Complaints of the arm, neck or shoulder (CANS) are frequently reported musculoskeletal conditions. To gain insight in prognostic factors of CANS that are related to recovery, a systematic review was conducted. Included are longitudinal prognostic cohort studies which investigated associations between prognostic factors and recovery in terms of symptoms, disability or sickness absence. Twenty six papers reporting on 20 cohorts were included following a search of electronic databases (Pubmed, Embase, Cinahl and Psychinfo). The risk of bias (ROB) was independently assessed by two reviewers using the Quality In Prognosis Studies (QUIPS tool). Sixteen studies were assessed as having ‘low’ ROB, and ten studies were assessed as having ‘high’ ROB. Because of heterogeneity in included studies, pooling was not possible. In the qualitative analysis, the number of studies that evaluated a factor, the ROB of each cohort, and consistency of available evidence were taken into account when summarizing the evidence. The question of whether follow-up duration altered the association of prognostic factors with recovery was investigated. The results of our best-evidence synthesis showed that for short term follow-up (<6 months) longer duration of complaints, higher symptom severity, more functional limitations, the use of specific coping styles, and accident as 'patients opinion regarding cause' were negatively associated with recovery.
For long term follow-up, this review found that longer duration of complaints at presentation had an unfavorable prognostic value for recovery. The evidence synthesis uncovered strong evidence for no prognostic impact of many factors which are suggested to be associated with recovery according to the primary studies.