Non-response Bias Analysis Plan

Attachment 18 –

Asthma Call-back Survey (ACBS)

Nonresponse Bias Analysis Plan

The Asthma Call-back Survey (ACBS) uses post-stratification weighting to ensure the sample conforms to the state estimated asthma population with respect to geography, age, sex, race, ethnicity and other characteristics. However, nonresponse bias can still occur. This plan documents analyses that will be conducted to analyze and report nonresponse bias for the ACBS.

Our approach is to analyze and report nonresponse bias annually with each data release. A nonresponse report will be published on the ACBS website with other supporting documentation. This report will communicate the potential impact of nonresponse bias on the published dataset and accompanying web tables. Annual ACBS web prevalence tables will include a footnote with the URL for the nonresponse report, to communicate nonresponse associated with the data in the tables.

We will report data by ACBS respondents and non-respondents, BRFSS eligible asthma respondents, and current prevalence to communicate the differences between these groups. ACBS respondents are those respondents who completed or partially completed the interview. Nonresponse for the ACBS is influenced by eligible BRFSS respondents for which no interview was conducted: 1) refusals, terminations, and non-consent; (2) lost to follow-up due to non-contact or communication; and 3) lost to follow-up due to technological circumstances. BRFSS eligible respondents are respondents on the BRFSS survey who responded “yes” to the question, “Has a doctor, nurse, or other health professional EVER told you that you had any of the following?” A respondent was classified as current prevalence if he or she also responded “yes” to the “Do you still have asthma” question.

Two tables will be reported. The first table will report ACBS unweighted frequencies for respondents and non-respondents and BRFSS eligible asthma respondents by age, sex, and race/ethnicity demographic categories for each state. See example Table 1 below. The second table will report current asthma prevalence among ACBS respondents and BRFSS eligible ever diagnosed asthma respondents. See example Table 2 below.

Table 1. Percent of ACBS respondents and non-respondents and BRFSS eligible asthma respondents by state and demographic groups

		ACBS				BRFSS
		Respondents		Non-Respondents		Eligible Asthma Respondents
State	Group	Sample size	Percent (unweighted)	Sample size	Percent (unweighted)	Sample size	Percent (unweighted)
AL	Male
AL	Female
AL	Age 18-24
AL	Age 25-34
AL	Age 35-44
AL	Age 45-64
AL	Age 65+
AL	NH White
AL	NH Black
AL	NH Other
AL	Hispanic

Table 2. Current asthma prevalence among ACBS and BRFSS respondents by state

	ACBS Respondents		BRFSS Eligible Asthma Respondents
State	Sample size	Current Prevalence (weighted percent)	Sample size	Current Prevalence (weighted percent)
AL
AK
AZ
AR