Predicting tophi formation risks amongst people with gout: a development
and assessment of a new predictive model
Abstract
Purpose: Tophi can cause several severe complications. However, the
predictors of tophi formation are not intensively researched. The aim of
the study is to develop and validate a new prediction model for tophi
formation amongst patients with gout. Methods: A prediction model was
developed using data collected from 158 gout patients treated in the
inpatient department of The First Affiliated Hospital of Zhejiang
Chinese Medical University from May 2018 to May 2020. For the
establishment and validation of the prediction nomogram, the least
absolute shrinkage and selection operator regression model and the
multivariable logistic regression analysis were conducted to determine
the predictors. C-index, calibration plot and decision curve analysis
were utilised to evaluate discrimination, calibration and clinical
effectiveness of the predicting nomogram. Then, the nomogram was
internally validated using a bootstrap procedure. Results: Nine
predictors – hospitalisation frequency, disease duration, number of
joints involved in gouty arthritis, gout flares frequency, smoking, and
whether combined with atherosclerosis, diabetes, hypertension and kidney
dysfunction – were determined from the prediction nomogram. The C-index
of the nomogram was 0.854 (95% confidence interval: 0.772-0.936), and
was confirmed to be 0.810 when tested through a bootstrap validation,
suggesting the model’s good discrimination and prediction capability.
Conclusion: A new model with nine predictors was developed to predict
the risks of tophi formation amongst gout patients. The included
predictors were practical and easy to obtain, whilst the nomogram was
proved to predict the risks of tophi formation effectively and
accurately. Keywords:tophi formation, gout, predictors, nomogram