Mapping AcroQoL scores to EQ-5D to obtain utility values for patients with acromegaly

Development of algorithms to estimate the EQ-5D-5L from the FACT-L in patients with lung cancer: a mapping study

OBJECTIVE

This study aimed to develop a mapping algorithm to evaluate the EQ-5D-5L according to the FACT-L when the EQ-5D-5L is not available.

METHODS

EQ-5D-5L and FACT-L data were collected from patients with lung cancer in Departments of Thoracic Surgery, Medical Oncology, Radiation Oncology, Sichuan Cancer Hospital. We used the ordinary least squares model (OLS), Tobit model (Tobit), two-part model (TPM), beta mixture regression (BM), and censored least absolute deviation model (CLAD) to map the results of the FACT-L according to EQ-5D-5L scores. To establish these models, the total score, dimension scores, squared items, and interaction items were introduced. Performance metrics including Adjusted R2, root mean square error (RMSE), and mean absolute error (MAE) were used to select the optimized model.

RESULTS

The model with the best mapping performance was the BM model (BETAMIX4) with the PWB (physical well-being) dimension, FWB (functional well-being) dimension, the squared term of the PWB dimension, and the squared term of the FWB dimension as covariates. The final prediction metrics were Adjusted R2 = 0.695, RMSE = 0.206, and MAE = 0.109. Fivefold cross-validation (CV) results also demonstrated that the BM model had the best mapping power.

CONCLUSIONS

This study developed an optimized mapping algorithm to predict the utility index from the FACT-L to the EQ-5D-5L, which provides an effective alternative reference for EQ-5D-5L estimation when the preference-based health utility values were unavailable.

Prediction of the SF-6D utility score from Lung cancer FACT-L: a mapping study in China

OBJECTIVE

To develop a mapping algorithm for generating the Short Form Six-Dimension (SF-6D) utility score based on the Functional Assessment of Cancer Therapy-Lung (FACT-L) of lung cancer patients.

METHODS

Data were collected from 625 lung cancer patients in mainland China. The Spearman rank correlation coefficient and principal component analysis were used to evaluate the conceptual overlap between the FACT-L and SF-6D. Five model specifications and four statistical techniques were used to derive mapping algorithms, including ordinary least squares (OLS), Tobit and beta-mixture regression models, which were used to directly estimate health utility, and ordered probit regression was used to predict the response level. The prediction performance was evaluated using the correlations between the root mean square error (RMSE), mean absolute error (MAE), concordance correlation coefficient (CCC), Akaike information criterion (AIC) and Bayesian information criterion (BIC) and the observed and predicted SF-6D scores. A five-fold cross-validation method was used to test the universality of each model and select the best model.

RESULTS

The average FACT-L score was 103.024. The average SF-6D score was 0.774. A strong correlation was found between FACT-L and SF-6D scores (ρ = 0.797). The ordered probit regression model with the total score of each dimension and its square term, as well as age and sex as covariates, was most suitable for mapping FACT-L to SF-6D scores (5-fold cross-validation: RMSE = 0.0854; MAE = 0.0655; CCC = 0.8197; AEs > 0.1 (%) = 53.44; AEs > 0.05 (%) = 21.76), followed by beta-mixture regression for direct mapping. The Bland‒Altman plots showed that the ordered probit regression M5 had the lowest proportion of prediction scores outside the 95% agreement limit (-0.166, 0.163) at 4.96%.

CONCLUSIONS

The algorithm reported in this paper enables lung cancer data from the FACT-L to be mapped to the utility of the SF-6D. The algorithm allows the calculation of quality-adjusted life years for cost-utility analyses of lung cancer.

Cost-effectiveness of direct surgery versus preoperative octreotide therapy for growth-hormone secreting pituitary adenomas

PURPOSE

The objective of this study was to compare the cost-effectiveness of preoperative octreotide therapy followed by surgery versus the standard treatment modality for growth-hormone secreting pituitary adenomas, direct surgery (that is, surgery without preoperative treatment) from a public third-party payer perspective.

