Development of physical and mental health summary scores from the patient-reported outcomes measurement information system (PROMIS) global items

Background  The use of global health items permits an efficient way of gathering general perceptions of health. These items provide useful summary information about health and are predictive of health care utilization and subsequent mortality. Methods  Analyses of 10 self-reported global health items obtained from an internet survey as part of the Patient-Reported Outcome Measurement Information System (PROMIS) project. We derived summary scores from the global health items. We estimated the associations of the summary scores with the EQ-5D index score and the PROMIS physical function, pain, fatigue, emotional distress, and social health domain scores. Results  Exploratory and confirmatory factor analyses supported a two-factor model. Global physical health (GPH; 4 items on overall physical health, physical function, pain, and fatigue) and global mental health (GMH; 4 items on quality of life, mental health, satisfaction with social activities, and emotional problems) scales were created. The scales had internal consistency reliability coefficients of 0.81 and 0.86, respectively. GPH correlated more strongly with the EQ-5D than did GMH (r = 0.76 vs. 0.59). GPH correlated most strongly with pain impact (r = −0.75) whereas GMH correlated most strongly with depressive symptoms (r = −0.71). Conclusions  Two dimensions representing physical and mental health underlie the global health items in PROMIS. These global health scales can be used to efficiently summarize physical and mental health in patient-reported outcome studies.     

Comparison of the PROMIS Preference Score (PROPr) and EQ-5D-5L Index Value in General Population Samples in the United Kingdom,France, and Germany

ObjectivesThe Patient-Reported Outcome Measurement Information System (PROMIS) Preference score (PROPr) can be used to assess health state utility (HSU) and estimate quality-adjusted life-years in cost-effectiveness analyses. It is based on item response theory and promises to overcome limitations of existing HSU scores such as ceiling effects. The PROPr contains 7 PROMIS domains: cognitive abilities, depression, fatigue, pain, physical function, sleep disturbance, and ability to participate in social roles and activities. We aimed to compare the PROPr with the 5-level EQ-5D (EQ-5D-5L) in terms of psychometric properties using data from 3 countries.MethodsWe collected PROMIS-29 profile and EQ-5D-5L data from 3 general population samples (United Kingdom = 1509, France = 1501, Germany = 1502). Given that cognition is not assessed by the PROMIS-29, it was predicted by the recommended linear regression model. We compared the convergent validity, known-groups construct validity, and ceiling and floor effects of the PROPr and EQ-5D-5L.ResultsThe mean PROPr (0.48, 0.53, 0.48; P<.01) and EQ-5D-5L scores (0.82, 0.85, 0.83; P<.01) showed significant differences of similar magnitudes (d = 0.34; d = 0.32; d = 0.35; P<.01) across all samples. The differences were invariant to sex, income, occupation, education, and most conditions but not for age. The Pearson correlation coefficients between both scores were r = 0.74, r = 0.69, and r = 0.72. PROPr’s ceiling and floor effects both were minor to moderate. The EQ-5D-5L’s ceiling (floor) effects were major (negligible).ConclusionsBoth the EQ-5D-5L and the PROPr assessed by the PROMIS-29 show high validity. The PROPr yields considerably lower HSU values than the EQ-5D-5L. Consequences for quality-adjusted life-year measurements should be investigated in future research.     

A Direct Comparison of the Measurement Properties of EQ-5D-5L,PROMIS-29+2 and PROMIS Global Health Instruments and EQ-5D-5L and PROPr Utilities in a General Population Sample

