Acta Dermato-Venereologica 99-2CompleteContent | Page 19

INVESTIGATIVE REPORT Measuring Patient Needs and Benefits in Dermatology using the Patient Benefit Index 2.0: A Validation Study Janine TOPP 1 , Matthias AUGUSTIN 1 , Kathrin VON USSLAR 1 , Ramona GOSAU 1 , Kristian REICH 2 , Michael REUSCH 3 and Christine BLOME 1 1 German Center for Health Services Research in Dermatology (CVderm), Institute for Health Services Research in Dermatology and Nursing (IVDP), University Medical Center Hamburg-Eppendorf (UKE), 2 Dermatologikum Berlin and SCIderm Research Institute, and 3 Dermatological Practice Tibarg, Hamburg, Germany This study investigated the validity and feasibility of the Patient Benefit Index 2.0 (PBI 2.0), a short in- strument to assess patient-relevant treatment bene- fit. In a cross-sectional study, patients with skin di- seases completed the PBI 2.0 alongside instruments on quality of life and disease-specific PBI long versions to assess convergent validity. Feasibility questions appraise comprehensibility, completeness, length, and readability. Data from a longitudinal study were used to explore responsiveness and test-retest reliability. Most patients rated the PBI 2.0 easy to understand, complete, legible, and not too long. The amount of missing values was overall low. In all groups, except for vitiligo, correlation analyses indicated good con- vergent validity of PBI 2.0. Responsiveness of the PBI 2.0 could not be clearly confirmed. Retest-reliability achieved satisfactory results. Thus, the PBI 2.0 may be a suitable instrument for its use in different skin di- seases. Its broad applicability allows for comparisons across diagnosis groups. Key words: patient-relevant benefit; patient-reported outco- mes; validation; skin diseases. Accepted Oct 11, 2018; E-published Oct 11, 2018 Acta Derm Venereol 2019; 99: 211–217. 211 Corr: Janine Topp, German Center for Health Services Research in Dermatology, Institute for Health Services Research in Der- matology and Nursing, University Medical Center Hamburg- Eppendorf, Martinistr. 52, DE-20246 Hamburg, Germany. E-mail: [email protected] P atients and healthcare professionals assess patients’ health state differently, and assessment results often do not coincide (1–3). Therefore, in order to evaluate treatment benefit comprehensively, the evaluation of the patients’ perspective should complement objective measures and outcomes. This demand for patient-relevant benefit assessment is increasingly recognized in clinical encounters as well as in research. Very commonly, patient-relevant benefit is determined using questionnaires on health-related quality of life (HRQoL), asking patients to rate their impairments due to the disease before and after treatment. A change in HRQoL is interpreted as patient-relevant treatment benefit. This prospective approach, however, is susceptible to recalibra- tion response shift (4), a bias due to changes in the patients’ interpretation of the questionnaire and its response scale SIGNIFICANCE Considering the patients’ perspective in clinical decision- making is a major goal in healthcare. To assess the patient perspective, valid and reliable instruments on individual needs and treatment benefits are needed. In the dermato- logical setting, the Patient Benefit Index (PBI) can be used to evaluate patient-relevant treatment benefit. This study analyses and confirms the reliability, feasibility and validity of a short version of the PBI, the PBI 2.0, which is applicable for patients with different skin diseases. The brevity of the instrument may foster its implementation in clinical practice. (5, 6). This bias is present only in repeated measurements, assessing changes over time. It is not present in retrospec- tive benefit assessment, taking place after treatment only. While potentially being susceptible to recall bias (6), the retrospective assessment has the advantage of measuring benefit close to the actual perception of the patient. This di- rect rating of benefit by the patient is crucial when assessing treatment satisfaction and estimating treatment adherence (7). Such retrospective approach is taken by the questionn- aire Patient Benefit Index (PBI). Furthermore, the PBI has the advantage that, in addition to a benefit assessment, it assesses the importance the individual patient assigns to different treatment benefits and therefore enables the cal- culation of an importance-weighted global benefit score. The PBI is based on earlier approaches to individualized benefit measurement. One of these approaches is the goal attainment scaling (8), which comprises the formulation of individualized treatment goals with each patient. Another approach is the goal-oriented outcome measurement (9), which includes the determination of individual patient- relevant treatment goals in the field of rehabilitation. The PBI consists of 2 parts: in the first part, patients rate the perceived importance of different treatment goals listed in the Patient Needs Questionnaire (PNQ). In the second part, the Patient Benefit Questionnaire (PBQ), patients rate the achievement of these treatment goals. Usually, the PNQ is completed before starting a new treatment, and the PBQ at a time when an effect of the treatment is expected and treatment benefit will be assessed (10). Thus far, a range of different PBI instruments have been developed and validated for various skin diseases. A short version of the PBI, the PBI 2.0, has been developed based This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3063 Acta Derm Venereol 2019; 99: 211–217