Table 1

Methodologies employed in 3 telephone surveys between 2000–2005.

Survey 1

Survey 2

Survey 3

Topic under survey

Frequency of gastroenteritis on the island of Ireland

Cardiovascular health promotion: attitudes and behaviours in one Irish health board region

Attitudes, perceptions and knowledge of the population of on the island of Ireland to blood transfusion

Data collection period

Dec 2000 – Nov 2001

Sept – Oct 2003

July 2004 – Jan 2005

Data collection duration

12 months

6 weeks

7 months

Region

ROI^†, NI^‡

Health Board Area in ROI

ROI, NI

Telephone number sourcing

Hundred-bank method

Telecom Eireann National Directory Database 2003

Hundred-bank method

Household randomisation

Next birth-date

First adult contact

Next birth-date

Attempts to make contact

Up to 4 calls

1 call

Up to 4 calls

Method of survey

Telephone to paper

CATI*

CATI*

Length of questionnaire

10 minutes

15–20 minutes

10–12 minutes

Age of respondents

Over 12 years

Over 18 years

Over 16 years

Schedule of interviews

Weekday evenings and all day Saturday

All day during week and Saturday

Weekday evenings and all day Saturday

Completed sample size

9,600

1,500

4,216

Total numbers generated/extracted

22,281

75,893

55,982

Contact attempts

45,603

6,893

32,786

† ROI = Republic Of Ireland

‡ NI = Northern Ireland

*CATI = computer assisted telephone interview

Boland et al. BMC Public Health 2006 6:208   doi:10.1186/1471-2458-6-208