Harris Katherine M, Carpenter Christopher, Bao Yuhua
Substance Abuse and Mental Health Services Administration, Rockville, Maryland, USA.
Med Care. 2006 Jun;44(6):499-505. doi: 10.1097/01.mlr.0000215813.16211.00.
We used a quasiexperimental research design to measure the effect of state parity laws on the use of mental health care in the past year.
We pooled cross-sectional data from the 2001, 2002, and 2003 National Surveys on Drug Use and Health. Our sample included 83,531 adults 18 years of age or over with private health insurance stratified by the level of mental and emotional distress experienced in the worst month of the past year. We used a state and year-fixed effects approach to measure the effect of parity. Similar to a difference-in-difference analysis, the effect of parity was measured by comparing pre-/postchanges in mental health service use within states that switched active parity status to changes in service use within states that did not change parity status in the same calendar year. For each subgroup, we report predictions of the percentage point change in any mental health care use, prescription drug use, and outpatient care use resulting from parity laws.
Depending on the time window used to define active parity status, we found that parity increased the probability of using any mental health care in the past year by as much as 1.2 percentage points (P<0.01) for the lower distress group and by as much as 1.8 percentage points (P<0.05) in the middle distress group. We found no statistically significant changes in service use for the upper distress group. Whether measured differences were attributable to changes in the use of prescription drug or outpatient care also depended on the definition of active parity status.
Overall, the results of this study suggest that state parity laws succeeded in expanding access to mental health care for those with relatively mild mental health problems.
我们采用了一种准实验研究设计，以衡量州均等法对过去一年心理健康护理使用情况的影响。
我们汇总了2001年、2002年和2003年全国药物使用和健康调查的横断面数据。我们的样本包括83531名18岁及以上拥有私人医疗保险的成年人，这些人按过去一年最糟糕月份所经历的心理和情绪困扰程度进行分层。我们采用州和年份固定效应方法来衡量均等法的影响。与双重差分分析类似，均等法的影响是通过比较在同一日历年内改变为积极均等状态的州内心理健康服务使用情况的前后变化，与未改变均等状态的州内服务使用情况的变化来衡量的。对于每个亚组，我们报告了均等法导致的任何心理健康护理使用、处方药使用和门诊护理使用的百分点变化预测。
根据用于定义积极均等状态的时间窗口，我们发现，对于低困扰组，均等法使过去一年使用任何心理健康护理的概率增加了多达1.2个百分点（P<0.01）；对于中等困扰组，增加了多达1.8个百分点（P<0.05）。我们发现高困扰组的服务使用情况没有统计学上的显著变化。衡量出的差异是否归因于处方药或门诊护理使用的变化，也取决于积极均等状态的定义。
总体而言，本研究结果表明，州均等法成功地扩大了心理健康问题相对较轻者获得心理健康护理的机会。
