Background and purpose:With the increasing use of medical imaging examinations,Computed tomography(CT)scans have become one of the primary sources of effective dose.This study analyzed the correlation between radiation dose,image quality and body composition in thyroid CT to provide a data foundation for better control of radiation dose and image quality in the future.Methods:A retrospective analysis was conducted on patients who underwent thyroid CT scans at Fudan University Shanghai Cancer Center from January 2015 to December 2019.CT values and standard deviations(SD)of the homogeneous parenchyma of the thyroid were collected,and CT values and SD values of adjacent subcutaneous fat tissue were measured with the same region of interest(ROI)size.All data were measured three times to obtain the average value,and the volume CT dose index(CTDIvol)and dose-length product(DLP)were recorded.Effective dose values and signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)for various parts were calculated.All patients underwent bone density examinations,and patient height,weight,body mass index(BMI),body surface area(BSA),and the percentage of muscle and fat in the spine and thighs were recorded.Results:A total of 104 patients were enrolled in this study.The SNR of thyroid CT images and the percentage of spinal muscle(r=0.284,P=0.004),CNR of thyroid CT images and the percentage of spinal fat(r=0.197,P=0.045),and the effective dose of thyroid CT images and age,weight,BMI,thigh fat percentage,and body surface area(r=0.221,0.247,0.260,0.262,and 0.222;P=0.024,0.011,0.008,0.007 and 0.024)were positively correlated.While,SNR and age,weight,BMI,and the percentage of spinal fat(r=-0.292,-0.198,-0.207,and-0.284;P=0.003,0.044,0.035,0.004),CNR and the percentage of spinal muscle(r=-0.197,P=0.045),and the effective dose and the percentage of thigh muscle(r=-0.262,P=0.007)were negatively correlated.Conclusion:The radiation dose in thyroid CT is correlated with female body composition.The image quality is related to female body composition,providing a data foundation for better control of radiation dose and image quality in the future.

Objective:To develop the Adolescent Mental Health Computerized Adaptive Test(AMH-CAT)for assessing psychological crises in adolescents using item response theory(IRT).Methods:A total of 8 679 students,aged 9 to 19 years,were sampled from 14 primary and secondary schools.The item bank was constructed by examining unidimensionality,independence,discrimination,and Differential Item Functioning(DIF).The AMH-CAT algorithm was developed using R software and validated for reliability and validity through real and simulated data.The School Psychological Interview Evaluation Form served as the criterion tool to assess the predictive validi-ty of AMH-CAT in evaluating psychological crises levels.Results:The item bank,consisting of 43 items,demon-strated unidimensionality and independence,with discrimination values＞0.80 and no DIF across genders.Under va-rious stopping rules,AMH-CAT showed ABS values＜0.40,RMSE values＜0.50,and a correlation(r)＞0.87(P＜0.001)between estimated and true psychological crises levels.Real participants answered an average of 10 items under the SE(θ)≤0.4 stopping rule,with a reliability of 0.89,and the scores were positively correlated with the complete item bank scores(r=0.95,P＜0.001).The predictive accuracy for Level 1 and Level 2 concerns was 0.89 and 0.90,respectively.Conclusion:The Adolescent Mental Health Computerized Adaptive Test(AMH-CAT)demonstrates excellent validity,reliability and assessment efficiency for evaluating adolescent psychological crises.

