Age-adjusted rate	A rate that is statistically modified to eliminate the differences in observed rates resulting from different populations being analyzed or from different age distributions within a population.4
Average	A value that represents the sum of values divided by the number of values in the set. It represents or summarizes the relevant features of a set of values.1
Binge-drinking	Heavy drinking characterized by the 5/4 rule  five or more drinks consumed on one occasion by a man and four or more drinks consumed by a woman.2
Body mass index (BMI)	A measure of bodyweight relative to height to determine if a person is overweight.  It is abbreviated as BMI. It is calculated as weight in kilograms divided by height in meters squared.  Healthy weight for adults is defined as a BMI of 18.5 to less than 25.3
Case	Defined as the occurrence of a particular event or disease in a person.9
Case fatality rate	The proportion of persons diagnosed with a particular disease that die from the disease, compared to the number of persons diagnosed with the particular disease within a given period of time.  See related case.4,9
Confidence interval (CI)	A range of values for a rate that contains the true value of the variable within a specified level of certainty.  The specified level is called the confidence interval, while the end points of the confidence interval (CI) are called the confidence limits.  For example, 95%CI=2-5  suggests that we have 95% confidence that the true rate lies between 2 and 5.4,9
Confidence limit	The end points of a confidence interval.  See related confidence interval.9
Cross sectional study	A study that analyzes the relationship between disease and other variables that exist in a specified population at a given point in time.9
Cross tabulation	This is the simplest technique for understanding patterns of differences between populations in a database. Cross-tabulations are used to examine the relationship between two or more variables.10
Crude mortality rate	An estimate of the percentage of a population that dies within a specified period of time.  It is determined by dividing the number of persons dying in a period by the number of persons living.9
Cumulative	The total number of persons/cases reported in a study.9
Cumulative incidence	The risk of developing a disease in a given period of time.9
Death rate	Death rate is calculated by dividing the number of deaths in a population in a year by the midyear resident population. Death rates are expressed as the number of deaths per 100,000 population. The rate may be restricted to deaths in specific age, race, sex, or geographic groups or from specific causes of death (specific rate), or it may be related to the entire population (crude rate).  See related crude mortality rate.3
Demographic	Relating to the characteristics of a population such as age, race/ethnicity, and gender.9
Epidemic	A significant increase in the incidence rate of a particular disease in given population.  See related incidence rate.9
Epidemiology	The study of incidence, distribution, and control of a disease in a specified population to promote protect and restore health in the population.9
Ethnicity	A group of persons defined by a distinctive cultural and social tradition that is maintained from generation to generation.  It is considered as a separate category from race.4
Exposure	Contact with a factor that may increase the risk of that person of developing a particular disease.9
Federal poverty level (FPL)	The income determined by the Federal Department of Health and Human Services as the minimum income needed to sustain a family of a particular size.5
Food insecurity	Uncertain or limited access to nutritious, safe foods necessary to lead a healthy lifestyle.8
Frequency distribution	The number of times a particular variable assumes a specific value.6
Incidence rate	Rate at which new events, such as cases of a particular disease, arise in a given population - for instance, the number of new cases diagnosed in a year divided by the population at risk in that same year.9
Median	A value that divides a range of values in half, such that half of the values in the given set lie below the median, and the other half lie above.4,9
Obesity	Defined as a BMI of greater than or equal to 30.  See related BMI.3
Odds ratio	A ratio that quantifies the relationship between developing a disease from exposure to a particular factor and not developing the disease from similar exposure to the factor.4,9
Overweight	Defined as a BMI at or above the sex and age-specific 95th percentile BMI from the 2000 CDC Growth Charts.  For adults it is defined as a BMI of greater than or equal to 25.3
Percentage	A ratio of a part to the whole indicated as a decimal fraction, fraction or with a percentage sign (%).4
Person-Years	The sum of the number of years that each member of a population has been afflicted by a certain condition; e.g., years of treatment with a certain drug.1
Prevalence	The number or proportion of persons in a given population with a particular condition over a period of time, in a single period of time, or in a specified area at a specified time.  See related incidence rate.4,5,6
Proportion	Ratio of a part of the whole to the whole - e.g. 45% of Angelenos are Latino.  See related percentage.9
Race	Current U.S. Census categories include African American, Asian and Pacific Islander, American Indian and Alaska Native, Hawaiian, White, Other.  It is considered separate from ethnicity.4
Random sample	A sample of individuals in which all individuals have a defined and equal chance of being selected.9
Rate	It is a measure of the frequency of a disease in a particular population during a specified period of time.  It can be used to compare the impact of a disease on one subpopulation with another.  See related incidence rate.9
Ratio	The number obtained by dividing one quantity by another.4
Sample	A subset of a population that is chosen for analysis.9
SPA	Los Angeles County is divided into eight "Service Planning Areas" (SPA's) for health care planning purposes.  Each SPA has an Area Health Office that is responsible for planning public health and clinical services according to the health needs of local communities.7
Statistic	A quantity that is calculated from a sample of data. It is used to give information about unknown values in the corresponding population. For example, the average of the data in a sample is a statistic used to give information about the overall average in the population from which the sample was drawn.6
References
1. Biology-Online.org
2. National Institute on Alcohol Abuse and Alcoholism
3. Health, United States, 2005 (CDC)
4. Iowa Department of Public Health
5. UW School of Public Health and Community Medicine
6. ReCAPP Research Glossary
7. Los Angeles County Department of Health Services, Public Health
8. World Hunger Year
9. Los Angeles County Department of Health Services, Epidemiology Report 2004 (pages 71-76)
10. SmartDrill: Data Mining