Chen Lei, McCombs Jeffrey S, Park Jinhee
Department of Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, Los Angeles, CA, USA.
Value Health. 2008 Jan-Feb;11(1):34-43. doi: 10.1111/j.1524-4733.2007.00212.x.
Using data in real-world clinical practice, this study aims to compare the health-care use patterns of patients with schizophrenia who use oral antipsychotics.
A total of 219,504 episodes of antipsychotic drug therapy initiated during the period from 2000 to 2002 were identified using data from the California Medicaid program. Four types of episodes were analyzed based on the patient's drug use history as far back as 1994: restarting therapy after a break in therapy using the same drug used in the preceding episode; switching therapy after a break in treatment using a different medication; switching therapy without a break in therapy; and augmentation. Health-care use patterns over a 1-year post-treatment period were analyzed using ordinary least squares (OLS) regressions, Cox proportional hazards models, and logistic regression.
The impact of atypical antipsychotics on health-care use in the first post-treatment year varies by episode type. Patients switching to atypical medications generally cost significantly more than similar patients switching to a conventional antipsychotic. Olanzapine and risperidone, however, were associated with reductions in total costs relative to conventional antipsychotics when used in restart and augmentation episodes. Differences across all three second-generation antipsychotics were relatively small.
Small differences across the atypical antipsychotics suggest that these drugs are interchangeable, raising the question of whether drug costs could be reduced through selectively contracting for a preferred drug. Potential savings may be limited by several factors. First, most episodes of treatment are restart episodes. Switching these patients to a preferred drug may have clinical risk. Second, patients with schizophrenia switch and augment therapies frequently, thus quickly reducing the population of patients who could be effectively treated with a single preferred drug.
本研究利用真实世界临床实践中的数据，旨在比较使用口服抗精神病药物的精神分裂症患者的医疗使用模式。
利用加利福尼亚医疗补助计划的数据，识别出2000年至2002年期间开始的总共219,504次抗精神病药物治疗发作。根据患者可追溯至1994年的用药史，分析了四种类型的发作情况：中断治疗后使用上一发作中使用的相同药物重新开始治疗；中断治疗后使用不同药物进行换药治疗；不间断治疗进行换药；以及增效治疗。使用普通最小二乘法（OLS）回归、Cox比例风险模型和逻辑回归分析了治疗后1年期间的医疗使用模式。
非典型抗精神病药物对治疗后第一年医疗使用的影响因发作类型而异。换用非典型药物的患者通常比换用传统抗精神病药物的类似患者花费显著更多。然而，在重新开始治疗和增效治疗发作中使用时，奥氮平和利培酮相对于传统抗精神病药物与总成本降低相关。所有三种第二代抗精神病药物之间的差异相对较小。
非典型抗精神病药物之间的微小差异表明这些药物具有可互换性，这就提出了是否可以通过选择性地采购首选药物来降低药物成本的问题。潜在的节省可能受到几个因素的限制。首先，大多数治疗发作是重新开始治疗发作。将这些患者换用首选药物可能存在临床风险。其次，精神分裂症患者频繁换药和进行增效治疗，因此能够用单一首选药物有效治疗的患者群体迅速减少。
