Health state utility estimates for value assessments of novel treatments in Huntington's disease: a systematic literature review.

BACKGROUND: Huntington's disease (HD) is a progressive neurodegenerative disease with a devastating impact on patients and their families. Quantifying how treatments affect patient outcomes is critical for informing reimbursement decisions. Many countries mandate a formal value assessment in which the treatment benefit is measured as quality-adjusted life-years, calculated with the use of utility estimates that reflect respondents' preferences for health states. OBJECTIVE: To summarize published health state utility data in HD and identify gaps and uncertainties in the data available that could be used to inform value assessments. METHODS: We conducted a systematic literature review of studies that used preference-based instruments (e.g., EQ-5D and SF-6D) to estimate utility values for people with HD. The studies were published between January 2012 and December 2022. RESULTS: Of 383 articles screened, 16 articles reported utility values estimated in 11 distinct studies. The utility measure most frequently reported was EQ-5D (9/11 studies). Two studies reported SF-6D data; one used time trade-off methods to value health state descriptions (vignettes). Although utility scores generally worsened to a lower value with increased HD severity, the estimates varied considerably across studies. The EQ-5D index range was 0.89 - 0.72 for mild/prodromal HD and 0.71 - 0.37 for severe/late-stage disease. CONCLUSIONS: This study uncovered high variability in published utility estimates, indicating substantial uncertainty in existing data. Further research is needed to better understand preferences and valuation across all stages and domains of HD symptoms and the degree to which generic utility measures capture the impact of cognitive changes on quality of life.

Initial Impairment and Recovery of Vision-Related Functioning in Participants With Acute Optic Neuritis From the RENEW Trial of Opicinumab.

BACKGROUND: Leucine-rich repeat and immunoglobulin domain-containing Nogo receptor-interacting protein 1 (LINGO-1) is a key suppressor of oligodendrocyte differentiation and axonal remyelination and regeneration. This analysis evaluated the potential benefit of opicinumab, a human monoclonal antibody against LINGO-1, vs placebo on exploratory clinical endpoints of patient-reported vision-related functioning and high-contrast visual acuity (HCVA) in RENEW participants with acute optic neuritis (AON). METHODS: Participants were randomized to 100 mg/kg opicinumab intravenous or placebo every 4 weeks (6 infusions). Assessments were conducted in the per-protocol (PP) population and included: 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25), 10-item Neuro-Ophthalmic Supplement (NOS-10), and HCVA. RESULTS: The opicinumab group (n = 33) had worse mean (SD) baseline patient-reported vision-related functioning scores vs placebo (n = 36): NEI-VFQ-25 composite, 75.5 (17.6) vs 79.0 (16.6); NOS-10 composite, 63.6 (19.8) vs 69.8 (21.2), respectively. By Week 24, the placebo and opicinumab groups experienced substantial mean improvements from baseline (NEI-VFQ-25 composite, 15.17 vs 13.51 [difference (95% CI): -1.66 (-5.11 to 1.78)]; NOS-10 composite, 17.40 vs 16.04 [difference (95% CI): -1.35 (-7.38 to 4.67)]). Between-treatment differences in mean change from baseline were not significantly different at any time point. Analysis of covariance-adjusted mean recovery from baseline in HCVA at Week 24 for the affected eyes was 11.8 and 8.7 letters for placebo and opicinumab, respectively (P = 0.202). CONCLUSIONS: Most participants in the RENEW PP population demonstrated substantial recovery from baseline in patient-reported vision-related functioning and HCVA, regardless of treatment and structural damage. Average scores after recovery remained lower than those of published disease-free control groups. These results provide important information on visual function recovery in patients with AON, as measured by NEI-VFQ-25 and NOS-10.

Development of a gait module to complement the 12-item Multiple Sclerosis Walking Scale: a mixed methods study.

