Studies in which comparisons are made between groups but exposures are not measured on the individual level. For instance, assessments are done on the community, population, or group levels.

A classification describing the nature of the relationship between the animals being studied and the humans to whom the studied animals might be in close proximity. Possible values include companion, [..]

Identifies the author or authors of the study.

Backward directionality describes a methodology in which individuals with a certain condition are compared with individuals without the condition in terms of history of previous exposures, thereby mov [..]

A subject meeting inclusion or exclusion criteria in a study. For instance, those subjects who contract the disease in the study.

Study groups are defined on the basis of disease (or outcome) status. The frequency of the risk factor (exposure) in the cases (diseased) is compared with the frequency of the risk factor (exposure) i [..]

Causative factors examined in a given study may be a specific hazard or disease agent, such as inorganic lead or the Lyme disease spirochete Borrellia Burgdorferi. Factors noted by curators could also [..]

A study in which a clearly identified group is characterized by exposure and is followed for the outcome.

Animals serving as companions such as dogs, cats and other pets. *

According to the classification algorithm, identifies whether the study used control animals from the same population as the affected animals (Yes or No). For example, many studies compare control ani [..]