Distribution-based Approach Research Articles

Transversus Abdominis Plane Block as a Strategy for Effective Pain Management in Patients with Pain during Laparoscopic Cholecystectomy: A Systematic Review.

Laparoscopic cholecystectomy (LC), unlike laparotomy, is an invasive surgical procedure, and some patients report mild to moderate pain after surgery. Transversus abdominis plane (TAP) block has been shown to be an appropriate method for postoperative analgesia in patients undergoing abdominal surgery. However, there have been few studies on the efficacy of TAP block after LC surgery, with unclear information on the optimal dose, long-term effects, and clinical significance, and the analgesic efficacy of various procedures, hence the need for this review. Five electronic databases (PubMed, Academic Search Premier, Web of Science, CINAHL, and Cochrane Library) were searched for eligible studies published from inception to the present. Post-mean and standard deviation values for pain assessed were extracted, and mean changes per group were calculated. Clinical significance was determined using the distribution-based approach. Four different local anesthetics (Bupivacaine, Ropivacaine, Lidocaine, and Levobupivacaine) were used at varying concentrations from 0.2% to 0.375%. Ten different drug solutions (i.e., esmolol, Dexamethasone, Magnesium Sulfate, Ketorolac, Oxycodone, Epinephrine, Sufentanil, Tropisetron, normal saline, and Dexmedetomidine) were used as adjuvants. The optimal dose of local anesthetics for LC could be 20 mL with 0.4 mL/kg for port infiltration. Various TAP procedures such as ultrasound-guided transversus abdominis plane (US-TAP) block and other strategies have been shown to be used for pain management in LC; however, TAP blockade procedures were reported to be the most effective method for analgesia compared with general anesthesia and port infiltration. Instead of 0.25% Bupivacaine, 1% Pethidine could be used for the TAP block procedures. Multimodal analgesia could be another strategy for pain management. Analgesia with TAP blockade decreases opioid consumption significantly and provides effective analgesia. Further studies should identify the long-term effects of different TAP block procedures.

An explanatory sequential mixed-methods design to establish thresholds of within-individual meaningful change on a sleep disturbance numerical rating scale score in atopic dermatitis

PurposeEstablishing a meaningful within-individual change (MWIC) threshold is a key aspect for interpreting scores used as endpoints for evaluating treatment benefit. A new patient-reported outcome (PRO), a sleep disturbance numerical rating scale (SD NRS), was developed in adults and adolescents with moderate-to-severe atopic dermatitis (AD). This research aims to establish a MWIC threshold of the SD NRS score in the context of a drug development program.MethodsAn explanatory sequential mixed-methods design was used to address the research objective. This mixed-methods design used phase IIb data and a stand-alone qualitative study. Quantitative anchor-based and distribution-based approaches supported by qualitative-based approaches were conducted, and results were triangulated to determine preliminary MWIC thresholds of the SD NRS score.ResultsTriangulation of results from both quantitative and qualitative approaches suggested that a 2- to 6-point decrease in the SD NRS score change constitutes a preliminary range of MWIC threshold estimates.ConclusionThis research determined MWIC threshold estimates for the SD NRS score in both adolescents and adults with moderate-to-severe AD using an explanatory sequential mixed-methods design. This mixed-methods design provides interesting insights for establishing MWIC thresholds of a PRO score in the context of a drug development program.

Performance of the Comprehensive Assessment Tool for Challenges in Hemophilia (CATCH) 2.0

