Cultural dissimilarities in general practice: development and validation of a patient's cultural background scale.

Due to increased migration physicians encounter more communication difficulties due to poor language proficiency and different culturally defined views about illness. This study aimed to develop and validate a 'patient's cultural background scale' in order to classify patients based on culturally conditioned norms instead of on ethnicity. A total of 986 patients from 38 multi-ethnic general practices were included. From a list of 36 questions, non-contributing and non-consistent questions were deleted and from the remaining questions the scale was constructed by principal component analysis. Comparing the scale with two other methods of construction assessed internal validity. Comparing the found dimensions with known dimensions from literature assessed the construct validity. Criterion validity was determined by comparing the patient's score with criteria assumed or known to have relationship with cultural background. Criterion validity was reasonably good but poor for income. A valid patient's cultural background scale was developed, for use in large-scale quantitative studies.