This was the first study to formally evaluate questionnaire length and prenotification in a full factorial design using multiple indicators of survey quality (i.e., response rates, time to respond, and item missing data totals).
It is considered as an indicator of quality survey estimates, by presuming that a high response rate is associated with a more representative sample and hence with lower bias[ 10].
Demographic indicators of safety survey respondents (gender, over 65 years of age, and of non-Swedish origin) were compared with official USK statistics at the parish level, which showed the survey population to be sufficiently representative of Stockholm Municipality as a whole.
Participation rates and non-response bias are two crucial indicators of the survey quality [ 4].
Provincial variables were based on the e-provincial indicators of the survey conducted by Statistics Korea by year, as follows: resident population, gross provincial domestic product (GRDP), crude divorce rate, and married couple [ 17].
Despite the aim of spatial parity, the recent 2009 Multiple Indicator Cluster Survey of the Bangladesh Bureau of Statistics, the national statistical organisation of the government, shows large disparities between districts in education, child health, maternal health, access to safe drinking water and improved sanitation (1).
However, comparing the multiple indicator cluster survey of 2001 with that of 2008, it can be seen that deliveries with skilled birth attendants had risen significantly at district and provincial level by the time of the introduction of the project, from 14%to40.5%5% in Battagram and from 28%to41%1% in the province as a whole.
This study, however, did not examine the validity of survey indicators.