Objective:To analyze the multimorbidity trends and influencing factors of internet addiction and depressive symptoms among middle school students in Zhejiang Province.Methods:From 2018 to 2023, a multistage stratified random cluster sampling method was used to select middle school students aged 12 to 18 in Zhejiang Province. Internet addiction and depression status were measured by the Internet Addiction Scale and the Center for Epidemiologic Studies Depression Scale. When both symptoms were present, it was defined as multimorbidity.The multivariate logistic regression model was used to analyze the influencing factors of multimorbidity among middle school students, and a trend Chi-square test was used to analyze the changing trends of internet addiction, depression and multimorbidity prevalence. Results:A total of 193 505 students were included in the study. From 2018 to 2023, the prevalence of multimorbidity of internet addiction and depressive symptoms among middle school students ranged from 2.7% to 3.5%. The prevalence of internet addiction ranged from 4.7% to 6.0%, while the prevalence of depressive symptoms ranged from 18.7% to 25.1%. Multivariate logistic regression showed that boarding students ( OR=1.34 , 95% CI: 1.26-1.42), low-frequency ( OR=1.59, 95% CI: 1.46-1.73), and high-frequency sugary drink consumption ( OR=3.91, 95% CI: 3.55-4.31) increased the risk of multimorbidity among middle school students. In contrast, higher frequencies of moderate-to-high-intensity exercise (medium: OR=0.54, 95% CI: 0.50-0.58; high: OR=0.49, 95% CI: 0.44-0.55) and sufficient sleep ( OR=0.52, 95% CI: 0.49-0.56) were protective factors. From 2018 to 2023, there was no significant change in the trend of multimorbidity prevalence among middle school students ( χ2trend=3.82, P=0.051). The prevalence of internet addiction showed an upward trend ( χ2trend=20.54, P<0.001), while depressive symptoms showed a downward trend ( χ2trend=181.41, P<0.001). Conclusion:The prevalence of internet addiction and depression symptoms among middle school students in Zhejiang Province remains stable from 2018 to 2023. The prevalence of internet addiction shows an upward trend, while the prevalence of depression symptoms shows a downward trend. The risk of multimorbidity is related to students′ boarding, consumption of sugary drinks, lack of exercise, and insufficient sleep.

Objective:To compare the efficacy of body posture combined with pharmacotherapy and pharmacotherapy alone in the treatment of chronic subdural hematoma(CSDH).Methods:Firstly, retrospective case series study was conducted. Thirty cases of CSDH that had received body posture combined with pharmacotherapy at Department of Neurosurgery, Huashan Hospital Affiliated to Fudan University from December 2016 to October 2020 were studied retrospectively. Twenty-seven patients were male, and 3 patients were female. The age of patients ( M(IQR)) was 66(16) years (range:28 to 84). Nineteen patients had unilateral hematoma, and 11 patients had bilateral hematoma. All patients received pharmacotherapy and body posture therapy that was to raise their lower limbs 20 to 30 cm with leg lift pad and get abdominal compressed with customized abdominal belt in supine position. Patients were required to maintain the body posture as much as possible, with the maximum to 16 to 18 hours per day. Patients with unilateral hematoma should tilt the head to the affected side and avoid tilting it to the opposite side. For patients with bilateral hematoma, there was no need for head lateralization. Patient were treated with oral dexamethasone and atorvastatin simultaneously. The preliminary efficacy of body posture combined with pharmacotherapy was determined by hematoma improvement rate which was analyzed by Clopper-Pearson method. Then, the multi-center, prospective, randomized controlled trial had carried out in 9 medical centers from August 2020 to November 2021. The stratified block randomization method was adopted. Patients were randomized in a ratio of 1∶1 to either receive pharmacotherapy alone(the control group) or body posture combined with pharmacotherapy(the experiment group) for 3 months and followed up for 6 months. Effective treatment was defined as complete absorption of hematoma, or the hematoma volume decreased by more than 10 ml and Markwalder grading scale score had improved by more than 1 point compared to the baseline. The efficacy rate and surgery conversion rate at 3 months and recurrence at 6 months were observed. Comparison between groups was performed with paired sample t test, Mann-Whitney U test, χ2 test, corrected χ2 test, or Fisher exact probability method. Logistic regression was used to compare the effective rate and operation rate between the two groups. Results:In the respective study, 30 patients completed follow-up 13 to 353 days after treatment. At the last follow-up, the incidence of almost complete absorption or significantly absorption of hematoma (hematoma volume was significantly reduced accompanied by symptom improvement) was 93.3%. The 95% CI for the incidence that analyzed by the Clopper-Pearson method was 77.9% to 99.2%. One hundred and six patients were enrolled in the multicenter study. Fifty-five patients underwent body posture combined with pharmacotherapy. The age was 74(17) years (range:26 to 92). Thirty-nine patients were males and 16 were females. Fifty-one patients underwent pharmacotherapy alone. The age was 69(12) years (range:48 to 84). Thirty-seven patients were males and 14 were females. The length of body posture recorded in diary card was (15.7±2.3) hours(range:7.6 to 19.3 hours). The efficacy rate in the body posture combined with pharmacotherapy group and pharmacotherapy alone group were 83.6% (46/55) and 56.9% (29/51), respectively at 3 months. The result of the logistic regression analysis showed that the efficacy of body posture combined with pharmacotherapy group was better than that of pharmacotherapy alone group ( OR=3.88,95% CI:1.57 to 9.58, P=0.003). Surgery rate in the body posture combined with pharmacotherapy group and pharmacotherapy alone group were 5.5% (3/55) and 21.6% (11/51) respectively. The result of Logistic regression showed that the pharmacotherapy alone group was more likely to be converted to surgery ( OR=0.21,95% CI:0.05 to 0.80, P=0.023). At the 6 months, no recurrence of cases was found in the body posture combined with pharmacotherapy group. However, the recurrence rate of pharmacotherapy alone group was 6.3% (3/48), there was no significant difference between the two groups ( P>0.05). Conclusion:The effect of body posture combined with pharmacotherapy for chronic subdural hematoma is better than that of pharmacotherapy alone.

