Some costs and challenges of conducting follow‐up studies of substance use in remote Aboriginal communities: an example from the Northern Territory

The objective of this study was to describe some costs and challenges for conducting follow‐up interviews about substance use in Indigenous groups in northern Australia. In a remote region in the Northern Territory in 2001, 131 Indigenous people (aged 13–36 years) were approached for interview regarding their substance use. Of these, 108 (54 males, 54 females) were interviewed successfully. Follow‐up interviews were attempted in 2004. Study records traced progress and costs. In 2001, the response rate was 82% (108/131). In 2004, 22 participants could not be found after four attempts although they were known by health workers to still reside in the region. Fifteen were not residing in the region during 2004 and were lost to follow‐up, four were in prison and three were deceased. Fourteen contacted either refused directly (n = 1) or repeatedly postponed interview (n = 13). Fifty follow‐up interviews were completed, a response rate of 78% among 64 participants contacted. The overall response rate in those approached was 64% (0.82 * 0.78). Costs for 108 interviews were 45 person‐days and $A19 000 (32% = travel/associated costs). Costs for 50 follow‐up interviews were 60 person‐days and $A25 500 (39% = travel/associated costs). Such follow‐up studies in these settings could be complemented by retrospective case‐control approaches and by using proxy respondents to increase study efficiency.