Prognostic factors for musculoskeletal injury identified through medical screening and training load monitoring in professional football (soccer): a systematic review Tom Hughes 1,2, Jamie. C. Sergeant 2,3, Matthew Parkes2, Michael. J. Callaghan 1,2,4,5 1Manchester United Football Club 2Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, The University of Manchester 3NIHR Manchester Musculoskeletal Biomedical Research Unit, 4Central Manchester University Hospitals NHS Foundation Trust 5Department of Health Professions, Manchester Metropolitan University 1. Background 4. Results cont.. The terms risk factors, predictive factors, predictors and prognostic factors are synonymous. For this review the term prognostic factors was used. Prognostic factors = variables associated with or predictive of clinical events in populations with defined baseline state In professional football, the risk of sustaining a lower extremity musculoskeletal injury is considerable Medical screening and training load monitoring processes are commonly used to identify prognostic factors for injury and develop preventative strategies to reduce perceived risk 49 Prognostic factors for 16 injury outcomes identified; the majority obtained through single studies Where prognostic factors and outcomes were investigated by more than one study this is presented in forest plots below: Prognostic factors for hamstring injuries in male participants, investigated by two or more studies- hazard ratio analyses 2. Objectives To identify prognostic factors and models for spinal and lower extremity injuries in adult professional/elite football players from medical screening and training load monitoring processes 3. Methods For every one-year age increase, there was an associated small increase in hazard 48 with a narrow confidence interval on the border of significance. A later study49 demonstrated no association. Previous hamstring injury was significantly associated with increased hazard of further hamstring injuries. Hagglund et al 48 demonstrated a greater association with larger confidence intervals, possibly due to the smaller sample size. Inclusion criteria: Prospective/retrospective cohort studies Participants defined as professional/elite players 16-40 years old Must present measures of association e.g. OR, RR, HR Studies investigating the following as prognostic factors/models: 1)general medical examination, 2)MSK examination, screening technique or physical performance test, 3) training load measurement Data sources: MEDLINE, AMED, EMBASE, CINAHL Plus, SPORTDiscus electronic bibliographic databases and the Cochrane Database of Systematic Reviews were searched from inception to July 2016 (limited to original research, published in peer reviewed journals of any language) Appraisal tool: Quality in Prognostic Studies (QUIPS) tool Synthesis: modified Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework Prognostic factors for hamstring, ankle sprain and knee sprain injuries, investigated by two or more studies- odds ratio analyses 4. Results Two studies stated odds ratios for previous hamstring injury.43 46 There was no agreement; point estimates lay either side of the line of no effect with wide confidence intervals, suggestive of a lack of precision Previous ankle sprains and new ankle sprains, and previous knee sprain and new knee sprains had significant associations in the male study,43 while non-significant increased associations were demonstrated in the female study. We could not ascertain whether these inconsistencies in results were due to gender, methodological quality or statistical power Results: 858 manuscripts were identified. Removing duplications left 551 studies but 531 studies were ineligible and were excluded. The full text of the remaining 20 studies were obtained; a further 10 studies were excluded. 10 studies were included for appraisal and analysis, for 3344 participants. No studies were identified that examined spinal injury outcomes or prognostic models. Critical appraisal: 5. Conclusions Heterogeneity and shortcomings in methodology and reporting The evidence is of very low or low quality Previous hamstring injury may be associated with increased hazard of further hamstring injury in male players but this must be interpreted with caution Evidence cannot be deemed robust enough to suggest conclusive prognostic factors for all lower limb musculoskeletal injury outcomes identified 6.References 42. van Dyk et al. Am J Sports Med 2016;44(7):1789-95. 43. Arnason et al. Am J Sports Med 2004;32(1 Suppl):5S-16S. 44. Bengtsson et al. Br J Sports Med 2013;47(12):743-7. 45. Faude et al. Br J Sports Med 2006;40(9):785-90. 46. Fousekis et al. Br J Sports Med 2011;45(9):709-14. 47. Fousekis et al Am J Sports Med 2012;40(8):1842-50. 48. Hägglund et al. Br J Sports Med 2006;40(9):767-72. 49. Hägglund et al. Am J Sports Med 2013;41(2):327-35. 50. Nilstad et al. Am J Sports Med 2014;42(4):940-48. 51. Walden et al.Br J Sports Med 2006;40(2):158-62. This report includes independent research supported by the National Institute for Health Research Biomedical Research Unit. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health. We thank Arthritis Research UK Centre for Epidemiology for their support.