The researchers also assessed two personality factors, self-esteem and a sense of personal control, that could play a role in susceptibility to illness.
In all the studies, researchers asked participants about social lives and assessed mental skills with simple tests.
In 2003, Freeze 24/7 had an outside company test the product by having a researcher treat the faces of 20 women and visually assess their wrinkles.
This process allows researchers to directly assess human immune responses.
Moreover, the researchers could not assess the relative importance of clinical management versus the placebo.
This means that a researcher can potentially assess the reasons for response changes by assessing the differences in respondents' experiences.
The researchers review the article and assess the quality of the science.
The researchers went on to implement the program and assessed the benefits.
The researchers assessed the diet of the study participants using a detailed food questionnaire.
The researchers also assessed the risk of heart attack based on whether the participant smoked medium- or low-tar cigarettes.