Predicting the individualized risk of nonadherence to zoledronic acid among osteoporosis patients receiving the first infusion of zoledronic acid: development and validation of new predictive nomograms

INTRODUCTION: Achieving optimal adherence to zoledronic acid (ZOL) among osteoporosis (OP) patients is a challenging task. Here, we aimed to develop and validate a precise and efficient prediction tool for ZOL nonadherence risk in OP patients. METHODS: We prospectively collected and analyzed survey data from a clinical registry. A total of 1010 OP patients treated for the first time with ZOL in two separate hospitals were selected for nonadherence analysis. The evaluation included a 16-item ZOL Nonadherence Questionnaire and potential risk factors for ZOL nonadherence were assessed via univariate and multivariate analyses. We next developed and validated two distinct-stage nomograms. Discrimination, calibration, and clinical usefulness of the predicting models were assessed using the area under the curve (AUC), calibration curves, and decision curve analysis (DCA). RESULTS: The total nonadherence rate was 20.30% after the first ZOL infusion. To generate a model predicting ZOL nonadherence risk, six predictors of 16 items were retained. Model 2 (AUC, 0.8486; 95% confidence interval [CI], 0.8171–0.8801) exhibited considerably more discrimination in desirable functional outcomes, relative to Model 1 (AUC, 0.7644; 95% CI, 0.7265–0.8024). The calibration curves displayed good calibration. DCA revealed that a cutoff probability of 5–54% (Model 1) and 1–85% (Model 2) indicated that the models were clinically useful. External validation also exhibited good discrimination and calibration. CONCLUSIONS: This study developed and validated two novel, distinct-stage prediction nomograms that precisely estimate nonadherence risk among OP patients receiving the first infusion of ZOL. However, additional evaluation and external validation are necessary prior to widespread implementation.