Table 1.

Methods used to select individuals of refugee background

Population selection method	Examples of studies that used the method	Strengths of method	Weaknesses of method
Linked data systems	Norredam, Garcia-Lopez, Keiding et al. 2009 [8]	• Uses a precise definition to accurately select individuals who have humanitarian residence permits.	• Use of the authority definition may misclassify individuals who have a refugee background but a non-humanitarian residence permit.
	Hollander, Bruce, Burstrom et al. 2011 [5]
		• Can be used to select asylum seekers and/or refugees as separate groups.
			• Not available in all countries or datasets so can be difficult to reproduce the method.
		• Facilitates simple results interpretation as the reader can be confident the sample is made up of individuals with a refugee background.
			• May be difficulties comparing to countries that have different migration systems or authority definitions.
Datasets from specialized health services	Johnston, Smith & Roydhouse 2011 [10]	• Uses a precise definition to accurately select individuals who have humanitarian residence permits.	• Excludes individuals who have a refugee background but a non-humanitarian residence permit.
	Martin & Mak 2006 [11]	• Can be used to select asylum seekers and/or refugees as separate groups.	• Some to individuals of refugee background may not access specialized refugee health services, thus findings may not generalizable to whole refugee population.
		• Facilitates simple results interpretation as the reader can be confident the sample is made up of individuals with a refugee background.
			• Residence permit type not commonly collected so can be difficult to reproduce the method using non-specialized datasets.
			• May be difficulties comparing to countries that have different migration systems or authority definitions.
COB alone as proxy for refugee background	Correa-Velez, Sundararajan, Brown et al. 2007 [19]	• Commonly collected by routine health datasets and therefore an easily reproducible method.	• Accuracy of selecting individuals of refugee background relies on an estimate of what proportion of individuals from each country of birth would be expected to be refugees.
	Correa-Velez & Ryan 2011 [24]
		• Can be used to compare findings from countries that have different migration systems or authority definitions.
			• Cannot be used to specifically select asylum seekers.
			• Not always enough information given to be confident the sample is primarily made up of individuals with a refugee background.