S. Al Sawah

Patient-reported fatigue and its impact on patients with systemic lupus erythematosus

Fatigue is a hallmark symptom of systemic lupus erythematosus (SLE), often associated with flares, side effects of treatment, and extensive organ damage and may have a significant impact on health-related quality of life (HrQoL). To date, the experience of fatigue in patients with SLE is underexplored. This study explored the experience of fatigue in patients with SLE and its impact on their lives through qualitative interviews. This cross-sectional qualitative study was conducted with 22 adult patients with SLE, recruited from two clinical sites in the United States. In-person semi-structured interviews were conducted and thematic analysis was performed focusing on the experience of fatigue in SLE. Results indicated that 21 out of 22 patients experienced fatigue due to SLE. Patients reported that fatigue was variable in nature in terms of both severity and frequency. Fatigue was described as having an impact on multiple aspects of a patient’s life: emotions, cognition, work, activities of daily living, leisure activities, social activities, and family activities. Understanding how patients with SLE describe the symptom of fatigue and how it impacts their lives is the key to better understanding how to measure fatigue in clinical studies evaluating new treatments for SLE.

Psychometric validation of the Brief Pain Inventory-Short Form in patients with systemic lupus erythematosus in the United States:

This study evaluated the Brief Pain Inventory-Short Form (BPI-SF) in patients with moderate-to-severe systemic lupus erythematosus (SLE). Patients ≥18 years old who self-reported a physician diagnosis of SLE (confirmed by medical record review) and active SLE (Systemic Lupus Activity Questionnaire (SLAQ) score of ≥11) were included. The BPI-SF and Short Form Health Survey version 2 (SF-36v2) were administered electronically at baseline, week 2 and week 12. Psychometric properties of the BPI-SF were evaluated. Cronbach alphas were >0.9 for all BPI-SF items, domains and total score. Test-retest reliability correlations for responses between baseline and week 2 of the BPI-SF had intraclass correlation coefficients (ICCs) ≥0.5. The BPI-SF domains and total score were moderately positively correlated to the SLAQ score (r ≥ 0.4), but negatively correlated to the SF-36v2 bodily pain domain (r ≤ –0.6). The BPI-SF domains and total score were moderately negatively correlated to the SF-36v2 physical functioning domain and physical component summary (r ≤ –0.4), with low correlations between the BPI-SF severity domain and SF-36v2 mental component summary (r = −0.16). Assessment of pain, as measured by the BPI-SF, demonstrated validity and reliability in a sample of patients with moderate-to-severe SLE.

The caregiver burden in lupus: findings from UNVEIL, a national online lupus survey in the United States.

Objectives: Lupus imposes a substantial burden on patients; however, little is known about its impact on those caring for patients with the disease. In this study, we examined the impact ‘caring for patients with lupus’ has on caregivers from their own perspective. Methods: UNVEIL was a one-time online national cross-sectional survey developed in partnership with the Lupus Foundation of America and fielded targeting the US Lupus Foundation of America constituents in 2014. Eligible caregivers were adults who self-identified as unpaid caregivers of patients with lupus. Eligible caregivers had to complete a series of sociodemographic questions as well as a series of well established outcome measures, such as the Short Form 12v2 Health Survey, the Work Productivity and Activity Index, the Caregiver Burden Inventory, and the Perceived Benefits of Caregiving Scale. Results: A total of 253 caregivers completed the survey. The majority of caregivers (90.1%) were aged 60 years or younger, more than half (54.2%) were men, and more than half (59.7%) identified themselves as either a spouse or a partner to the patient with lupus they were caring for. Overall health-related quality of life was close to the norm mean of the general US population. Caregivers who were employed missed an average of 12.8% of paid work time due to caregiving responsibilities and reported a 33.5% reduction in on-the-job effectiveness. Nearly half of the caregivers surveyed (49.4%) indicated that their caregiving responsibilities impacted their ability to socialize with friends, and almost all caregivers (97.6%) reported experiencing increased anxiety and stress in relation to their caregiving role. Conclusions: Caregiving for patients with lupus has a substantial impact on the work productivity and the social and emotional functioning of caregivers. Healthcare professionals and policymakers should continually assess the impact of healthcare decisions on the well-being of those caring for patients with lupus.

