Center for Health Services Research in Primary Care (152), Durham VA Medical Center, 508 Fulton St, Durham, NC 27705, USA.
Am J Manag Care. 2010 Jan 1;16(1):e20-34.
To examine the impact of a medication copayment increase on adherence to diabetes, hypertension, and hyperlipidemic medications.
Retrospective pre-post observational study.
This study compared medication adherence at 4 Veterans Affairs medical centers between veterans who were exempt from copayments and propensity-matched veterans who were not exempt. The diabetes sample included 1069 exempt veterans and 1069 nonexempt veterans, the hypertension sample included 3545 exempt veterans and 3545 nonexempt veterans, and the sample of veterans taking statins included 2029 exempt veterans and 2029 nonexempt veterans. The main outcome measure was medication adherence 12 months before and 23 months after the copayment increase. Adherence differences were assessed in a difference-in-difference approach by using generalized estimating equations that controlled for time, copayment exemption, an interaction between time and copayment exemption, and patient demographics, site, and other factors.
Adherence to all medications increased in the short term for all veterans, but then declined in the longer term (February-December 2003). The change in adherence between the preperiod and the postperiod was significantly different for exempt and nonexempt veterans in all 3 cohorts, and nonadherence increased over time for veterans required to pay copayments. The impact of the copayment increase was particularly adverse for veterans with diabetes who were required to pay copayments.
A $5 copayment increase (from $2 to $7) adversely impacted medication adherence for veterans subject to copayments taking oral hypoglycemic agents, antihypertensive medications, or statins.
考察药物自付额增加对糖尿病、高血压和高血脂药物依从性的影响。
回顾性前后观察研究。
本研究比较了在退伍军人事务部的 4 个医疗中心，在有和没有药物自付豁免的退伍军人之间，药物依从性的差异。糖尿病组包括 1069 名豁免自付的退伍军人和 1069 名非豁免自付的退伍军人，高血压组包括 3545 名豁免自付的退伍军人和 3545 名非豁免自付的退伍军人，服用他汀类药物的退伍军人样本包括 2029 名豁免自付的退伍军人和 2029 名非豁免自付的退伍军人。主要结局指标是自付额增加前 12 个月和增加后 23 个月的药物依从性。采用广义估计方程，控制时间、自付豁免、时间和自付豁免之间的相互作用以及患者人口统计学、地点和其他因素，采用差异中的差异方法评估依从性差异。
所有退伍军人在短期内对所有药物的依从性都有所提高，但在长期内（2003 年 2 月至 12 月）则有所下降。在所有 3 个队列中，豁免和非豁免退伍军人在预期间和后期间的依从性变化差异显著，需要支付自付费用的退伍军人的不依从性随着时间的推移而增加。对于需要支付自付费用的糖尿病退伍军人来说，自付额增加的影响尤其不利。
5 美元的自付额增加（从 2 美元增加到 7 美元）对需要支付自付费用的服用口服降糖药、降压药或他汀类药物的退伍军人的药物依从性产生了不利影响。
