The aim of this thesis was to investigate if the outcome of rehabilitation efforts is depending on what view health care has in relation to what need of care people have and if the outcome for different groups of patients with low-back complaints (specific versus non-specific complaints) is various successful. The outcome is measured in length of sick leave, number of spells and granted sickness and disability pensions. This thesis combines a theoretical analysis of different theories of health with studies of two empirical materials. One material comprises a group of individuals with low-back complaints (specific versus non-specific complaints) from a nation-wide survey of Living Conditions conducted by Statistics Sweden in 1981. The other material comprises a sample of individuals on sick leave either due to low-back complaints or other kinds of complaints than low-back complaints. The outcome of these studies are measured as to what extent people with low-back complaints are granted a disability pension (Study I) and which the characteristics are of those on sick leave due to low-back complaints compared to those with other kinds of complaints (Study II).