Objective:To analyze the multimorbidity trends and influencing factors of internet addiction and depressive symptoms among middle school students in Zhejiang Province.Methods:From 2018 to 2023, a multistage stratified random cluster sampling method was used to select middle school students aged 12 to 18 in Zhejiang Province. Internet addiction and depression status were measured by the Internet Addiction Scale and the Center for Epidemiologic Studies Depression Scale. When both symptoms were present, it was defined as multimorbidity.The multivariate logistic regression model was used to analyze the influencing factors of multimorbidity among middle school students, and a trend Chi-square test was used to analyze the changing trends of internet addiction, depression and multimorbidity prevalence. Results:A total of 193 505 students were included in the study. From 2018 to 2023, the prevalence of multimorbidity of internet addiction and depressive symptoms among middle school students ranged from 2.7% to 3.5%. The prevalence of internet addiction ranged from 4.7% to 6.0%, while the prevalence of depressive symptoms ranged from 18.7% to 25.1%. Multivariate logistic regression showed that boarding students ( OR=1.34 , 95% CI: 1.26-1.42), low-frequency ( OR=1.59, 95% CI: 1.46-1.73), and high-frequency sugary drink consumption ( OR=3.91, 95% CI: 3.55-4.31) increased the risk of multimorbidity among middle school students. In contrast, higher frequencies of moderate-to-high-intensity exercise (medium: OR=0.54, 95% CI: 0.50-0.58; high: OR=0.49, 95% CI: 0.44-0.55) and sufficient sleep ( OR=0.52, 95% CI: 0.49-0.56) were protective factors. From 2018 to 2023, there was no significant change in the trend of multimorbidity prevalence among middle school students ( χ2trend=3.82, P=0.051). The prevalence of internet addiction showed an upward trend ( χ2trend=20.54, P<0.001), while depressive symptoms showed a downward trend ( χ2trend=181.41, P<0.001). Conclusion:The prevalence of internet addiction and depression symptoms among middle school students in Zhejiang Province remains stable from 2018 to 2023. The prevalence of internet addiction shows an upward trend, while the prevalence of depression symptoms shows a downward trend. The risk of multimorbidity is related to students′ boarding, consumption of sugary drinks, lack of exercise, and insufficient sleep.

Background and purpose:With the increasing use of medical imaging examinations,Computed tomography(CT)scans have become one of the primary sources of effective dose.This study analyzed the correlation between radiation dose,image quality and body composition in thyroid CT to provide a data foundation for better control of radiation dose and image quality in the future.Methods:A retrospective analysis was conducted on patients who underwent thyroid CT scans at Fudan University Shanghai Cancer Center from January 2015 to December 2019.CT values and standard deviations(SD)of the homogeneous parenchyma of the thyroid were collected,and CT values and SD values of adjacent subcutaneous fat tissue were measured with the same region of interest(ROI)size.All data were measured three times to obtain the average value,and the volume CT dose index(CTDIvol)and dose-length product(DLP)were recorded.Effective dose values and signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)for various parts were calculated.All patients underwent bone density examinations,and patient height,weight,body mass index(BMI),body surface area(BSA),and the percentage of muscle and fat in the spine and thighs were recorded.Results:A total of 104 patients were enrolled in this study.The SNR of thyroid CT images and the percentage of spinal muscle(r=0.284,P=0.004),CNR of thyroid CT images and the percentage of spinal fat(r=0.197,P=0.045),and the effective dose of thyroid CT images and age,weight,BMI,thigh fat percentage,and body surface area(r=0.221,0.247,0.260,0.262,and 0.222;P=0.024,0.011,0.008,0.007 and 0.024)were positively correlated.While,SNR and age,weight,BMI,and the percentage of spinal fat(r=-0.292,-0.198,-0.207,and-0.284;P=0.003,0.044,0.035,0.004),CNR and the percentage of spinal muscle(r=-0.197,P=0.045),and the effective dose and the percentage of thigh muscle(r=-0.262,P=0.007)were negatively correlated.Conclusion:The radiation dose in thyroid CT is correlated with female body composition.The image quality is related to female body composition,providing a data foundation for better control of radiation dose and image quality in the future.

