Application of latent semantic analysis for open-ended responses in a large, epidemiologic study

Table 3 Example Responses From Millennium Cohort Study Participants Within the Top Seven Concerns Expressed in the Open-Ended Question

Area of Concern^a	Example Response
Illness/injury^b	I recently had my blood pressure medication dose increased to control hypertension
Illness/injury	I was involved in a motor vehicle collision...It has caused delays in my return to reserve duty/flight duty. I suffered a head injury/laceration and orthopedic injury/laceration to left knee.
Exposure	Exposed to hepatitis, asbestos, and enriched uranium in Uzbekistan and Afghanistan.
	Exposure to welding fumes.
Exercise	Lower back, knee, and ankle pain due to extended periods of massive weight-bearing duties and exercise.
Mental health	Mental and emotional problems due to sexual child abuse.
Anxiety/disorientation	Extreme stress and anxiety due to superiors' incompetence.
Vaccination	Allergic reactions to anthrax vaccine.

^a A single participant response could be categorized into multiple areas of concern.
^bThe cluster labeled "illness/injury" describes responses across a broad number of concerns. Several examples are provided in Table 4 to better illustrate these topic areas within the cluster.

ISSN: 1471-2288