Hahn Ursula, Neuhann Irmingard, Schmickler Stefanie, Krummenauer Frank
Institut für Medizinische Biometrie und Epidemiologie, Fakultät für Gesundheit der Universität Witten/Herdecke, Alfred-Herrhausen-Straße 50, 58448 Witten, Germany.
BMC Health Serv Res. 2014 Jun 25;14:279. doi: 10.1186/1472-6963-14-279.
Risk adjustment is crucial for comparison of outcome in medical care. Knowledge of the external factors that impact measured outcome but that cannot be influenced by the physician is a prerequisite for this adjustment. To date, a universal and reproducible method for identification of the relevant external factors has not been published. The selection of external factors in current quality assurance programmes is mainly based on expert opinion. We propose and demonstrate a methodology for identification of external factors requiring risk adjustment of outcome indicators and we apply it to a cataract surgery register.
Defined test criteria to determine the relevance for risk adjustment are "clinical relevance" and "statistical significance". Clinical relevance of the association is presumed when observed success rates of the indicator in the presence and absence of the external factor exceed a pre-specified range of 10%. Statistical significance of the association between the external factor and outcome indicators is assessed by univariate stratification and multivariate logistic regression adjustment.The cataract surgery register was set up as part of a German multi-centre register trial for out-patient cataract surgery in three high-volume surgical sites. A total of 14,924 patient follow-ups have been documented since 2005. Eight external factors potentially relevant for risk adjustment were related to the outcome indicators "refractive accuracy" and "visual rehabilitation" 2-5 weeks after surgery.
The clinical relevance criterion confirmed 2 ("refractive accuracy") and 5 ("visual rehabilitation") external factors. The significance criterion was verified in two ways. Univariate and multivariate analyses revealed almost identical external factors: 4 were related to "refractive accuracy" and 7 (6) to "visual rehabilitation". Two ("refractive accuracy") and 5 ("visual rehabilitation") factors conformed to both criteria and were therefore relevant for risk adjustment.
In a practical application, the proposed method to identify relevant external factors for risk adjustment for comparison of outcome in healthcare proved to be feasible and comprehensive. The method can also be adapted to other quality assurance programmes. However, the cut-off score for clinical relevance needs to be individually assessed when applying the proposed method to other indications or indicators.
风险调整对于医疗护理结果的比较至关重要。了解影响测量结果但医生无法控制的外部因素是进行这种调整的前提条件。迄今为止，尚未发表一种通用且可重复的识别相关外部因素的方法。当前质量保证计划中外部因素的选择主要基于专家意见。我们提出并展示了一种识别需要对结果指标进行风险调整的外部因素的方法，并将其应用于白内障手术登记册。
确定风险调整相关性的既定测试标准为“临床相关性”和“统计学显著性”。当存在和不存在外部因素时指标的观察成功率超过预先指定的10%范围时，假定该关联具有临床相关性。通过单变量分层和多变量逻辑回归调整评估外部因素与结果指标之间关联的统计学显著性。白内障手术登记册是德国三个高容量手术地点的门诊白内障手术多中心登记试验的一部分。自200�年以来，共记录了14924例患者随访情况。八个可能与风险调整相关的外部因素与术后2至5周的“屈光准确性”和“视力恢复”结果指标相关。
临床相关性标准确认了2个（“屈光准确性”）和5个（“视力恢复”）外部因素。显著性标准通过两种方式得到验证。单变量和多变量分析显示几乎相同的外部因素：4个与“屈光准确性”相关，7个（6个）与“视力恢复相关”。两个（“屈光准确性”）和5个（“视力恢复”）因素符合两个标准，因此与风险调整相关。
在实际应用中，所提出的识别医疗保健结果比较中风险调整相关外部因素的方法被证明是可行且全面的。该方法也可适用于其他质量保证计划。然而，将所提出的方法应用于其他适应症或指标时，临床相关性的截止分数需要单独评估。
