Psychometric validation and meaningful change thresholds of the Worst Itching Intensity Numerical Rating Scale for assessing itch in patients with chronic kidney disease-associated pruritus

Background Chronic kidney disease-associated pruritus (CKD-aP) is characterized by persistent itch that often leads to substantially impaired quality of life. The Worst Itching Intensity Numerical Rating Scale (WI-NRS) is a single-item patient-reported outcome measure in which patients indicate the intensity of the worst itching they experienced over the past 24 h. Here, we evaluated the content validity and psychometric properties of the WI-NRS and confirmed the threshold of meaningful change in hemodialysis patients with moderate-to-severe CKD-aP. Methods Content validity interviews were conducted in 23 patients. Psychometric properties of the WI-NRS were assessed using data from one phase 2 (N = 174) and two phase 3 (N = 848) clinical trials investigating an anti-pruritic treatment. Anchor-based methods were used to confirm meaningful within-patient change score thresholds in the phase 3 trial patients and mixed-method exit interviews (N = 70) contributed further insight. Results Content validity interviews indicated patients considered the WI-NRS to be straightforward, comprehensive, and relevant. Test–retest reliability was strong in both trial cohorts (intraclass correlation coefficients > 0.75). Construct validity analyses indicated high correlation between the WI-NRS and other measures of itch. Anchor-based analyses showed a reduction of ≥ 3 points from baseline score represented an appropriate clinically meaningful within-patient change on the WI-NRS. In the exit interviews, all patients with a reduction ≥ 3 points considered the change meaningful. Conclusions The WI-NRS is a reliable, valid, and responsive measure of itch intensity for patients with moderate-to-severe CKD-aP. These results support its use to assess treatment efficacy and in clinical evaluation and management of pruritus in hemodialysis patients.

Cognitive and gait outcomes after primary endoscopic third ventriculostomy in adults with chronic obstructive hydrocephalus

OBJECTIVE The object of this study was to determine the short- and long-term efficacy of primary endoscopic third ventriculostomy (ETV) on cognition and gait in adults with chronic obstructive hydrocephalus. METHODS Patients were prospectively accrued through the Adult Hydrocephalus Clinical Research Network patient registry. Patients with previously untreated congenital or acquired obstructive hydrocephalus were included in this study. Gait velocity was assessed using a 10-m walk test. Global cognition was assessed with the Montreal Cognitive Assessment (MoCA). Only patients with documented pre- and post-ETV gait analysis and/or pre- and post-ETV MoCA were included. RESULTS A total of 74 patients had undergone primary ETV, 42 of whom were analyzed. The remaining 32 patients were excluded, as they could not complete both pre- and post-ETV assessments. The mean age of the 42 patients, 19 (45.2%) of whom were female, was 51.9 ± 17.1 years (range 19–79 years). Most patients were White (37 [88.1%]), and the remainder were Asian. Surgical complications were minor. Congenital etiologies occurred in 31 patients (73.8%), with aqueductal stenosis in 23 of those patients (54.8%). The remaining 11 patients (26.2%) had acquired cases. The gait short-term follow-up cohort (mean 4.7 ± 4.1 months, 35 patients) had a baseline median gait velocity of 0.9 m/sec (IQR 0.7–1.3 m/sec) and a post-ETV median velocity of 1.3 m/sec (IQR 1.1–1.4 m/sec). Gait velocity significantly improved post-ETV with a median within-patient change of 0.3 m/sec (IQR 0.0–0.6 m/sec, p < 0.001). Gait velocity improvements were sustained in the long term (mean 14 ± 2.8 months, 12 patients) with a baseline median velocity of 0.7 m/sec (IQR 0.6–1.3 m/sec), post-ETV median of 1.3 m/sec (IQR 1.1–1.7 m/sec), and median within-patient change of 0.4 m/sec (IQR 0.2–0.6 m/sec, p < 0.001). The cognitive short-term follow-up cohort (mean 4.6 ± 4.0 months, 38 patients) had a baseline median MoCA total score (MoCA TS) of 24/30 (IQR 23–27) that improved to 26/30 (IQR 24–28) post-ETV. The median within-patient change was +1 point (IQR 0–2 points, p < 0.001). However, this change is not clinically significant. The cognitive long-term follow-up cohort (mean 14 ± 3.1 months, 15 patients) had a baseline median MoCA TS of 23/30 (IQR 22–27), which improved to 26/30 (IQR 25–28) post-ETV. The median within-patient change was +2 points (IQR 1–3 points, p = 0.007), which is both statistically and clinically significant. CONCLUSIONS Primary ETV can safely improve symptoms of gait and cognitive dysfunction in adults with chronic obstructive hydrocephalus. Gait velocity and global cognition were significantly improved, and the worsening of either was rare following ETV.

Comparison of Raw And Regression Approaches To Capturing Change On Patient Reported Outcome Measures

PurposePatient-reported outcome (PRO) analyses often involve calculating raw change scores, but limitations of this approach are well documented. Regression estimators can incorporate information about measurement error and potential covariates, potentially improving change estimates. Yet, adoption of these regression-based change estimators is rare in clinical PRO research. Methods Both simulated and PROMIS® pain interference items were used to calculate change employing three methods: raw change scores and regression estimators proposed by Lord and Novick (LN) and Cronbach and Furby (CF). In the simulated data, estimators’ ability to recover true change was compared. Standard errors of measurement (SEM) and prediction (SEP) with associated 95% confidence limits were also used to identify criteria for significant improvement. These methods were then applied to real-world data from the PROMIS® study. Results In the simulation, both regression estimators reduced variability compared to raw change scores by almost half. Compared to CF, the LN regression better recovered true simulated differences. Analysis of the PROMIS® data showed similar themes, and change score distributions from the regression estimators showed less dispersion. Using distribution-based approaches to calculate thresholds for significant within-patient change, smaller changes could be detected using both regression estimators.ConclusionsThese results suggest that calculating change using regression estimates may result in more increased measurement sensitivity. Using these scores in lieu of raw differences can help better identify individuals who experience real underlying change in PROs in the course of a trial, and enhance the established methods for identifying thresholds for meaningful within-patient change in PROs.

