The PlexiQoL, a patient-reported outcome measure on quality of life in neurofibromatosis type 1-associated plexiform neurofibroma: translation, cultural adaptation and validation into the Dutch language for the Netherlands.

BACKGROUND: Half of the patients with Neurofibromatosis type 1 (NF1) develop one or more tumours called plexiform neurofibromas, which can have a significant impact on Quality of Life (QoL). The PlexiQoL questionnaire is a disease-specific QoL measure for adults with NF1-associated plexiform neurofibromas. The aim of this study was to adapt and validate a Dutch version of the PlexiQoL for the Netherlands. METHODS: The PlexiQoL was translated using the dual-panel methodology, followed by cognitive debriefing interviews to assess face and content validity. The psychometric properties were evaluated by administering the questionnaire on two separate occasions to a sample of adults with NF1 and plexiform neurofibromas. Feasibility was evaluated by the presence of floor/ceiling effects. Reliability was assessed by evaluating Cronbach's alpha coefficient and test-retest reliability, using Spearman's rank correlation coefficients. Mann-Whitney U tests were used to check for known group validity. The Nottingham Health Profile (NHP) questionnaire was used as comparator questionnaire to evaluate convergent validity. RESULTS: The translation and cognitive debriefing interviews resulted in a Dutch version of the PlexiQoL that reflected the original concept and underlying semantic meanings of the UK English version. Forty participants completed the validation survey. The Dutch PlexiQoL demonstrated excellent internal consistency (Cronbach's α 0.825) and test-retest reliability (Spearman correlation coefficient 0.928). The questionnaire detected differences in PlexiQoL scores between participants based on self-reported general health and disease severity. Convergent validity was confirmed for relevant NHP subsections. CONCLUSIONS: The Dutch PlexiQoL demonstrated excellent psychometric properties and can be reliably used to measure plexiform neurofibroma-related QoL in adults with NF1 in the Netherlands.

Adaptation and validation of the Bulgarian version of the Systemic Lupus Erythematosus Quality of Life Questionnaire (L-QoL).

OBJECTIVE: Systemic lupus erythematosus (SLE) is a heterogeneous disease with multiple clinical manifestations, which causes a significant deterioration in the quality of life (QoL). The Systemic Lupus Erythematosus Quality of Life Questionnaire (L-QoL) is a lupus-specific measure used to determine the burden of the disease and it applies the need-based model of QoL. Our aim was to produce the first successfully validated foreign language version of the questionnaire. METHODS: The development of the Bulgarian version involved three stages: translation, field testing and psychometric evaluation. Translation was conducted by an expert linguist working with a developer of the original L-QoL, followed by interviews with monolingual lay individuals. Face and content validity of the translation were assessed by cognitive debriefing interviews with Bulgarian SLE patients. Finally, the L-QoL was validated by administering the questionnaire to a random sample of SLE patients on two occasions, 2 weeks apart to evaluate its reliability and validity. RESULTS: In the validation survey, the new Bulgarian version demonstrated high internal consistency (the Cronbach's alpha coefficient was 0.92), and test-retest reliability (0.97). Additionally, scores on the L-QoL were correlated with those on the SF-36 sections to determine convergent validity and the strongest correlation was observed between L-QoL scores and the social functioning section of the SF-36. Known group validity was established by testing the ability of the Bulgarian L-QoL to distinguish between subgroups of patients from the study pool. CONCLUSIONS: The demonstrated excellent psychometric properties ensure that the Bulgarian L-QoL accurately captures the impact of SLE on the quality of life. Key points • The Bulgarian version of the L-QoL is a valid and reliable measure of QoL in lupus patients. • The Bulgarian version of the L-QoL can be used as an outcome measure in research, clinical trials and routine clinical practice.

Evaluation of the Unidimensional Fatigue Impact Scale (U-FIS) in Crohn's Disease: The Importance of Local Item Dependency.

BACKGROUND AND PURPOSE: The Unidimensional Fatigue Impact Scale (U-FIS) was developed for use in a multiple sclerosis population. The aim was to determine whether the U-FIS is a valid tool for measuring the impact of fatigue in Crohn's disease (CD). METHOD: CD patients completed the U-FIS as part of a validation study of the Crohn's Life Impact Questionnaire (CLIQ). Data were analyzed according to Rasch measurement theory (RMT). RESULTS: Two hundred sixty-one completed U-FIS questionnaires were available for analysis. After rescoring the items to resolve disordered thresholds, all 22 items showed acceptable RMT fit. However, there was considerable local item dependency (LID). CONCLUSION: The U-FIS did not provide unidimensional measurement in a sample of CD patients due to high levels of LID. Combining the three FIS outcomes into a single measure was not justified.