Introduction: The Comprehensive Assessment Tool for Challenges in Hemophilia (CATCH) was developed in 2018 to capture various outcomes that were important to children and adult persons with hemophilia (PwH) and their caregivers. It contains concepts related to quality of life, lifestyle restrictions, and physical activity, and was intended to be used in clinical trial and clinical practice settings across therapies, with adult and pediatric PwH A or B (with or without inhibitors) and caregivers of PwH. In this study, the abbreviated CATCH 2.0 was developed and validated to capture a selected set of outcomes that are most important to PwH and their caregivers. Methods: This was a psychometric validation study using data from a prospective multi-center single arm trial (that included children and adult PwH with mild to moderate hemophilia A), a US-based psychometric study (that included children and adult PwH A or B), and a nationwide survey of adult PwH A. Item-level analyses assisted in the identification of potential questions for deletion, followed by exploratory factor analysis - which examined relationships between the measured survey items and their domains. Reliability (internal consistency and test-retest), validity (construct, convergent, criterion and known-groups), responsiveness to change, and thresholds for meaningful change for each domain were evaluated. Results: Data from 126 children, 232 adults, and 118 caregivers were analyzed across the 3 studies. This included data from 396 (83%) PwH A and 80 (17%) PwH B, of which 68 (14%) had severe disease and 408 (86%) had mild or moderate hemophilia, and 115 (24%) had active inhibitors. In general, the CATCH 2.0 demonstrated acceptable psychometric properties. Internal consistency reliability for all domains (alpha > 0.87) and test-retest reliability (intraclass correlation coefficient >0.70) were acceptable for 6 of 8 domains. Medium to large correlations (correlation coefficient 0.3 to 0.6) were reported between associated measures (EQ-5D, WPAI, and pain rating) and the majority of CATCH domains. Known-groups validity for most domains (based on categorizations of severity and inhibitor status) was good. Treatment Burden was the only domain which demonstrated any responsiveness over time. Most correlations with annualized bleed rate (ABR) were not significant. Since anchor-based methods using ABR were not feasible (due to poor correlation), thresholds for clinically meaningful change were estimated using a distribution-based approach (standard error of measurement ranged from 6.7 to 16.5). Table 1 contains a list of the domains included in each of the 3 versions. Each version is expected to take < 10 minutes to complete. Conclusions: The CATCH 2.0, an abbreviated version of the original CATCH, captures important outcomes for PwH A and B, along with their caregivers. CATCH 2.0 has an excellent factor structure and its psychometric properties demonstrated acceptable performance, particularly for reliability, convergent validity, and known-groups validity. Support for responsiveness in mild/moderate populations however, was limited. Results highlight the need for more longitudinal data in heterogeneous groups of PwH to further refine the performance of this tool. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Minimally important differences in oral health-related quality of life after fixed orthodontic treatment: a prospective cohort study.

The minimally important difference (MID, the smallest difference that patients perceive as beneficial) has been proposed to assess whether study results are clinically meaningful, reducing the shortcoming of P-values-based approaches in the assessment of clinical outcomes. The post-treatment changes and the MID in Oral Health-Related Quality of Life (OHRQoL) among adults undergoing fixed orthodontic treatment were investigated. Ninety-two patients (29.1 ± 6.3 years old, 18 males and 74 females) were prospectively included. Oral Health Impact Profile (OHIP-14) and United Kingdom Oral Health-related Quality of Life (OHQoL-UK) were used to assess OHRQoL at baseline and post-treatment (50.8 ± 15.7 months). Global Transition Rating (GTR) was used to assess oral health/well-being, Peer Assessment Review (PAR), and Index of Complexity, Outcome and Need (ICON) were used to assess occlusion. Wilcoxon signed-rank test was used to assess changes in OHRQoL and occlusion, Kruskal-Wallis one-way ANOVA and Mann-Whitney U-test were used to assess associations between OHRQoL and oral health/well-being or occlusion. MID for OHIP-14 and OHQoL-UK was estimated via anchor-based (PAR, ICON, GTR) and distribution-based approach (effect size, standardized response mean, standard error of measurement). The median OHIP-14 and OHQoL-UK post-treatment scores were significantly changed, indicating improved OHRQoL. Based on the agreement between different methods, the MID of OHIP-14 and OHQoL-UK were at least 15 and 6 scale points, corresponding to a large effect size (1.5-1.7). Orthodontic treatment had a positive long-term impact on OHRQoL. MID for the OHIP-14 and OHQoL-UK provide guidance to interpreting the impact of orthodontic treatment on the OHRQoL of patients.

Comparison of raw and regression approaches to capturing change on patient-reported outcome measures.

Patient-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. 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 estimation (SEE) 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. 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. These 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.

