, no one overturned the results of these clinical trials by quantitatively analyzing them. We reviewed ten large-scale clinical trials about clopidogrel. On the basis of results of CAPRIE, CREDO and CHARISMA trials, we re-estimated their minimal sample sizes and their powers by three well-established statistical methodologies. From the results of CAPRIE, we inferred that the minimal sample size should be 85 086 or 84 968 but its power was only 30.70%. A huge gap existed. The same was also true of CREDO and CHARISMA trials. Moreover, in CAPRIE trial, 0 was included in the 95% confidence interval and 1 was included in the 95% confidence interval for the relative risk. There were some paradoxical data in CAPRIE trial. We are led to conclude that the results in CAPRIE, CREDO, and from the subgroup analysis in CHARISMA trials were questionable. These results failed to demonstrate that clopidogrel was superior to aspirin or that clopidogrel used in combination with aspirin was better than aspirin alone. The cost-effectiveness analyses by some previous studies were not reliable.

Clopidogrel was believed to be superior to aspirin by the well-known CAPRIE trial. However, no other large clinical trials demonstrated the same results, but all focused on the combina-tion use of clopidogrel with aspirin, and combination therapy in CREDO was called the "Emperor's New Clothes". However, no one overturned the results of these clinical trials by quantitatively ana-lyzing them. We reviewed ten large-scale clinical trials about clopidogrel. On the basis of results of CAPRIE, CREDO and CHARISMA trials, we re-estimated their minimal sample sizes and their powers by three well-established statistical methodologies. From the results of CAPRIE, we inferred that the minimal sample size should be 85 086 or 84 968 but its power was only 30.70%. A huge gap existed. The same was also true of CREDO and CHARISMA trials. Moreover, in CAPRIE trial, 0 was included in the 95% confidence interval and 1 was included in the 95% confidence interval for the relative risk. There were some paradoxical data in CAPRIE trial. We are led to conclude that the results in CAPRIE, CREDO, and from the subgroup analysis in CHARISMA trials were questionable. These results failed to demonstrate that clopidogrel was superior to aspirin or that clopidogrel used in combination with aspirin was better than aspirin alone. The cost-effectiveness analyses by some pre-vious studies were not reliable.