Fundamental Measurement: The Need Fulfilment Quality of Life (N-QOL) Measure.

The quality adjusted life year (QALY) has serious problems related to its failure to adhere to measurement theory. If a QALY is to be meaningful, the utility score that translates time spent to an equivalent time spent in so-called perfect health must have ratio properties (i.e., it must support multiplication). Multiattribute utility scores (e.g. those generated by the EQ-5D-5L) fail to meet this standard. The multiattribute instruments produce ordinal scores that lack a true zero and they generate negative values. The manifest deficiencies of multiattribute utility instruments render them unfit, not only as a measure of therapy response but also in generating QALY claims. After 30 years of belief in their use, utilities and QALYs are clearly analytical dead ends. The purpose of this commentary is to demonstrate a coherent way forward in health technology assessment by focusing, not on clinical attributes as surrogates for quality of life, but on measures that are based on a conceptual model describing patient value in terms of need-fulfilment. Building on an extensive, yet often overlooked literature, need-based measures that fit Rasch Measurement Theory criteria are converted from ordinal scores to interval scores to evaluate response to therapy. These measures meet the requirements of single attribute fundamental measurement which is the standard in the physical sciences. It is proposed that a translation from a Rasch interval scale (defined by logits) can be transformed to a bounded ratio scale. Need based Quality of Life (N-QOL) scales bounded by 0 (where no needs are fulfilled) to 1 (where all needs are fulfilled) form such scales. The N-QOL supports the full range of arithmetic operations. Multiattribute utilities and mathematically invalid QALYs can be put to one side as unfortunate historical curiosities in favor of a disease or target population specific N-QOL scale. Such a scale has the required properties to evaluate disease specific response to therapy This can also support N-QOL adjusted life years with a need- fulfillment life year (NALY) metric with ratio properties.

Fundamental Outcome Measurement: Selecting Patient Reported Outcome Instruments and Interpreting the Data they Produce.

Over the past 40 years literally thousands of generic and disease specific patient reported outcome (PRO) instruments have been developed. While most were developed for a specific study and were never used again, there is still the question of how manufacturers and others should select a PRO instrument for a study. These studies may be clinical pivotal trials or observational tracking studies to support therapy response. Formulary committees also need to be able to interpret PRO data to make decisions about whether to accept claims for therapy response. It is possible to argue that the many different approaches to outcome measurement have resulted from the lack of agreed methodologies. However, a more likely explanation is that the authors have failed to apply the axioms of fundamental measurement when creating their measures. The result is a plethora of ordinal PRO instruments that inform little about the impact of interventions. Clinical trials rarely report PRO data. Where they do, analyses are generally restricted to (for example) changes in the experimental group's scores. Comparisons between the treatment and placebo groups or between active groups are infrequently reported, most likely due to the failure of the instrument to show differences or changes in outcome. This is unfortunate as it means no assessment is made of the value that patients gain from the intervention. This commentary is intended to make researchers and formulary committees aware of the issues that need to be addressed when selecting PRO instruments for a study or evaluating publications and claims for therapy response. The latter is crucial as reported data influence the selection of medicines and healthcare products. In the latter case a particular concern is with PRO claims embedded in simulation models.

Setting and maintaining standards for patient-reported outcome measures: can we rely on the COSMIN checklists?

