منابع مشابه
Reducing selection bias in case-control studies from rare disease registries
BACKGROUND In clinical research of rare diseases, where small patient numbers and disease heterogeneity limit study design options, registries are a valuable resource for demographic and outcome information. However, in contrast to prospective, randomized clinical trials, the observational design of registries is prone to introduce selection bias and negatively impact the validity of data analy...
متن کاملSelection Bias
data in Haneuse et al. [1] . The risk ratio of dementia by exposure in the total target population is 2.0, and is the true association (there is no confounding in our simple DAG; fig. 1 ). Table 1 shows the expected distribution by exposure and outcome by strata of dead/alive under the following assumptions: half of the population dies; there is a risk ratio of death for the exposed compared to...
متن کاملSelection Bias, Label Bias, and Bias in Ground Truth
Language technology is biased toward English newswire. In POS tagging, we get 97–98 words right out of a 100 in English newswire, but results drop to about 8 out of 10 when running the same technology on Twitter data. In dependency parsing, we are able to identify the syntactic head of 9 out of 10 words in English newswire, but only 6–7 out of 10 in tweets. Replace references to Twitter with re...
متن کاملTweedie's Formula and Selection Bias.
We suppose that the statistician observes some large number of estimates z(i), each with its own unobserved expectation parameter μ(i). The largest few of the z(i)'s are likely to substantially overestimate their corresponding μ(i)'s, this being an example of selection bias, or regression to the mean. Tweedie's formula, first reported by Robbins in 1956, offers a simple empirical Bayes approach...
متن کاملBias Estimation and Model Selection
%b%G%kA*Br$NLdBj$O!$65;UIU$-3X=,$K$*$$$F9b$$HF2=G=NO$r3MF@$9$k$?$a$K=EMW$G$"$k!%%b%G%kA*Br$NpJsNL5,=‘(AIC) $,$3$l$ $̂G$K9-$/MQ$$$i$l$F$-$?!%$7$+$7$J$,$i!$AIC $G$O71N} %G!<%?$K4X$9$kA26a6a;w$rMQ$$$F$$$k$?$a!$71N}%G!<%??t$,>/$J$$>l9g$K$OE,@Z$K%b%G%kA*Br$r9T$&$3$H$, $G$-$J$$!%$=$3$GK\O@J8$G$O!$subspace information criterion (SIC) $H$h$P$l$k?7$7$$%b%G%kA*Br$N5,=‘$r Ds0F$7!$...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Circulation: Cardiovascular Quality and Outcomes
سال: 2009
ISSN: 1941-7713,1941-7705
DOI: 10.1161/circoutcomes.109.916601