BACKGROUND AND OBJECTIVE: The 12-item Multiple Sclerosis Walking Scale (MSWS-12) is a patient-reported outcome instrument that quantifies the progressive loss of walking ability from the patient perspective. However, previous psychometric analyses indicated floor and ceiling effects across the multiple sclerosis severity spectrum. This study aimed to address floor effects by creating a gait module that can be used in conjunction with the MSWS-12 for better measurement of treatment benefit in the higher functioning multiple sclerosis population. METHODS: We used a step-wise mixed methods study design, with relapsing-remitting multiple sclerosis patients (wave 1, n=88; wave 2, n=30), combining qualitative (concept elicitation and cognitive debriefing interviews) and quantitative (Rasch Measurement Theory) data collection and analytical techniques and consultation interviews with three neurologists specializing in multiple sclerosis. RESULTS: Thirty-seven walking ability concepts were identified, and a five-domain conceptual framework was created. Draft items were generated and refined with patient and neurologist input. Draft items covered gait-related concepts such as dragging, shuffling, limping, tripping and falling. Rasch measurement theory psychometric analysis indicated administering MSWS-12 plus gait items improved measurement precision in targeted populations with better walking ability. CONCLUSION: Study findings indicate that new gait items could improve sensitivity to detect clinical change in walking ability for higher functioning multiple sclerosis patients.

Addressing the targeting range of the ABILHAND-56 in relapsing-remitting multiple sclerosis: A mixed methods psychometric study.

BACKGROUND: ABILHAND, a manual ability patient-reported outcome instrument originally developed for stroke patients, has been used in multiple sclerosis clinical trials; however, psychometric analyses indicated the measure's limited measurement range and precision in higher-functioning multiple sclerosis patients. OBJECTIVE: The purpose of this study was to identify candidate items to expand the measurement range of the ABILHAND-56, thus improving its ability to detect differences in manual ability in higher-functioning multiple sclerosis patients. METHODS: A step-wise mixed methods design strategy was used, comprising two waves of patient interviews, a combination of qualitative (concept elicitation and cognitive debriefing) and quantitative (Rasch measurement theory) analytic techniques, and consultation interviews with three clinical neurologists specializing in multiple sclerosis. RESULTS: Original ABILHAND was well understood in this context of use. Eighty-two new manual ability concepts were identified. Draft supplementary items were generated and refined with patient and neurologist input. Rasch measurement theory psychometric analysis indicated supplementary items improved targeting to higher-functioning multiple sclerosis patients and measurement precision. The final pool of Early Multiple Sclerosis Manual Ability items comprises 20 items. CONCLUSION: The synthesis of qualitative and quantitative methods used in this study improves the ABILHAND content validity to more effectively identify manual ability changes in early multiple sclerosis and potentially help determine treatment effect in higher-functioning patients in clinical trials.

Measuring the impact of multiple sclerosis: Enhancing the measurement performance of the Multiple Sclerosis Impact Scale (MSIS-29) using Rasch Measurement Theory (RMT).

BACKGROUND: Study objectives were to evaluate the Multiple Sclerosis Impact Scale (MSIS-29) and explore an optimized scoring structure based on empirical post-hoc analyses of data from the Phase III ADVANCE clinical trial. METHODS: ADVANCE MSIS-29 data from six time-points were analyzed in a sample of patients with relapsing-remitting multiple sclerosis (RRMS). Rasch Measurement Theory (RMT) analysis was undertaken to examine three broad areas: sample-to-scale targeting, measurement scale properties, and sample measurement validity. Interpretation of results led to an alternative MSIS-29 scoring structure, further evaluated alongside responsiveness of the original and revised scales at Week 48. RESULTS: RMT analysis provided mixed evidence for Physical and Psychological Impact scales that were sub-optimally targeted at the lower functioning end of the scales. Their conceptual basis could also stand to improve based on item fit results. The revised MSIS-29 rescored scales improved but did not resolve the measurement scale properties and targeting of the MSIS-29. In two out of three revised scales, responsiveness analysis indicated strengthened ability to detect change. CONCLUSION: The revised MSIS-29 provides an initial evidence-based improved patient-reported outcome (PRO) instrument for evaluating the impact of MS. Revised scoring improves conceptual clarity and interpretation of scores by refining scale structure to include Symptoms, Psychological Impact, and General Limitations. CLINICAL TRIAL: ADVANCE (ClinicalTrials.gov identifier NCT00906399).

Development of a new Rasch-based scoring algorithm for the National Eye Institute Visual Functioning Questionnaire to improve its interpretability.

