A multisource approach to health care use: concordance between register and self-reported physician visits in the foreign-born population in Finland.

backgroundReliable information on the use of health services is important for health care planning, monitoring and policy. It is critical to assess the validity of the sources used for this purpose, including register and survey-based data. Studies on foreign-born populations' health care use have usually implemented either survey or register data. The concordance of such data among groups of different cultural background remains largely unknown. In this study, we presented an approach to examine routinely how survey and register-related characteristics may explain disagreement found between the two information sources.

methodsWe linked register- and survey-based data pertaining to the Finnish Register of Primary Health Care general physician visits and the Survey on Well-Being among Foreign Born Population (FinMonik, 2018-2019), a nationally representative survey. The sample comprised n = 5,800 informants for whom registered general physician visits were tracked in the 12-month period preceding their participation in the survey. Cohen's kappa was used as measure of multisource concordance, hierarchical loglinear models for the association between single predictors and multisource discrepancy, and a logistic regression model for examining source-related predictors of source discrepancy. Survey weights were used in all sample analyses.

resultsSource concordance was poor. When dichotomizing general physician visits (zero vs one or more), 35% of informants had reported one or more visits while none were found from register. Both register- and informant-related predictors were associated to this discrepancy (i.e. catchment area, private health care use, inability to work, region of origin and reason for migration).

conclusionsWe found high discrepancy between the reported and the registered physician visits among the foreign-born population in Finland, with a particularly high number of reported physician visits when none were found in the register. There was a strong association between the specific catchment area and mismatch, indicating that both register under-coverage and survey over-report are plausible and may coexist behind the discrepancy. However, associations of informant's characteristics and mismatch were less pronounced. Implications on the validity of medical information sources are discussed.