AIM To develop and internally validate prognostic models on the long-term durability of glycaemic control in patients with type 2 diabetes after metformin failure. MATERIALS AND METHODS DISCOVER is a 3-year, prospective observational study across six continents investigating second-line glucose-lowering therapies. In this analysis from 35 countries, we included patients on metformin initiating second-line glucose-lowering medication(s) because of physician-defined lack of efficacy. The outcome was durability of glycaemic control, defined as three consecutive levels of HbA1c at 6-, 12- and 24-month follow-up at target (HbA1c equal to or lower than the level when the physician initiated the second-line therapy in patients with baseline HbA1c ≤7% [53 mmol/mol]; and equal to or lower than 7% in those with baseline HbA1c >7%). We developed and internally validated two prognostic models: a base model, which included age, sex, ethnicity, country income group, baseline HbA1c and second-line therapy, and an advanced model, established through statistical variable selections from a model including base variables and 13 additional predictors selected from a literature review. We used logistic regression to develop and 500 bootstrapping samples to internally validate the models; discrimination and calibration were used to assess model performance. RESULTS Overall, 896 out of 2995 participants (29.9%) had sustained glycaemic control. The base model performed well: Nagelkerke R2 was 0.13, C-index 0.70 (95% CI: 0.68, 0.71) and bias-corrected C-index 0.69 after internal validation. Diabetes duration, insurance type, estimated glomerular filtration rate and glucose self-monitoring were additionally selected in the advanced model, which had only a slightly better performance compared with the base model: Nagelkerke R2 0.20, C-index 0.71 (95% CI: 0.69, 0.73) and bias-corrected C-index 0.70. Calibration plots showed good calibrations of both validated models. CONCLUSION These prognostic models, which include simple demographic and routinely collected clinical information, enabled the estimation of the probability of 2-year sustained glycaemic control in patients after metformin failure. The models have been implemented into a web-based tool to support healthcare professionals in their decisions.

中文翻译：

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二甲双胍治疗失败后2型糖尿病患者血糖控制的持久性：使用DISCOVER研究得出预后模型并进行验证。

目的开发并内部验证二甲双胍治疗失败后2型糖尿病患者血糖控制长期持久性的预后模型。材料和方法发现是一项为期3年的前瞻性观察性研究，横跨六大洲，研究二线降糖疗法。在这项来自35个国家/地区的分析中，我们纳入了因医生定义的疗效欠缺而开始服用二甲双胍降糖药物的患者。结果是血糖控制的持久性，定义为在目标的6个月，12个月和24个月随访中连续三个HbA1c水平（HbA1c等于或低于医师在患者中开始二线治疗时的水平基线HbA1c≤7％[53 mmol / mol]；等于或低于基线HbA1c> 7％的那些）。我们开发并内部验证了两个预后模型：一个基础模型，包括年龄，性别，种族，国家收入组，基线HbA1c和二线治疗，以及一个高级模型，该模型是通过从包括基础变量和从文献综述中选择了13个其他预测变量。我们使用逻辑回归来开发和500个自举样本来内部验证模型。判别和校准用于评估模型性能。结果总体而言，在2995名参与者中，有896名（29.9％）受到了持续的血糖控制。基本模型表现良好：内部验证后，Nagelkerke R2为0.13，C指数为0.70（95％CI：0.68，0.71），偏差校正后的C指数为0.69。糖尿病持续时间，保险类型，在高级模型中还额外选择了估计的肾小球滤过率和葡萄糖自我监测，与基本模型相比，该模型的性能仅稍好一些：Nagelkerke R2 0.20，C指数0.71（95％CI：0.69、0.73）和偏倚-校正后的C指数0.70。校准图显示了两个已验证模型的良好校准。结论这些预后模型包括简单的人口统计学资料和常规收集的临床信息，能够估算二甲双胍失败后患者2年持续血糖控制的可能性。该模型已实施到基于Web的工具中，以支持医疗保健专业人员的决策。69，0.73）和经过偏差校正的C-index 0.70。校准图显示了两个已验证模型的良好校准。结论这些预后模型包括简单的人口统计学资料和常规收集的临床信息，能够估算二甲双胍失败后患者2年持续血糖控制的可能性。该模型已实施到基于Web的工具中，以支持医疗保健专业人员的决策。69，0.73）和经过偏差校正的C-index 0.70。校准图显示了两个已验证模型的良好校准。结论这些预后模型包括简单的人口统计学资料和常规收集的临床信息，能够估算二甲双胍失败后患者2年持续血糖控制的可能性。该模型已实施到基于Web的工具中，以支持医疗保健专业人员的决策。