Power to detect differences between alternative treatments in comparative psychotherapy outcome research.
Power to detect differences between alternative treatments in comparative psychotherapy outcome research.
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在比较心理治疗结果研究中发现替代疗法之间差异的能力。
DOI：
10.1037//0022-006x.57.1.138
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发表时间：
1989
影响因子：
5.9
通讯作者：
Bass,D
中科院分区：
文献类型：
--
作者：
Kazdin,AE;Bass,D
心理治疗的比较研究往往发现，替代治疗产生的结果很少或没有差异。虽然这些发现可能很好地反映了替代治疗的可比性，但通常情况下，研究往往没有足够的力量来检测当两种或更多种治疗方法进行对比时可能发现的效应大小。本调查评估了心理治疗结果研究的力量，以检测两种或两种以上治疗和治疗与无治疗对照条件的差异。结果研究（N= 85）来自9个期刊在3年内（1984-1986）。首先检查每篇文章中的数据，以提供效应量的估计值，然后评估治疗后和随访时的统计功效。研究结果表明，鉴于这种比较通常明显的相对较大的效应量，研究检测治疗和不治疗之间差异的能力通常相当充分。另一方面，当替代治疗相互对比时，检测可能明显的中小效应量的把握度相对较弱。因此，治疗产生的等效结果（即“无差异”）可能是由于检验的效力相对较弱。解释目前的成果研究和设计未来的比较研究的影响突出。
Comparative studies of psychotherapy often find few or no differences in the outcomes that alternative treatments produce. Although these findings may well reflect the comparability of alternative treatments, as a rule, studies are often not sufficiently powerful to detect the sorts of effects sizes likely to be found when two or more treatments are contrasted. The present survey evaluated the power of psychotherapy outcome studies to detect differences for contrasts of two or more treatments and treatment versus no-treatment control conditions. Outcome studies (N= 85) were drawn from nine journals over a 3-year period (1984–1986). Data in each article were examined first to provide estimates of effect sizes and then to evaluate statistical power at posttreatment and follow-up. The findings indicate that the power of studies to detect differences between treatment and no treatment is generally quite adequate given the relatively large effect sizes usually evident for this comparison. On the other hand, the power is relatively weak to detect the small-to-medium effect sizes likely to be evident when alternative treatments are contrasted with each other. Thus, the equivalent outcomes that treatments produce (ie,“no difference”) may be due to the relatively weak power of the tests. The implications for interpreting current outcome studies and for designing future comparative studies are highlighted.