Changes

Descriptive epidemiology aims to describe the distribution of disease in terms of animal, place and time, as shown below. In a purely descriptive study, no attempt is made to formally investigate reasons for the patterns of disease observed, although hypotheses regarding possible reasons will commonly be generated and developed as a result of these investigations. A description of the different types of descriptive studies is provided [[Descriptive studies#Study design|elsewhere]].<br>

Descriptive epidemiology aims to describe the distribution of disease in terms of animal, place and time, as shown below. In a purely descriptive study, no attempt is made to formally investigate reasons for the patterns of disease observed, although hypotheses regarding possible reasons will commonly be generated and developed as a result of these investigations. A description of the different types of descriptive studies is provided [[Study design#Descriptive studies|elsewhere]].<br>

=='''Animal''' ''(which animals are affected)''==

=='''Animal''' ''(which animals are affected)''==

=='''Time''' ''(when cases occur)''==

=='''Time''' ''(when cases occur)''==

Again, the timing of disease is accounted for to some degree in all investigations - meaning that a study investigating the worldwide incidence of Rinderpest in 1900 would give very different results from that in 2010. However, some studies may further investigate and quantify the temporal pattern of disease. One example of this is outbreak investigation,  where the number of cases of disease within a population over time may be plotted in the form of an 'epidemic curve'. This can provide useful information regarding trends of disease, and may advise upon the effectiveness of any control measures instigated.<br>

Again, the timing of disease is accounted for to some degree in all investigations - meaning that a study investigating the worldwide incidence of [[Rinderpest]] in 1900 would give very different results from that in 2010. However, some studies may further investigate and quantify the temporal pattern of disease. One example of this is outbreak investigation,  where the number of cases of disease within a population over time may be plotted in the form of an 'epidemic curve'. This can provide useful information regarding trends of disease, and may advise upon the effectiveness of any control measures instigated.<br>

=='''Sampling'''==

=='''Sampling'''==