THU0435 Evaluation of Dimensionality and Sensitivity in Physical Functioning Construct When Combining the Health Assessment Questionnaire with the Sf-36® Health Survey Physical Functioning Scale

Background The SF-36® 10 items Physical Functioning domain (PF10) and the Health Assessment Questionnaire (HAQ) are widely used measurements to evaluate rheumatoid arthritis (RA) treatments. However, there are competing theories about the dimensionality in the overall latent Physical Functioning (PF) construct when combining PF10 and HAQ items. Objectives To explore the dimensionality of the PF construct when PF10 and HAQ items are combined into a single instrument and then evaluate the psychometric properties of the combined instrument. Methods Item Response Theory (IRT)[1] was used to analyze data from a phase 3, randomized, placebo-controlled study in patients with RA. Dimensionality of the combined instrument was explored by factor analyses (exploratory and confirmatory). A sequence of unidimensional Rasch [1] and generalized partial credit (GPC)[1,2] models were fitted to address the multi-factor/dimensionality issue identified through factor analyses. Model comparisons and diagnoses were performed to assess the adequacy of model fitting and to detect any violation of the underlying assumptions. In addition to building IRT models for individual factor, another IRT model that includes all 30 items was built to derive a total score. Pearson correlation was used to assess the validity of the IRT-based health status scores, whereas analysis of covariance was used to assess sensitivity of response change (defined by the American College of Rheumatology [ACR] 20% improvement criteria [3]). Results The factor analysis suggested there were three underlying factors in the combined PF10 and HAQ. These three factors can be best characterized as hygiene (including 1 item from PF10 and 4 from HAQ), lower body activity (including 6 items from PF10 and 8 from HAQ), and upper body activity (including 3 items from PF10 and 7 from HAQ). In all models considered, the GPC model significantly outperformed the Rasch model counterpart (all p-value<0.0001), implying divergent discriminability among items. In addition to the factor analysis-based IRT scales, IRT-based scales derived from all the 30 combined items also show strong convergent validity (all p-value<0.0001) and strong sensitivity (all p-values<0.0001) when comparing across ACR groups. Conclusions The pooled PF10 and HAQ represent multiple domains of physical functioning. The superior performance of the GPC model over Rasch model suggested divergent discriminability among items. Strong convergent validity and sensitivity were demonstrated for all IRT-based scales. References Edelen, MO and Reeve, BB (2007) Applying item response theory (IRT) modeling to questionnaire development, evaluation, and refinement. Qual. Life Res. 16 Suppl 1: 5-18. Li, Y and Baser, R (2012) Using R and WinBUGS to fit a generalized partial credit model for developing and evaluating patient-reported outcomes assessments. Statist. Med. 31: 2010-2026 Felson, D and American College of Rheumatology Committee to Reevaluate Improvement Criteria (2007) A proposed revision to the ACR20: the hybrid measure of American College of Rheumatology response. Arthritis Rheum 57: 193-202 Disclosure of Interest : None declared DOI 10.1136/annrheumdis-2014-eular.5254

THU0422 Psychometric Properties of the Brief Fatigue Inventory-Short Form in Systemic Lupus Erythematosus

Background A 12-week prospective, observational study was conducted to evaluate the psychometric properties of the Brief Fatigue Inventory-Short Form (BFI-SF)1 and determine its appropriate use for the measurement of fatigue in systemic lupus erythematosus (SLE) clinical trials. Objectives The aim of this study was to validate the performance of BFI-SF in a sample of patients with moderate-to-severe SLE. Methods Participants ≥18 years, who self-reported a physician diagnosis of SLE (confirmed by medical record review) and active SLE demonstrated by a Systemic Lupus Activity Questionnaire (SLAQ) score of ≥11 (0-44 scale), were recruited using a free electronic medication monitoring service. All participants completed the BFI-SF, Multidimensional Assessment of Fatigue (MAF), and Medical Outcome Study 36-Item Short Form Health Survey (SF-36) electronically at baseline, week 2, and week 12. Score distributions, internal consistency, test-retest reliability, and construct validity were evaluated. Results A total of 122 participants were included in the study. The mean age was 45.7 years, 95.9% were female, and 68.9% were non-Hispanic white. Cronbachs alpha were >0.9 for all BFI-SF items. Test-retest reliability of the BFI-SF showed a stable intraclass correlation for item #7 (ICC 0.76), and BFI domain scores had higher correlations (around 0.5) than most items (around 0.3-0.4). Construct validity was measured by strength of the correlations of the BFI-SF severity domains and global scores, and were moderately positively correlated to the SLAQ score (r>0.4). The domain and global scores were moderately negatively correlated to the SF-36 Vitality and Physical Function domains and SF-36 Physical Component scores (all r<-0.3). The BFI-SF item #3 for worst fatigue was highly positively correlated to the MAF (r=0.6). Patients with less severe fatigue (MAF≤36) scored lower than patients with more severe fatigue (MAF>36) on all domains of the BFI-SF (total score, 4.66±1.55 vs. 6.80±1.13; p<0.0001). Conclusions Assessment of fatigue severity and the impact of fatigue on daily functioning as measured by the BFI-SF demonstrated validity and reliability in a sample of patients with SLE and may be used as a patient-reported outcome tool in clinical trials. References Mendoza TR, et al. Cancer 1999;85:1186-96 Acknowledgements This research was funded by Eli Lilly and Company, Indianapolis, IN. Disclosure of Interest : S. Al Sawah Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, A. Naegeli Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company DOI 10.1136/annrheumdis-2014-eular.2055