Objective:To develop the Adolescent Mental Health Computerized Adaptive Test(AMH-CAT)for assessing psychological crises in adolescents using item response theory(IRT).Methods:A total of 8 679 students,aged 9 to 19 years,were sampled from 14 primary and secondary schools.The item bank was constructed by examining unidimensionality,independence,discrimination,and Differential Item Functioning(DIF).The AMH-CAT algorithm was developed using R software and validated for reliability and validity through real and simulated data.The School Psychological Interview Evaluation Form served as the criterion tool to assess the predictive validi-ty of AMH-CAT in evaluating psychological crises levels.Results:The item bank,consisting of 43 items,demon-strated unidimensionality and independence,with discrimination values＞0.80 and no DIF across genders.Under va-rious stopping rules,AMH-CAT showed ABS values＜0.40,RMSE values＜0.50,and a correlation(r)＞0.87(P＜0.001)between estimated and true psychological crises levels.Real participants answered an average of 10 items under the SE(θ)≤0.4 stopping rule,with a reliability of 0.89,and the scores were positively correlated with the complete item bank scores(r=0.95,P＜0.001).The predictive accuracy for Level 1 and Level 2 concerns was 0.89 and 0.90,respectively.Conclusion:The Adolescent Mental Health Computerized Adaptive Test(AMH-CAT)demonstrates excellent validity,reliability and assessment efficiency for evaluating adolescent psychological crises.

Objective:To compare the efficacy of body posture combined with pharmacotherapy and pharmacotherapy alone in the treatment of chronic subdural hematoma(CSDH).Methods:Firstly, retrospective case series study was conducted. Thirty cases of CSDH that had received body posture combined with pharmacotherapy at Department of Neurosurgery, Huashan Hospital Affiliated to Fudan University from December 2016 to October 2020 were studied retrospectively. Twenty-seven patients were male, and 3 patients were female. The age of patients ( M(IQR)) was 66(16) years (range:28 to 84). Nineteen patients had unilateral hematoma, and 11 patients had bilateral hematoma. All patients received pharmacotherapy and body posture therapy that was to raise their lower limbs 20 to 30 cm with leg lift pad and get abdominal compressed with customized abdominal belt in supine position. Patients were required to maintain the body posture as much as possible, with the maximum to 16 to 18 hours per day. Patients with unilateral hematoma should tilt the head to the affected side and avoid tilting it to the opposite side. For patients with bilateral hematoma, there was no need for head lateralization. Patient were treated with oral dexamethasone and atorvastatin simultaneously. The preliminary efficacy of body posture combined with pharmacotherapy was determined by hematoma improvement rate which was analyzed by Clopper-Pearson method. Then, the multi-center, prospective, randomized controlled trial had carried out in 9 medical centers from August 2020 to November 2021. The stratified block randomization method was adopted. Patients were randomized in a ratio of 1∶1 to either receive pharmacotherapy alone(the control group) or body posture combined with pharmacotherapy(the experiment group) for 3 months and followed up for 6 months. Effective treatment was defined as complete absorption of hematoma, or the hematoma volume decreased by more than 10 ml and Markwalder grading scale score had improved by more than 1 point compared to the baseline. The efficacy rate and surgery conversion rate at 3 months and recurrence at 6 months were observed. Comparison between groups was performed with paired sample t test, Mann-Whitney U test, χ2 test, corrected χ2 test, or Fisher exact probability method. Logistic regression was used to compare the effective rate and operation rate between the two groups. Results:In the respective study, 30 patients completed follow-up 13 to 353 days after treatment. At the last follow-up, the incidence of almost complete absorption or significantly absorption of hematoma (hematoma volume was significantly reduced accompanied by symptom improvement) was 93.3%. The 95% CI for the incidence that analyzed by the Clopper-Pearson method was 77.9% to 99.2%. One hundred and six patients were