Total number of events (e.g., deaths, births, hospitalizations) divided by the total population for a given time period and geography.
If one is interested in knowing the true event rates in a particular geographic area then unadjusted or crude rate should be used instead of age standardized rate.
‘Chronic respiratory diseases are chronic diseases of the airways and other parts of the lung. Some of the most common are asthma, chronic obstructive pulmonary disease (COPD), lung cancer, cystic fibrosis, sleep apnea and occupational lung diseases. Respiratory diseases affect all ages-children, teens, adults and seniors.’ Public Health Agency of Canada 2011 http://www.phac-aspc.gc.ca/cd-mc/crd-mrc/index-eng.php