Although this study was not sufficiently powered to look at the different treatment conditions, it may be the case that stereotype confirmation concerns are more relevant for group treatment than for individual treatment.
Our rationale is that provider costs are the most relevant measure for groups considering adopting the study interventions.
We also believe that the grouping performed by us is more relevant for immigrant groups in the Nordic countries and Northern Europe.
Although group-level associations are informative and relevant for planning group-level interventions, associations with group-level characteristics cannot be assumed to represent associations with the same characteristics defined at individual level.
Again, at least to some degree, this seems to be balanced by policy issues specifically relevant for these groups in which they participate to a larger degree.
Minority classes may correspond to specific information needs which are relevant for specific groups of users.
De Vries et al. [ 64] noted that this genomics-related concern could be relevant for ethnic groups in Africa for which stigmatisation and discrimination is already present.
We found no systematic difference in data quality after stratification by each of the variables relevant for both groups for intent of treatment (data not shown).
The context of Canadians accessing CCSVI treatment is unique, but these lessons are also relevant for other groups accessing unproven interventions abroad.
This could be especially relevant for patient groups that are hard to reach in surveys 20 and might be most relevant in large and resource intensive national indicator systems as in Norway.