BACKGROUND: The NEI VFQ-25 has undergone psychometric evaluation in patients with varying ocular conditions and the general population. However, important limitations which may affect the interpretation of clinical trial results have been previously identified, such as concerns with reliability and validity. The purpose of this study was to evaluate the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) and make recommendations for a revised scoring structure, with a view to improving its psychometric performance and interpretability. METHODS: Rasch Measurement Theory analyses were conducted in two stages using pooled baseline NEI VFQ-25 data for 2487 participants with retinal diseases enrolled in six clinical trials. In stage 1, we examined: scale-to-sample targeting; thresholds for item response options; item fit statistics; stability; local dependence; and reliability. In stage 2, a post-hoc revision of the scoring structure (VFQ-28R) was created and psychometrically re-evaluated. RESULTS: In stage 1, we found that the NEI VFQ-25 was mis-targeted to the sample, and had disordered response thresholds (15/25 items) and mis-fitting items (8/25 items). However, items appeared to be stable (differential item functioning for three items), have minimal item dependency (one pair of items) and good reliability (person-separation index, 0.93). In stage 2, the modified Rasch-scored NEI VFQ-28-R was assessed. It comprised two broad domains: Activity Limitation (19 items) and Socio-Emotional Functioning (nine items). The NEI VFQ-28-R demonstrated improved performance with fewer disordered response thresholds (no items), less item misfit (three items) and improved population targeting (reduced ceiling effect) compared with the NEI VFQ-25. CONCLUSIONS: Compared with the original version, the proposed NEI VFQ-28-R, with Rasch-based scoring and a two-domain structure, appears to offer improved psychometric performance and interpretability of the vision-related quality of life scale for the population analysed.

Quantifying the Benefits of Dimethyl Fumarate Over ß Interferon and Glatiramer Acetate Therapies on Work Productivity Outcomes in MS Patients.

INTRODUCTION: Dimethyl fumarate (DMF) is a novel oral therapy used for the treatment of relapse-remitting multiple sclerosis (RRMS). In two 2-year pivotal Phase 3 trials in patients with RRMS, DMF significantly reduced disease activity based on both clinical and magnetic resonance imaging (MRI) findings and demonstrated an acceptable safety profile. However, there is currently a lack of comparative data which explore the relationship between work productivity and health-related quality of life (HRQoL) outcomes in RRMS and how these differ among RRMS therapies, including DMF. METHODS: We explored this relationship through patient-reported data from the EuroQol Five-Dimensions (EQ-5D) tool, Work Productivity and Activity Impairment Questionnaire (WPAI), and the Hamburg Quality of Life Questionnaire in Multiple Sclerosis (HAQUAMS) using the Adelphi MS DSP® dataset. RESULTS: Our data demonstrated that patients receiving DMF experienced better outcomes, relative to patients receiving beta (ß)interferons or glatiramer acetate, in all WPAI subscales [overall; average treatment effect (ATE) -13.92, 95% confidence interval (CI) -18.87 to -7.08; p < 0.001], EQ-5D (ATE +0.075, 95% Cl 0.014-0.136; p = 0.016) and HAQUAMS [ATE -0.45, 95% Cl -0.61 to -0.29; p < 0.001]. The EQ-5D and HAQUAMS were used with WPAI to determine the relationship between HRQoL outcomes and work productivity. Multiple linear regression analyses were performed, adjusting for age, sex, body mass index, ethnicity and number of comorbid conditions. CONCLUSIONS: These data demonstrate that therapy with DMF was associated with increased work productivity and HRQoL for patients with RRMS and that these outcomes were consistently improved compared to outcomes with interferon and glatiramer acetate therapies.

Three-year patient-reported visual function outcomes in diabetic macular edema managed with ranibizumab: the RESTORE extension study.

