Study title

Data collection was performed for 42 randomly selected days during the periods from 31/1 to 20/6 and 19/8 to 12/12 2005. The selection of interview days was stratified to achieve a balance between the different days of the week, which means that the interviews were conducted on 6 over the year distributed Mondays, Tuesdays, Wednesdays, etc. The sample consisted of a simple random sample of individuals of the Swedish population aged between 9 and 79 years. The sample was drawn from the population register and included 5860 persons living in Sweden. Non-response consisted of set of sampling units without a telephone number, wrong number, outside the target group and out of town during the whole period, etc.,and in the result a net sample of 5223 people was achieved. Of these, interviews were conducted with 3436 people. This means that the survey has a response rate of 70 percent. The proportion of pronounced refusals was 15 percent, while the remaining nonresponse is made up of those not reached, short-term sick, etc.

Probability: Stratified

Probability: Simple random