chronic non-specific low back pain is assumed to be a multi-factorial affliction, implying that a number of different risk factors contribute to its development and persistence. after onset, prognostic factors can potentially predict the future course. risk factors for the development of chronic pain (i.e. transition from acute to chronic pain) are well documented in the literature. however, when pain becomes persistent, less knowledge is available on the risk factors for future outcome. increased knowledge on the prognostic factors for chronic complaints will allow to better inform and advise patients, by supporting clinical decisions about the type of treatment and identifying patients at risk of a poor outcome. the objective of this thesis was to describe the clinical course of chronic non-specific low back pain in patients referred to a rehabilitation centre in tertiary care, to identify prognostic factors for recovery, and to analyse the influence of various outcomes and statistical techniques on the development of a prognostic model. this study included 1,760 patients with chronic non-specific low back which completed a 2-month multidisciplinary treatment and were followed up at 5- and 12-months. in summary, the clinical course of patients with chronic non-specific low back pain who did not recover during primary and secondary care seemed to improve after a rehabilitation program, with success rates up to 60% at 12-months follow-up depending on the definition of recovery. younger age, being female, being married or living with one adult, lower pain intensity and disabilities, higher quality of life (physical and mental) and a higher work participation increased the change for recovery. karin verkerk is senior lecturer and researcher at the department of health care of the rotterdam university of applied sciences.