Dormuth Colin R, Schneeweiss Sebastian, Brookhart Alan M, Carney Greg, Bassett Ken, Adams Stephen, Wright James M
Open Med. 2008;2(3):e74-82. Epub 2008 Aug 12.
The price per milligram for most statin medications decreases at higher strengths, which provides an economic incentive to split tablets. We sought to determine the frequency with which statin tablets are split, and to evaluate factors associated with this practice.
We obtained prescription claims data for statins from the BC Ministry of Health for the period Jan. 1, 1996, to Dec. 31, 2006. We estimated the number of tablets per day, based on the ratio of the number of tablets to days-supply in each prescription, to estimate the frequency with which splitting occurred with each statin. We used multivariable logistic regression to assess patient and physician characteristics and the level of public drug plan coverage associated with tablet splitting. To estimate related cost savings, we used information on drug costs and quantities of dispensed statins reported by pharmacies.
During the 11-year study period, we estimated that tablet splitting occurred in 2.6% of 7.2 million statin prescriptions. There was an increasing trend in the practice over time, to 4.5% of prescriptions in 2006. Lovastatin was the only scored tablet and was the most likely to be split, followed by rosuvastatin and atorvastatin. Fifty percent of the prescriptions in which tablet splitting occurred were prescribed by only 7.9% of the routine statin prescribers (i.e., > 10 statin prescriptions over the study period). Specialists were less likely than general practitioners to prescribe statins that were subsequently split (odds ratio [OR] 0.43, 95% confidence interval [CI] 0.40-0.46). Statin prescriptions that were fully covered by the public drug plan were half as likely as those with no such coverage to involve tablet splitting (OR 0.48, 95% CI 0.44-0.92). Having no public drug coverage, having a low annual household income and being female were patient factors found to be positively associated with tablet splitting. In 2006, the cost savings associated with tablet splitting was $2.3 million.
The frequency of tablet splitting in statin prescriptions in British Columbia was low but increased over time. It varied between patients, physicians and different levels of insurance coverage. In the final study year, 94.5% of the statin prescriptions were dispensed at strengths for which a tablet of twice the strength was available and could have been split, which suggests a potentially enormous cost savings.
大多数他汀类药物每毫克的价格会随着剂量增加而降低，这为分药提供了经济诱因。我们试图确定他汀类药物分药的频率，并评估与这种做法相关的因素。
我们获取了不列颠哥伦比亚省卫生部1996年1月1日至2006年12月31日期间他汀类药物的处方报销数据。我们根据每张处方中片剂数量与供应天数的比例来估计每日片剂数量，以估算每种他汀类药物分药的频率。我们使用多变量逻辑回归来评估患者和医生特征以及与分药相关的公共药物计划覆盖水平。为了估算相关的成本节省，我们使用了药房报告的药物成本和他汀类药物配药数量信息。
在11年的研究期间，我们估计在720万张他汀类药物处方中，有2.6%出现了分药情况。随着时间的推移，这种做法呈上升趋势，到2006年达到了处方的4.5%。洛伐他汀是唯一有划痕的片剂，也是最有可能被分的，其次是瑞舒伐他汀和阿托伐他汀。发生分药的处方中有50%仅由7.9%的常规他汀类药物开处方者开出（即研究期间开出超过10张他汀类药物处方）。专科医生开出随后被分的他汀类药物的可能性低于全科医生（优势比[OR]为0.43，95%置信区间[CI]为0.40 - 0.46）。公共药物计划全额覆盖的他汀类药物处方涉及分药的可能性是没有这种覆盖的处方的一半（OR为0.48，95%CI为0.44 - 0.92）。没有公共药物覆盖、家庭年收入低以及女性是与分药呈正相关的患者因素。2006年，与分药相关的成本节省为230万美元。
不列颠哥伦比亚省他汀类药物处方的分药频率较低，但随时间增加。它在患者、医生和不同保险覆盖水平之间存在差异。在研究的最后一年，94.5%的他汀类药物处方是以有两倍强度片剂可供分药的强度配药的，这表明可能会节省大量成本。
