Important Statistics Terms

Prevalence: Prevalence is the fraction of people in a population who have a disease/condition/characteristic at a point in time.
Rate: A calculation describing the speed at which new disease or health events occur. For example, the rate of asthma death in Michigan is 12.6 per million people per year.
Work-Related Asthma: Work-related asthma is asthma caused by exposures at work. It can also be existing asthma made worse by exposures at work.
Asthma Emergency Department Visit: An asthma emergency department visit is one where asthma is the primary reason for the visit. (International Classification of Disease (ICD) Version 10 Clinical Modification code J45)
Asthma Hospitalization: An asthma hospitalization is one where asthma is the primary reason for the hospital stay. (International Classification of Disease (ICD) Version 10 Clinical Modification code J45)
Asthma Death: An asthma death is one where asthma is the primary reason for the death. (International Classification of Disease (ICD) Version 10 codes J45 and J46)
Persistent Asthma HEDIS®: Persistent asthma is defined according to the Health Plan and Employer Data and Information Set (HEDIS®) definition from the National Committee for Quality Assurance (NCQA). The criteria for this definition are:

at least four occasions where asthma medicine is given out OR
at least one visit to an emergency room where the primary reason was asthma OR
at least one visit to the hospital where the primary reason was asthma OR
at least four visits to a doctor where the primary reason was asthma and at least two occasions where asthma medicine is given out.

Statistically Significant Result: A result is called statistically significant if it is unlikely to have occurred by chance. "A statistically significant difference" simply means there is statistical evidence that there is a difference; it does not mean the difference is necessarily large, important, or significant in the common meaning of the word.