CT Lamont Primary Health Care Research Centre, Bruyère Research Institute, 113-43, rue Bruyère St, K1N 5C7, Annex E, Ottawa, ON, Canada.
Department of Family Medicine, University of Ottawa, Ottawa, ON, Canada.
BMC Med Res Methodol. 2019 Aug 7;19(1):171. doi: 10.1186/s12874-019-0809-6.
Participants in voluntary research present a different demographic profile than those who choose not to participate, affecting the generalizability of many studies. Efforts to evaluate these differences have faced challenges, as little information is available from non-participants. Leveraging data from a recent randomized controlled trial that used health administrative databases in a jurisdiction with universal medical coverage, we sought to compare the quality of care provided by participating and non-participating physicians prior to the program's implementation in order to assess whether participating physicians provided a higher baseline quality of care.
We conducted clustered regression analyses of baseline data from provincial health administrative databases. Participants included all family physicians who were eligible to participate in the Improved Delivery of Cardiovascular Care (IDOCC) project, a quality improvement project rolled out in a geographically defined region in Ontario (Canada) between 2008 and 2011. We assessed 14 performance indicators representing measures of access, continuity, and recommended care for cancer screening and chronic disease management.
In unadjusted and patient-adjusted models, patients of IDOCC-participating physicians had higher continuity scores at the provider (Odds Ratio (OR) [95% confidence interval]: 1.06 [1.03-1.09]) and practice (1.06 [1.04-1.08]) level, lower risk of emergency room visits (Rate Ratio (RR): 0.93 [0.88-0.97]) and hospitalizations (RR:0.87 [0.77-0.99]), and were more likely to have received recommended diabetes tests (OR: 1.25 [1.06-1.49]) and cancer screening for cervical cancer (OR: 1.32 [1.08-1.61] and breast cancer (OR: 1.32 [1.19-1.46]) than patients of non-participating physicians. Some indicators remained statistically significant in the model after adjusting for provider factors.
Our study demonstrated a participation bias for several quality indicators. Physician characteristics can explain some of these differences. Other underlying physician or practice attributes also influence interest in participating in quality improvement initiatives and existing quality levels. The standard for addressing participation bias by controlling for basic physician and practice level variables is inadequate for ensuring that results are generalizable to primary care providers and practices.
参与自愿研究的参与者与不参与的参与者呈现出不同的人口统计学特征，这影响了许多研究的普遍性。由于非参与者提供的信息很少，因此评估这些差异的工作面临挑战。利用最近一项随机对照试验中的数据，该试验在一个拥有全民医疗覆盖的司法管辖区使用了健康管理数据库，我们试图比较在该计划实施之前参与和不参与的医生提供的护理质量，以评估参与医生是否提供了更高的基线护理质量。
我们对省级健康管理数据库中的基线数据进行了聚类回归分析。参与者包括所有有资格参与改善心血管护理交付（IDOCC）项目的家庭医生，该项目于 2008 年至 2011 年在安大略省（加拿大）一个地理定义的区域推出。我们评估了 14 项绩效指标，代表癌症筛查和慢性病管理的可及性、连续性和推荐护理措施。
在未经调整和患者调整的模型中，IDOCC 参与医生的患者在提供者（优势比（OR）[95%置信区间]：1.06 [1.03-1.09]）和实践（1.06 [1.04-1.08]）层面的连续性评分更高，急诊就诊（率比（RR）：0.93 [0.88-0.97]）和住院（RR：0.87 [0.77-0.99]）的风险更低，并且更有可能接受推荐的糖尿病检查（OR：1.25 [1.06-1.49]）和宫颈癌（OR：1.32 [1.08-1.61]）和乳腺癌（OR：1.32 [1.19-1.46]）筛查。在调整提供者因素后，一些指标在模型中仍然具有统计学意义。
我们的研究表明，一些质量指标存在参与偏见。医生特征可以解释其中的一些差异。其他潜在的医生或实践属性也会影响对质量改进计划的兴趣和现有质量水平。通过控制基本医生和实践水平变量来解决参与偏见的标准不足以确保结果可推广到初级保健提供者和实践。
