Another large proportion (20%) described the use of interviewer- and/or clinician-administered outcome measures.
The objective of this survey was to assess vaccination coverage and its determinants in this rural community in Nigeria A cross-sectional survey was conducted in September 2006, which included the use of interviewer-administered questionnaire to assess knowledge of mothers of children aged 12 23 months and vaccination coverage.
Second, the use of interviewers can lead to forms of bias for example, the interviewer may give subtle clues that influence the respondent towards certain preferences or choice strategies.
Specific effort was given to encouraging response from hard to reach groups, through use of plain direct questions, the development of an audio/visual support DVD provided on request, and the use of interviewers to assist in completion of the questionnaire if requested.
33 Reasons for the higher odds ratios in three of these articles compared with our study might be higher age of the study population, 33 restriction to stress urinary incontinence, 33 investigations 3 months postpartum 9, 11 and the use of interviewers.
In fact, Dillman and colleagues further suggest completing an interview over the telephone as a mechanism to increase response rates, albeit with increased implementation and completion costs due to the use of interviewers to administer the survey versus merely reminding prospective respondents to fill out the mailed form [ 5].
We have shown that training, the use of experienced interviewers, interview guides, supervision and educational meetings do not automatically prevent interviewer effects.
Data collection was through the use of an interviewer administered questionnaire.
Details of the non-fatal self-poisoning act, nature of substances ingested and socio-demographic details were assessed by the use of an interviewer administered questionnaire.
We acknowledge that the use of an interviewer may contribute a source of bias in our survey, although we sought to mitigate against this possibility by using experienced youth commissioners and training interviewers not to lead participants in their responses.
