Agreement between Proxy and Patient Reports of HRQoL using the EQ-5D: The interaction effect of perspective, timing and patient cognition Steven McPhail,2 Elaine Beller,2 Terry Haines,2 The University of Queensland 2 Princess Alexandra Hospital Health-Related Quality of Life Domains of Health + Influences Physical Psychological Social Experiences Expectations Perceptions Environment
Measuring HRQoL Usually measured via patient self-report Generic instruments Disease specific instruments Problematic in some populations Poor cognition Communication difficulty Proxy reporting proposed as an alternative to self-report where a valid self-report is not viable Proxy reporting Various investigations of agreement Mixed results -5 Two perspectives of Proxy reports are possible 6 Proxy-patient Proxy responds as they believe patient would Proxy-proxy Proxy s responds with own perspective Most prior investigations not clear which, if any consistent perspective has been used by proxies No previous investigations of both perspectives
Three things considered Perspective proxy-proxy versus proxy-patient Timing (exposure to patient) Admission assessment versus discharge assessment Basic cognition Intact (MMSE>23) versus not intact (MMSE <23) Method Design: Prospective cohort investigations of inter-rater agreement Participants and Settings: Patients admitted to the Geriatric Assessment and Rehabilitation Unit Their treating physiotherapist Outcome Measure EQ-5D
Procedure Perspective A (Proxy-Patient) Patients admitted to rehabilitation unit July January Both Proxy Types (A & B) January Perspective B (Proxy-Proxy) Patients admitted to rehabilitation unit January June Admission Assessment Proxy-Patient & Patient Self Report Total pairs n = 69 Patients in both A & B n=3 Proxy-Proxy & Patient Self Report Total pairs n = 33 Discharge assessment not complete Total n = 22 Usual care during admission Usual care during admission Discharge Assessment Proxy-Patient & Patient Self Report Total pairs n = 5 Patients in both A & B n=3 Proxy-Proxy & Patient Self Report Total pairs n = 3 Data Analysis 5 complete datasets with proxy reports from Perspective A 3 complete datasets with proxy reports from Perspective B Results Complete datasets Proxy-patient = 5 (proxies n= 23) Proxy-proxy = 3 (proxies n= 2) 22 Incomplete datasets unexpected transfer/discharge from ward (8) patient self discharged against medical advice without reassessment (6), death before discharge assessment (5), patient refused assessment (2), English translator not available ()
Results - Demographics Proxy-Patient (Perspective-A) n=5 Proxy-Proxy (Perspective-B) n=3 Median Age (IQR) 79 (69-85) 77 (67-84) Median Length of stay (IQR) 42 (3-69) 4 (22-67) Basic cognition group median MMSE (IQR) Intact group (MMSE >23) Not Intact group (MMSE <23) 28 (27-3) n=99 2 (6-22) n=5 28 (26-3) n=78 2 (6-22) n=52 Both groups combined 27 (2-3) 25 (2-29) Agreement (kappa) Basic Cognition Mobility kappa (95%CI) Personal Care kappa (95%CI) Usual Activities kappa (95%CI) Pain / Discomfort kappa (95%CI) Anxiety / Depression kappa (95%CI) Intact.86.78.75.7.75 n=99 (.73,.95) (.66,.87) (.62,.86) (.57,.8) (.62,.86) Proxy Patient (Phase-A) Admission Discharge Not intact n=5 Combined n=5 Intact n=99 Not intact n=5.53 (.26,.78).75 (.63,.86).9 (.8,.98).84 (.7,.).52 (.33,.7).69 (.58,.78).85 (.73,.94).84 (.68,.96).76 (.56,.9).76 (.65,.85).78 (.65,.89).88 (.76,.97).6 (.4,.77).66 (.55,.76).93 (.85,.98).95 (.82,.).47 (.24,.68).65 (.54,.76).76 (.56,.9).78 (.55,.95) Combined.89.85.83.93.77 n=5 (.8,.95) (.76,.92) (.74,.9) (.87,.98) (.63,.88) Intact n=78.76 (.57,.9).55 (.36,.72).57 (.4,.74).8 (.67,.92).62 (.44,.77) Proxy Proxy (Phase-B) Admission Discharge Not intact n=52 Combined n= 3 Intact n=78 Not intact n=52 Combined n= 3.4 (.9,.6).59 (.45,.72).77 (.62,.9).42 (.26,.63).62 (.5,.74).23 (.8,.4).39 (.26,.52).68 (.49,.85).29 (.4,.49).5 (.38,.63).32 (.5,.5).45 (.33,.57).67 (.49,.82).3 (.5,.5).49 (.37,.6).6 (.42,.77).72 (.6,.8).72 (.57,.86).8 (.62,.97).76 (.64,.86).52 (.29,.72).58 (.43,.7).95.82,.).67 (.44,.87).8 (.68,.92)
Domain Kappa scores Admission Discharge Proxy Patient Kappa.75.5.25.75.5.25 Mobility Personal Care Usual Activities Proxy Proxy Kappa.75.5.25 < 2 2-23 24-27 28-3.75.5.25 < 2 2-23 24-27 28-3 Pain Discomfort Anxiety Depression Cognition (MMSE) Group Cognition (MMSE) Group Proxy-Patient Poor Cognition Admission.8.6.4.2 -.2 -.4 95% CI -.6 -.8 - - -.8 -.6 -.4 -.2.2.4.6.8
Proxy-Patient Poor Cognition Discharge.8.6.4.2 -.2 -.4 -.6 -.8 - - -.8 -.6 -.4 -.2.2.4.6.8 Proxy-Patient Good Cognition Admission.8.6.4.2 -.2 -.4 -.6 -.8 - - -.8 -.6 -.4 -.2.2.4.6.8
.8.6.4.2 -.2 -.4 Proxy-Patient Good Cognition Discharge -.6 -.8 - - -.8 -.6 -.4 -.2.2.4.6.8 Proxy-Proxy Poor Cognition Admission.8.6.4.2 -.2 -.4 -.6 -.8 95% CI Difference not - - -.8 -.6 -.4 -.2.2.4.6.8
Proxy-Proxy Poor Cognition Discharge.8.6.4.2 -.2 -.4 -.6 -.8 - - -.8 -.6 -.4 -.2.2.4.6.8 Proxy-Proxy Good Cognition Admission.8.6.4.2 -.2 -.4 -.6 -.8 - - -.8 -.6 -.4 -.2.2.4.6.8
Proxy-Proxy Good Cognition Discharge.8.6.4.2 -.2 -.4 -.6 -.8 - - -.8 -.6 -.4 -.2.2.4.6.8 Discussion Generally kappa values were quite high compared with previous investigations Interaction of all three factors under consideration Perspective Cognition Timing Necessary to consider perspective when using proxy reports Important to clearly instruct proxy reporters Describe which perspective used Which perspective?proxy-proxy for poor cognition No gold standard!
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