Collecting high-quality survey data on hard-to-reach populations: lessons from Finland

Abstract

Abstract Issue Hard-to-reach populations refer to groups that may be difficult to involve in research. Minorities and persons with migration background (PMB) are often underrepresented in population-based surveys. This may lead to serious bias. Description of the problem: Several surveys on the health and wellbeing of hard-to-reach populations have been conducted in Finland since 2010. Strategies for collecting high-quality data have been identified in five surveys focused on specific migrant groups (Maamu n = 3000), the foreign-origin population (UTH n = 6000; FinMONIK n = 13650), newly-arrived asylum seekers (TERTTU n = 1087) and Finnish Roma (ROOSA n = 365). Also few routinely collected studies include indicators of ethnic background or origin (e.g. School Health Promotion study). Results Country of birth and foreign origin can be identified in Finland using register-based sampling. Snowball sampling was needed for the Roma population. Strategies to reach participants included information dissemination, translated questionnaires, multilingual personnel, telephone contacts and door-to-door visits. Stakeholders and participants were involved in planning and reporting. Participation rates as high as 70-80% were reached from register-based samples. Lessons: High-quality survey data can be collected on hard-to-reach populations. This requires adequate resources including multilingual personnel and researcher-participant trust. The cross-cultural validity of survey questions is critical; cognitive interviews can be used to improve cultural sensitivity. Researchers should be sensitive of sense of belonging, e.g. PMB may object being seen as “migrants”. Members of hard-to-reach populations should be involved in research, and not merely objects of a study. Main messages High participation rates can be achieved with adequate time, financial resources and established researcher-participant trust. Data collection should be inclusive and clearly benefit the individuals and populations in concern.