Sentence examples for a valid control group from inspiring English sources
Constructing a valid control group under these circumstances is challenging, and we relate our discussion to recent advances in econometric methods for evaluation studies based on non-experimental data.
In another one [39], the appliance was not used exclusively in patients with anterior open bite and there was not a valid control group.
For this pilot study we enrolled a few tuberculosis (TB) patients with a variable degree of disease activity and healthy young and middle-age Finnish vaccinees who were practically free from any previous contact with M. tuberculosis and thus served as a valid control group.
Test-negative ILIs are therefore a valid control group (the source population of cases).
First, as a real-world single-center registry, the study is limited by a lack of a valid control group.
Another difficulty will be to find studies with a valid control group to estimate the effect attributable to the nutrition intervention alone.
Using the key words: "occupational disease", "work" and "Dupuytren contracture" without limitation on language or year of publication, epidemiological studies were selected from four databases (Pub-Med, Embase, Web of science, BDSP) after two rounds (valid control group, valid work exposure).
At this point, an estimate length of study to see perceptible results should be determined as well as valid control groups and an adequate analysis technique.
Developing valid control groups that generate similar perceptions and expectations to experimental complementary and alternative (CAM) treatments can be challenging.
Since animals from these last two groups have an isogenic mother and are not fostered, they can not be considered as fully valid control groups and thus cannot be included in the analysis of the impact of maternal environment.
Other surveillance studies lacked valid control groups (Rosenstock et al, 1985; Lofberg et al, 1990; Nugent et al, 1991; Jonsson et al, 1994; Friedman et al, 2001; Biasco et al, 2002; Hata et al, 2003) or were not designed to answer this question (Eaden et al, 2000).