As test-developers we have often been troubled by published reviews of patient-reported outcome measures (PROMs). Too often minor issues are judged important while other reviews exclude the best measures available. Perhaps this led several groups to make recommendations for evaluating the quality of PROMs. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist is the latest set of recommendations. While reviewing the COSMIN literature and reviews conducted using their recommendations several concerns became apparent. The checklist is not evidence-based, relying on the opinion of researchers experienced in health-related quality of life. PROMs measuring other types of outcomes are inadequately covered by the checklist. COSMIN choose to focus on Classical Test Theory and the checklists are not appropriate for use with PROMs developed using modern measurement. Such an approach only obstructs progress in the field of outcome measurement. The retrospective nature of the evaluations also penalizes new PROMs. While the checklists imply that composite, ordinal level measurement is acceptable, crucial aspects of instrument development and quality are excluded. Reviews based on the COSMIN checklist produce contradictory conclusions and fail to provide evidence to support the recommendations. These problems suggest that the checklists themselves lack reliability and validity. It is also clear that several reviewers lack the expertise to apply the checklists. Researchers require a good grounding in instrument development and psychometrics to produce quality reviews. The science of modern PROM development is still in an early phase. Few available PROMs have sufficient quality, limiting the need for complex reviews. Standards need to be agreed for high quality outcome measurement. The issue is who should set these standards? Most published reviews merely scratch the surface and lack essential detail. All reviews of PROMs should be treated with caution, irrespective of whether the COSMIN checklist was employed.

Psoriatic Arthritis Quality of Life Questionnaire: translation, cultural adaptation and validation into Brazilian Portuguese language.

INTRODUCTION: Psoriatic arthritis (PsA) is a multifaceted inflammatory disease that can cause joint destruction and impair quality of life. The Psoriatic Arthritis Quality of Life Questionnaire (PsAQoL) was the first disease-specific tool for determining the impact of the disease on the quality of life of people with PsA. OBJECTIVES: The primary objective was to develop and validate a Brazilian Portuguese version of the PsAQoL. METHODS: The UK PsAQoL was translated into Brazilian Portuguese using two translation panels. This translation then checked for face validity and construct validity with new samples of patients. Finally, a test-retest validation study was conducted with 52 patients with PsA. The survey included the Nottingham Health Profile (NHP) as a comparator instrument. RESULTS: Internal consistency and reproducibility were both excellent for the new adaptation (0.91 and 0.90 respectively Scores on the PsAQoL were found to correlate as expected with the comparator measure and the instrument was able to detect differences in score related to perceived severity of PsA, general health status and presence of a flare. CONCLUSION: The Brazilian PsAQoL was found easy to understand and complete and has excellent reliability and construct validity. The new measure will be a valuable new tool for use in routine PsA practice and clinical trials.

Psoriatic Arthritis Quality of Life Questionnaire: translation, cultural adaptation and validation into Brazilian Portuguese language

Abstract Introduction: Psoriatic arthritis (PsA) is a multifaceted inflammatory disease that can cause joint destruction and impair quality of life. The Psoriatic Arthritis Quality of Life Questionnaire (PsAQoL) was the first disease-specific tool for determining the impact of the disease on the quality of life of people with PsA. Objectives: The primary objective was to develop and validate a Brazilian Portuguese version of the PsAQoL. Methods: The UK PsAQoL was translated into Brazilian Portuguese using two translation panels. This translation then checked for face validity and construct validity with new samples of patients. Finally, a test-retest validation study was conducted with 52 patients with PsA. The survey included the Nottingham Health Profile (NHP) as a comparator instrument. Results: Internal consistency and reproducibility were both excellent for the new adaptation (0.91 and 0.90 respectively Scores on the PsAQoL were found to correlate as expected with the comparator measure and the instrument was able to detect differences in score related to perceived severity of PsA, general health status and presence of a flare. Conclusions: The Brazilian PsAQoL was found easy to understand and complete and has excellent reliability and construct validity. The new measure will be a valuable new tool for use in routine PsA practice and clinical trials.

Measurement, modeling and QALYs.

Over the past 30 years, a mainstay of health technology assessment has been the creation of modeled incremental cost-per-quality adjusted life year (QALY) claims. These are intended to inform resource allocation decisions. Unfortunately, the reliance on the construction of QALYs from generic utility scales is misplaced. Those advocating QALY-based lifetime modeled claims fail to appreciate the limitations placed on these constructs by the axioms of fundamental measurement. Utility scales, such as those created by the EQ-5D-3L instrument, are nothing more than multidimensional, ordinal scales. Such scales cannot support basic arithmetic operations. Interval scales can support addition and subtraction; ratio scales the further operations of multiplication and division. Those who advocate the construction of QALYs fail to appreciate that such an operation is only possible if the utility scale is unidimensional and has ratio properties with a true zero. The utility measures available do not meet these requirements. As we cannot produce meaningful utility values, the QALY is an invalid construct. Consequently, cost-per-incremental QALY claims are impossible to sustain and the application of cost-per QALY thresholds meaningless. As utility is a latent, unidimensional variable, the best a measure of utility could achieve would be unidimensionality and interval scaling properties. Where such measures are available, they could support claims for response to therapy. Consequently, there would be no need to continue constructing imaginary lifetime value assessment frameworks. Admitting that the QALY is a fatally flawed construct means rejecting 30 years of cost-per-QALY models.