ObjectivesWe aimed to compare measurement properties of the 5-level version of EQ-5D (EQ-5D-5L) and 2 Patient-Reported Outcomes Measurement Information System (PROMIS) short forms, PROMIS-29+2 and PROMIS Global Health (PROMIS-GH-10), and of EQ-5D-5L and PROMIS-preference scoring system (PROPr) utilities.MethodsA cross-sectional survey was conducted in a general population sample in Hungary (N = 1631). We compared the following measurement properties at the level of items, domains, and utilities, the latter using corresponding US value sets: ceiling and floor, informativity (Shannon’s indices), agreement, convergent, and known-group validity. For the analyses, PROMIS items/domains were matched to EQ-5D-5L domains that cover similar concepts of health.ResultsThe majority of PROMIS items showed enhanced distributional characteristics, including lower ceilings and higher informativity than the EQ-5D-5L. Good convergent validity was established between EQ-5D-5L and PROMIS domains capturing similar aspects of health. Mean EQ-5D-5L utilities were substantially higher than those of PROPr (0.864 vs 0.535). EQ-5D-5L utilities correlated moderately or strongly with PROPr (r = 0.61), PROMIS-GH-10 physical (r = 0.68), and mental health summary scores (r = 0.53). EQ-5D-5L utilities decreased with age, whereas PROPr utilities slightly increased with age. EQ-5D-5L utilities discriminated significantly better in 12/28 (ratio of F-statistics) and 18/26 (area under the receiver-operating characteristics curve ratio) known groups defined by age, self-perceived health status, and self-reported physician-diagnosed health conditions, including hypertension, diabetes, coronary heart disease, chronic kidney disease, and stroke.ConclusionsThis study provides comparative evidence on the measurement properties of EQ-5D-5L, PROMIS-29+2, and PROMIS-GH-10 and informs decisions about the choice of instruments in population health surveys for assessment of patients’ health and for cost-utility analyses.     

EQ-5D in a general population survey – A description of the most commonly reported EQ-5D health states using the SF-36

The importance of studying health-related quality of life in the general population has increasingly been emphasized. From a public health perspective, this benefits the identification of population inequalities in health status. One of the currently most popular instruments is the EQ-5D. Evaluations of the EQ-5D generally focus on the overall preference-based index. As this index has a built-in value, exploration of the information from the underlying health states is also important. In this study, the ten most commonly reported EQ-5D health states are described using the SF-36. Data collected in 1999 by questionnaires mailed to a random sample aged 20-74 in south-eastern Sweden were used (n = 9489). Almost 43% reported the best possible EQ-5D health state and 78% were accounted for by three EQ-5D health states. The EQ-5D health state classification was largely reflected by the SF-36, with the EQ-5D items mobility, usual activities, pain/discomfort and anxiety/depression tapping most clearly on the SF-36 scales physical functioning, role limitations due to physical health problems, bodily pain, and mental health, respectively. However, within the same level of EQ-5D (i.e., moderate problems) there was a rather large variation of SF-36 scale scores, particularly regarding the EQ-5D item pain/discomfort and the SF-36 scale BP.     

An item response analysis of the pediatric PROMIS anxiety and depressive symptoms scales

Purpose  

The Patient-Reported Outcomes Measurement Information System (PROMIS) aims to develop self-reported item banks for clinical research. The PROMIS pediatrics (aged 8–17) project focuses on the development of item banks across several health domains (physical function, pain, fatigue, emotional distress, social role relationships, and asthma symptoms). The psychometric properties of the anxiety and depressive symptom item banks are described.     

Patient-reported outcomes measurement information system (PROMIS) domain names and definitions revisions: further evaluation of content validity in IRT-derived item banks

Purpose  

Content validity of patient-reported outcomes (PROs) is evaluated primarily during item development, but subsequent psychometric analyses, particularly for item response theory (IRT)-derived scales, often result in considerable item pruning and potential loss of content. After selecting items for the PROMIS banks based on psychometric and content considerations, we invited external content expert reviews of the degree to which the initial domain names and definitions represented the calibrated item bank content.     