METHODS

We developed an individual-level state-transition microsimulation model to simulate costs and outcomes associated with preoperative octreotide therapy followed by surgery and direct surgery for patients with growth-hormone secreting pituitary adenomas. Transition probabilities, utilities, and costs were estimated from recent published data and discounted by 3% annually over a lifetime time horizon. Model outcomes included lifetime costs [2020 United States (US) Dollars], quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs).

RESULTS

Under base case assumptions, direct surgery was found to be the dominant strategy as it yielded lower costs and greater health effects (QALYs) compared to preoperative octreotide strategy in the second-order Monte Carlo microsimulation. The ICER was most sensitive to probability of remission following primary therapy and duration of preoperative octreotide therapy. Accounting for joint parameter uncertainty, direct surgery had a higher probability of demonstrating a cost-effective profile compared to preoperative octreotide treatment at 77% compared to 23%, respectively.

CONCLUSIONS

Using standard benchmarks for cost-effectiveness in the US ($100,000/QALY), preoperative octreotide therapy followed by surgery may not be cost-effective compared to direct surgery for patients with growth-hormone secreting pituitary adenomas but the result is highly sensitive to initial treatment failure and duration of preoperative treatment.

Questionnaire and tools: clinical powerful instrument in acromegaly diagnosis and management

PURPOSE

Acromegaly is a rare chronic disease characterized by systemic comorbidity and reduced quality of life. Although achieving biochemical control has always been the primary goal of acromegaly therapy, recent evidence has shown that the traditional assessment does not adequately capture the complexity of symptoms and patients' perception. These findings result in the need to improve a fast decision-making process of the clinician, who should not only take into account biochemical-instrumental criteria, but also patients' symptoms. With the aim of supporting the clinician in the diagnostic and therapeutic decision-making process several disease-specific tools have been developed. The aim of this review is to provide a description of the acromegaly-specific tools, presenting their main features, their application in daily practice, and their efficacy and utility.

METHODS

A systematic search of Medline/PubMed, ISI-Web of Knowledge, and Google Scholar databases was done.

RESULTS

Specific instruments and questionnaires have recently been developed to assist clinicians in the assessment of acromegaly. These are either Patient-Reported Outcome tools, such as Acromegaly Quality of Life Questionnaire (AcroQoL) and Pain Assessment Acromegaly Symptom Questionnaire (PASQ), or Clinician-Reported Outcome tools, such as ACROSCORE, SAGIT^® and Acromegaly Disease Activity Tool (ACRODAT^®). Such tools are extremely flexible and, therefore, have been widely adopted by endocrinologists and other professionals, so much so that they have also been included as recommendations in the 2018 international guidelines.

CONCLUSION

Questionnaires and tools are useful in the management of acromegaly patients. They help clinicians evaluate patients' symptoms and could assist in the evaluation of disease activity.

Patient-reported outcomes in patients with acromegaly treated with pegvisomant in the ACROSTUDY extension: A real-world experience

PURPOSE

To report the effects of pegvisomant (PEGV) treatment on patient-reported outcomes in acromegaly patients.

METHODS

We conducted an extension study of an open-label, multinational, non-interventional study (ACROSTUDY) evaluating the long-term safety and efficacy of PEGV for acromegaly in routine clinical practice. Enrolled patients were rollover patients from ACROSTUDY, or treatment naïve/semi-naïve (NSN; no PEGV within 6 months of enrollment). Exploratory efficacy endpoints were changes in symptoms with the Patient-Assessed Acromegaly Symptom Questionnaire (PASQ) and quality of life with the Acromegaly Quality of Life questionnaire (AcroQoL) analyzed by controlled or uncontrolled IGF-I levels. Results were analyzed in all patients, in NSN patient subgroup, and by diabetes status.

