Swedish Council on Technology Assessment in Health Care (SBU). Chapter 12. Future need for research.

Despite the extensive consequences of sickness absence, scientific research is both surprisingly scarce and theoretically and conceptually underdeveloped. There are few longitudinal studies, and even fewer intervention studies. The medical aspects in sickness insurance are seldom addressed, effects of factors at different structural levels are not considered,and the consequences of sick leave have barely been studied. Furthermore, little is known about the employer's role and the layperson's perspectives. Gender and ethnicity factors should be considered further. The concept of work ability needs to be defined, problematized, and operationalized. However, it is not only more, but mainly it is studies of better quality that are needed, e.g. longitudinal studies, international comparative studies, and randomised controlled trials. This would require multidisciplinary research groups, long-term research environments, international commitment, opportunities for good professional development within the field, and reliable basic data, including sick-listing diagnoses.