OBJECTIVE: To determine the impact of ranibizumab 0.5 mg on patient-reported visual function over 36 months in individuals with visual impairment from diabetic macular edema. METHODS: RESTORE comprises a phase 3, randomized, multicenter, 12 month core study and a 24 month open-label extension study. Eyes assigned to ranibizumab in the core study received ranibizumab for 36 months; eyes assigned to laser monotherapy in the core study received ranibizumab during the extension. The primary outcome was least-squares mean change in National Eye Institute 25-item Visual Functioning Questionnaire (NEI VFQ-25) overall composite and subscale scores. RESULTS: Of 303 core study participants, 240 (79%) entered the extension, comprising 83 (35%) participants initially assigned to ranibizumab, 83 (35%) assigned to ranibizumab plus laser combination therapy, and 74 (31%) assigned to laser monotherapy. Least-squares mean (standard error) change in NEI VFQ-25 composite score from baseline to month 12 (+5.9 [1.5]; +5.0 [1.5], for the ranibizumab and combination therapy groups, respectively) decreased by month 36 (+4.1 [1.7]; +4.0 [1.7], respectively, from baseline to month 36) following reduced injection frequency relative to the core study. At 36 months, the least-squares mean (standard error) change in the laser monotherapy group was similar to that in the ranibizumab groups (+4.1 [1.8]). Most subscale scores showed outcomes similar to that for the composite score. The greatest NEI VFQ-25 gains were consistently observed in participants for whom the study eye was the better-seeing eye. LIMITATIONS: Patients entering the extension were not randomized, and 21% of the core study participants did not enter the extension, which may have affected the results. CONCLUSIONS: Gains in patient-reported visual function at month 12 among eyes receiving ranibizumab in the core study decreased slightly by 36 months. Eyes originally receiving laser monotherapy for 12 months then ranibizumab for 24 months achieved similar gains by 36 months to eyes receiving ranibizumab for 36 months. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00687804 and NCT00906464.

Treatment Satisfaction and Well-Being in Patients with Myopic Choroidal Neovascularization Treated with Ranibizumab in the REPAIR Study.

The Ranibizumab for the Treatment of Choroidal Neovascularisation (CNV) Secondary to Pathological Myopia (PM): an Individualized Regimen (REPAIR) trial was a prospective study exploring the efficacy and safety of intravitreal ranibizumab 0.5 mg using an individualized treatment regimen over 12 months. The current study investigated the impact of treatment with ranibizumab as needed (pro re nata [PRN]) on individuals with myopic choroidal neovascularization (mCNV) in the REPAIR study, using patient-reported outcome measures (PROMs) for treatment satisfaction and well-being. This study included 65 adults with mCNV and a best-corrected visual acuity (BCVA) letter score of 24-78 in the study eye. Patients completed the Macular Disease Treatment Satisfaction Questionnaire (MacTSQ) at months 1, 6 and 12, and the 12-item Well-Being Questionnaire (W-BQ12) at baseline and months 1, 6 and 12. Subgroup analyses investigated the relationship between PROM scores and treatment in the better- or worse-seeing eye (BSE/WSE), number of injections received, baseline BCVA, BCVA improvement and age. Pearson correlations between change in BCVA, MacTSQ scores and W-BQ12 scores were calculated. The main outcome measures were treatment satisfaction measured with the MacTSQ (score 0-72) and well-being measured with the W-BQ12 (score 0-36). Treatment satisfaction significantly increased over the study period (p = 0.0001). Mean MacTSQ scores increased by 9.7 and 10.0 in patients treated in their WSE and BSE, respectively. Treatment satisfaction was highest in individuals receiving only one injection at month 1; however, by month 12, scores were similar across injection subgroups. Patients aged 68 years or older had the highest MacTSQ scores. Well-being scores also significantly increased over the study period (p = 0.03). Mean W-BQ12 scores increased by 1.7 in patients treated in their WSE and by 2.1 in patients treated in their BSE. Individuals aged 40 years or younger had the greatest increases in general well-being. Patients who experienced stable or improved BCVA at month 12 had greater increases in W-BQ12 scores than those who experienced a decrease. Correlations between BCVA, MacTSQ scores and W-BQ12 scores were largely non-significant. In conclusion, treatment satisfaction and well-being increased during treatment with ranibizumab PRN. Although directly comparable data are limited for the MacTSQ and W-BQ12 in mCNV, these results complement PROM outcomes reported in related studies.

Assessment of Parkinson's disease levodopa-induced dyskinesia: a qualitative research study.