The development of the PlexiQoL: A patient-reported outcome measure for adults with neurofibromatosis type 1-associated plexiform neurofibromas.

BACKGROUND: To develop and validate a patient-reported outcome (PRO) measure of quality of life (QoL), specific to patients with Neurofibromatosis Type 1 (NF1)-associated plexiform neurofibromas (pNFs), suitable for use in clinical efficacy trials. The study was conducted in parallel in the UK and US. METHODS: Qualitative interviews were conducted with patients to generate questionnaire content. Face and content validity of the draft scale was assessed by cognitive debriefing interviews (CDIs). A postal validation survey was conducted to identify the final version of the questionnaire (the PlexiQoL), establish its unidimensionality, and assess its psychometric properties. RESULTS: Thematic analysis was performed on 42 interview transcripts. Thirty-one CDIs revealed that patients found the draft scale to be comprehensible, relevant, and easy to complete. The postal validation survey was completed by 273 patients. Rasch analysis identified an 18-item unidimensional scale that showed excellent internal consistency, reproducibility, and sensitivity to differences in patient-perceived pNF severity, general health, and the use of pain medication. CONCLUSIONS: The PlexiQoL is the first disease-specific PRO assessing the ability of adults with NF-1 associated pNFs to meet their basic human needs. Clinical trials are planned to assess the sensitivity to change of the PlexiQoL in people undergoing treatment for pNFs.

International Development of the Alzheimer's Patient Partners Life Impact Questionnaire (APPLIQue).

AIM: Informal caregivers play a vital role in the care of people with Alzheimer's Disease (AD), yet caregiving is associated with caregivers' burden. The initial objective of the study was to develop a new outcome measure to assess quality of life (QoL) in AD caregivers. METHODS: Informal (non-professional) caregivers providing 75% or more of the care activities for, and living in the same household as, a person with AD were invited to take part in the study. Qualitative interviews (N = 40) were conducted with AD caregivers in the UK and thematic analyses were applied to generate a pool of potential items. A draft questionnaire was produced and adapted for use in Italy, Spain, Germany and the US. In each of the 5 countries, cognitive debriefing interviews (N = 76) were conducted to determine the questionnaire's face and content validity, followed by a postal validation survey (N = 268). The data from these surveys were combined to reduce the number of items and assess the new questionnaire's psychometric properties. RESULTS: Thematic analysis of the UK interview transcripts generated a draft questionnaire, which was successfully translated into each additional language. The items were well accepted and easy to complete. However, reanalysis of the qualitative interview data revealed that spousal and non-spousal caregivers identified different experiences of caregiving. A review of the item pool indicated that items were primarily targeted at spousal caregivers. Therefore, further analyses of the postal survey data included spousal caregivers only (n = 116). The results supported scaling assumptions (e.g., corrected item-total correlations ≥0.32), targeting (e.g., floor/ceiling effects <2.5%), internal consistency (α ≥0.93) and test-retest reliability (rs = 0.88) of the new questionnaire, according to classical test theory. Assessment of external construct validity yielded results in accordance with a priori expectations. QoL scores were most strongly related to scores on the emotional reactions sections of the Nottingham Health Profile and the General Well-Being Index. The new questionnaire was found to be capable of detecting meaningful differences between respondents; spousal caregivers had worse QoL when the person with AD was confused (p < .001), could not be left alone (p < .001), did not recognize the caregiver (p < .001), was incontinent (p < .05), and wandered around the house (p = .01). CONCLUSIONS: The Alzheimer's Disease Patient Partners Life Impact Questionnaire (APPLIQue) is a questionnaire specific to spousal caregivers of people with AD. Data support its scaling assumptions and it exhibits excellent psychometric properties according to classical test theory. The questionnaire is recommended for use in intervention studies where the QoL of spousal caregivers is of interest.

Adaptation and validation of the Rheumatoid Arthritis Quality of Life (RAQoL) questionnaire for use in Bulgaria.

