Development and external validation of a nomogram for neurosyphilis diagnosis among non-HIV patients: a cross-sectional study

Abstract Background The diagnosis of neurosyphilis is challenging due to the requirement of a lumbar puncture and cerebrospinal fluid (CSF) laboratory tests. Therefore, a convenient diagnostic nomogram for neurosyphilis is warranted. This study aimed to construct diagnostic models for diagnosing neurosyphilis. Methods This cross-sectional study included data of two patient cohorts from Western China Hospital of Sichuan University between September 2015 and April 2021 and Shangjin Hospital between September 2019 and April 2021 as the development cohort and the external validation cohort, respectively. A diagnostic model using logistic regression analysis was constructed to readily provide the probability of diagnosis at point of care and presented as a nomogram. The clinical usefulness of the diagnostic models was assessed using a receiver operating characteristic (ROC) and Harrell concordance (Harrell C) index for discrimination and calibration plots for accuracy, which adopted bootstrap resampling 500 times. Results One hundred forty-eight and 67 patients were included in the development and validation cohorts, respectively. Of those, 131 were diagnosed as having reactive neurosyphilis under the criteria of positive results in both CSF treponemal and non-treponemal tests. In the development cohort, male, psychiatric behaviour disorders, and serum toluidine red unheated serum test were selected as diagnostic indicators applying a stepwise procedure in multivariable logistic model. The model reached 80% specificity, 79% sensitivity, and 0·85 area under the curves (AUC) (95% confidence interval, 0·76–0·91). In the validation cohorts, the Harrell C index for the diagnostic possibility of reactive neurosyphilis was 0·71. Conclusions A convenient model using gender, presence of psychiatric behaviour disorders, and serum TRUST titre was developed and validated to indicate diagnostic results in patients suspected of neurosyphilis. Checking the model value of factors on nomogram is a feasible way to assist clinicians and primary health servers in updating patients’ medical charts and making a quantitatively informed decision on neurosyphilis diagnosis. Trial registration This research was retrospectively registered in the Ethics committee on biomedical research, West China Hospital of Sichuan University. The research registration and committee’s reference number was 1163 in 2020 approval.

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Development and External Validation of a Nomogram for Neurosyphilis Diagnosis Among Non-HIV Patients: A Cross-sectional Study

10.21203/rs.3.rs-778055/v1 ◽

2021 ◽

Author(s):

Wenjing Ge ◽

Yang Zhang ◽

Chao Peng ◽

Dongdong Li ◽

Lijie Gao ◽

...

Keyword(s):

Psychiatric Symptoms ◽

External Validation ◽

Cross Sectional Study ◽

Western China ◽

Sectional Study ◽

Roc Curve Analysis ◽

Cross Sectional ◽

Logistic Analysis ◽

Diagnostic Models ◽

Development And Validation

Abstract Background: The diagnosis of neurosyphilis (NS) is challenging due to the requirement of a lumbar puncture and cerebrospinal fluid (CSF) tests. Methods: This cross-sectional study constructed diagnostic models for diagnosing NS with data gathered from the Western China Hospital of Sichuan University between September 2015 and April 2021 and Shangjin hospital between September 2019 and April 2021, which formed the development and validation cohorts, respectively. A logistic analysis was performed to predict reactive neurosyphilis diagnosis and was presented as a nomogram. Clinical usefulness of the diagnostic models was assessed using a receiver operating characteristic (ROC) curve analysis, and Harrell C index was used for discrimination and calibration plots for accuracy, adopting bootstrap resampling 500 times. Results: Overall, 149 and 67 patients were included in development and validation cohorts, respectively. Of those, 131 were diagnosed as having reactive NS with positive results in CSF treponemal and non-treponemal tests. In the development cohort, male sex, psychiatric symptoms, and serum toluidine red unheated serum test were selected as diagnostic indicators. The model reached 80% specificity, 79% sensitivity, and 0·85 area under the curves (AUC) (95% CI, 0·76-0·91). In the validation cohorts, the Harrell C index for the diagnostic possibility of reactive NS was 0·71. Conclusion: A convenient model using gender, presence of psychiatric symptoms and serum TRUST titre was developed and validated to indicate diagnostic results in patients suspected of NS. Checking model value of factors on nomogram is a feasible way to assist clinicians and primary health servers in updating patients’ medical chart and making quantitatively informed decision on NS diagnosis. Trial registration: This research was retrospectively registered in Ethics committee on biomedical research, West China Hospital of Sichuan University.

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Clinical and laboratory data-based nomograms for neurosyphilis diagnosis in non-HIV syphilis patients: a cross-sectional study.

10.21203/rs.3.rs-123296/v1 ◽

2020 ◽

Author(s):

Wenjing Ge ◽

Yang Zhang ◽

Chao Peng ◽

Dongdong Li ◽

Lijie Gao ◽

...

Keyword(s):

Psychiatric Symptoms ◽

Laboratory Data ◽

Cross Sectional Study ◽

Western China ◽

Diagnostic Model ◽

Sectional Study ◽

Combined Model ◽

Cross Sectional ◽

Basic Model ◽

Diagnostic Models

Abstract Background: The diagnosis of neurosyphilis (NS) is challenging due to the requirement of lumbar puncture and time-consuming cerebrospinal fluid tests. Therefore, a convenient high-accuracy diagnostic nomogram for NS is warranted. Methods: This cross-sectional study (108 patients) aimed to construct diagnostic models for diagnosing NS with data gathered between September 2015 and January 2020 at Western China Hospital of Sichuan University. We constructed two types of diagnostic models using 108 training samples: 1) symptoms and toluidine red unheated serum test (TRUST) (basic model) and 2) the combined model of symptoms, serum TRUST, and findings of CSF routine tests including CSF protein concentration and CSF glucose concentration (combined model). The clinical usefulness of the diagnostic models was assessed through the comparison of a receiver operating characteristic (ROC) and decision curve analysis (DCA), which adopted bootstrap resampling 500 times. Results: A total of 108 patients were analysed (82% males, mean age: 46 years). Of those, 76 were diagnosed as having reactive neurosyphilis under the criteria of positive results in both CSF treponemal and non-treponemal tests. Psychiatric symptoms and serum TRUST were the strongest diagnostic indicators in serum. A diagnostic model was constructed to readily provide the probability of diagnosis at point of care and presented as two nomograms. The basic model reached 79% specificity, 74% sensitivity and 0.82 Area Under the Curves (AUC) (95% CI, 0.72-091), while the combined model showed 82% specificity, 90% sensitivity and 0.88 AUC (95% CI, 0.80-0.94). The integrated discrimination improvement(IDI) index was 0.05 in comparison of two models. Conclusions: A convenient model using serum TRUST titre and presence of psychiatric symptoms was developed to indicate diagnostic results in patients suspected of NS. Two simple nomograms can be offered to clinicians to facilitate their assessment of patient diagnosis, strengthen the diagnostic decision making, enhance patient stratification, and inform patients in the clinic. Trial registration: This research was retrospectively registered in Ethics committee on biomedical research, West China Hospital of Sichuan University.

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