NHS GGC
AIP Impact Evaluation Research
Progressive Data Technical Summary
Date: 05/04/18
Method
1.
The data was gathered by conducting face-to-face CAPI (Computer Aided Personal
Interviewing) interviews.
2.
The target group for this research study was pregnant women, their partners, families,
friend and wider community who reside within the NHS Greater Glasgow and Clyde
catchment area.
3.
The target sample size was 300, 100 in hospital antenatal clinics and 200 in-street
interviews. The final achieved sample size was 330; 108 in hospital antenatal clinics (Queen
Elizabeth University Hospital, Inverclyde Royal Hospital, Royal Alexandra Hospital and the
Princess Royal Maternity Hospital) and 222 in-street (Parkhead, Clarkston, Paisley, Pollok
and Greenock).
4.
Fieldwork was completed between 17th March 2018 – 28th March 2018.
5.
For the in-street surveys respondents were selected using a stratified random sampling
technique, whereby interviewers worked to specified quota controls on key sample criteria,
and selected respondents randomly within these quotas. These were set on age and gender,
and were based on population statistics (census 2011). At antenatal clinics respondents
were selected randomly.
6.
In total, 9 interviewers worked on data col ection.
7.
Each interviewer’s work is validated as per the requirements of the international standard
ISO 20252. Validation was achieved by re-contacting (by telephone or email) a minimum of
10% of the sample to check profiling details and to re-ask key questions from the survey.
Where telephone/email details were not available re-contact may have been made by post.
All interviewers working on the study were subject to validation on their work.
8.
All research projects undertaken by Progressive comply fully with the requirements of ISO
20252.
10121 Beatson Cancer Charity Research – Technical Summary
Data Processing
1.
The final data set was not weighted.
2.
Quota controls were used to guide sample selection for this study. This means that we
cannot provide statistically precise margins of error or significance testing as the sampling
type is non-probability. The margins of error outlined below should therefore be treated as
indicative, based on an equivalent probability sample. The overall sample size of 330
provides a dataset with an approximate margin of error of between ±1.5% and ±5.2%,
calculated at the 95% confidence level (market research industry standard).
3.
Our data processing department undertakes a number of quality checks on the data to
ensure its validity and integrity. For
CAPI Questionnaires these checks include:
- Responses are checked to ensure that interviewer and location are identifiable. Any
errors or omissions detected at this stage are referred back to the field department,
who are required to re-contact interviewers to check.
- A computer edit of the data is carried out prior to analysis, involving both range and
inter-field checks. Any further inconsistencies identified at this stage are investigated by
reference back to the raw data on the questionnaire.
- Where ‘other’ type questions are used, the responses to these are checked against the
parent question for possible up-coding.
- Responses to open-ended questions are spell and sense checked.
Small Base Sizes
1.
Care should be taken when interpreting data where the cell base size is less than 100. This is
due to the fact that lower base sizes provide lower levels of statistical reliability.
10121 Beatson Cancer Charity Research – Technical Summary