Rheumatoid arthritis (RA) is a chronic disease with an enormous impact on patients' quality of life. The Rheumatoid Arthritis Quality of Life (RAQoL) questionnaire is a disease-specific measure of QoL for individuals with rheumatoid arthritis. Our aim was to adapt and validate the RAQoL for use in Bulgaria. The development of a new language version of the RAQoL consisted of three stages: translation, field testing and psychometric evaluation. The dual-panel methodology, requiring two independent panels of Bulgarian speakers, was applied to translate the UK English version of the RAQoL into Bulgarian. Face and content validity of the translated questionnaire were assessed through cognitive debriefing interviews. Lastly, the RAQoL was administered on two occasions to a random sample of RA patients to evaluate reliability and validity. At the first occasion, the SF-36 was also administered for use as a comparator scale. The RAQoL was successfully adapted into Bulgarian and considered easy to understand, acceptable and comprehensive by RA patients. A psychometric study demonstrated that the new language version has excellent internal consistency (Cronbach's alpha coefficients = 0.93 and 0.94) and test-retest reliability (a Spearman's rank correlation coefficient = 0.97). Convergent validity was established by correlating scores on the RAQoL with a comparator measure, the SF-36. A strong correlation between RAQoL scores and the physical functioning section of the SF-36 was observed. Known group validity was established by the ability of the measure to distinguish between subgroups of patients, who differed according to their perceived general health, disease severity (p < 0.001) and whether they were experiencing a flare-up (p < 0.01). The new language version is recommended for use in future research studies, clinical trials and routine practice with Bulgarian RA patients.

Composite outcome measurement in clinical research: the triumph of illusion over reality?

Composite measures that combine different types of indicators are widely used in medical research; to evaluate health systems, as outcomes in clinical trials and patient-reported outcome measurement. The potential advantages of such indices are clear. They are used to summarise complex data and to overcome the problem of evaluating new interventions when the most important outcome is rare or likely to occur far in the future. However, many scientists question the value of composite measures, primarily due to inadequate development methodology, lack of transparency or the likelihood of producing misleading results. It is argued that the real problems with composite measurement are related to their failure to take account of measurement theory and the absence of coherent theoretical models that justify the addition of the individual indicators that are combined into the composite index. All outcome measures must be unidimensional if they are to provide meaningful data. They should also have dimensional homogeneity. Ideally, a specification equation should be developed that can predict accurately how organisations or individuals will score on an index, based on their scores on the individual indicators that make up the measure. The article concludes that composite measures should not be used as they fail to apply measurement theory and, consequently, produce invalid and misleading scores.

Adaptation and validation of the quality of life assessment of the Cambridge pulmonary hypertension outcome review (CAMPHOR) for Brazil.

BACKGROUND: Pulmonary Hypertension (PH) impacts negatively on patients' health-related quality of life (HRQoL). The Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) was the first PH-specific and validated instrument for use in different languages worldwide. This report describes the adaptation and psychometric validation of the CAMPHOR into Brazilian Portuguese language. METHODS: The translation and validation process included a bilingual and lay panel translation; cognitive debriefing interviews; psychometric testing in two repeated times assessing internal consistency, reproducibility and validity of the questionnaire. The Nottingham Health Profile (NHP) questionnaire was used as a comparator to test for convergent validity. RESULTS: The translation captured the same concepts as the English questionnaire and produced a comprehensive instrument in a Brazilian-Portuguese version expressing common, natural language. The psychometric evaluation involved 102 patients (48.8 ± 14.5 years, 80,4% female]. Cronbach's alpha coefficients were above 0.9 on all three CAMPHOR scales. There was excellent test-retest reliability (coefficients above 0.85 on all scales). CAMPHOR Symptoms scale and Activities scale correlated highly with Physical Mobility section and CAMPHOR QoL scale was strongly associated with the Emotional Reactions and Social Isolation sections of NHP. There was a significant association between gender and perceived general health (p < 0.05). There were significant differences in CAMPHOR scale scores between patients who differed according to their perceived disease severity and general health. CONCLUSIONS: The present CAMPHOR version demonstrated good psychometric properties and provides a reliable instrument for assessing HRQL and QoL in Brazilian PH patients, addressing patients' perspective of their illness in a comprehensive way.

Improving Scoring Precision and Internal Construct Validity of the Bath Ankylosing Spondylitis Disease Activity Index Using Rasch Measurement Theory.

