Table 1

Call outcomes for all numbers dialled by contact method

Fixed-line

%

Mobile

%


Total numbers dialled

5390

100.0%

3697

100.0%


Eligible for study

190

3.5%

145

3.9%


Completed interview

140

2.6%

128

3.5%


Personal refusal

19

0.4%

10

0.3%


Terminated/Incomplete interview

0

0.0%

0

0.0%


Unavailable for duration of survey

31

0.6%

7

0.2%


Ineligible (due to age, sex, language***)

1935

35.9%

1215

32.9%


Unknown eligibility

785

14.6%

1309

35.4%


No answer

386

7.2%

284

7.7%


Message left on recording device

331

6.1%

941

25.5%


Engaged

34

0.6%

70

1.9%


Refusal/Other

34

0.6%

14

0.4%


Number invalid

2480

46.0%

1028

27.8%


Business

284

5.3%

111

3.0%


Disconnected

1902

35.3%

897

24.3%


Fax/data line

294

5.5%

20

0.5%


Crude response rate* (%)

73.7%

88.3%


Estimated response rate** (%)

53.8%

45.0%


*completed interviews/eligible; see methods for detailed description

** completed interviews/(eligible + eligible/(eligible+ineligible) × unknown eligible); see methods for detailed description

***numbers with language difficulty comprised 15 of the ineligible fixed-line calls and 2 of the mobile calls

Liu et al. BMC Medical Research Methodology 2011 11:159   doi:10.1186/1471-2288-11-159

Open Data