BACKGROUND AND OBJECTIVES: The 26-item Parkinson disease dyskinesia scale (PDYS-26) was developed to assess the impact of Parkinson's disease levodopa-induced dyskinesias (PD-LID). The purpose of this qualitative research study was to assess the content validity of the PDYS-26 in an independent sample and to use the findings to suggest a conceptual framework around the impact of PD-LID. METHODS: PD patients experiencing LID and their caregivers were recruited from four US clinical sites. Stage I involved 22 qualitative concept elicitation interviews with patients and caregivers, and 11 qualitative cognitive interviews (CI) with patients about the PDYS-26. The PDYS-26 was modified based on Stage I findings. Stage II consisted of 13 CI on the Modified PDYS. RESULTS: Forty-six participants were interviewed across both stages of the study. Patient mean age was 67.3 (SD ± 9.55) years; 19 (54.3 %) female; 34 (97.1 %) white. The content validity of the PDYS-26 was generally supported. A revised conceptual framework with three hypothesized domains (body control, activities of daily living, social consequences) was developed. Modifications were made to the PDYS-26 (i.e., emphasizing LID in the instructions; response scale modification; deleting or modifying items), which resulted in the 22-item Modified PDYS. CONCLUSIONS: Stage I and II findings suggested a number of modifications to the scale in order to improve the content validity. Psychometric testing of the revised scale with a larger patient sample is suggested to evaluate item performance, establish scoring, and provide quantitative support for the conceptual framework.

Using classical test theory, item response theory, and Rasch measurement theory to evaluate patient-reported outcome measures: a comparison of worked examples.

OBJECTIVE: To provide comparisons and a worked example of item- and scale-level evaluations based on three psychometric methods used in patient-reported outcome development-classical test theory (CTT), item response theory (IRT), and Rasch measurement theory (RMT)-in an analysis of the National Eye Institute Visual Functioning Questionnaire (VFQ-25). METHODS: Baseline VFQ-25 data from 240 participants with diabetic macular edema from a randomized, double-masked, multicenter clinical trial were used to evaluate the VFQ at the total score level. CTT, RMT, and IRT evaluations were conducted, and results were assessed in a head-to-head comparison. RESULTS: Results were similar across the three methods, with IRT and RMT providing more detailed diagnostic information on how to improve the scale. CTT led to the identification of two problematic items that threaten the validity of the overall scale score, sets of redundant items, and skewed response categories. IRT and RMT additionally identified poor fit for one item, many locally dependent items, poor targeting, and disordering of over half the response categories. CONCLUSIONS: Selection of a psychometric approach depends on many factors. Researchers should justify their evaluation method and consider the intended audience. If the instrument is being developed for descriptive purposes and on a restricted budget, a cursory examination of the CTT-based psychometric properties may be all that is possible. In a high-stakes situation, such as the development of a patient-reported outcome instrument for consideration in pharmaceutical labeling, however, a thorough psychometric evaluation including IRT or RMT should be considered, with final item-level decisions made on the basis of both quantitative and qualitative results.

Developing a utility index for the Aberrant Behavior Checklist (ABC-C) for fragile X syndrome.

PURPOSE: This study aimed to develop a utility index (the ABC-UI) from the Aberrant Behavior Checklist-Community (ABC-C), for use in quantifying the benefit of emerging treatments for fragile X syndrome (FXS). METHODS: The ABC-C is a proxy-completed assessment of behaviour and is a widely used measure in FXS. A subset of ABC-C items across seven dimensions was identified to include in health state descriptions. This item reduction process was based on item performance, factor analysis and Rasch analysis performed on an observational study dataset, and consultation with five clinical experts and a methodological expert. Dimensions were combined into health states using an orthogonal design and valued using time trade-off (TTO), with lead-time TTO methods used where TTO indicated a state valued as worse than dead. Preference weights were estimated using mean, individual level, ordinary least squares and random-effects maximum likelihood estimation [RE (MLE)] regression models. RESULTS: A representative sample of the UK general public (n = 349; mean age 35.8 years, 58.2% female) each valued 12 health states. Mean observed values ranged from 0.92 to 0.16 for best to worst health states. The RE (MLE) model performed best based on number of significant coefficients and mean absolute error of 0.018. Mean utilities predicted by the model covered a similar range to that observed. CONCLUSIONS: The ABC-UI estimates a wide range of utilities from patient-level FXS ABC-C data, allowing estimation of FXS health-related quality of life impact for economic evaluation from an established FXS clinical trial instrument.