OBJECTIVE: To test the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) according to Rasch Measurement Theory and investigate whether measurement precision can be improved. METHODS: Secondary analysis of a BASDAI database. The data had been collected from individuals starting an Ankylosing Spondylitis Exercise Course at the Royal National Hospital for Rheumatic Diseases in Bath, UK. RESULTS: Data were available for 250 participants (23.6% female) aged between 18 and 85 years (mean 52.8, SD 14.6). Initial fit of the data to the Rasch model appeared good and item thresholds were consistent, but local item dependence (LID) was identified. After addressing the LID, a unidimensional measure was achieved. The Person Separation Index (reliability) was 0.83 and the location of the items was well matched to that of the respondents. A transformation table was generated to convert total raw BASDAI scores into linearized Rasch transformed scores that form an interval scale. The Smallest Detectable Difference improved from 2 to 1.2. This finding suggests that a change score of > 1.2 points on the modified BASDAI is required to achieve meaningful change. CONCLUSION: Applying the Rasch transformed scores simplifies completion and scoring of the measure and confirms internal construct validity. It also ensures linear measurement and justifies the use of parametric statistical analyses when analyzing datasets. The transformation table can be used with existing BASDAI datasets to allow direct comparisons of disease activity scores with those generated from future studies.

The Polish adaptation of the CAMbridge Pulmonary Hypertension Outcome Review (CAMPHOR).

BACKGROUND: Pulmonary hypertension (PH) results in severely impaired quality of life (QoL) in people with this condition. The CAMbridge Pulmonary Hypertension Outcome Review (CAMPHOR) is the only questionnaire providing a disease-specific measurement of symptoms, functioning and QoL in PH patients. It has already been adapted for use in several countries. The aim of this study was to adapt and validate CAMPHOR for the Polish-speaking population. METHODS: Two panels (bilingual and lay) were conducted to translate CAMPHOR into Polish. This new version was then tested by cognitive debriefing interviews with 15 patients. Finally, a postal validation survey was conducted with 56 patients on two occasions 2 weeks apart to assess its psychometric properties. RESULTS: No problems were experienced in producing a Polish translation of CAMPHOR. Interviewees responded well to the Polish CAMPHOR, finding it relevant, comprehensible and easy to complete. For all three CAMPHOR scales (Symptoms, Activity, QoL), The Cronbach alpha coefficients were above 0.8 at both time points, indicating high internal consistency. Test-retest reliability for the three scales achieved a value above 0.80. Predicted correlations with the Nottingham Health Profile provided evidence of the construct validity of CAMPHOR scales. The Polish CAMPHOR could distinguish between patients who differed according to their perceived general health and perceived disease severity. No significant differences in scores were found between participants grouped by gender or age. CONCLUSIONS: The Polish version of CAMPHOR demonstrated good psychometric properties and is recommended for use in clinical practice.

Assessment of the performance of the Brazilian Portuguese Nottingham Health Profile in adult growth hormone deficiency and pulmonary hypertension.

Background: The Nottingham Health Profile (NHP) is a generic measure of perceived distress that has been used widely as an outcome measure in clinical practice and trials. The availability of two Brazilian datasets provided the opportunity to assess the psychometric performance of the NHP in different populations - adult growth hormone deficiency (GHD) and pulmonary hypertension (PH). The purpose of the study was to see how valuable the NHP could be in assessing outcomes in diseases where no disease-specific measures are available. Methods: Secondary analyses were performed with NHP data. Patients diagnosed with adult GHD or PH were administered the NHP during clinic visits on two occasions, two weeks apart. A disease-specific measure of quality of life (QoL) was also administered to the relevant sample of patients on each occasion. Results: The psychometric properties of the NHP were good for both disease groups. As expected, both samples reported high scores on energy level, the PH sample scored high on physical functioning and the GHD sample on emotional reactions. For both samples, most of the NHP sections were able to distinguish between groups of respondents with different ratings of perceived general health. While most sections of the NHP were relatively highly correlated with the QoL measures, pain and sleep did not seem to be important predictors of QoL in either of the samples. Conclusions: The use of the NHP in adult GHD and PH populations in Brazil is not recommended as there are high-quality disease-specific measures available for each disease. However, where no disease-specific measures are available, the NHP can provide good descriptive information of the impact of disease on different patient populations.