Multivariate Relevance Vector Regression Based Degradation Modeling and Remaining Useful Life Prediction

Relevance vector regression (RVR) is a useful tool for degradation modeling and remaining useful life (RUL) prediction. However, most RVR models are for 1-D degradation processes and can only handle univariate observations. This article proposes a degradation path-based RUL prediction framework using a dynamic multivariate relevance vector regression model. Specifically, a multistep regression model is established for describing the degradation dynamics and extending the classical RVR into a multivariate one with consideration of the multivariate environment. The article introduces a matrix Gaussian distribution-based RVR approach and then estimates the hyperparameters with Nesterov’s accelerated gradient method to avoid the exhausting re-estimation phenomenon in seeking analytical solutions. It further forecasts the degradation path for monitoring the degradation status. Based on the forecasted path, the RUL is predicted by the first hitting time method. Finally, the proposed methods are illustrated by two case studies, one is presented in this article and the other in the supplement, which investigate the capacitors’ and bearings’ performance degradations.

Multiple attribute decision making with flexible linguistic expressions: A linguistic distribution-based approach with interval estimations

In linguistic multiple attribute decision making (MADM), flexible linguistic expressions can provide a general way to express complex preference data linguistically, which presents the challenge of handling such complex linguistic data. In this paper, we investigate the linguistic MADM with the concept of flexible linguistic expressions, and present a linguistic distribution-based approach with interval estimations to support the MADM with the data of flexible linguistic expressions. We first convert flexible linguistic expressions approximately to linguistic distributions through developing two models to estimate the lower and upper bounds of the approximated linguistic distributions’ expectations on the attribute level. Then, we generate the interval estimations of comprehensive values of approximated linguistic distributions on the alternative level, and propose the solution algorithm to support the linguistic MADM with flexible linguistic expressions. Finally, the numerical and comparative analysis is performed to illustrate and justify the flexible linguistic MADM methods.

Assessing the meaningful change threshold of Quality of Life in Depression Scale using data from two phase 3 studies of esketamine nasal spray

BackgroundMajor depressive disorder (MDD) directly impacts patients’ lives including symptoms, functioning and health-related quality-of-life (HRQoL). Patient-reported outcomes can capture these impacts, however interpretation of clinical meaningfulness of these measurements are often not readily available. Meaningful change thresholds (MCTs) can be derived for clinical outcome assessments to quantify the change in symptoms that is meaningful to the patient following pharmacologic treatment or other interventions. The objective of this analysis was to determine the within-patient MCT of the self-reported Quality-of-Life in Depression Scale (QLDS) among patients with MDD and active suicidal ideation with intent (MDSI) using an anchor-based approach.MethodsData from 2 randomized phase-3 trials of esketamine nasal spray (ASPIRE I and ASPIRE II) were analyzed. The Montgomery–Åsberg Depression Rating Scale (MADRS) was the primary anchor with three different severity criteria. Other anchor variables utilized were Clinical Global Impression of Severity of Suicidality-revised version, Clinical Global Impression of Imminent Suicide Risk, and EuroQol Visual Analog Scale [EQ-VAS]. Spearman correlation coefficients between the change in QLDS and anchor variables were calculated. The mean change in QLDS score at Day 25 from baseline was calculated based on the categorical change in the anchor. Coefficient yield from linear regression of the mean changes in EQ-VAS and QLDS, and distribution-based approach with ½ SD of change in QLDS were considered.ResultsIn ASPIRE I, mean (SD) improvement in QLDS score among patients with one category improvement in MADRS from baseline to Day 25 was − 8.22 (8.87), − 8.30 (9.01), and − 8.20 (8.92) using severity criteria #1, #2, and #3, respectively. Patients who achieved a 7-point improvement (MCT) in EQ-VAS yielded a mean − 9.69-point improvement in QLDS at Day 25. The ½ SD of change in QLDS was 5.63. Similar results were obtained for ASPIRE II. The MCTs identified using multiple anchors across both trials ranged from − 11.4 to − 6.7 and had an overall mean of − 7.90 (ASPIRE I) and − 7.92 (ASPIRE II). Thus, an 8-point change was recommended as the MCT for QLDS.ConclusionThe recommended MCT will help quantify within-person changes in HRQoL using patient-reported QLDS and determine meaningful treatment benefit in an MDD patient population with acute suicidal ideation or behavior.Trial registration: Name of the registry: ClinicalTrials.gov. Trial registration number: ASPIRE I (NCT03039192), ASPIRE II (NCT03097133). Date of registration: February 01, 2017; March 31, 2017. URL of trial registry record: https://clinicaltrials.gov/ct2/show/NCT03039192; https://clinicaltrials.gov/ct2/show/NCT03097133.

