How many days did you have this back pain during the last 30 days?
This question is only asked to respondents who reported experiencing back pain during the last 30 days. The intention is to distinguish a back pain caused by a mild temporary problem, such as muscle strain, from a more serious problem related to the disease of spine and the spine joints. Record the number of days (to a maximum of 30 days) as mentioned. The answer does not need to ascertain the exact amount of time (for example, if the respondent says they had back pain for about two weeks, record "14" days).