RESULTS

A total of 544 patients with acromegaly were enrolled, including 434 rollover subjects from ACROSTUDY and 110 NSN patients. Mean PEGV treatment duration was 7.8 years (range, 0-19.6 years). Overall, the majority of PASQ scores improved over time, but there was no significant difference between IGF-I controlled or uncontrolled groups. In the NSN subgroup, most PASQ and AcroQoL scores remained similar to baseline up to 1 year, regardless of IGF-I control. Patients with diabetes reported better PASQ scores over time with PEGV treatment, regardless of IGF-I control. IGF-I normalization increased from 10% of patients at baseline to more than 78% at year 10, with a mean daily PEGV dose of 18.7 mg.

CONCLUSIONS

Overall, patients treated with PEGV had small improvements in PASQ. While IGF-I normalization increased with PEGV treatment, IGF-I control had no effects on PASQ and AcroQoL scores.

The Effect of Aging on Quality of Life in Acromegaly Patients Under Treatment

CONTEXT

With the increasing number of older patients with acromegaly, it is important to understand the effects of aging on the quality of life (QoL) in acromegaly.

OBJECTIVE

To investigate the factors associated with the QoL of older acromegaly patients.

DESIGN

This was a single-center, retrospective, cross-sectional study conducted between 2014 and 2019.

METHODS

Among 90 acromegaly patients at Kobe University Hospital, 74 who had completed the QoL evaluation under treatment were enrolled (age = 62.0 [50.7-70.0], female 52%). SF-36 and the AcroQoL questionnaire were used to quantify QoL. The patients were divided into two groups: the young and middle-aged group, aged <65 years (51.0 [46.0-59.2], n =42), and the older group, aged ≥65 years (70.5 [69.0-73.0], n =32). The factors associated with the QoL scores were analyzed using univariate and multivariate regression analyses.

RESULTS

The scores for the physical component summary of SF-36 were negatively associated with age (P <0.01), while those for the mental or role/social component summary were positively associated (P <0.01, P =0.03, respectively). In contrast, AcroQoL scores were not associated with age. However, the different factors were associated with lower AcroQoL scores; arthropathy and higher BMI in the older group (P <0.01, and P =0.01, respectively), and treatment modalities and size of pituitary tumor in the young and middle-aged group (P <0.01, P =0.04, respectively). Replacement of hydrocortisone was commonly associated both in young and middle-aged group (P =0.04), and in older group (P =0.02).

CONCLUSION

We showed that the factors associated with impaired QoL differed in the young and middle-aged, and older patients with acromegaly. In older patients, arthropathy and higher BMI were associated with poor QoL. These suggest the importance of early diagnosis and appropriate treatment in preventing arthropathy in acromegaly.

Mapping of the acromegaly quality of life questionnaire to ED-5D-5L index score among patients with acromegaly

OBJECTIVE

This study aimed to develop a mapping function that links the acromegaly quality of life (AcroQoL) questionnaire to EQ-5D-5L to obtain a preference-based utility value to inform economic evaluation.

METHODS

A nationwide cross-sectional questionnaire survey among patients with acromegaly was conducted online in China during 17 December 2019 to 6 January 2020. The study sample was randomly divided into a training set and a validation set. Ordinary least squares (OLS), Tobit, beta-based mixture, and adjusted limited dependent variable mixture models were tested for development of the function in the training set. Total and subscale scores and individual items of AcroQoL were included as predictors in the models along with their squared terms and demographic and clinical characteristics, and selected by backward stepwise selection. The root mean square error, mean absolute error, Akaike's information criterion, Bayesian information criterion and adjusted R-square were used to assess goodness of fit and predictive ability of the models.

RESULTS

There were 424 adult patients with acromegaly eligible for this analysis. Average EQ-5D-5L index score and AcroQoL score for them was 0.82 (SD = 0.15) and 44.3 (SD = 22.9), respectively. A total of 60 candidate models were tested. Considering model simplicity and predictive ability in both training and validation set, the best model was the OLS model using scores of physical dimension and its square term as predictors.

