Hypothesis testing, statistical power, and confidence limits in the presence of epistemic uncertainty.
Hypothesis testing, statistical power, and confidence limits in the presence of epistemic uncertainty.
复制标题
存在认知不确定性时的假设检验、统计功效和置信限度。
DOI:
10.1097/01.hp.0000270272.98824.66
复制
发表时间:
2007
期刊:
影响因子:
2.2
通讯作者:
Kopecky,KennethJ
中科院分区:
文献类型:
--
作者:
Stram,DanielO;Thomas,DuncanC;Kopecky,KennethJ
We are writing in regard to an article published in the March 2007 issue of Health Physics by Eduard Hofer (Hofer 2007) on the interesting and important subject of dealing with subjective uncertainty in radiation dosimetry when dose estimates are applied to epidemiological studies, especially when a sequence of alternative dose estimates rather than a single “best estimate” of dose is provided for the epidemiological application. We have described several approaches to this problem (Stram and Kopecky 2003; Kopecky et al. 2004), and while these may not provide the last word on this problem we have an important concern regarding the proposed analysis of Hofer, namely the type I error (or “false positive” error) properties of the proposed analysis.Our approach (Stram and Kopecky 2003) and that of Hofer are similar in that both start with an assumption (often requiring a considerable leap of faith) that the dosimetry system used to estimate dose for each individual in the study can be regarded as providing estimates from a distribution of true dose conditional upon what is known about the determinants of the actual exposure. Specifically, both Hofer and we assume that the dosimetry system generates m independent sequences (or “replications”) of dose estimates {x i, j}(i= 1,…, n, is the index for individuals in the study and j= 1,…, m for the sequence number) for the n subjects from the conditional distribution of true dose given all that is known about the parameters, source terms, individual data (excluding outcome data), etc., determining the true exposures. In our 2003 paper, we described some of the operating characteristics of treating the sequences in a manner analogous to what is done in the so called “Berkson error” problem (Thomas et al. 1993). Specifically, we described some statistical implications of using the mean,{z i}, of true dose given “all that is known” about true dose as the dose variable in a linear regression analysis relating disease to exposure.(We may estimate {z i} by averaging the m sequences,{x i, j}, over j, assuming that m is large enough so that the estimation of this mean is very accurate.) Thus, for example, we reject the null hypothesis of “no exposure effect” in this analysis only if standard statistical tests (ignoring dosimetry error) concluded that there was an association between the mean doses, z i, and the outcome of interest, Y i, with the appropriate degree of confidence.
登录
查看更多内容
影响因子:
2.2
作者:
T. Semkow
通讯作者:
T. Semkow
影响因子:
2.2
作者:
T. Borak;T. Kirchner
通讯作者:
T. Kirchner
影响因子:
2.2
作者:
K. Kopecky;S. Davis;Thomas E. Hamilton;Mark S Saporito;L. Onstad
通讯作者:
L. Onstad
影响因子:
2.2
作者:
M. Tries
通讯作者:
M. Tries