Comparison of Anchor- and Distribution-Based Methods for Estimating Thresholds of Meaningful Within-Patient Change Using Simulated PROMIS PF 20a Data Under Various Joint Distribution Characteristic Conditions

PurposeTo compare the performance of anchor-based and distribution-based methods for estimating thresholds of meaningful within-patient change of clinical outcome assessments in conditions reflecting data characteristics of small- to medium-sized clinical trials.MethodsData sets were generated from the joint distributions of the PROMIS PF 20a T-score changes and a seven-point global change anchor measure. The 108 simulation conditions (1,000 replications per condition) included combinations of three marginal distributions of T-score changes, three improvement percentages in the anchor measure, four levels of responsiveness correlations, and three sample sizes. Threshold estimation methods included mean change, median change, ROC curve, predictive modeling, half SD, and SEM. Relative bias, precision, accuracy, and measurement significance of the estimates were evaluated based on comparison with true thresholds and IRT-based individual reliable changes of PROMIS scores. Quantile regression models were applied to select and interpret effects of simulation conditions on estimation bias.ResultsWhen PROMIS T-score changes were distributed normally, the predictive modeling method performed best with 50% or more responders identified by the anchor; the mean and median methods were preferred with 30% responders. For skewed distributions, the median method and ROC method gained more advantages. Among the evaluated study conditions, the improvement percentage condition had the most obvious effects on estimation bias.ConclusionTo establish accurate and precise thresholds, clinical researchers are recommended to prioritize study designs with at least 50% anchor-defined responders and strongly responsive target endpoints with highly reliable scoring calibration and to select optimal anchor-based methods given the data characteristics.

Ultraviolet-C decontamination of a dental clinic setting: required amount of UV light

Viruses can spread to the environment, and it can be challenging to clear it. A direct approach to limit airborne transmission of pathogens in dental clinic offices is to inactivate viruses within a short time of their production and block the person-to-person transmission routes in dental clinics. For this, we can use chemical substances on surfaces and germicidal ultraviolet light (UV), typically at 254 nm, for complementary disinfection of surfaces and air contaminated by aerosols produced by high-speed handpiece or ultrasound scaler. Based on the literature review and the similarity of Sars-Cov-2 with other previously studied corovaviruses, COVID-19 is sensitive to UV irradiation that can break the genome of this virus, inactivating it. In our study, we performed the calculation of the time required to decontaminate a dental care room between each patient change. We can conclude that the use of UVC can be incorporated into the dental care routine to reduce cross contamination.KeywordsUVC-decontamination; Sterilization; Ultraviolet light; Dentistry; Sars-Cov-2.

AB0554 CONCORDANCE IN THE CLASSIFICATION CRITERIA IN A PATIENT COHORT WITH IDIOPATHIC INFLAMMATORY MYOPATHIES (IIM).

Background:Differents classifications criteria for IIM exist. New classification criteria are superior to previous in capturing different subgroups of IIM.Objectives:To compare the concordance and disparity of Bohan and Peter and EULAR/ACR 2017 classification criteria at the level of diagnostic certainty, in a group of chilean patients with IIM.Methods:40 adults patients with IIM (27 Dermatomyositis (DM) and 13 Polimyositis (PM)), according Bohan and Peter criteria were analized. The patients were reclassified with EULAR/ACR criteria. The level of diagnostic certainty (definitive, probable and possible) was registered for both Classification Criteria. The concordance and disparity between criteria was evaluated. Concordance and disparity analysis were made considering the strict agreement between level of certainty of both criteria, using Cohen´s Kappa coefficient. The analysis was done for the complete cohort and for separated groups.Patients with discordance belonging to the same subgroup were evaluated using contingency tables. The direction of the change (gain or lost of certainty) and the relation with diagnostic subgroup was also analized. Descriptive statistics is expressed as diagnostic categories, number of patients and rates.Results:For the complete cohort and for DM and PM groups the concordance was low. For 27 patients with DM, the observed concordance rate was 63% (16 definitives, 1 probable). The observed disparity rate was 37%. The direction of the change was gain of one level of certainty in 14.5% and two levels in 22.2% of patients applying EULAR/ACR criteria compared to Bohan y Peter criteria. For 13 pacients with PM, the observed concordance rate was 46% (3 definitives and 3 probables). The observed disparity rate was 54%. The direction of the change was loss of certainty. The loss of certainty was one level in 85,7% (one patient change from probable to posible). Only one patiente had gain of certainty of one level (14.3%).Conclusion:The strict concordance between both classification criteria was low. The observed concordances were better in patients with DM that PM. The disparities involved gain of level of diagnostic certainty in DM patients, while in PM patients there was mostly lost of level of certainty.References:[1]Bohan A, Peter JB. Polymyositis and dermatomyositis (first of two parts). NEJM 1975;292:344-7.[2]Bohan A, Peter JB. Polymyositis and dermatomyositis (second of two parts). NEJM 1975;292:403-7.[3]2017 European League Against Rheumatism/American Colllege of Rheumatology Classification Criteria for Adult and Juvenile Idiopathic Inflammatory Myopathies and Their major Subgroups. Arthritis Rheum 2017;0:1-12.Disclosure of Interests: :None declared