Patient-reported visual function outcomes improve after ranibizumab treatment in patients with vision impairment due to diabetic macular edema: randomized clinical trial.

IMPORTANCE: Few data are available on relative changes in vision-related function after treatment for diabetic macular edema (DME). OBJECTIVE: To determine the impact of intravitreal ranibizumab, 0.5 mg, compared with laser on patient-reported visual function. DESIGN: Phase 3, randomized, double-masked, 12-month study (RESTORE). SETTING: Outpatient retina practices in Australia, Canada, and Europe. PARTICIPANTS: Patients 18 years or older with type 1 or 2 diabetes mellitus and visual impairment due to DME. INTERVENTIONS: Patients were randomized to ranibizumab plus sham laser (n = 116), ranibizumab plus laser (n = 118), or sham injections plus laser (n = 111). Ranibizumab and sham injections were given for 3 consecutive months then as needed; laser or sham laser treatment was given at baseline then as needed. MAIN OUTCOMES AND MEASURES: National Eye Institute Visual Functioning Questionnaire 25 (NEI VFQ-25) scores at 0, 3, and 12 months for patients receiving 1 or more study treatments with 1 or more postbaseline NEI VFQ-25 assessments and last observation carried forward for missing data. RESULTS: Mean baseline NEI VFQ-25 composite scores were 72.8, 73.5, and 74.1 in the ranibizumab, laser, and ranibizumab plus laser groups, respectively. At 12 months, the mean composite scores (95% CIs) improved by 5.0 (ranibizumab vs laser, 2.6 to 7.4; P = .01 vs laser) and 5.4 (ranibizumab plus laser vs laser alone, 3.3 to 7.4; P = .004 vs laser) from baseline in the ranibizumab and ranibizumab plus laser groups, respectively, compared with 0.6 (-1.8 to 3.0) for the laser group. Near activities scores improved by 9.0 (ranibizumab vs laser, 5.0 to 13.0; P = .01) and 9.1 (ranibizumab plus laser vs laser, 5.6 to 12.6; P = .006) compared with 1.1 (-3.0 to 5.2) for the laser group, whereas distance activities scores improved by 5.3 (ranibizumab vs laser, 1.8 to 8.9; P = .04) and 5.6 (ranibizumab plus laser vs laser, 2.3 to 9.0; P = .03) compared with 0.4 (-3.1 to 3.8) for the laser group. Patients with better baseline visual acuity or lower central retinal thickness had greater improvements with ranibizumab treatment compared with laser in composite and some subscale scores compared with patients with worse visual acuity or higher central retinal thickness. CONCLUSIONS AND RELEVANCE: These data provide vision-related, patient-reported outcome evidence that mirrors visual acuity outcomes and supports benefits from ranibizumab or ranibizumab plus laser treatment for patients with DME and characteristics similar to those enrolled in this randomized clinical trial. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00687804.

Development of the Shortness of Breath with Daily Activities questionnaire (SOBDA).

OBJECTIVES: Based on qualitative research of patients with chronic obstructive pulmonary disease (COPD), the Shortness of Breath (SOB) with Daily Activities (SOBDA) questionnaire was developed as a patient-reported outcome instrument to evaluate the impact of therapy on SOB and assess how SOB affects daily activities. METHODS: Development of the SOBDA questionnaire consisted of three components. First, focus groups of patients with COPD were asked to describe their experiences of SOB with daily activities. A pool of items was drafted on the basis of information from the focus groups and literature reviews, and then discussed among instrument development and clinical experts. Cognitive debriefing interviews of patients were conducted to assess the draft item pool, and their feedback was used to develop newer versions of the questionnaire. Input was also sought from the Food and Drug Administration, patients, and clinicians. RESULTS: Forty patients participated in seven focus groups. The terms most often used to describe SOB were "short of breath" or "difficulty breathing." Patients were clearly able to distinguish SOB from chest congestion and wheezing, other common symptoms associated with COPD. The resulting item pool contained 37 items to assess SOB associated with everyday activities, and concept saturation was reached. Thirty-seven patients participated in the subsequent cognitive debriefing interviews. Patients found the items clear and easy to understand with relevance to their everyday experiences, and easy to use in an electronic format. CONCLUSIONS: Instructions and response options to the SOBDA questionnaire were well understood by patients with COPD, and item relevance was confirmed. Prospective validation and item reduction studies are highly anticipated.

