Evaluation of patient-relevant outcomes of lymphedema and lipedema treatment: development and validation of a new benefit tool.
OBJECTIVE
Patient-relevant treatment benefit is traditionally measured with health-related quality of life (HRQoL) instruments. The Patient Benefit Index (PBI) methodology allows for a more direct measurement, with the patients rating both importance and achievement of treatment goals. Here, we developed and validated a PBI version specific for the assessment of benefit in lymphedema and lipedema treatment (PBI-L).


METHODS
The development included five steps: (1) open item collection; (2) consensus of items in a multidisciplinary expert panel; (3) application of the German PBI-L in a cross-sectional study (n = 301); (4) translation into English; (5) application of the English PBI-L in a randomized clinical trial (n = 82). Subscales were developed using factor analysis. Construct validity was analyzed by correlating PBI-L and convergent criteria such as HRQoL and quality of care. To test for responsiveness, the association to change in HRQoL measures was computed.


RESULTS
Floor and ceiling effects were low. There were few missing values. Two well-interpretable subscales were found with Cronbach's alpha >0.8 each. Global and subscale scores correlated with convergent criteria and with change in disease-specific HRQoL, but not with change in generic HRQoL.


CONCLUSIONS
The PBI-L is an internally consistent, valid, and responsive instrument for the assessment of patient-relevant benefit of edema treatment.
CVderm - German Center for Health Services Research in Dermatology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: c.blome@uke.de.
C
C
Blome
CVderm - German Center for Health Services Research in Dermatology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
M
M
Augustin
CVderm - German Center for Health Services Research in Dermatology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
K
K
Heyer
CVderm - German Center for Health Services Research in Dermatology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
J
J
Knöfel
Lymphtherapeutic Praxis, Hamburg, Germany.
H
H
Cornelsen
CVderm - German Center for Health Services Research in Dermatology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
S
S
Purwins
CVderm - German Center for Health Services Research in Dermatology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
K
K
Herberger
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D005060:Europe; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008209:Lymphedema / Q000175:diagnosis* / Q000523:psychology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011788:Quality of Life; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014175:Translating; D016896:Treatment Outcome; D014481:United States; D055815:Young Adult
Lipedema; Lymphedema; Patient benefit; Patient-reported outcomes; Quality of life; Validation