Department of Epidemiology and Preventive Medicine, Monash University, The Alfred Centre, 99 Commercial Rd, Melbourne, Victoria 3004, Australia.
BMC Health Serv Res. 2013 Jan 26;13:30. doi: 10.1186/1472-6963-13-30.
Understanding the factors that impact on disability is necessary to inform trauma care and enable adequate risk adjustment for benchmarking and monitoring. A key consideration is how to adjust for pre-existing conditions when assessing injury outcomes, and whether the inclusion of comorbidity is needed in addition to adjustment for age. This study compared different approaches to modelling the impact of comorbidity, collected as part of the routine hospital episode data, on disability outcomes following orthopaedic injury.
12-month Glasgow Outcome Scale - Extended (GOS-E) outcomes for 13,519 survivors to discharge were drawn from the Victorian Orthopaedic Trauma Outcomes Registry, a prospective cohort study of admitted orthopaedic injury patients. ICD-10-AM comorbidity codes were mapped to four comorbidity indices. Cases with a GOS-E score of 7-8 were considered "recovered". A split dataset approach was used with cases randomly assigned to development or test datasets. Logistic regression models were fitted with "recovery" as the outcome and the performance of the models based on each comorbidity index (adjusted for injury and age) measured using calibration (Hosmer-Lemshow (H-L) statistics and calibration curves) and discrimination (Area under the Receiver Operating Characteristic (AUC)) statistics.
All comorbidity indices improved model fit over models with age and injuries sustained alone. None of the models demonstrated acceptable model calibration (H-L statistic p < 0.05 for all models). There was little difference between the discrimination of the indices for predicting recovery: Charlson Comorbidity Index (AUC 0.70, 95% CI: 0.68, 0.71); number of ICD-10 chapters represented (AUC 0.70, 95% CI: 0.69, 0.72); number of six frequent chronic conditions represented (AUC 0.70, 95% CI: 0.69, 0.71); and the Functional Comorbidity Index (AUC 0.69, 95% CI: 0.68, 0.71).
The presence of ICD-10 recorded comorbid conditions is an important predictor of long term functional outcome following orthopaedic injury and adjustment for comorbidity is indicated when assessing risk-adjusted functional outcomes over time or across jurisdictions.
了解影响残疾的因素对于告知创伤护理和实现基准和监测的充分风险调整是必要的。一个关键的考虑因素是在评估伤害结果时如何调整预先存在的条件，以及除了调整年龄之外，是否需要纳入合并症。本研究比较了不同的方法来模拟合并症的影响，这些合并症是作为常规医院病例数据的一部分收集的，这些方法对骨科损伤后的残疾结果有影响。
从维多利亚州骨科创伤结果登记处（一项对入院骨科损伤患者的前瞻性队列研究）中抽取了 13519 名存活至出院的患者的 12 个月格拉斯哥结局量表-扩展（GOS-E）结果。ICD-10-AM 合并症代码被映射到四个合并症指数。GOS-E 评分为 7-8 的病例被认为是“康复”。采用分割数据集方法，将病例随机分配到开发数据集或测试数据集。使用校准（Hosmer-Lemeshow（H-L）统计和校准曲线）和判别（接收者操作特征（ROC）曲线下面积（AUC））统计来测量每个合并症指数（调整损伤和年龄）的“恢复”作为结果，拟合逻辑回归模型。
所有的合并症指数都提高了模型对年龄和单独受伤的预测能力。没有一个模型显示出可接受的模型校准（所有模型的 H-L 统计量 p<0.05）。预测恢复的指标之间的判别能力差异不大：Charlson 合并症指数（AUC 0.70，95%置信区间：0.68，0.71）；代表的 ICD-10 章节数（AUC 0.70，95%置信区间：0.69，0.72）；代表的六种常见慢性病数（AUC 0.70，95%置信区间：0.69，0.71）；以及功能合并症指数（AUC 0.69，95%置信区间：0.68，0.71）。
ICD-10 记录的合并症的存在是骨科损伤后长期功能结果的重要预测因素，在评估随时间或在司法管辖区之间的风险调整功能结果时，需要进行合并症调整。