enrolled in the multicenter study. Fifty-five patients underwent body posture combined with pharmacotherapy. The age was 74(17) years (range:26 to 92). Thirty-nine patients were males and 16 were females. Fifty-one patients underwent pharmacotherapy alone. The age was 69(12) years (range:48 to 84). Thirty-seven patients were males and 14 were females. The length of body posture recorded in diary card was (15.7±2.3) hours(range:7.6 to 19.3 hours). The efficacy rate in the body posture combined with pharmacotherapy group and pharmacotherapy alone group were 83.6% (46/55) and 56.9% (29/51), respectively at 3 months. The result of the logistic regression analysis showed that the efficacy of body posture combined with pharmacotherapy group was better than that of pharmacotherapy alone group ( OR=3.88,95% CI:1.57 to 9.58, P=0.003). Surgery rate in the body posture combined with pharmacotherapy group and pharmacotherapy alone group were 5.5% (3/55) and 21.6% (11/51) respectively. The result of Logistic regression showed that the pharmacotherapy alone group was more likely to be converted to surgery ( OR=0.21,95% CI:0.05 to 0.80, P=0.023). At the 6 months, no recurrence of cases was found in the body posture combined with pharmacotherapy group. However, the recurrence rate of pharmacotherapy alone group was 6.3% (3/48), there was no significant difference between the two groups ( P>0.05). Conclusion:The effect of body posture combined with pharmacotherapy for chronic subdural hematoma is better than that of pharmacotherapy alone.

Objective:To investigate the value of three-dimensional (3D) T 1WI structural images using different acceleration methods including parallel acquisition technique, joint compressed sensing (uCS) technique, and artificial intelligence-assisted compressed sensing (ACS) technique for brain region segmentation. Methods:In this cross-sectional study, fifty patients (female: n=25, age range: 13 to 87 years old) at Corning Hospital of Ningbo University from July to September 2023 were prospectively and consecutively collected. All the subjects underwent brain MRI. Six groups of 3D T 1WI structural images were obtained using different acceleration technique and parameters, including 3D T 1WI without acceleration factor (3D-T 1WI group), 3D T 1WI with parallel acquisition technique with acceleration factor 3 (3D-T 1WI-PI-3 group), 3D T 1WI with uCS technique with acceleration factor 4.5 and 6.9 (3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group), 3D T 1WI by ACS technique with acceleration factors of 3 and 5 (3D-T 1WI-ACS-3 group, 3D-T 1WI-ACS-5 group). T 2WI fluid-attenuated inversion recovery (FLAIR) images were also acquired. Subjective scores (cerebral grey matter and white matter clarity scores, clarity scores of cerebral white matter degeneration lesions in relation to the surrounding white matter, and Gibbs artifact scores) and objective metrics [signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), cerebrospinal fluid signal homogeneity, peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), and natural image quality evaluator (NIQE)] were used to evaluate image quality in different groups. Totally 109 brain regions were segmented and volumes were measured using the uAI Research Portal image analysis tool. Kappa or intraclass correlation coefficient ( ICC) was used to evaluate the agreement of subjective and objective evaluation indexes between the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, 3D-T 1WI-ACS-5 group, and 3D-T 1WI group. Kappa or ICC value>0.70 was considered as good agreement. Results:The acquisition time for the 3D-T 1WI group, 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, and 3D-T 1WI-ACS-5 group were 527, 204, 169, 95, 133, 90 s, respectively. Subjective evaluation showed that the 3D-T 1WI-uCS-4.5, 3D-T 1WI-ACS-3, and 3D-T 1WI-ACS-5 groups had excellent agreement with the 3D-T 1WI group in terms of the distribution of cases of cerebral grey matter and white matter clarity scores, respectively (all Kappa value=1.000); The distribution of cases of clarity score of cerebral white matter lesions and surrounding white matter in the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, and 3D-T 1WI-ACS-3 group were in good agreement with that of the 3D-T 1WI group ( Kappa