Mapping World Health Organization Quality of Life–BREF Onto 5-Level EQ-5D in Thai Patients With Chronic Diseases

ObjectivesThis study aimed to map the World Health Organization Quality of Life–BREF (WHOQOL-BREF) onto the 5-level EQ-5D (EQ-5D-5L) using a real Thai valuation set of the EQ-5D-5L. The second objective was to explore the impacts of the differences between observed and predicted EQ-5D-5L index scores on the incremental cost-utility ratio (ICUR) using 5 hypothetical scenarios.MethodsThis is a secondary data analysis. A total of 800 outpatients with chronic diseases were recruited from 2 university hospitals in Bangkok, Thailand, between July 2014 and March 2015. The 800 patients were randomly divided into 2 samples: estimation and validation samples. The estimation sample was used to assess the relationships between the EQ-5D-5L index score and 4 WHOQOL-BREF dimension scores and to find the best-fit model and its equation. For the validation sample, the equation of the best-fit model from the estimation sample was used to calculate predicted EQ-5D-5L index scores.ResultsA multiple linear regression showed that only the physical domain of the WHOQOL-BREF was significantly associated with the EQ-5D-5L. Among 11 regression models, the curve estimation found that the inverse model was the best-fit model. The prediction equation of EQ-5D-5L was equal to 1.385 minus 7.572/physical domain of the WHOQOL-BREF. The impacts of the differences between the observed and predicted EQ-5D-5L index scores on ICUR were only 0.4% to 1.8% from the base case.ConclusionsA nonlinear relationship between the physical domain of the WHOQOL-BREF and EQ-5D-5L utility was shown. The impacts of the differences between the observed and predicted EQ-5D-5L index scores on ICUR were minimal.     

Correspondence between EQ-5D health state classifications and EQ VAS scores

Background  

The EQ-5D health-related quality of life instrument comprises a health state classification followed by a health evaluation using a visual analogue scale (VAS). The EQ-5D has been employed frequently in economic evaluations, yet the relationship between the two parts of the instrument remains ill-understood. In this paper, we examine the correspondence between VAS scores and health state classifications for a large sample, and identify variables which contribute to determining the VAS scores independently of the health states as classified.     

A Comparison of a Preliminary Version of the EQ-HWB Short and the 5-Level Version EQ-5D

ObjectivesThe EQ Health and Wellbeing Short (EQ-HWB-S) is a new broad generic measure of health and wellbeing for use in economic evaluations of interventions across healthcare, social care, and public health. This measure conceptually overlaps with the 5-level version EQ-5D (EQ-5D-5L), while expanding on the coverage of health and social care related dimensions. This study aims to examine the extent to which the EQ-HWB-S and EQ-5D-5L overlap and are different.MethodsA sample of US-based respondents (n = 903; n = 400 cancer survivors and n = 503 general population) completed a survey administered via an online panel. The survey included the EQ-HWB item pool (62 items, including 11 items used in this analysis), EQ-5D-5L, and questions about sociodemographic and health characteristics. The analysis included (Spearman’s) correlations, the comparison of patterns of response (distributions and ceiling effects), and the ability to discriminate between known groups.ResultsModerate to strong associations were found between conceptually overlapping dimensions of the EQ-5D-5L and the EQ-HWB-S (r_s > 0.5, P < .001). Among respondents reporting full health on the EQ-5D-5L (n = 161, 18.23%), the EQ-HWB-S identified ceiling effects, particularly with the item “feeling exhausted.” Most EQ-5D-5L and EQ-HWB-S items demonstrated discriminative ability among those with and without physical and mental conditions, yielding medium (> 0.5) to large effect sizes (> 0.8). Nevertheless, only EQ-HWB-S items distinguished between caregivers and noncaregivers and those with low and high caregiver burden, albeit with small effect sizes (0.2-0.5).ConclusionsResults indicate a convergence between the measures, especially between overlapping dimensions, lending support to the validity of the EQ-HWB-S. The EQ-HWB-S performed similarly or better than the EQ-5D-5L among patient groups and is better able to differentiate among caregivers and respondents closer to full health.     

