Question

In Exercises 1.17-1.22, state whether the investigation in question is an observational study or a designed experiment. Justify your answer in each case.

Sex, Sleep, and PTSD. In the article, "One's Sex, Sleep, and Posttraumatic Stress Disorder" (Biology of Sex Differences, Vol. 3, No. 29, pp. 1-7), I. Kobayashi et al. study the relationship between one's sex, sleep patterns, and posttraumatic stress disorder (PTSD) after trauma exposure. The authors report that women have a higher lifetime prevalence of PTSD as well as a greater risk of developing PTSD following trauma exposure. Relationships between sleep and physical health have been documented in a number of studies, and the authors explore the possibility that disruptive sleep habits are common among people with PTSD and also a possible risk factor for the development of PTSD. A questionnaire of men and women with and without PTSD produced data on their sleep habits.

Short answer

The given investigation is an observational study.

Step-by-step solution

Step 1. Given information.

The given statement is:

In the article, "One's Sex, Sleep, and Posttraumatic Stress Disorder" (Biology of Sex Differences, Vol. 3, No. 29, pp. 1-7), I. Kobayashi et al. study the relationship between one's sex, sleep patterns, and posttraumatic stress disorder (PTSD) after trauma exposure. The authors report that women have a higher lifetime prevalence of PTSD as well as a greater risk of developing PTSD following trauma exposure. Relationships between sleep and physical health have been documented in a number of studies, and the authors explore the possibility that disruptive sleep habits are common among people with PTSD and also a possible risk factor for the development of PTSD. A questionnaire of men and women with and without PTSD produced data on their sleep habits.

Step 2. State whether the given investigation is an observational study or a designed experiment.

The researchers in this study gathered information on men's and women's sleeping patterns.

In other words, the researchers look at both males and women with post-traumatic stress disorder (PTSD). The individuals are also not subjected to any therapy by the researchers.

As a result, the research issue is an observational study.