Response rate formulae

Attachment 12 –

ACBS Response Rate Formula

Table ACBS sample disposition codes and categories
Category	Disposition Code Definitions	Notes
Completed interviews	1100, 1200	Interview finished through Section 8
Terminations and refusals at BRFSS	4413	At BRFSS
Terminations and refusals at ACBS	2112, 2120, 2211, 2212,	At ACBS
Contacted eligible at ACBS	1100, 1200, 2120, 2211, 2212, 2112, 2330, 2320	At ACBS
Eligible lost: unable to contact	2111, 2210, 2220, 2320, 2330, 3100, 3130, 3140, 3200, 3322, 3330, 4100, 4900, 4306, 5050, 5100, 5111, 5112, 5120, 5130, 5140, 5220, 5320, 5330, 5550, 5560	Unable to contact or communicate with eligible respondent
Eligible lost: Not interviewed for technical problems	3150, 3700, 4200, 4300, 4400, 4430, 4450, 4460, 4470, 4500, 4510, 5400, 5150, 5200, 5300, 5599, 5700, 5900, 9999	Technical problems
Ineligible for Asthma Call-back at BRFSS	2290, 2291, 4480, 4490, 4491	At BRFSS
Ineligible at ACBS	4405, 4700, 4411, 4471	At ACBS
No ACBS attempt	4412	No ACBS attempt

The response rate formulae for the ACBS are described below.

We used the following formulas to calculate the rates:

Agree to be called back rate = (Yes to be called back / BRFSS asthma eligible respondents who were asked whether to participate for ACBS)*100

Eligibility factor = Contacted eligible at ACBS / (Contacted eligible at ACBS + Ineligible for Asthma Call-back at BRFSS + Ineligible at ACBS + No ACBS attempt)

CASRO Rate = (Completed interviews / (Contacted eligible at ACBS + Terminations and refusals at BRFSS + (Eligibility factor * Eligible lost )))* 100

Cooperation rate = (Completed interviews / (Contacted eligible at ACBS + Terminations and refusals at ACBS))*100

Refusal rate = ((Terminations and refusals at BRFSS + Terminations and refusals at ACBS) / (Contacted eligible at ACBS + Terminations and refusals at BRFSS + (Eligibility factor * Eligible lost))) * 100

The Council of American Survey Research Organizations (CASRO) rate is a measure of respondent cooperation and is generally defined as the proportion of all eligible respondents in the sample for whom an interview has been completed. The numerator of the CASRO rate includes completed interviews (COIN). The denominator includes Contacted eligible at ACBS and terminations and refusals at BRFSS and a proportion of those eligible but lost to follow-up. The proportion represents an estimate of the number of those lost to follow-up who would be expected to remain eligible if they had been contacted.

The Refusal Rate is the percentage of all eligible respondents that refuse to be interviewed or terminate an interview early in the questionnaire. The numerator includes terminations and refusals at BRFSS and at ACBS. The denominator is the same as for the CASRO rate.

The ACBS Cooperation Rate is the proportion of completed interviews (COIN) among all eligible respondents who are recruited and actually contacted for the ACBS interview. Eligible respondents who refuse the call-back at the time of the BRFSS interview are included. Non-contacts are excluded from the denominator but contacts with communication problems specific to the respondent with asthma are included.