The Patient-Reported Outcomes Measurement Information System (PROMIS) developed and tested its first wave of adult self-reported health outcome item banks: 2005–2008

ObjectivesPatient-reported outcomes (PROs) are essential when evaluating many new treatments in health care; yet, current measures have been limited by a lack of precision, standardization, and comparability of scores across studies and diseases. The Patient-Reported Outcomes Measurement Information System (PROMIS) provides item banks that offer the potential for efficient (minimizes item number without compromising reliability), flexible (enables optional use of interchangeable items), and precise (has minimal error in estimate) measurement of commonly studied PROs. We report results from the first large-scale testing of PROMIS items.Study Design and SettingFourteen item pools were tested in the U.S. general population and clinical groups using an online panel and clinic recruitment. A scale-setting subsample was created reflecting demographics proportional to the 2000 U.S. census.ResultsUsing item-response theory (graded response model), 11 item banks were calibrated on a sample of 21,133, measuring components of self-reported physical, mental, and social health, along with a 10-item Global Health Scale. Short forms from each bank were developed and compared with the overall bank and with other well-validated and widely accepted (“legacy”) measures. All item banks demonstrated good reliability across most of the score distributions. Construct validity was supported by moderate to strong correlations with legacy measures.ConclusionPROMIS item banks and their short forms provide evidence that they are reliable and precise measures of generic symptoms and functional reports comparable to legacy instruments. Further testing will continue to validate and test PROMIS items and banks in diverse clinical populations.     

Having a fit: impact of number of items and distribution of data on traditional criteria for assessing IRT’s unidimensionality assumption

Purpose  Confirmatory factor analysis fit criteria typically are used to evaluate the unidimensionality of item banks. This study explored the degree to which the values of these statistics are affected by two characteristics of item banks developed to measure health outcomes: large numbers of items and nonnormal data. Methods  Analyses were conducted on simulated and observed data. Observed data were responses to the Patient-Reported Outcome Measurement Information System (PROMIS) Pain Impact Item Bank. Simulated data fit the graded response model and conformed to a normal distribution or mirrored the distribution of the observed data. Confirmatory factor analyses (CFA), parallel analysis, and bifactor analysis were conducted. Results  CFA fit values were found to be sensitive to data distribution and number of items. In some instances impact of distribution and item number was quite large. Conclusions  We concluded that using traditional cutoffs and standards for CFA fit statistics is not recommended for establishing unidimensionality of item banks. An investigative approach is favored over reliance on published criteria. We found bifactor analysis to be appealing in this regard because it allows evaluation of the relative impact of secondary dimensions. In addition to these methodological conclusions, we judged the items of the PROMIS Pain Impact bank to be sufficiently unidimensional for item response theory (IRT) modeling.     

An Investigation of Age-Related Differential Item Functioning in the EQ-5D-5L Using Item Response Theory and Logistic Regression

ObjectivesIn economic evaluations, quality of life is measured using patient-reported outcome measures (PROMs), such as the EQ-5D-5L. A key assumption for the validity of PROMs data is measurement invariance, which requires that PROM items and response options are interpreted the same across respondents. If measurement invariance is violated, PROMs exhibit differential item functioning (DIF), whereby individuals from different groups with the same underlying health respond differently, potentially biasing scores. One important group of healthcare consumers who have been shown to have different views or priorities over health is older adults. This study investigates age-related DIF in the EQ-5D-5L using item response theory (IRT) and ordinal logistic regression approaches.MethodsMultiple-group IRT models were used to investigate DIF, by assessing whether older adults aged 65+ years and younger adults aged 18 to 64 years with the same underlying health had different IRT parameter estimates and expected item and EQ-5D-5L level sum scores. Ordinal logistic regression was also used to examine whether DIF resulted in meaningful differences in expected EQ level sum scores. Effect sizes examined whether DIF indicated meaningful score differences.ResultsThe anxiety/depression item exhibited meaningful DIF in both approaches, with older adults less likely to report problems. Pain/discomfort and mobility exhibited DIF to a lesser extent.ConclusionsWhen using the EQ-5D-5L to evaluate interventions and make resource allocation decisions, scoring bias due to DIF should be controlled for to prevent inefficient service provision, where the most cost-effective services are not provided, which could be detrimental to patients and the efficiency of health budgets.     

A comparison of EQ-5D index scores derived from the US and UK population-based scoring functions.