An assessment of the minimal clinically important difference for the pain disability quality-of-Life Questionnaire-Spine

ObjectiveThe Pain Disability Quality-Of-Life Questionnaire-Spine (PDQQ-S) is a validated six question patient reported outcome measure designed for usage in minimally invasive spine intervention. The purpose of this study was to determine the Minimal Clinically Important Difference (MCID) for the PDQQ-S. DesignRetrospective single arm cohort study involving 411 patients who had undergone lumbar facet and/or sacroiliac joint RFN and had completed pre-and 3-month post RFN PDQQ-S. MethodsThe MCID using both distribution and anchor-based (“Rebook RFN”; “Analgesic Requirements”) methods were calculated. ResultsThe distribution-based approach (using standard error of measurement) estimated the MCID to be −17.3 [PDQQ-S baseline mean (SD): 46.9 (7.9)]. This is supported by the anchor based approach, which calculated the MCID to be: −21.5 for rebook RFN; −11.3, -17.2 and −30.5 for mildly, moderately and dramatically decreased NSAID use respectively; and −11.7, -16.9 and −31.7 for mildly, moderately and dramatically decreased opioid use respectively. A moderate reduction in medication use was deemed to be clinically relevant. ConclusionThe MCID value for the PDQQ-S is a score reduction of 17.

Minimal clinically important difference of the Berg Balance Scale and comfortable walking speed in patients with acute stroke: A multicenter, prospective, longitudinal study

Objective To determine the minimal clinically important difference between the Berg Balance Scale and comfortable walking speed in acute-phase stroke patients. Design Multicenter, prospective, longitudinal study. Setting Inpatient acute stroke rehabilitation. Subjects Seventy-five patients with acute stroke, mean (SD) age 71.7 (12.2) years. Intervention Inpatients with acute stroke were assessed with the Berg Balance Scale and comfortable walking speed before and after rehabilitation. Physiotherapy was conducted to improve balance and gait over a 2-week period: an average of 40 min/day on weekdays and 20 min/day on weekends and holidays. Main measures The patients’ Berg Balance Scale, comfortable walking speed, Global Rating of Change scale (patient-rated and physiotherapist-rated), and motor score of the Functional Independence Measure were obtained. Minimal clinically important differences were estimated using both anchor- (receiver operating characteristic curves and change difference) and distribution-based approaches (minimal detectable change and 0.5× the change score [SD]). Results The baseline scores were 31.2 (18.9) for the Berg Balance Scale and 0.79 (0.35) m/s for comfortable walking speed. The minimal clinically important difference in the Berg Balance Scale was 6.5–12.5 points by the anchor-based approach and 2.3–4.9 points by the distribution-based approach. The minimal clinically important difference in comfortable walking speed was 0.18–0.25 m/s by the anchor-based and 0.13–0.15 m/s by the distribution-based approach. Conclusions A change of 6.5–12.5 points in the Berg Balance Scale and 0.18–0.25 m/s in the comfortable walking speed is required in these measurements’ anchor-based minimal clinically important differences to be beyond measurement error, and to be perceptible by both patients and clinicians.

Minimally Clinically Important Difference in Health Status Scores in Patients With HFrEF vs HFpEF

