Risk Factor Analysis On Surgical Intervention In Patients With Tubo-Ovarian Abscess And Stablishment Of A Nomogram Prediction Model

Objectives: To investigate the risk factors associated with surgical intervention in patients with tubo-ovarian abscess and construct a nomogram prediction model.Methods: This study was a retrospective case-control study that collected and reviewed the clinicopathological and microbiological data of patients with ovarian abscess in the Department of gynecology and obstetrics of Fujian Union Hospital from January 2013 to December 2019.All patients were empirically treated with antibiotic therapy after admission.Patients who failed in the medicine treatment needed surgical intervention,which divided all the patients into two groups,the medication group and the surgical intervention group.Clinicopathological data,including age,body mass index(BMI),pregnancy times,abortion times,menopause,IUD in use,history of pelvic or abdominal surgery,history of pelvic inflammatory disease,with endometriosis,admission temperature,admission leukocyte count,neutrophil count,CRP,PCT,hemoglobin,albumin,CA125,the maximum diameter of the abscess,bilateral abscess,the uterine cavity culture,Whether antibiotics are used before admission and whether the antibiotics are sensitive,were analyzed with univariate analysis to identify predictors for whether patients with TOA will require surgical intervention.Then,incorporated these predictors,which were screened by multivariate logistic regression,were plotted by the "rms" package in R software to establish a nomogram model.According to the scale of the nomogram of each risk factor,the total score could be obtained by adding each single score,then the corresponding probability of surgical intervention could be acquired.The area under ROC curve(AUC)was used to evaluate the predictive ability of each risk factor and nomogram on model.AUC >0.75 indicated that the model had good predictive ability.Bootstrap method(1000bootstrapping resamples)was applied as internal verification to show the robustness of the model.The discrimination of the nomogram was determined by calculating the average consistency index(C-index)whose rage was 0.5 to 1.0.Higher C-index indicated better consistency with actual risk.The calibration curve was used to assess the calibration of prediction model.The Hosmer-Lemeshow test yielding a non-significant statistic(P>0.05)suggested no departure from the perfect fit.Results: A total of 75 patients were included in the study,29 patients(38.7%)required surgical intervention.Univariate analysis showed that admission leukocyte count,the maximum diameter of the abscess and bilateral abscess were associated with surgical intervention of patients with TOA(P<0.05).Multivariate logistic analysis revealed that admission leukocyte count(OR =1.164,95% CI: 1.105-1.347,P=0.043),the maximum diameter of abscess(OR =1.583,95% CI: 1.174-2.134,P=0.003)and bilateral abscess(OR =3.676,95% CI: 1.072-12.610,P=0.038)were significant independent risk factors for surgical intervention of patients with TOA.According to this result,the prediction model of nomogram was constructed.Adding all the points of each risk factor,the corresponding probability of total score would indicated the morbidity of surgical intervention of patients with TOA predicted by this nomogram modal.The AUC of the model was 0.826(95% CI:0.729 ～ 0.927),and the C-index was 0.826 after internal verification.The calibration curve showed that the predictive results were well correlated with the actual results(P=0.937).Conclusion: Admission leukocyte count,the maximum diameter of the abscess and bilateral abscess are independent risk factors for surgical intervention of patients with TOA.The nomogram prediction model is helpful to predict the probability of surgical intervention of patients with TOA.