Measuring impact of environmental factors on human functioning and disability: a review of various scientific approaches

Purpose. The objective of this paper is to present a framework for systematically describing different approaches to measure environmental factors (EF) and to discuss some strengths and weaknesses of these approaches. Methods. Identification of suitable criteria for ordering measurements of EF was based on an analysis of existing reviews, a qualitative literature review and feedback from experts. Items of selected EF measures were linked to the International Classification of Functioning, Disability and Health. Results. Experimental and observational designs for the study of EF are distinguished and illustrated with examples. Approaches to study EF are differentiated into those directly measuring an environmental interaction with function and those relying on an independent assessment of environmental features. By applying these criteria, a three-dimensional matrix framework for measurement of EF in observational studies is developed. Conclusion. The acknowledgement of different measurement approaches to the scientific study of EF is one pathway towards an increased understanding of the connection between environments and functioning. Many different measures may be used to approximate the realities of disabling or enabling environments. This review provides an initial framework for improving our fundamental comprehension of the complexity of the measurement of EF in the context of human health and disability.