Solomon Matthew D, Goldman Dana P, Joyce Geoffrey F, Escarce José J
Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA .
Arch Intern Med. 2009 Apr 27;169(8):740-8; discussion 748-9. doi: 10.1001/archinternmed.2009.62.
Increased cost sharing reduces utilization of prescription drugs, but little evidence demonstrates how this reduction occurs or the factors associated with price sensitivity.
We conducted a retrospective cohort study of older adults with employer-provided drug coverage from 1997 to 2002 from 31 different health plans. We measured the time until initiation of medical therapy for 17 183 patients with newly diagnosed hypertension, diabetes, or hypercholesterolemia.
For all study conditions, higher copayments were associated with delayed initiation of therapy. In survival models, doubling copayments resulted in large reductions in the predicted proportion of patients initiating pharmacotherapy at 1 and 5 years after diagnosis: for hypertension, 54.8% vs 39.9% at 1 year and 81.6% vs 66.2% at 5 years (P < .001); for hypercholesterolemia, 40.2% vs 31.1% at 1 year and 64.3% vs 53.8% at 5 years (P < .002); and for diabetes, 45.8% vs 40.0% at 1 year and 69.3% vs 62.9% at 5 years (P < .04). However, patients' rate of initiation and sensitivity to copayments strongly depended on their prior experience with prescription drugs. Those without prior drug use (26.1%, 10.4%, and 12.9%) initiated later (833, >1170, and >1402 days later in median time until initiation) and were far more price sensitive (increase of 34.5%, 20.1%, and 27.2% remaining untreated after 5 years when copayments doubled) than those with a history of drug use among patients with newly diagnosed hypertension, hypercholesterolemia, and diabetes, respectively. These results were robust to a wide range of sensitivity analyses.
High cost sharing delays the initiation of drug therapy for patients newly diagnosed with chronic disease. This effect is greater among patients who lack experience with prescription drugs. Policy makers and physicians should consider the effects of benefits design on patient behavior to encourage the adoption of necessary care.
增加费用分担会降低处方药的使用，但几乎没有证据表明这种降低是如何发生的，也没有表明与价格敏感性相关的因素。
我们对1997年至2002年来自31个不同健康计划的、由雇主提供药物保险的老年人进行了一项回顾性队列研究。我们测量了17183例新诊断为高血压、糖尿病或高胆固醇血症患者开始药物治疗的时间。
对于所有研究疾病，更高的自付费用与治疗开始延迟相关。在生存模型中，自付费用翻倍导致诊断后1年和5年开始药物治疗的患者预测比例大幅降低：对于高血压，1年时为54.8%对39.9%，5年时为81.6%对66.2%（P<.001）；对于高胆固醇血症，1年时为40.2%对31.1%，5年时为64.3%对53.8%（P<.002）；对于糖尿病，1年时为45.8%对40.0%，5年时为69.3%对62.9%（P<.04）。然而，患者的开始治疗率和对自付费用的敏感性很大程度上取决于他们以前使用处方药的经历。在新诊断的高血压、高胆固醇血症和糖尿病患者中，那些以前未使用过药物的患者（分别为26.1%、10.4%和12.9%）开始治疗较晚（开始治疗的中位时间分别晚833天、>1170天和>1402天），并且对价格更为敏感（当自付费用翻倍时，5年后仍未治疗的比例分别增加34.5%、20.1%和27.2%）。这些结果在广泛的敏感性分析中是稳健的。
高费用分担会延迟新诊断慢性病患者开始药物治疗。这种影响在缺乏处方药使用经验的患者中更大。政策制定者和医生应考虑福利设计对患者行为的影响，以鼓励采用必要的治疗。
