Measuring PROMIS pain interference in German patients with chronic conditions: calibration, validation, and cross-cultural use of item parameters

PURPOSE

To calibrate the item parameters of the German PROMIS® Pain interference (PROMIS PI) items using an item-response theory (IRT) model and investigate psychometric properties of the item bank.

METHODS

Forty items of the PROMIS PI item bank were collected in a convenience sample of 660 patients, which were recruited during inpatient rheumatological treatment or outpatient psychosomatic medicine visits in Germany. Unidimensionality, monotonicity, and local independence were tested as required for IRT analyses. Unidimensionality was examined using confirmatory factor analyses (CFA) and exploratory factor analysis (EFA). Unidimensional and bifactor graded-response IRT models were fitted to the data. Bifactor indices were used to investigate whether multidimensionality would lead to biased scores. To evaluate convergent and discriminant validity, the item bank was correlated with legacy pain instruments. Potential differential item functioning (DIF) was examined for gender, age, and subsample. To investigate whether U.S. item parameters may be used to derive T-scores in German patients, T-scores based on previously published U.S. and newly estimated German item parameters were compared with each other after adjusting for sample specific differences.

RESULTS

All items were sufficiently unidimensional, locally independent, and monotonic. Whereas the fit of the unidimensional IRT model was not acceptable, a bifactor IRT model demonstrated acceptable fit. Explained common variance and Omega hierarchical suggested that using the unidimensional model would not lead to biased scores. One item demonstrated DIF between subsamples. High correlations with legacy pain instruments supported construct validity of the item bank. T-scores based on U.S. and German item parameters were similar suggesting that U.S. parameters could be used in German samples.

CONCLUSION

The German PROMIS PI item bank proved to be a clinically valid and precise instrument for assessing pain interference in patients with chronic conditions.

Scale agreement, ceiling and floor effects, construct validity, and relative efficiency of the PROPr and EQ-5D-3L in low back pain patients

BACKGROUND

The PROMIS Preference score (PROPr) is a new health state utility (HSU) score that aims to comprehensively incorporate the biopsychosocial model of health and apply favorable psychometric properties from the descriptive PROMIS system to HSU measurements. However, minimal evidence concerning comparisons to the EQ-5D-3L and the PROPr's capability to differentiate clinical severity are available. Therefore, the aim of this study was to compare the PROPr to the EQ-5D-3L in terms of scale agreement, ceiling/floor effects, distribution, construct validity, discriminatory power, and relative efficiency (RE) in terms of the Oswestry Disability Index (ODI) for patients with low back pain (LBP).

METHODS

We used intra-class correlation coefficients (ICC) and Bland-Altman plots to compare the PROPr and EQ-5D-3L with regared to scale agreement in a cross-sectional routine sample of LBP patients. For distribution, we used the Pearson's coefficient for skewness and for ceiling/floor effects, a 15%-top/bottom threshold. For convergent validity, we used Pearson's correlation coefficients. For known-groups validity, we applied a linear regression with interaction terms (predictors sex, age, and ODI level) and an analysis of variance (ANOVA). For discriminatory power, we calculated the effect size (ES) using Cohen's d and the ratio of the area under the receiver-operating characteristics curves (AUROC-ratio = AUROCPROPr/AUROCEQ-5D-3L). RE was measured using the ratio of F-values (RE = FPROPr/FEQ-5D-3L).

RESULTS

Of 218 LBP patients, 50.0% were female and the mean age was 61.8 years. The mean PROPr (0.20, 95%CI: 0.18; 0.22) and EQ-5D-3L scores (0.55, 95%CI: 0.51; 0.58) showed low agreement (d = 0.35, p < 0.001; ICC 0.27, 95%CI: -0.09; 0.59). The PROPr's distribution was positively skewed, whereas the EQ-5D-3L's was negative. Neither tool showed ceiling/floor effects, but all EQ-5D-3L dimensions did. Pearson correlation was r = 0.66 (95%CI: 0.58; 0.73). Differences were invariant to sex and age but not to ODI severity: ESEQ-5D-3L > ESPROPr and RE < 1 in higher ODI severity; ESEQ-5D-3L < ESPROPr and RE > 1 in lower ODI severity. AUROC-ratios did not show significant differences in terms of ODI severity.

CONCLUSIONS

All PROPr and EQ-5D-3L biopsychosocial dimensions of health showed impairment in LPB patients. The capability of EQ-5D-3L and PROPr to differentiate ODI levels depends on ODI severity. Joint application of both tools may provide additional information.

Are OMERACT recommendations followed in clinical trials on fibromyalgia? A systematic review of patient-reported outcomes and their measures

PURPOSE

Patient-Reported Outcomes (PROs) and its measures (PROMs) are key to outcome assessment in Fibromyalgia (FM) trials. The aim of this review was to investigate which domains and instruments were assessed in recent FM trials and to compare them to recommendations by the Outcome Measures in Rheumatology (OMERACT) initiative. In addition, we investigated the overlap with a generic health assessment approach, i.e. eight domains suggested by the Patient-Reported Outcome Measurement Information System® (PROMIS®).

METHODS

In compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature search in scientific databases including PubMed, PsycInfo, and Embase was conducted to identify studies that assessed at least two dimensions of health-related quality of life (HRQoL) from 2015 to June 2022. Non-randomized and randomized controlled trials were included in the analysis. We extracted PROs and PROMs used in each study.

RESULTS

From 1845 identified records, 107 records out of 105 studies met the inclusion criteria. Studies investigated 50 PROs using 126 different PROMs. Most frequently assessed domains were pain, depression, fatigue, and anxiety (> 95% of the studies). The disease-specific FIQ was the most frequently applied PROM (82%). Overall, only 9% of the studies covered all domains deemed mandatory by OMERACT. Very few studies covered all eight generic health domains suggested by PROMIS.