The authors recently introduced a new preference-based scoring function for the EQ-5D (D1 model) based on time tradeoff valuations from the general adult US population: In this study, they compared the EQ-5D index scores derived from the US (D1) algorithm to the more familiar UK (N3) algorithm. They compared preference-based EQ-5D index scores for all possible EQ-5D health states and differences in EQ-5D index scores between pairs of EQ-5D health states predicted by the D1 and N3 models. The responsiveness of D1- and N3-predicted EQ-5D index scores was assessed using simulated transitions between EQ-5D health states. The mean (SD) EQ-5D index scores for all 243 health states predicted by the D1 and N3 models were 0.37 (0.23) and 0.14 (0.31), respectively. The mean (SD) absolute difference in EQ-5D index scores for all 29,403 pairs of health states was 0.25 (0.19) and 0.35 (0.27), according to the D1 and N3 models, respectively. The D1 and N3 models were consistent in predicting gains/losses for 27,592 (94%) transitions between EQ-5D health state pairs; Cohen effect size, calculated using these 27,592 consistent transitions, was 1.58 and 1.59 for the D1 and N3 models, respectively. Based on these simulation results, it appears that the D1 model would lead to smaller gains in quality-adjusted life years than the N3 model; however, their responsiveness appears to be similar. Empirical studies are needed to examine whether these 2 EQ-5D scoring functions would lead to different conclusions in cost-utility analyses.     

The Development of a New International Generic Measure (EQ-HWB): Face Validity and Psychometric Stages in Argentina

ObjectivesThis study aimed to present the face validity and psychometric stages performed in Spanish in Argentina, the only Spanish-speaking country of an international collaboration that undertook the construction of a new measure that can be used in economic evaluation across health, social care, and public health, the EQ EQ-HWB (EQ Health and Wellbeing). We also explored the relationship among 3-level version EQ-5D (EQ-5D-3L), 5-level version EQ-5D (EQ-5D-5L), and EQ-HWB.MethodsFace validity was based on semistructured face to face interviews of a purposive sample to explore translatability of language and concepts of 97 candidate items, translated into Argentina Spanish. The psychometric evaluation using an online panel assessed the psychometric properties of 64 items that were carried forward (floor and ceiling effects, item correlations, known-group differences in relevant prespecified subgroups by the international and local teams, exploratory and confirmatory factor analysis, and item response theory). EQ-5D-3L, EQ-5D-5L, and EQ-HWB correlations were explored.ResultsIn the face validity stage, 24 interviews with carers, general public, patients, and users of social services were included. Most items showed adequate face validity. In the psychometric assessment, 497 participants were recruited (64% reporting a long-term health condition). Most of the items showed adequate psychometrics in an Argentinian context. EQ-5D-3L and EQ-5D-5L had strong correlations, and EQ-HWB was moderately correlated to EQ visual analog scale. The Argentina team recommended 23 of the final 25 items.ConclusionsThe assessment of Spanish items contributed to the overall development of EQ-HWB and helped inform the design of an internationally relevant 25-item and a short 9-item measure intended to be used in economic evaluations.     

Mapping of the PDQ-39 to EQ-5D scores in patients with Parkinson’s disease

Purpose

The EuroQoL (EQ-5D) is ideal to compare quality of life across conditions. However, the Parkinson’s Disease Questionnaire (PDQ-39) is often the only quality-of-life instrument used in Parkinson’s disease research. We aimed to identify associations between PDQ-39 domains and EQ-5D domains, and compare different methods of developing a function to map the PDQ-39 to EQ-5D scores.

Methods

Adults with Parkinson’s disease self-completed both instruments. Ordinal regression identified associations between PDQ-39 domain scores and each EQ-5D domain. Modeling (n = 80) and validation sets (n = 16) were randomly generated. Overall performance of four methods of mapping the PDQ-39 to EQ-5D scores (using PDQ-39 domains and total score in ordinal and linear regression) was assessed with the validation set, followed by assessing the equivalence of observed and predicted EQ-5D scores on the full dataset controlling for sociodemographic factors.

