Tang Chao-Hsiun, Wang Han-I, Hsu Chun-Sen, Su Hung-Wen, Chen Mei-Ju, Lin Herng-Ching
School of Health Care Administration, Taipei Medical University, Taipei, Taiwan.
BMC Public Health. 2006 Oct 9;6:246. doi: 10.1186/1471-2458-6-246.
Over the past decade, about one-third of all births nationwide in Taiwan were delivered by cesarean section (CS). Previous studies in the US and Europe have documented the need for risk adjustment for fairer comparisons among providers. In this study, we set out to determine the impact that adjustment for patient-specific risk factors has on CS among different physicians in Taiwan.
There were 172,511 live births which occurred in either hospitals or obstetrics/gynecology clinics between 1 January and 31 December 2003, and for whom birth certificate data could be linked with National Health Insurance (NHI) claims data, available as the sample for this study. Physicians were divided into four equivalent groups based upon the quartile distribution of their crude (actual) CS rates. Stepwise logistic regressions were conducted to develop a predictive model and to determine the expected (risk-adjusted) CS rate and 95% confidence interval (CI) for each physician. The actual rates were then compared with the expected CS rates to see the proportion of physicians whose actual rates were below, within, or above the predicted CI in each quartile.
The proportion of physicians whose CS rates were above the predicted CI increased as the quartile moved to the higher level. However, more than half of the physicians whose actual rates were higher than the predicted CI were not in the highest quartile. Conversely, there were some physicians (40 of 258 physicians) in the highest quartile who were actually providing obstetric care that was appropriate to the risk. When a stricter standard was applied to the assessment of physician performance by excluding physicians in quartile 4 for predicting CS rates, as many as 60% of physicians were found to have higher CS rates than the predicted CI, and indeed, the CS rates of no physicians in either quartile 3 or quartile 4 were below the predicted CI.
Overall, our study found that the comparison of unadjusted CS rates might not provide a valid reflection of the quality of obstetric care delivered by physicians, and may ultimately lead to biased judgments by purchasers. Our study has also shown that when we changed the standard of quality assessment, the evaluation results also changed.
在过去十年中，台湾地区全国范围内约三分之一的分娩是剖宫产（CS）。美国和欧洲此前的研究表明，为了在医疗服务提供者之间进行更公平的比较，需要进行风险调整。在本研究中，我们旨在确定针对患者特定风险因素进行调整对台湾不同医生剖宫产率的影响。
2003年1月1日至12月31日期间，在医院或妇产科诊所发生了172,511例活产，其出生证明数据可与国民健康保险（NHI）理赔数据相链接，以此作为本研究的样本。根据医生的粗（实际）剖宫产率的四分位数分布，将医生分为四个同等组。进行逐步逻辑回归以建立预测模型，并确定每位医生的预期（风险调整后）剖宫产率及95%置信区间（CI）。然后将实际率与预期剖宫产率进行比较，以查看每个四分位数中实际率低于、处于或高于预测CI的医生比例。
随着四分位数向更高水平移动，剖宫产率高于预测CI的医生比例增加。然而，实际率高于预测CI的医生中，超过一半并不在最高四分位数中。相反，在最高四分位数中有一些医生（258名医生中的40名）实际上提供了与风险相适应的产科护理。当通过排除预测剖宫产率处于四分位数4的医生来对医生表现进行更严格的评估标准时，发现多达60%的医生剖宫产率高于预测CI，实际上，四分位数3或四分位数4中的医生的剖宫产率均未低于预测CI。
总体而言，我们的研究发现，未调整的剖宫产率比较可能无法有效反映医生提供的产科护理质量，并最终可能导致购买者做出有偏差的判断。我们的研究还表明，当我们改变质量评估标准时，评估结果也会改变。