CONCLUSION

The majority of trials covered most OMERACT domains or generic PROMIS health domains. There was, however, great variability in the instruments used to assess the domains, which points at a limited degree of standardization in the field.

Health state utility differed systematically in breast cancer patients between the EORTC QLU-C10D and the PROMIS Preference Score

BACKGROUND AND OBJECTIVES

The EORTC Quality of Life Utility Core 10 Dimensions (QLU-C10D) and the Patient-Reported Outcome Measurement Information System Preference Score (PROPr) are new health state utility (HSU) scores for quality-adjusted life years in cost-effectiveness analyses. Both are expected to measure HSU more comprehensively than existing measures in cancer patients by including cancer-related health domains such as fatigue. The aim of this study is to compare both scores in a sample of breast cancer patients.

METHODS

We collected QLU-C10D and PROPr from 291 patients 90 days after treatment in the outpatient clinic of the breast cancer center at Charité - University Medicine Berlin between June 2018 and April 2021. We assessed both scores' convergent and known-groups validity, agreement, and ceiling and floor effects.

RESULTS

The mean QLU-C10D score [0.71, 95% confidence interval (CI) 0.69-0.74] and the mean PROPr score (0.43, 95% CI 0.41-0.46) differed systematically (0.28, 95% CI 0.27-0.30) and showed fair agreement (intraclass correlation coefficient 0.46, 95% CI 0.32-0.57). The Pearson correlation coefficient was 0.83 (95% CI 0.79-0.86). Both scores showed similar discrimination across known groups of age, treatment, cancer stage, marital status, and education. The QLU-C10D showed relevant ceiling effects.

CONCLUSION

QLU-C10D and PROPr measure HSU differently as a result of different utility models. The choice between QLU-C10D and PROPr should be informed by context, population, disease, and treatment.

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

OBJECTIVES

The 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.

METHODS

We 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.

RESULTS

The 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).

CONCLUSIONS

Both 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.

Psychometric properties of the PROMIS Preference score (PROPr) in patients with rheumatological and psychosomatic conditions

Background

The PROMIS Preference score (PROPr) is a new generic preference-based health-related quality of life (HRQoL) score that can be used as a health state utility (HSU) score for quality-adjusted life years (QALYs) in cost-utility analyses (CUAs). It is the first HSU score based on item response theory (IRT) and has demonstrated favorable psychometric properties in first analyses. The PROPr combines the seven PROMIS domains: cognition, depression, fatigue, pain, physical function, sleep disturbance, and ability to participate in social roles and activities. It was developed based on preferences of the US general population. The aim of this study was to validate the PROPr in a German inpatient sample and to compare it to the EQ-5D.

Methods

We collected PROPr and EQ-5D-5L data from 141 patients undergoing inpatient treatment in the rheumatology and psychosomatic departments. We evaluated the criterion and convergent validity, and ceiling and floor effects of the PROPr and compared those characteristics to those of the EQ-5D.

Results

The mean PROPr (0.26, 95% CI: 0.23; 0.29) and the mean EQ-5D (0.44, 95% CI: 0.38; 0.51) scores differed significantly (d = 0.18, p < 0.001). Compared to the EQ-5D, the PROPr scores were less scattered across the measurement range which has resulted in smaller confidence intervals of the mean scores. The Pearson correlation coefficient between the two scores was r = 0.72 (p < 0.001). Both scores showed fair agreement with an Intraclass Correlation Coefficient (ICC) of 0.48 (p < 0.05). The PROPr and EQ-5D demonstrated similar discrimination power across sex, age, and conditions. While the PROPr showed a floor effect, the EQ-5D showed a ceiling effect.

Conclusion

The PROPr measures HSU considerably lower than the EQ-5D as a result of different construction, anchors and measurement ranges. Because QALYs derived with the EQ-5D are widely considered state-of-the-art, application of the PROPr for QALY measurements would be problematic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00245-3.

Predicting EQ-5D-5L crosswalk from the PROMIS-29 profile for the United Kingdom, France, and Germany

Background

EQ-5D health state utilities (HSU) are commonly used in health economics to compute quality-adjusted life years (QALYs). The EQ-5D, which is country-specific, can be derived directly or by mapping from self-reported health-related quality of life (HRQoL) scales such as the PROMIS-29 profile. The PROMIS-29 from the Patient Reported Outcome Measures Information System is a comprehensive assessment of self-reported health with excellent psychometric properties. We sought to find optimal models predicting the EQ-5D-5L crosswalk from the PROMIS-29 in the United Kingdom, France, and Germany and compared the prediction performances with that of a US model.

Methods

We collected EQ-5D-5L and PROMIS-29 profiles and three samples representative of the general populations in the UK (n = 1509), France (n = 1501), and Germany (n = 1502). We used stepwise regression with backward selection to find the best models to predict the EQ-5D-5L crosswalk from all seven PROMIS-29 domains. We investigated the agreement between the observed and predicted EQ-5D-5L crosswalk in all three countries using various indices for the prediction performance, including Bland–Altman plots to examine the performance along the HSU continuum.

Results

The EQ-5D-5L crosswalk was best predicted in France (nRMSE_FRA = 0.075, nMAE_FRA = 0.052), followed by the UK (nRMSE_UK = 0.076, nMAE_UK = 0.053) and Germany (nRMSE_GER = 0.079, nMAE_GER = 0.051). The Bland–Altman plots show that the inclusion of higher-order effects reduced the overprediction of low HSU scores.

Conclusions

Our models provide a valid method to predict the EQ-5D-5L crosswalk from the PROMIS-29 for the UK, France, and Germany.