Question

note: the content of this abstract has been modified from its original format.
objective
to assess whether high school football played between 1946 and 1956, when headgear was less protective than today, was associated with development of neurodegenerative diseases later in life.
methods
all male students who played football from 1946 to 1956 in the high schools of rochester, minnesota, plus a non - football - playing referent group of male students in the band, glee club, or choir were identified. using the records - linkage system of the rochester epidemiology project, we reviewed (from october 31, 2010, to march 30, 2011) all available medical records to assess later development of dementia, parkinsons disease, or amyotrophic lateral sclerosis (als).
results
we found no increased risk of dementia, parkinsons disease, or als among the 438 football players compared with the 140 non - football - playing male classmates. parkinson disease and als were slightly less frequent in the football group, whereas dementia was slightly more frequent, but not significantly so.
what is the exposure? (1 point)
a attending high school between 1946 and 1956
b rochester, mn
c playing high school football between 1946 and 1956
d neurodegenerative diseases (dementia, parkinsons disease, als)

Explanation:

In epidemiology, the exposure is the factor being studied for its association with an outcome. Here, the study is about whether playing high - school football (when headgear was less protective) between 1946 and 1956 (the time frame in the objective) is associated with neurodegenerative diseases. Option A is about attending high school (not playing football), option B is a location (not relevant to the exposure factor in the study), and option D is the outcome (neurodegenerative diseases).

Answer:

C. Playing high school football between 1946 and 1956