Results

Different sets of PDQ-39 domains were associated with each EQ-5D domain. For example, PDQ-39 “Activities of Daily Living” and “Social Support” were associated with EQ-5D “Personal Care,” while PDQ-39 “Emotional Well-being” was associated with EQ-5D “Anxiety/Depression.” Over one-third (37.5 %) of predictions from ordinal regressions had an error <0.01 % (compared to 6.3 % for linear regressions). The EQ-5D scores predicted with ordinal regression using PDQ-39 domains were similar in distribution and association with sociodemographic factors to the observed EQ-5D scores.

Conclusions

Of the four methods tested, using PDQ-39 domains in ordinal regression was superior for mapping EQ-5D scores. The function reported here may prove particularly useful for cost-utility analyses comparing Parkinson’s disease with other conditions.     

Feasibility and validity of EQ-5D-5L proxy by nurses in measuring health-related quality of life of nursing home residents

Objective

Our study examined the feasibility and validity of the EQ-5D-5L proxy questionnaire in measuring health-related quality of life (HRQoL) of nursing home residents.

Methods

Twenty-four nurses and 229 residents from 3 nursing homes in Singapore participated in this cross-sectional study. Nurses assessed residents under their care with the EQ-5D-5L proxy questionnaire. Two experienced mappers conducted Dementia Care Mapping (DCM) within 1 month in a subsample of the residents. Feasibility was evaluated according to percentage of unanswered EQ-5D-5L items and proportion of nurses who failed to respond to all items. Convergent validity was assessed by examining the correlation between EQ-5D-5L measures and DCM scores. Known-groups validity was assessed by comparing differences in EQ-5D-5L scores for residents with varying communication abilities and physical functions.

Results

The nurses’ mean age was 35.4 years while the residents’ was 73.4 years. Most residents were female (51.3%) and had the ability to communicate (81.3%). For 6 of the 229 residents (2.6%), not all items in the EQ-5D-5L were completed. The EQ-5D-5L index score correlated positively and moderately with the DCM’s well/ill-being score (r?=?0.433, n?=?90, P?<?0.01). Residents who were able to communicate effectively or had better physical function were assessed to have less severe health problems and better EQ-5D-5L scores.

Conclusion

The EQ-5D-5L proxy questionnaire has adequate feasibility and validity when used by nurses to assess the HRQoL of nursing home residents. As it is brief and can be conveniently administered, it can be deployed on a larger scale to assess HRQoL of nursing home residents.

     

Change in health status (EQ-5D) over 5 years among individuals with and without type 2 diabetes mellitus in the SHIELD longitudinal study

ABSTRACT: BACKGROUND: Health-related quality of life studies among adults with type 2 diabetes mellitus, using the EQ-5D, have been short term and have not assessed change over years. This study assessed the change in health status and health-related quality of life over 5 years among individuals with and without diabetes. METHODS: Respondents to the US Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD) completed the EuroQol-5D (EQ-5D) at baseline (2004) and 5 years later (2009). Visual analog scale (VAS) score and health index score were computed at baseline and year 5, and the change over 5 years was measured for individuals with type 2 diabetes mellitus (T2DM) and those without diabetes, and T2DM adults with and without diabetic complications. Linear regression models were used to determine change in EQ-5D score, controlling for age, gender, race, education, household income, and body mass index (BMI). RESULTS: There was significantly greater decline in the EQ-5D index score in the T2DM group (-0.031 [SD 0.158]), compared with those without diabetes (-0.016 [0.141], p = 0.001). Compared with respondents without diabetes, those with T2DM had a larger reduction in EQ-5D index score, after controlling for demographics (p = 0.001). EQ-5D VAS score declined over 5 years for both groups: -1.42 (18.1) for the T2DM group, and -0.63 (15.8) for the group without diabetes, but the between-group difference was not significant either before (p = 0.09) or after (p = 0.12), controlling for demographics. T2DM respondents with diabetic complications had a greater decline in EQ-5D scores than T2DM respondents without complications (p < 0.05). CONCLUSION: Over a 5-year period, health status of respondents with T2DM declined significantly compared with those with no diabetes, indicating that the burden of the disease has a long-term detrimental impact. This decline in health status is likely to impact utility scores (fewer quality-adjusted life years) for economic evaluations.