CONCLUSION

A validated mapping function was developed in this study for estimating EQ-5D scores using AcroQoL outcomes. Its external validity can be further tested in other population with Acromegaly.

SF-12 or SF-36 in pituitary disease? Toward concise and comprehensive patient-reported outcomes measurements

PURPOSE

Pituitary diseases severely affect patients' health-related quality of life (HRQoL). The most frequently used generic HRQoL questionnaire is the Short Form-36 (SF-36). The shorter 12-item version (SF-12) can improve efficiency of patient monitoring. This study aimed to determine whether SF-12 can replace SF-36 in pituitary care.

METHODS

In a longitudinal cohort study (August 2016 to December 2018) among 103 endoscopically operated adult pituitary tumor patients, physical and mental component scores (PCS and MCS) of SF-36 and SF-12 were measured preoperatively, and 6 weeks and 6 months postoperatively. Chronic care was assessed with a cross-sectional study (N = 431). Mean differences and agreement between SF-36 and SF-12 change in scores (preoperative vs. 6 months) were assessed with intraclass correlation coefficients (ICC) and limits of agreement, depicting 95% of individual patients.

RESULTS

In the longitudinal study, mean differences between change in SF-36 and SF-12 scores were 1.4 (PCS) and 0.4 (MCS) with fair agreement for PCS (ICC = 0.546) and substantial agreement for MCS (ICC = 0.931). For 95% of individual patients, the difference between change in SF-36 and SF-12 scores varied between -14.0 and 16.9 for PCS and between -7.8 and 8.7 for MCS. Cross-sectional results showed fair agreement for PCS (ICC = 0.597) and substantial agreement for MCS (ICC = 0.943).

CONCLUSIONS

On a group level, SF-12 can reliably reproduce MCS in pituitary patients, although PCS is less well correlated. However, individual differences between SF-36 and SF-12 can be large. For pituitary diseases, alternative strategies are needed for concise, but comprehensive patient-reported outcome measurement.

'Mapping' Health State Utility Values from Non-preference-Based Measures: A Systematic Literature Review in Rare Diseases

BACKGROUND

The use of patient-reported outcome measures (PROMs) to monitor the effects of disease and treatment on patient symptomatology and daily life is increasing in rare diseases (RDs) (i.e. those affecting less than one in 2000 people); however, these instruments seldom yield health state utility values (HSUVs) for cost-utility analyses. In such a context, 'mapping' allows HSUVs to be obtained by establishing a statistical relationship between a 'source' (e.g. a disease-specific PROM) and a 'target' preference-based measure [e.g. the EuroQol-5 Dimension (EQ-5D) tool].

OBJECTIVE

This study aimed to systematically review all published studies using 'mapping' to derive HSUVs from non-preference-based measures in RDs, and identify any critical issues related to the main features of RDs, which are characterised by small, heterogeneous, and geographically dispersed patient populations.

METHODS

The following databases were searched during the first half of 2019 without time, study design, or language restrictions: MEDLINE (via PubMed), the School of Health and Related Research Health Utility Database (ScHARRHUD), and the Health Economics Research Centre (HERC) database of mapping studies (version 7.0). The keywords combined terms related to 'mapping' with Orphanet's list of RD indications (e.g. 'acromegaly') in addition to 'rare' and 'orphan'. 'Very rare' diseases (i.e. those with fewer than 1000 cases or families documented in the medical literature) were excluded from the searches. A predefined, pilot-tested extraction template (in Excel^®) was used to collect structured information from the studies.