Utility estimation in chronic obstructive pulmonary disease: a preference for change?

Economic evaluations of chronic obstructive pulmonary disease (COPD) incorporate utilities through multi-attribute utility (MAU) measures, most commonly the EQ-5D, to report health-related quality-of-life (HR-QOL) changes or differences. Questions have been raised about the sensitivity of these measures in COPD. Limitations in detecting adequate patient-level changes in HR-QOL over time in stable and exacerbation states compared with disease-specific instruments could also result in underestimation of known treatment benefits. The purpose of this article was to present and discuss the empirical evidence on the validity of generic MAU measures within the COPD population. We built upon a previously conducted validation review for the period 1997-2007 that used 'respiratory disease' and 'EQ-5D' as keywords. For this discussion, PubMed and EMBASE databases were searched for articles in English from 1988 to August 2009, using similar search words. Based on the performance of MAU measures in COPD and exacerbations, they appear to have limited discriminatory ability, particularly between moderate and severe COPD, despite known differences in HR-QOL. Sensitivity to clinically relevant change in stable COPD over time due to treatment also appears limited. Current research suggests adequate sensitivity regarding detecting the onset and resolution of an exacerbation; however, sensitivity is limited in the short term, such as daily changes in health status. The evidence suggests responsiveness of MAU measures may be restricted to large within-patient change, which leads to difficulties in evaluating the subtle but important impact of exacerbations. Studies presenting alternative methods of deriving COPD-related utilities are also discussed. Overall, the insensitivities of generic MAU measures in COPD can lead to biased cost-effectiveness analyses and ill-informed economic decisions. Alternative measures such as condition-specific preference-based measures may be used in circumstances where more sensitivity is needed. The trade-off allows relevant and sensitive matters most important to patients to be evaluated; however inevitable gaps such as those related to adverse events are not considered.

Development of the EXACT-U: a preference-based measure to report COPD exacerbation utilities.

BACKGROUND: The exacerbations of chronic obstructive pulmonary disease tool (EXACT) is a condition-specific daily diary recently developed to evaluate the frequency, severity, and duration of chronic obstructive pulmonary disease (COPD) exacerbations. A preference-based algorithm for the EXACT would allow utilities to be reported from patients during an exacerbation when EQ-5D data are not available. OBJECTIVE: To develop the exacerbations of chronic obstructive pulmonary disease tool-utility (EXACT-U), a condition-specific preference-based measure to report utilities from the EXACT for use in cost-effectiveness studies. METHODS: Five items with three to five levels comprise the EXACT-U. Two groups of health states and respondents were constructed to allow for model development (Development group) and predictive validity testing (Validation group) using independent samples. Members of the UK general public each valued 11 randomized health states using time trade-offs (TTOs) scaled from full health/dead with 10-year durations. Regression models estimated from the Development group using individual data, mean data, and panel designs. Models assessed by number of inconsistent coefficients estimated and R(2) and tested against observed utilities from the Validation group using mean absolute error (MAE) and root mean squared error (RMSE). RESULTS: A total of 55 health states, including the best and worst states, were valued in TTO interviews conducted with 400 respondents. Ten models were developed. The final preferred model contained no logical inconsistencies and found MAE = 0.04 and RMSE = 0.05 with a predicted utility range from 0.09 to 0.95. CONCLUSIONS: The EXACT-U is a condition-specific preference-based measure with strong predictive validity to report daily utilities during an exacerbation.

Development of the EXAcerbations of Chronic Obstructive Pulmonary Disease Tool (EXACT): a patient-reported outcome (PRO) measure.

