title: The DAMASK trial protocol: a pragmatic randomised trial to evaluate whether GPs should have direct access to MRI for patients with suspected internal derangement of the knee.
abstract: BACKGROUND
  Though new technologies like Magnetic Resonance Imaging (MRI) may be accurate, they often diffuse into practice before thorough assessment of their value in diagnosis and management, and of their effects on patient outcome and costs. MRI of the knee is a common investigation despite concern that it is not always appropriate. There is wide variation in general practitioners (GPs) access to, and use of MRI, and in the associated costs. The objective of this study was to resolve uncertainty whether GPs should refer patients with suspected internal derangement of the knee for MRI or to an orthopaedic specialist in secondary care.
  
  
  METHODS
  The design consisted of a pragmatic multi-centre randomised trial with two parallel groups and concomitant economic evaluation. Patients presenting in general practice with suspected internal derangement of the knee and for whom their GP was considering referral to an orthopaedic specialist in secondary care were eligible for inclusion. Within practices, GPs or practice nurses randomised eligible and consenting participants to the local radiology department for an MRI examination, or for consultation with an orthopaedic specialist. To ensure that the waiting time from GP consultation to orthopaedic appointment was similar for both trial arms, GPs made a provisional referral to orthopaedics when requesting the MRI examination. Thus we evaluated the more appropriate sequence of events independent of variations in waiting times. Follow up of participants was by postal questionnaires at six, twelve and 24 months after randomisation. This was to ensure that the evaluation covered all events up to and including arthroscopy.
  
  
  CONCLUSIONS
  The DAMASK trial should make a major contribution to the development of evidence-based partnerships between primary and secondary care professionals and inform the debate when MRI should enter the diagnostic pathway.
authors.affiliation: Department of Health Sciences, York Trials Unit, Seebohm Rowntree Building, University of York, Heslington, York YO10 5DD, UK. sb143@york.ac.uk
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Brealey
authors.forename: Christine
authors.initials: C
authors.lastname: Atwell
authors.forename: Stirling
authors.initials: S
authors.lastname: Bryan
authors.forename: Simon
authors.initials: S
authors.lastname: Coulton
authors.forename: Helen
authors.initials: H
authors.lastname: Cox
authors.forename: Ben
authors.initials: B
authors.lastname: Cross
authors.forename: Fiona
authors.initials: F
authors.lastname: Fylan
authors.forename: Andrew
authors.initials: A
authors.lastname: Garratt
authors.forename: Fiona J
authors.initials: FJ
authors.lastname: Gilbert
authors.forename: Maureen G C
authors.initials: MG
authors.lastname: Gillan
authors.forename: Maggie
authors.initials: M
authors.lastname: Hendry
authors.forename: Kerenza
authors.initials: K
authors.lastname: Hood
authors.forename: Helen
authors.initials: H
authors.lastname: Houston
authors.forename: David
authors.initials: D
authors.lastname: King
authors.forename: Veronica
authors.initials: V
authors.lastname: Morton
authors.forename: Jo
authors.initials: J
authors.lastname: Orchard
authors.forename: Michael
authors.initials: M
authors.lastname: Robling
authors.forename: Ian T
authors.initials: IT
authors.lastname: Russell
authors.forename: David
authors.initials: D
authors.lastname: Torgerson
authors.forename: Valerie
authors.initials: V
authors.lastname: Wadsworth
authors.forename: Clare
authors.initials: C
authors.lastname: Wilkinson
mesh_terms: D000293:Adolescent; D000328:Adult; D002983:Clinical Competence; D002985:Clinical Protocols; D016001:Confidence Intervals; D005194:Family Practice / Q000193:education / Q000592:standards*; D005260:Female; D006297:Health Services Accessibility / Q000458:organization & administration*; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009985:Orthopedics; D026761:Physical Therapy Specialty; D016059:Range of Motion, Articular; D012017:Referral and Consultation / Q000458:organization & administration*; D012107:Research Design; D012307:Risk Factors; D006113:United Kingdom