Weiner Mark, Long Judith
Center for Health Equity and Research and Promotion, Philadelphia VA Medical Center, PA 19104, USA.
Med Care. 2004 Feb;42(2 Suppl):II34-9. doi: 10.1097/01.mlr.0000109167.86509.24.
Performance assessments help to quantify the level of adherence with practice standards and are often used to measure and compare the quality of care. However, most performance assessments are based on a cross-sectional analysis of patient information, whereas patient care is inherently longitudinal. This discordance could confound the relationship between the performance measure and the true quality of care.
The objective of this study was to illustrate differences in performance assessment as measured by a traditional cross-sectional analysis compared with a longitudinal analysis.
We conducted a cross-sectional and longitudinal analysis of a cohort of diabetic patients in an integrated delivery system having primary care visits and hemoglobin A1c (HBA1c) testing in both 1999 and 2000.
In the cross-sectional analysis of 4661 patients, we found a modestly increasing proportion achieved an HBA1c level of <8.0%: 73.1% in 1999 and 75.6% in 2000. Longitudinal analysis, however, suggested that certain subsets of patients were more likely to switch from good to poor control or retain their level of poor control over the 2 years studied. In particular, compared with whites, blacks were 1.76 (95% confidence interval [CI], 1.31-2.37) times as likely to switch from good to poor control and only 0.56 (95% CI, 0.41-0.76) times as likely to switch from poor to good control. Patients aged 35 to 49 were 2.54 (95% CI, 1.79-3.45) times as likely to switch from good to poor and only 0.66 (95% CI, 0.47-0.94) times as likely to switch from poor to good control than patients over age 64 years.
Cross-sectional performance assessments could mask changes in diabetes control among individuals belonging to a cohort and, conceptually, are poorer indicators of care process than longitudinal measures. In addition, longitudinal analyses suggest the influence of patient sociodemographic factors on the performance assessment that should be accounted for when comparing quality of care for diabetes.
绩效评估有助于量化对实践标准的遵守程度，常用于衡量和比较医疗质量。然而，大多数绩效评估基于对患者信息的横断面分析，而患者护理本质上是纵向的。这种不一致可能会混淆绩效指标与真正医疗质量之间的关系。
本研究的目的是说明传统横断面分析与纵向分析在绩效评估方面的差异。
我们对一个综合医疗系统中的一组糖尿病患者进行了横断面和纵向分析，这些患者在1999年和2000年都进行了初级保健就诊和糖化血红蛋白（HbA1c）检测。
在对4661名患者的横断面分析中，我们发现糖化血红蛋白水平<8.0%的患者比例略有上升：1999年为73.1%，2000年为75.6%。然而，纵向分析表明，在研究的两年中，某些患者亚组更有可能从良好控制转为不良控制或维持不良控制水平。特别是，与白人相比，黑人从良好控制转为不良控制的可能性是白人的1.76倍（95%置信区间[CI]，1.31 - 2.37），而从不良控制转为良好控制的可能性仅为白人的0.56倍（95%CI，0.41 - 0.76）。35至49岁的患者从良好控制转为不良控制的可能性是64岁以上患者的2.54倍（95%CI，1.79 - 3.45），而从不良控制转为良好控制的可能性仅为64岁以上患者的0.66倍（95%CI，0.47 - 0.94）。
横断面绩效评估可能掩盖队列中个体糖尿病控制情况的变化，从概念上讲，与纵向测量相比，它作为护理过程指标的效果较差。此外，纵向分析表明患者社会人口学因素对绩效评估有影响，在比较糖尿病护理质量时应予以考虑。