RESULTS

Two groups of studies were identified in the review. The first group (n = 19) developed novel mapping algorithms in 13 different RDs. As a target measure, the majority used EQ-5D, and the others used the Short-Form Six-Dimension (SF-6D) and 15D; most studies adopted ordinary least squares (OLS) regression. The second group of studies (n = 9) applied previously published algorithms in non-RDs to comparable RDs, mainly in the field of cancer. The critical issues relating to 'mapping' in RDs included the availability of very few studies, the relatively high number of cancer studies, and the absence of research in paediatric RDs. Moreover, the reviewed studies recruited small samples, showed a limited overlap between RD-specific and generic PROMs, and highlighted the presence of cultural and linguistic factors influencing results in multi-country studies. Lastly, the application of existing algorithms developed in non-RDs tended to produce inaccuracies at the bottom of the EQ-5D scale, due to the greater severity of RDs.

CONCLUSIONS

More research is encouraged to develop algorithms for a broader spectrum of RDs (including those affecting young children), improve mapping study quality, test the generalisability of algorithms developed in non-RDs (e.g. HIV) to rare variants or evolutions of the same condition (e.g. AIDS wasting syndrome), and verify the robustness of results when mapped HSUVs are used in cost-utility models.

An Updated Systematic Review of Studies Mapping (or Cross-Walking) Measures of Health-Related Quality of Life to Generic Preference-Based Measures to Generate Utility Values

BACKGROUND

Mapping is an increasingly common method used to predict instrument-specific preference-based health-state utility values (HSUVs) from data obtained from another health-related quality of life (HRQoL) measure. There have been several methodological developments in this area since a previous review up to 2007.

OBJECTIVE

To provide an updated review of all mapping studies that map from HRQoL measures to target generic preference-based measures (EQ-5D measures, SF-6D, HUI measures, QWB, AQoL measures, 15D/16D/17D, CHU-9D) published from January 2007 to October 2018.

DATA SOURCES

A systematic review of English language articles using a variety of approaches: searching electronic and utilities databases, citation searching, targeted journal and website searches.

STUDY SELECTION

Full papers of studies that mapped from one health measure to a target preference-based measure using formal statistical regression techniques.

DATA EXTRACTION

Undertaken by four authors using predefined data fields including measures, data used, econometric models and assessment of predictive ability.

RESULTS

There were 180 papers with 233 mapping functions in total. Mapping functions were generated to obtain EQ-5D-3L/EQ-5D-5L-EQ-5D-Y (n = 147), SF-6D (n = 45), AQoL-4D/AQoL-8D (n = 12), HUI2/HUI3 (n = 13), 15D (n = 8) CHU-9D (n = 4) and QWB-SA (n = 4) HSUVs. A large number of different regression methods were used with ordinary least squares (OLS) still being the most common approach (used ≥ 75% times within each preference-based measure). The majority of studies assessed the predictive ability of the mapping functions using mean absolute or root mean squared errors (n = 192, 82%), but this was lower when considering errors across different categories of severity (n = 92, 39%) and plots of predictions (n = 120, 52%).

CONCLUSIONS

The last 10 years has seen a substantial increase in the number of mapping studies and some evidence of advancement in methods with consideration of models beyond OLS and greater reporting of predictive ability of mapping functions.

Systemic Complications of Acromegaly and the Impact of the Current Treatment Landscape: An Update

Acromegaly is a chronic systemic disease with many complications and is associated with increased mortality when not adequately treated. Substantial advances in acromegaly treatment, as well as in the treatment of many of its complications, mainly diabetes mellitus, heart failure, and arterial hypertension, were achieved in the last decades. These developments allowed change in both prevalence and severity of some acromegaly complications and furthermore resulted in a reduction of mortality. Currently, mortality seems to be similar to the general population in adequately treated patients with acromegaly. In this review, we update the knowledge in complications of acromegaly and detail the effects of different acromegaly treatment options on these complications. Incidence of mortality, its correlation with GH (cumulative exposure vs last value), and IGF-I levels and the shift in the main cause of mortality in patients with acromegaly are also addressed.