values of 0.775, 0.701, and 0.777, respectively); the distribution of the number of cases of the Gibbs artifact score of the 3D-T 1WI-uCS-4.5, 3D-T 1WI-ACS-3, and 3D-T 1WI-ACS-5 groups was in good agreement with the 3D-T 1WI group (all Kappa value=1.000). Objective evaluation showed the CNR of the images in the 3D-T 1WI-PI-3, 3D-T 1WI-uCS-4.5, and 3D-T 1WI-uCS-6.9 groups were in good agreement with those of the 3D-T 1WI group ( ICC of 0.720, 0.759, and 0.752, respectively); PSNR and SSIM were in good agreement among the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, and 3D-T 1WI-ACS-5 group (PSNR: ICC=0.854; SSIM: ICC=0.851). NIQE of 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, and 3D-T 1WI-ACS-3 group images were in good agreement with the 3D-T 1WI group ( ICC value of 0.866, 0.727, 0.753, respectively). The ICC values of the volume of each segmented brain region among the 3D-T 1WI-PI-3, 3D-T 1WI-uCS-4.5, 3D-T 1WI-uCS-6.9, 3D-T 1WI-ACS-3, 3D-T 1WI-ACS-5 group and the 3D-T 1WI group images showed decreased in order (all ICC≥0.62). Conclusions:The uCS and ACS techniques used in 3D-T 1WI show high agreement with 3D-T 1WI in terms of brain segmentation. The application of these accelerating techniques can significantly shorten the acquisition time with obtaining images with good image quality, displaying great value.

Objective:To explore the relevant risk factors for deep venous thrombosis (DVT) of lower limb occurring 3 months after joint replacement surgery.Methods:A retrospective analysis was conducted on the clinical data of 1,782 patients who underwent joint replacement surgery at Drum Tower Hospital, School of Medicine of Nanjing University, from February 2015 to December 2018. Of these, 1,298 were male and 484 were female, with an average age of 65.4±12.3 years (range, 18-95 years). Fourteen factors associated with DVT occurrence at 3 months were investigated, including age, gender, body mass index (BMI), season of surgery, preoperative coagulation function, type of surgery, selection of minimally invasive approach, occurrence of lower limb venous thrombosis 1 day after surgery, history of previous thrombotic diseases, smoking, tumors, diabetes, hypertension, and heart disease. Independent sample t-tests and chi-square tests were used to analyze the risk factors for DVT occurrence. Indicators with statistically significant differences were included in a binary logistic regression analysis to determine the risk factors for DVT 3 months after surgery. The risk prediction model was established according to the results of logistic regression analysis, and the receiver operating characteristic curve was drawn. The area under the curve of the prediction model was calculated. Results:A total of 1,782 patients were included. The overall incidence of DVT occurring 3 months after joint replacement surgery was 10.5% (187/1,782). The thrombosis group included 5 symptomatic cases and 182 asymptomatic cases, with 13 proximal and 174 distal cases. DVT was found in the iliac vein (1 case), femoral vein (10 cases), popliteal vein (8 cases), peroneal vein (14 cases), and intramuscular vein (168 cases). Single-factor analysis showed that female gender, increasing age, previous thrombotic disease, hypertension, surgery in autumn, and the occurrence of DVT on the first day after surgery were correlated with DVT occurring 3 months after joint replacement surgery ( P<0.05). After excluding the missing data, a total of 1,744 patients were included in the final analysis. DVT occurrence on the first day after surgery [ OR=7.498, 95% CI (5.312, 10.584), P<0.001], surgery in autumn [ OR=1.834, 95% CI (1.215, 2.769), P=0.004], age [ OR=1.024, 95% CI (1.007, 1.042), P=0.009], female gender [ OR=1.863, 95% CI(1.184, 2.931), P=0.007], and history of previous thrombotic diseases [ OR=0.012, 95% CI (1.136, 2.830), P=0.012] were found to be associated with DVT occurrence at 3 months after surgery. The area under the curve (AUC) for predicting DVT three months after hip or knee arthroplasty was 0.803 [95% CI (0.761, 0.844)]. Conclusion:Advanced age, female gender, history of previous thrombotic diseases, occurrence of DVT on the first day after surgery, and surgery in autumn are risk factors for DVT occurring 3 months after joint replacement surgery.