American Community Survey
ACS PUMS files consist of sub-samples of ACS HU and GQ respondents. These files are designed to include one percent of both the HU and GQ populations estimated by the full ACS. HU and GQ PUMS samples were constructed separately, and sampling intervals for each are calculated to yield target sample sizes at the state level.
Data Collection Procedures:
ACS data are collected in one of four modes: internet, mail, telephone, and personal visit. For most HUs, mailed invitations to participate via internet are extended initially. If no response is received, this is followed by invitations to participate via mail, telephone, or personal visit, in that order, based on participant response or non-response to each previous option. Data are collected from GQ residents via personal interview only. For sampled HUs, information is collected for all residents living in the household. The participation rate in 2014 was 96.7% for people living in HUs and 95.9% for people living in GQs. Participation rates in 2015 were 95.8% and 95.3% for HU and GQ residents, respectively.
For the VEHSS team, NORC estimated the prevalence rate and sample size for each survey instrument selected for inclusion. We analyzed the 2014 and 2015 PUMS files separately. The prevalence rate was defined as the number of people who gave an affirmative response to the question divided by the total number of respondents who gave an affirmative or negative response and multiplied by 100 for presentation in percentage format. Estimates that were based on a sample size of less than 30 and/or with a relative standard error greater than 30% were suppressed.
A detailed description of the analytical steps is described in the report “VEHSS Survey Analysis Plan [PDF – 480 KB]external icon.” Full analysis documentation is included in the “VEHSS ACS Data Report [PDF – 359 KB]external icon.”
Variables Analyzed in VEHSS:
ACS contains a single question relevant to VEHSS: “Is this person blind or does he/she have serious difficulty seeing even when wearing glasses?” This question, which was first fielded in 2008, was categorized under the VEHSS ‘Visual Function‘ topic and ‘Difficulty Seeing with Glasses’ category. Table 1 presents additional details about the question, including the ACS variable name, the year(s) survey data are available, the survey question, and the response options.
Table 1. Overview of ACS Variables Included in VEHSS
|VEHSS Indicator Topic||VEHSS Indicator Category||ACS Variable Name||ACS Question Text||Years Available
|Visual Function||Difficulty Seeing with Glasses||DIFFEYE||Is this person blind or does he/she have serious difficulty seeing even when wearing glasses?||2008-2016
Additional information about ACS can be found on the U.S. Census Bureau [PDF – 10.1 MB]external icon website.
 American Community Survey design and methodology. Washington, DC: US Census Bureau; 2014. https://www2.census.gov/programs-surveys/acs/methodology/design_and_methodology/acs_design_methodology_ch04_2014.pdf [PDF – 607 KB]external icon. Accessed September 01, 2016.
 PUMS accuracy of the data. Washington, DC: US Census Bureau; 2015. https://www2.census.gov/programs-surveys/acs/tech_docs/pums/accuracy/2015AccuracyPUMS.pdf [PDF – 2.5 MB]external icon. Accessed September 01, 2016.