Absolute risk estimation of new-onset proteinuria in patients with systemic lupus erythematosus: a Danish nationwide cohort study.

OBJECTIVES: Kidney involvement and medical compliance are frequent challenges in systemic lupus erythematosus (SLE). Additional data reporting such as absolute risk estimates may strengthen risk stratification and compliance. This study provides absolute risk estimations of risk of new-onset proteinuria among SLE patients. METHODS: Danish SLE centres provided clinical data on first time observations of proteinuria and other clinical parameters listed in the 1997 American College of Rheumatology Classification Criteria for SLE. Time from first occurring non-renal manifestation to new-onset proteinuria or censoring defined time at risk. Multivariate Cox-regression models were used to identify risk factors for new-onset proteinuria and to calculate risk of proteinuria stratified by risk factor debut age, duration, and sex. RESULTS: The patient population consisted of 586 patients with SLE, mainly Caucasian (94%) women (88%), mean age at inclusion of 34.6 years (standard deviation, SD=14.4 years), observed for a mean of 14.9 years (SD=11.2 years). The cumulative prevalence of proteinuria was 40%. Discoid rash, HR =0.42 (p=0.01) and lymphopenia HR=1.77 (p=0.005) were associated with new-onset proteinuria. Male patients with lymphopenia had the highest predictive risks of proteinuria with a 1-, 5- and 10-year risk of proteinuria ranging from 9-27%, 34-75% and 51-89%, depending on the age at presentation (debut at 20, 30, 40 or 50 years). The corresponding risk profiles for women with lymphopenia were 3-9%, 8-34% and 12-58%, respectively. CONCLUSIONS: Large differences in absolute risk estimates for new-onset proteinuria were identified. The differences may aid risk stratification and patient compliance among high-risk individuals.

Patient-reported outcome measures in systemic lupus erythematosus by a web-based application: A randomized, crossover, agreement study.

OBJECTIVES: Patient-reported outcome measures (PROMs) are evaluated in randomized controlled trials (RCTs) in patients with systemic lupus erythematosus (SLE), but not widely used in clinical practice. However, interest in incorporating PROMs into the management of SLE is increasing as PROMs provide a unique insight into the patient's perception of lupus disease activity. The objective was to assess agreement in PROMs answered using a web app versus an outpatient touchscreen among patients with SLE. METHODS: In a crossover RCT, SLE patients answered the following PROMs in a random order using the web app and the outpatient touchscreen: Systemic Lupus Erythematosus Activity Questionnaire (SLAQ) Global Health, SLAQ Symptom, SLAQ Total, SLAQ Worsening, Pain Visual Analog Scale (VAS), Fatigue VAS, Patient Global Health VAS, Health Assessment Questionnaire Disability Index (HAQ-DI), Patient Acceptable Symptom State (PASS), and an Anchoring Question. Equivalence between the two device types was demonstrated if the 95% confidence interval (95% CI) of the difference in PROM scores was within the prespecified equivalence margin. Agreement between the two device types was assessed using mixed linear models. RESULTS: Thirty-four patients with SLE were included. Equivalence was demonstrated between the two device types for SLAQ Global Health with a difference of -0.21 (95% CI: -0.65 to 0.23). Moreover, equivalence was also found for HAQ-DI, Pain VAS, and Fatigue VAS whereas only comparability within the limits of the Minimal Clinically Important Difference (MCID) was demonstrated for VAS Patient Global Health. Statistical comparability was demonstrated for SLAQ Total, SLAQ Worsening, PASS, and Anchoring Question (no predefined MCID/equivalence margins available). However, a statistically significant difference between device types was observed for the SLAQ Symptom of -0.56 (95% CI: -1.10 to -0.01). The difference was, however, very small when considering the scale range of 0-24; thus, it was not judged to be of clinical relevance. Preference for the web app was very high (91.2%). CONCLUSION: For the first time ever, equivalence and comparability between two electronic device types for various PROMs were demonstrated among patients with SLE. Implementation of the device is expected to improve the management of SLE.