BACKGROUND: This article describes the qualitative methods used to develop the EXAcerbation of Chronic Pulmonary Disease Tool (EXACT), a new patient-reported outcome (PRO) instrument for evaluating frequency, severity, and duration of exacerbations of chronic obstructive pulmonary disease (COPD). METHODS: Focus groups and interviews were conducted in the United States with COPD patients treated for exacerbations during the past 6 months. Participants were asked to describe exacerbation attributes, care-seeking cues, and indications of progression and recovery. An iterative process was used to identify themes in the data to inform instrument content and structure. Cognitive debriefing interviews were performed to evaluate and revise the draft item pool. Experts in COPD, instrument development, and clinical research participated in the process. RESULTS: Eighty-three subjects participated in elicitation focus groups or interviews (n=48); elicitation interviews with cognitive debriefing (n=23), or cognitive interviews alone (n=12). Mean age of the sample was 65 years (SD=10); 45% were male; mean FEV-1% predicted was 44% (SD=16). Participants characterized exacerbations as a persistent increase in the severity of respiratory symptoms and other systemic manifestations accompanied by a dramatic reduction in activity. Specific attributes included shortness of breath, chest congestion, cough, sputum, chest discomfort, feeling weak or tired, sleep disturbances, and concern or worry. The diary card of 23 candidate items was debriefed in booklet and electronic format. CONCLUSIONS: Qualitative data from patients and input from experts formed the basis of the EXACT's structure and item pool, ready for empirically based item reduction and reliability and validity testing.

Development and validation of the patient and clinician sedation satisfaction index for colonoscopy and upper endoscopy.

BACKGROUND & AIMS: Recent increases in gastrointestinal endoscopic procedures and sedation options show a need for better sedation evaluation. This article describes the development and validation of 2 instruments: the Patient Satisfaction with Sedation Instrument (PSSI) and the Clinician Satisfaction with Sedation Instrument (CSSI) for assessing satisfaction in patients undergoing outpatient upper endoscopy and colonoscopy. METHODS: A total of 118 patients who underwent outpatient colonoscopy or esophagogastroduodenoscopy and 22 physicians were recruited across 5 US gastroenterology practices. Physicians completed the CSSI and patients completed the PSSI after each procedure. Patients completed the SF-12 Health Survey, Patient Satisfaction Questionnaire, and Socially Desirable Response Scale; clinicians completed the Observer's Assessment of Alertness Scale after procedures. RESULTS: Study patients were mostly women (59%), white (88%), had a mean age of 57.5 +/- 15.7 years, and had a colonoscopy (70%). Internal consistency reliabilities assessed result consistencies across test items. Coefficients greater than 0.70 indicate good reliability; greater than 0.85 indicate excellent reliability. Internal consistency reliabilities of the PSSI and CSSI total and subscale scores were greater than 0.76. Correlations were assessed using Pearson product moment correlation. PSSI and CSSI scores were correlated (P < .05). PSSI totals scores were correlated significantly with the SF-12 Health Survey (P < .05), the Patient Satisfaction Questionnaire (P < .05), and CSSI total scores were correlated with the Observer's Assessment of Alertness Scale (P < .01) and a visual analogue scale (P < .01). PSSI scores were not correlated with the Socially Desirable Response Scale (P > .05). CONCLUSIONS: The PSSI and CSSI provide for feasible, reliable, and valid assessment of procedural sedation satisfaction for outpatient colonoscopy and esophagogastroduodenoscopies and can be used for future sedation studies.

Converting condition-specific measures into preference-based outcomes for use in economic evaluation.

Quality-adjusted life-years (QALYs) play an important role in reimbursement decisions when one of the criteria is the cost-effectiveness of the health technology. While for many generic QALYs (e.g., based on the EQ-5D) are viewed as the gold standard, there has been a considerable increase in interest in using condition-specific data to generate QALYs. There are two main methods: mapping from the condition-specific data to a generic health-related quality of life measure; and direct valuation of condition-specific health states. Whether one believes condition-specific data are useful even if generic QALY data are available, or simply that condition-specific data are helpful in the absence of generic measures of health-related quality of life, it is timely to review recent research activity directed at making greater use of condition-specific data to inform assessments of cost-effectiveness.