BackgroundDifferences in clinically important thresholds in patient-reported outcomes measures such as the Kansas City Cardiomyopathy Questionnaire (KCCQ) remain less well-established in patients with heart failure with preserved ejection fraction (HFpEF) versus heart failure with reduced ejection fraction (HFrEF). ObjectivesThe purpose of this study was to estimate meaningful thresholds for improvement or deterioration in the KCCQ-Total Symptom Score (TSS) in patients with HFrEF versus HFpEF. MethodsThis secondary analysis of EMPERIAL program used anchor- and distribution-based approaches to estimate thresholds for improvement or deterioration in the KCCQ-TSS using Patient Global Impression of Severity (PGIS) as the primary anchor. Mean change in KCCQ-TSS from baseline to week 12 was calculated for each PGIS. ResultsA total of 312 HFrEF and 315 HFpEF patients were enrolled. At week 12, mean changes in KCCQ-TSS corresponding to PGIS changes of “any improvement,” “1-category improvement,” and “1-category deterioration” were 13 ± 17, 12 ± 17, −3 ± 16 points in HFrEF, and 15 ± 18, 13 ± 17, −7 ± 18 points in HFpEF. Threshold for meaningful within-patient change in KCCQ-TSS was ≥9 points in HFrEF and ≥7 points in HFpEF patients. Sensitivity and specificity of ≥9 points/≥7 points change was 0.65 and 0.70 for HFrEF and 0.64 and 0.66 for HFpEF. Cumulative distribution function curves of KCCQ-TSS change from baseline to week 12 showed a shift to higher scores in both HFrEF and HFpEF patients. ConclusionsIn the EMPERIAL program, a change in KCCQ-TSS of ≥9 points in HFrEF and ≥7 points in HFpEF represents the minimal clinically important difference for improvement, confirming the broad range of 5-10 points as meaningful thresholds.

Reproxalap Activity and Estimation of Clinically Relevant Thresholds for Ocular Itching and Redness in a Randomized Allergic Conjunctivitis Field Trial.

IntroductionThis clinical trial assessed the activity of reproxalap, a novel reactive aldehyde species modulator, and estimated clinically relevant thresholds for changes in ocular itching and redness in an allergic conjunctivitis field trial.MethodsThis was a randomized, double-masked, vehicle-controlled phase 2 trial. Patients with ragweed-associated allergic conjunctivitis were assessed over 28 days in an environmental setting with approximately four doses per day of either 0.25% reproxalap, 0.5% reproxalap, or vehicle. Patients recorded ocular itching, redness, tearing, and eyelid swelling scores (each with a 0–4 scale, except for a 0–3 scale for swelling), and completed the Allergic Conjunctivitis Quality of Life Questionnaire at the beginning and end of the trial.ResultsMixed model of repeated measures analysis demonstrated statistically lower itching and tearing scores (pooled P = 0.026 and P < 0.001, respectively) and numerically lower redness and eyelid swelling scores than vehicle on days when pollen exceeded the 95th percentile value. Using three anchor-based and three distribution-based approaches, the meaningful within-patient change and the between-group meaningful difference for patient-reported ocular itching and redness was estimated to be approximately 0.5. The most common treatment-emergent adverse event associated with reproxalap was transient irritation upon instillation.ConclusionIn a field clinical trial, reproxalap was well tolerated and superior to vehicle in reducing ocular itching on high-pollen days. The clinical meaningfulness threshold estimates of 0.5 units are among the first such calculations generated for the standard ocular itching and redness scores, providing important context for the clinical interpretation of clinical trials in allergic conjunctivitis.

Minimal clinically important difference of the King’s Parkinson’s disease Pain Scale

Objective Pain is a common and debilitating symptom of Parkinson's disease (PD) and has no specific treatment. King's Parkinson's disease Pain Scale (KPPS) is the only specific scale for pain measurement in PD with established psychometric properties. The minimal clinically important difference (MCID) of KPPS, an important parameter for the design and interpretation of therapeutic interventions, has not yet been measured. The aim of our study was to assess the MCID of KPPS. Methods Two hundred and seven PD patients were evaluated by KPPS before and after receiving the intervention. The Clinical Global Impression of Improvement Scale was used as an anchor, and a Receiver Operating Characteristic (ROC) curve was used to determine the optimal MCID cut-off point for KPPS. The distribution-based approach applied one-third standard deviation (SD), 0.5 SD, and one standard error of measurement (SEM) of the total score of KPPS to determine the MCID. Results The MCID achieved from the ROC curve was 3 points (sensitivity: 74.4%; specificity: 81.9%). For the distribution-based method, the MCIDs corresponding to 0.3 SD, 0.5 SD, and one SEM were 5.65, 9.41, and 2.54 points, respectively. Conclusion KPPS is a valid scale for measuring pain in PD with demonstrable MCID. IMPLICATIONS FOR REHABILITATION The King's Parkinson's disease Pain Scale (KPPS) is a valid scale for measuring pain in patients with Parkinson's disease (PD) with demonstrable minimal clinically important difference (MCID). The MCID obtained in the current study will assist clinicians and researchers when interpreting KPPS change score to determine clinically meaningful changes of pain in both PD progression and response to interventions.

