Abellan-Perpiñan Jose-Maria, Martinez-Perez Jorge-Eduardo, Pinto-Prades Jose-Luis, Sanchez-Martinez Fernando-Ignacio
Applied Economics Department, Faculty of Economics and Business, University of Murcia, Murcia, Spain.
Department of Economics, School of Economics and Business, University of Navarra, Pamplona, Spain.
Med Decis Making. 2024 Jan;44(1):42-52. doi: 10.1177/0272989X231207814. Epub 2023 Nov 10.
The main aim of this article is to test monotonicity in life duration. Previous findings suggest that, for poor health states, longer durations are preferred to shorter durations up to some threshold or maximum endurable time (MET), and shorter durations are preferred to longer ones after that threshold.
Monotonicity in duration is tested through 2 ordinal tasks: choices and rankings. A convenience sample ( = 90) was recruited in a series of experimental sessions in which participants had to rank-order health episodes and to choose between them, presented in pairs. Health episodes result from the combination of 7 EQ-5D-3L health states and 5 durations. Monotonicity is tested comparing the percentage rate of participants whose preferences were monotonic with the percentage of participants with nonmonotonic preferences for each health state. In addition, to test the existence of preference reversals, we analyze the fraction of people who switch their preference from rankings to choices.
Monotonicity is frequently violated across the 7 EQ-5D health states. Preference patterns for individuals describe violations ranging from almost 49% with choices to about 71% with rankings. Analysis performed by separate states shows that the mean rates of violations with choices and ranking are about 22% and 34%, respectively. We also find new evidence of preference reversals and some evidence-though scarce-of transitivity violations in choices.
Our results show that there is a medium range of health states for which preferences are nonmonotonic. These findings support previous evidence on MET preferences and introduce a new "choice-ranking" preference reversal. It seems that the use of 2 tasks with a similar response scale may make preference reversals less substantial, although it remains important and systematic.
Two procedures based on ordinal comparisons are used to elicit preferences: direct choices and rankings. Our study reports significant rates of nonmonotonic preferences (or maximum endurable time [MET]-type preferences) for different combinations of durations and EQ-5D health states.Analysis for separate health states shows that the mean rates of nonmonotonicity range from 22% (choices) to 34% (rankings), but within-subject analysis shows that nonmonotonicity is even higher, ranging from 49% (choices) to 71% (rankings). These violations challenge the validity of multiplicative QALY models.We find that the MET phenomenon may affect particularly those EQ-5D health states that are in the middle of the severity scale and not so much the extreme health states (i.e., very mild and very severe states).We find new evidence of preference reversals even using 2 procedures of a similar (ordinal) nature. Percentage rates of preference reversals range from 1.5% to 33%. We also find some (although scarce) evidence on violations of transitivity.
本文的主要目的是检验寿命的单调性。先前的研究结果表明，对于健康状况较差的情况，在达到某个阈值或最大耐受时间（MET）之前，较长的持续时间比较短的持续时间更受青睐，而超过该阈值后，较短的持续时间比较长的持续时间更受青睐。
通过两项有序任务（选择和排序）来检验持续时间的单调性。在一系列实验环节中招募了一个便利样本（n = 90），参与者必须对健康事件进行排序，并在成对呈现的健康事件中进行选择。健康事件由7种EQ-5D-3L健康状态和5种持续时间组合而成。通过比较偏好呈单调的参与者的百分比与每种健康状态下偏好非单调的参与者的百分比来检验单调性。此外，为了检验偏好逆转的存在，我们分析了从排序转向选择时改变偏好的人群比例。
在7种EQ-5D健康状态中，单调性经常被违背。个体的偏好模式显示，违背率从选择时的近49%到排序时的约71%不等。按单独状态进行的分析表明，选择和排序时的平均违背率分别约为22%和34%。我们还发现了偏好逆转的新证据，以及选择中传递性违背的一些证据（尽管很少）。
我们的结果表明，存在一个中等范围的健康状态，其偏好是非单调的。这些发现支持了先前关于MET偏好的证据，并引入了一种新的“选择 - 排序”偏好逆转。似乎使用具有相似反应量表的两项任务可能会使偏好逆转不那么显著，尽管它仍然很重要且具有系统性。
基于有序比较的两种程序用于引出偏好：直接选择和排序。我们的研究报告了不同持续时间和EQ-5D健康状态组合的非单调偏好（或最大耐受时间[MET]型偏好）的显著比率。对单独健康状态的分析表明，非单调性的平均比率从22%（选择）到34%（排序）不等，但个体内分析表明非单调性甚至更高，从49%（选择）到71%（排序）。这些违背挑战了乘法QALY模型的有效性。我们发现MET现象可能特别影响那些处于严重程度量表中间的EQ-5D健康状态，而对极端健康状态（即非常轻微和非常严重的状态）影响较小。即使使用两种性质相似（有序）的程序，我们也发现了偏好逆转的新证据。偏好逆转的百分比从1.5%到33%不等。我们还发现了一些（尽管很少）传递性违背的证据。
