**3.1 Public health survey**

The public health survey was distributed in 2004 as a postal questionnaire in Skåne, the southernmost region of Sweden as well as the most productive agricultural region. The study population consisted of a total of 855,599 individuals. The population was stratified by gender and geographical area. Samples were randomly selected from the population registry. In total 50,000 questionnaires were sent out to individuals 18-80 years of age who had geocoded residential addresses. The participation rate was 59%. Survey questions posed to respondents included topics such as neighbourhood satisfaction, time spent on moderate physical activity per week, body mass index (BMI), self-rated physical and psychological health at present, and a 36-item short-form health survey item called "vitality". Neighbourhood satisfaction was measured in the survey by the question 'How much do you like the environment you live in?' Participants scored their level of satisfaction on a fourpoint ordinal scale with an additional 'don't know' option. For individuals using that answer, neighbourhood satisfaction was unknown and was therefore excluded in the analyses that use neighbourhood satisfaction as outcome vatiable. Blank answers to this question, or to any of the other questions that represent outcome variables (i.e. physical activity, length and weight used to calculate BMI and self-rated health), were also excluded in corresponding analyses and for the same reason (Björk et al., 2008).

The questionnaire was not pretested for clarity, but parts of the survey had been used in the year 2000 in the same region. A steering committee, with representatives from the county, municipalities and the research community, drafted the survey questions carefully before launching the questionnaire. Validated questions were used when available.