Estimating the minimal clinically important difference for balance and gait outcome measures in individuals with vestibular disorders.

Vestibular Rehabilitation Therapists (VRT) utilize outcome measures to quantify gait and balance abilities in individuals with vestibular disorders (IVD). The minimal clinically important difference (MCID) in gait and balance outcome measures for IVD is unknown. The purpose of this study is to estimate the MCID of the Activities-specific Balance Confidence Scale (ABC), Functional Gait Assessment (FGA), and Gait Speed (GS) using distribution and anchor-based methods relative to the Dizziness Handicap Inventory (DHI) in IVD. Data were collected using a retrospective chart review from two outpatient Vestibular Rehabilitation (VR) clinics. Data included demographic characteristics, diagnosis, VR course, and pre and post outcome measures including DHI, ABC, FGA, and GS. The DHI was used to classify subjects as "responders" or "non-responders" in order to calculate MCID values. The total number of subjects analyzed for each outcome measure was 222 for the ABC, 220 for FGA, and 237 for GS. Subjects made statistically significant improvements in ABC, DHI, FGA, and GS (p < 0.001) from pre to post VR. The MCID calculated for ABC, FGA, and GS using the anchor-based approach was 18.1%, 4 points, and 0.09 m/s respectively. The MCIDs calculated using distribution-based approach for the ABC ranged between 7.5-23.5%, FGA ranged between 1.31-4.15 points, and GS ranged between 0.07 m/s-0.22 m/s. The anchor-based calculations of the MCID of 18.1%, 4 points, and 0.09 m/s for ABC, FGA, and GS respectively for IVD should be used over distribution-based calculations. This is due to strength of DHI as the anchor and statistical analysis. VRT and researches can use these values to indicate meaningful changes in gait and balance function in IVD.

Validation and minimally important difference of the Child-OIDP in a socioeconomically diverse sample of Indian adolescents

IntroductionWhile different measures have been validated and used to assess the oral health related quality of life (OHRQoL) of children and adolescents, no previous study has tested the psychometric performance of OHRQoL amongst the most marginalized adolescents, living in extremely deprived neighbourhoods like urban slums and resettlement areas in modern cities. Our study assessed the internal consistency reliability, construct validity and Minimally Important Difference (MID) of the Child-OIDP in a sample of adolescents aged 12–15 years reporting oral health problems that lived in three different types (including two extremely vulnerable) of neighbourhoods (urban slums, resettlement colonies, and middle and upper middle-class neighbourhoods) in the National Capital Territory of Delhi.MethodsWe conducted data analysis on a cross-sectional study, comprising of 840 adolescents. The Child-OIDP was used as a measure of OHRQoL. Internal consistency reliability was tested using the standardized Cronbach’s Alpha Coefficient. The Child-OIDP was also tested for content and construct validity (the latter through the median test), while a distribution-based approach was used to identify the MID.ResultsThe Indian Child-OIDP showed good internal consistency, as the Cronbach’s alpha coefficient was 0.77. Inter-item correlation coefficients among the items ranged from 0.13 to 0.50, with the mean inter-item correlation being 0.30. The corrected item-total correlations ranged from 0.30 (social contact) to 0.54 (speaking). For construct validity, the Child-OIDP extent was significantly associated with three subjective oral and general health variables in the expected direction. The calculated effect sizes for these differences indicated that they were moderate (0.50–0.79). We also calculated the standard error of measurement (SEM) of Child-OIDP extent as 0.75.ConclusionThis study demonstrated that the Indian Child-OIDP is a reliable and valid measure for the assessment of the oral health related quality of life among Indian adolescents especially from marginalised and socioeconomically vulnerable groups. This is an essential step towards assessing oral health and evaluating oral health promotion interventions in those populations and settings.

Minimal Important Difference of the Psychosocial Impact of Dental Aesthetics Questionnaire Following Orthodontic Treatment: A Cohort Study.

