Table 1

Characteristics of included studies reporting MIDs for knee symptoms and health-related quality of life

StudyDisease/conditionInterventionInstrument/scale (abbreviated name)Score rangeConstruct(s) measuredAnchor
Angst et al 200222Knee/hip OAComprehensive rehabilitation interventionWOMAC0 to 100*Pain, function, stiffnessGROC (5-point)
Bellamy et al 201523Knee/hip OANSAIDsWOMAC0 to 100*Pain, function, stiffnessGROC 2-step approach (4-point)
Browne et al 201024NRTKAEQ-5D−0.4 to 1HRQoLGROC (5-point)
Escobar et al 200725Knee OATKAWOMAC0 to 100*Pain, function, stiffnessGROC (5-point)
SF-360 to 100HRQoL
Escobar et al 2013/201418 20Knee OATKAWOMAC†0 to 100Pain, FunctionTransition rating for pain and function (5-point)
Ornetti et al 201126Knee OANSAIDsWOMAC0 to 100*FunctionGROC (4-point)
Mills et al 201614Knee OAOsteoarthritis chronic care programme‡KOOS0 to 100Pain, ADL, HRQoL2 anchors: walking and knee health (7-point)
Monticone et al 201327Knee OARehabilitation following TKAKOOS§0 to 100Pain, symptoms, ADL, sport/rec, HRQoLGROC (5-point)
Terwee et al 200928Knee/hip OATKAWOMAC¶0 to 20*0 to 68*Pain
Transition rating for pain and function (15-point)
Terwee et al 201029aPatients who reported knee pain in the past 12 monthsaUsual careWOMAC0 to 100Pain, functionTransition rating for pain (6-point)
bPatients who visited their GP with a new episode of non-traumatic knee symptomsbUsual careWOMAC0 to 100Pain, functionTransition rating for knee symptoms (6-point)
cPatients who visited their GP with a new episode of knee symptomscUsual careWOMAC0 to 100Pain, functionTransition rating for knee symptoms (5-point)
dKnee OAdBehavioural-graded activity or usual careWOMAC0 to 100Pain, functionTransition rating for knee symptoms (8-point)
eKnee OAeTKAWOMAC0 to 100Pain, functionTransition rating for pain and function (15-point)
Tubach et al 2005/200619 21Knee OANSAIDsVAS pain0 to 100*PainResponse to treatment (5-point)
WOMAC0 to 100*Function
Tubach et al 201230Knee and/or hip OANSAIDsPain NRS0 to 10*PainGROC 2-step approach (4-point)
Walters et al 200531Patients with knee OA recruited from rheumatology clinics and those assessed preoperatively for TKANREQ-5D−0.59 to 1HRQoLGROC (5-point)
  • Bold text were those that provided credible MIDs (those with a correlation of 0.4 or greater between change in the index instrument and the global rating of change).

  • a–eTerwee et al29 reported on five cohorts of patients from different studies. a=cohort 1; b=cohort 2; c=cohort 3; d=cohort 4; e=cohort 5.

  • *Higher scores on the PRO scale represent a worse outcome.

  • ‡Surgical therapy: debridement, shaving, drilling, autologous chondrocyte implantation, abrasion arthroplasty, microfracture and cell therapy.

  • ‡Osteoarthritis chronic care programme: multidisciplinary non-surgical management strategy.

  • ¶Dutch.

  • §Italian.

  • †Spanish.

  • ADL, activities of daily living; EQ-5D, EuroQol five dimensions Questionnaire; GP, general practitioner; GROC, global rating of change; HRQoL, health-related quality of life; KOOS, Knee injury and Osteoarthritis Outcome Score; MID, minimal important difference; NR, not reported; NRS, Numeric Rating Scale; NSAID, non-steroidal anti-inflammatory drugs; OA, osteoarthritis; OKS, Oxford Knee Score; PRO, patient-reported outcome; SF-36, 36-Item Short Form Survey; TKA, total knee arthroplasty; VAS, visual analogue scale; WOMAC, Western Ontario and McMaster University Osteoarthritis Index.