Brennan David S, Spencer A John
Australian Research Centre for Population Oral Health, School of Dentistry, Faculty of Health Sciences, The University of Adelaide, South Australia.
BMC Health Serv Res. 2006 Aug 7;6:96. doi: 10.1186/1472-6963-6-96.
A summary utility index is useful for deriving quality-adjusted life years (QALY) for cost analyses or disability weights for burden of disease studies. However, many quality of life instruments provide descriptive profiles rather than a single utility index. Transforming quality of life instruments to a utility index could extend the use of quality of life instruments to costs analyses and burden of disease studies. The aims of the study were to map a specific oral health measure, the Oral Health Impact Profile to a generic health state measure, the EuroQol, in order to enable the estimation of health state values based on OHIP data.
Data were collected from patients treated by a random sample of South Australian dentists in 2001-02 using mailed self-complete questionnaires. Dentists recorded the diagnosis of dental conditions and provided patients with self-complete questionnaires to record the nature, severity and duration of symptoms using the EuroQol (EQ-5D) and 14-item version of the Oral Health Impact Profile (OHIP-14) instruments. Data were available from 375 patients (response rate = 72%). A random two-thirds sample of patients was used in tobit regressions of EQ-5D health state values estimated using OHIP-14 in a model with categories of OHIP responses as indicator variables and in a model with OHIP responses as continuous variables. Age and sex were included as covariates in both models. The remaining one-third sample of patients was used to test the models.
The OHIP item 'painful aching in mouth' was significantly related to health state values in both models while 'life less satisfying' was also significant in the continuous model. Mean forecast errors relative to the mean observed health state value were higher when fitted to the categorical model (17.4%) compared to the continuous model (15.2%) (P < 0.05).
The findings enable health state values to be derived from OHIP-14 scores for populations where utility has not or cannot be measured directly.
一个汇总效用指数对于成本分析中得出质量调整生命年（QALY）或疾病负担研究中的残疾权重很有用。然而，许多生活质量工具提供的是描述性概况而非单一效用指数。将生活质量工具转化为效用指数可以将生活质量工具的使用扩展到成本分析和疾病负担研究。本研究的目的是将一种特定的口腔健康测量工具——口腔健康影响程度量表（OHIP）映射到一种通用的健康状态测量工具——欧洲五维度健康量表（EuroQol），以便能够根据OHIP数据估算健康状态值。
2001年至2002年，通过邮寄自填问卷从南澳大利亚州随机抽取的牙医治疗的患者中收集数据。牙医记录牙齿疾病诊断情况，并向患者提供自填问卷，让他们使用欧洲五维度健康量表（EQ - 5D）和14项版口腔健康影响程度量表（OHIP - 14）记录症状的性质、严重程度和持续时间。共有375名患者的数据可用（回复率 = 72%）。在一个以OHIP回答类别作为指示变量的模型以及一个以OHIP回答作为连续变量的模型中，使用随机抽取的三分之二患者样本对用OHIP - 14估算的EQ - 5D健康状态值进行托比特回归分析。年龄和性别在两个模型中均作为协变量纳入。其余三分之一患者样本用于检验模型。
在两个模型中，OHIP项目“口腔疼痛”均与健康状态值显著相关，而在连续模型中“生活满意度降低”也具有显著性。与连续模型（15.2%）相比，拟合分类模型时相对于观察到的健康状态值均值的平均预测误差更高（17.4%）（P < 0.05）。
这些发现使得在效用未直接测量或无法直接测量的人群中，能够从OHIP - 14得分得出健康状态值。