(1) This study aimed to do a longitudinal validation of the psychosocial impact of dental aesthetics questionnaire (PIDAQ) and determine its minimal important difference (MID) following orthodontic treatment; (2) 42 adolescents (11 to 18 years old) were recruited for treatment with fixed appliances and the participants answered the Malaysian PIDAQ prior to treatment (T0), mid-treatment (T1), and post-treatment (T2), plus a global health transition scale at T1 and T2. Data analyses included repeated measures ANOVA and paired sample t-tests. Test–retest was administered 2 to 6 weeks from T0; (3) The final sample comprised 37 subjects (response rate = 88.1%). The 95% limits of agreement were −10.3 to 8.5 points. In the anchor-based approach, those who experienced the smallest changes by reporting their dental aesthetics as “a little improved” had an insignificant PIDAQ score change of −5.3 at T1. At T2, the PIDAQ scores of those in this category were reduced significantly (mean change = −26.2; effect size (ES) = 1.0; p = 0.34). In the distribution-based approach, standardized PIDAQ scores were significantly reduced, with medium (0.7) to large (1.5) ES at T1 and T2, respectively; (4) The PIDAQ can detect orthodontic-related changes in patients’ psychosocial well-being. The post-treatment MID is 26 scale points with large ES.

Minimally important differences of EORTC QLQ-C30 scales in patients with lung cancer or malignant pleural mesothelioma – Interpretation guidance derived from two randomized EORTC trials

ObjectivesA minimally important difference (MID) is the smallest difference in quality of life (QoL) perceived as relevant by patients or clinicians. MIDs aid interpretation of QOL data in research and clinical practice. We aimed to determine MIDs for the EORTC QLQ-C30 for patients with lung cancer or malignant pleural mesothelioma. Materials and MethodsData were drawn from two EORTC-sponsored randomized clinical trials (RCTs): a three-arm RCT of two cisplatin-based treatments and paclitaxel plus gemcitabine in advanced non–small-cell lung cancer, and an RCT comparing cisplatin with or without raltitrexed in patients with malignant pleural mesothelioma. MIDs for interpreting within-group change and between-group differences in change over time were computed using anchor-based approaches, for improvements and deteriorations separately. Distribution-based approaches provided corroborative evidence. ResultsThe combined data from the trials comprised 730 patients. Available data allowed us to determine 8/14 anchor-based MIDs for EORTC scales for improvements, and 9/14 MIDs for deterioration. Furthermore, we provided distribution-based estimates for all 14 QLQ-C30 scales. Most MIDs for improvements ranged between 5 and 10, for both within-group and between-group differences. Outliers were appetite loss and constipation, with MIDs up to 15 score points. MIDs were slightly larger for within-group deterioration, ranging from –5 to − 15, with the largest for Nausea/vomiting (−1 to 4) and Appetite loss (−1 to 5). MIDs for between-group differences in deterioration ranged from − 4 (Physical, Role, and Social functioning, and Global quality of life) to −9 (Nausea/vomiting, Appetite loss and Constipation). ConclusionsMIDs vary over scales and for between- versus within-group comparisons; this must be taken into account when interpreting changes. Nevertheless, the majority of MIDs range between 5 and 10 score points, in line with previously used thresholds for QLQ-C30. These findings and those from other tumor-specific MID analyses will inform a planned consensus process identifying commonalities and differences across tumor sites.

Holistic Process Models: A Bayesian Predictive Ensemble Method for Single and Coupled Unit Operation Models

The coupling of individual models in terms of end-to-end calculations for unit operations in manufacturing processes is a challenging task. We present a probability distribution-based approach for the combined outcomes of parametric and non-parametric models. With this so-called Bayesian predictive ensemble, the statistical moments such as mean value and standard deviation can be accurately computed without any further approximation. It is shown that the ensemble of different model predictions leads to an uninformed prior distribution, which can be transformed into a predictive posterior distribution using Bayesian inference and numerical Markov Chain Monte Carlo calculations. We demonstrate the advantages of our method using several numerical examples. Our approach is not restricted to certain unit operations, and can also be used for the more robust interpretation and assessment of model predictions in general.

