Population estimates by age, sex, race and Hispanic ethnicity (ASRH) are invaluable for the estimation of rates of health and illness in Connecticut’s towns and counties.  While the Census Bureau is a primary resource for population estimates, it falls short for Connecticut in two ways: 1) the decennial estimates occur on April 1 – not the center of the calendar year, and 2) the annual town population estimates between decennial census years do not include demographics.  To address these gaps, the Connecticut Department of Public Health developed town-level ASRH data for 2000, 2010, 2011-2014, and 2020. The town*ASRH data allows CTDPH to calculate metrics by demographic characteristics to support annual surveillance activities. These town-level estimates are also used by other state agencies to support state governance activities.

Decennial Town ASRH Estimates: July 1, 2020

The standard reference point for population estimates is July 1 as it represents the center of the calendar and, theoretically, represents the average of the population for that year.  An April 1 estimate likely underestimates the population compared to the July 1 mid-year point. By creating a July 1 reference point for decennial census data, our state and town population estimates are now consistent with the reference point for all non-decennial estimates, such as the annual post-censal estimates series. To adjust the April 1, 2020 estimates to match the July 1 reference points, the town-level ASRH distribution from the decennial April 1 estimates were smoothed or ‘raked’ to the annual July 1 population estimates for town totals and for county demographic (ASRH) totals. See our methodology for a detailed explanation. 

Post-censal Town ASRH Estimates: July 1, 2011 - 2014

Although the US Census Bureau publishes county-level estimates with demographics, town (also known as MCD) estimates with demographics are not produced for publication.  Since Connecticut utilizes town-based units of government, production of town-level health statistics are valuable to public health surveillance, planning, and promotion. 

The Connecticut DPH Health Statistics and Surveillance staff, in collaboration with staff from the UConn State Data Center, developed a method for estimating town-level ASRH counts annually between decennial census years.  The method begins with age-specific prediction models fit the July 1, 2010 Town-ASRH estimates.  Once fitted, the models are updated with annual model inputs to extend the prediction models through, at present, 2014.  The annual model estimates are then smoothed or ‘raked’ to the July 1 estimates by town totals and by county ASRH totals for each year.  Please see our technical documentation (initial model, modified model) for a detailed explanation of the two stages of model development.  

Decennial Town ASRH Estimates: July 1, 2000, and July 1, 2010

The standard reference point for population estimates is July 1 as it represents the center of the calendar and, theoretically, represents the average of the population for that year.  An April 1 estimate likely underestimates the population compared to the July 1 mid-year point. By creating a July 1 reference point for decennial census data, our state and town population estimates are now consistent with the reference point for all non-decennial estimates, such as the annual post-censal estimates series. To adjust the April 1, 2000 and April 1, 2010 estimates to match the July 1 reference points, the town-level ASRH distribution from the decennial April 1 estimates were smoothed or ‘raked’ to the annual July 1 population estimates for town totals and for county demographic (ASRH) totals. For a detailed explanation for 2000 and 2010, please see our technical documentation.

           Pre-2020 Town*ASRH Datasets:  Excel:  2010-2014,  2000      SAS:  2010-2014

Estimates of the resident population of Connecticut as of July 1 are tabulated by:

• 169 towns (also known as MCDs),
• 18 five-year age group (0-4, 5-9, 10-14 … 85 years and over), 
• 2 sexes (male, female), and
• 5 bridged-race/ethnicity categories (White, Black, Am.Indian, Asian/PI, Hispanic/Latino).