Operationalising treatment success in aphasia rehabilitation

ABSTRACT Background Treatment success is the desired outcome in aphasia rehabilitation. However, to date, there is a lack of consensus on what defines a 'successful' result on a given aphasia outcome measurement instrument (OMI). Aim In this methodological paper, we present strategies for how to define and measure treatment success on a given OMI at the group-level, as well as for an individual person with aphasia. The latter is particularly important when research findings from group studies are clinically implemented for individuals in rehabilitation. Scope We start by presenting methods to calculate the average statistically significant change across several (group) studies (e.g., standardised mean difference, raw unstandardised mean difference) for a given OMI. Such metrics are useful to summarise the overall effect of the intervention of interest, particularly in meta-analyses. However, benchmarks based on group effects are not feasible for assessing an individual participant’s treatment success and thus for determining the proportion of patients who had a beneficial response to therapy (overall response rate of an intervention). We therefore recommend a distribution-based approach to determine benchmarks of a statistically significant treatment response at the individual level, i.e., the 'smallest detectable change' for a given OMI, which refers to the smallest change that can be detected by the OMI beyond measurement error. However, the statistical significance of an individual treatment effect does not necessarily correspond to its clinical impact. This requires an additional indicator. The benchmark to determine a clinically relevant improvement on a given OMI is the 'minimal important change'. The minimally important change is defined as the smallest OMI change score perceived as important by the relevant stakeholder group (i.e., people with aphasia, their relatives/caregivers, clinicians). It therefore requires relating the individual OMI change scores to 'anchors', i.e., meaningful external criteria, preferably based on patient-perceived therapy success. Currently, there is no consensus regarding the optimal 'anchors' and their respective definition of clinically important change in aphasia outcome research. Conclusions/Recommendations Operationalising individual treatment success based on both statistically significant and (patient-reported) clinically meaningful benchmarks is a key priority in aphasia rehabilitation. Availability of such measures will (a) facilitate estimates of therapy response rate in intervention studies and thus optimise therapeutic decisions and (b) provide stakeholder groups (e.g., the society, the stroke team, people with aphasia, family, clinicians, healthcare professionals) with objective, statistically reliable and meaningful feedback on individual treatment response in the clinical setting.

485 Identifying the Minimum Clinically Important Differences (MCID) in ISNCSCI Score for Patients with Traumatic Spinal Cord Injury: An Analysis from the National Spinal Cord Injury Model Systems (SCIMS) Database

INTRODUCTION: Spinal Cord Injury (SCI) is a major cause of disability, mostly presenting due to a traumatic event such as a motor vehicle accident or a fall. To evaluate and follow-up the neurological recovery for patients with SCI, several scales, and scoring systems have been published with the collaborative multidisciplinary efforts, including the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). Identifying an MCID for this scoring system is crucial to evaluate patient improvement and provide hints about the success of any intervention. METHODS: National Spinal Cord Injury Model Systems Database was queried from 2001-2016 for patients admitted to rehabilitation centers following traumatic spinal cord injury. The following methods were used to identify MCIDs; (i) anchor-based methods where an outcome measure is selected to be the “anchor” (Functional Independence Measure) and defined changes in this anchor is linked to the changes in the investigated outcome measure (ISNCSCI motor scores) and (ii) distribution-based methods where several different parameters (Standard error of measurement, half standard deviation, etc.) are used determine one MCID. RESULTS: A total of 1,521 patients were identified. MCIDs for the overall cohort ranged from 3.25 to 6.6 for the anchor-based methods and 0.93 to 5.30 based on the distribution-based methods. Although slight changes were seen, the range of MCIDs was found to be similar to the overall cohort when cohorts were stratified by sex, the level of injury, complete/incomplete injury, and different age groups. The highest MCID was detected for patients with cervical injury in both anchor-based (9.03) and distribution-based approaches (6.06), while the lowest MCID was detected for patients with thoracic injury in both anchor-based (1.0) and distribution-based approaches (0.23). CONCLUSION: Our findings demonstrated similar results with regards to MCIDs for ISNCSCI scoring between different patient profiles (stratified by sex, the level of injury, complete/incomplete injury, and age groups) with scores ranging from 0.23 to 9.09 based on different approaches. Anchor-based methods provided higher MCIDs overall when compared to distribution-based methods.