Lynda C. Doward

Development of the ASQoL: a quality of life instrument specific to ankylosing spondylitis

Background: Although disease-specific health status measures are available for ankylosing spondylitis (AS), no instrument exists for assessing quality of life (QoL) in the condition. Objective: To produce an AS-specific QoL measure that would be relevant and acceptable to respondents, valid, and reliable. Methods: The ASQoL employs the needs-based model of QoL and was developed in parallel in the UK and the Netherlands (NL). Content was derived from interviews with patients in each country. Face and content validity were assessed through patient field test interviews (UK and NL). A postal survey in the UK produced a more efficient version of the ASQoL, which was tested for scaling properties, reliability, internal consistency, and validity in a further postal survey in each country. Results: A 41 item questionnaire was derived from interview transcripts. Field testing interviews confirmed acceptability. Rasch analysis of data from the first survey (n=121) produced a 26 item questionnaire. Rasch analysis of data from the second survey (UK: n=164; NL: n=154) showed some item misfit, but showed that items formed a hierarchical order and were stable over time. Problematic items were removed giving an 18 item scale. Both language versions had excellent internal consistency (α=0.89–0.91), test-retest reliability (rs=0.92 UK and rs=0.91 NL), and validity. Conclusions: The ASQoL provides a valuable tool for assessing the impact of interventions for AS and for evaluating models of service delivery. It is well accepted by patients, taking about four minutes to complete, and has excellent scaling and psychometric properties.

The Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR): a measure of health-related quality of life and quality of life for patients with pulmonary hypertension

Objective: No outcome measures specific to pulmonary hypertension (PH) currently exist. The aim of the study was to develop health-related quality of life (symptoms and functioning) scales and a quality of life scale that would allow comprehensive, accurate and valid patient-reported outcome assessment in clinical studies. Methods: The content of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) was derived from qualitative interviews conducted with 35 patients. Item reduction was based on the analysis of responses to a postal survey (n=75) and patient interviews (n=15) designed to determine face and content validity. A final postal validation study (n=91) was performed to determine reproducibility and construct validity. Results: The questionnaire was well received by participants who found it to be relevant, comprehensible and quick and easy to complete. Rasch and factor analyses were conducted to ensure unidimensionality of the final CAMPHOR scales; Overall symptoms (made up of Energy, Breathlessness and Mood subscales), Functioning and Quality of life. The CAMPHOR scales had good internal consistency (α=0.90–0.92) and reproducibility (test–retest correlations=0.86–0.92). They also exhibited convergent, divergent and known groups validity. Conclusions: The CAMPHOR is a valuable new instrument for assessing patient-reported outcome in PH clinical trials and routine practice.

Development of the PsAQoL: a quality of life instrument specific to psoriatic arthritis

Background: Patient reported outcome measures used in studies of psoriatic arthritis (PsA) have been found to be inadequate for determining the impact of the disease from the patient’s perspective. Objective: To produce the PsAQoL, a PsA-specific quality of life (QoL) instrument, employing the needs based model of QoL that would be relevant and acceptable to respondents, valid, and reliable. Methods: Content was derived from qualitative interviews conducted with patients with PsA. Face and content validity were assessed by field test interviews with a new sample of patients with PsA. A postal survey was conducted to improve the scaling properties of the new measure. Finally, a test-retest postal survey was used to identify the final measure and to test its scaling properties, reliability, internal consistency, and validity. Results: Analysis of the qualitative interview transcripts identified a 51 item questionnaire. Field test interviews confirmed the acceptability and relevance of the measure. Analysis of data from the first postal survey (n = 94) reduced the questionnaire to 35 items. Rasch analysis of data from the test-retest survey (n = 286) identified a 20 item version of the PsAQoL with good item fit. This version had excellent internal consistency (α = 0.91), test-retest reliability (0.89), and validity. Conclusions: The PsAQoL is a valuable tool for assessing the impact of interventions for PsA in clinical studies and trials. It is well accepted by patients, taking about three minutes to complete, is easy to administer, and has excellent scaling and psychometric properties.

Development of the PSORIQoL, a psoriasis-specific measure of quality of life designed for use in clinical practice and trials

Summary  Background Patients with psoriasis have significant impairment in their quality of life (QoL). Several patient‐completed instruments are available to measure outcome in dermatological conditions but these primarily focus on severity of disease rather than on QoL.

The development of the L-QoL: a quality-of-life instrument specific to systemic lupus erythematosus

OBJECTIVES Complex diseases, such as systemic lupus erythematosus (SLE), present dilemmas over choice of outcome measures. Using a battery of instruments to capture the impact of different impairments or activity limitations experienced does not provide assessment of the wider impact on quality of life (QoL). This paper describes the development and testing of a new instrument to measure QoL in systemic lupus erythematosus (L-QoL). METHODS The development combines theoretical strengths of the needs-based QoL model with statistical and diagnostic powers of the Rasch model. Content was derived from in-depth interviews with relevant patients. Cognitive debriefing interviews assessed face and content validity. Rasch analysis was applied to data from an initial postal survey to remove misfitting items. A second postal survey assessed scaling properties, reliability, internal consistency and validity. RESULTS A 55-item questionnaire was derived from interview transcripts. Cognitive debriefing confirmed acceptability. Rasch analysis of postal survey data (n = 95) removed misfitting items. A second postal survey (n = 93), produced a 25-item version with good item fit and stability, excellent test-retest reliability (0.92), internal consistency (0.92) and strict unidimensionality. CONCLUSIONS It is concluded that the L-QoL should prove a valuable instrument for assessing patient-based outcome in clinical trials and practice.

Patient reported outcomes: looking beyond the label claim

The use of patient reported outcome scales in clinical trials conducted by the pharmaceutical industry has become more widespread in recent years. The use of such outcomes is particularly common for products developed to treat chronic, disabling conditions where the intention is not to cure but to ameliorate symptoms, facilitate functioning or, ultimately, to improve quality of life. In such cases, patient reported evidence is increasingly viewed as an essential complement to traditional clinical evidence for establishing a products competitive advantage in the marketplace. In a commercial setting, the value of patient reported outcomes is viewed largely in terms of their potential for securing a labelling claim in the USA or inclusion in the summary of product characteristics in Europe. Although, the publication of the recent US Food and Drug Administration guidance makes it difficult for companies to make claims in the USA beyond symptom improvements, the value of these outcomes goes beyond satisfying requirements for a label claim. The European regulatory authorities, payers both in the US and Europe, clinicians and patients all play a part in determining both the availability and the pricing of medicinal products and all have an interest in patient-reported data that go beyond just symptoms. The purpose of the current paper is to highlight the potential added value of patient reported outcome data currently collected and held by the industry for these groups.

The international development of the RGHQoL: a quality of life measure for recurrent genital herpes

This paper describes the international development and psychometric testing of the Recurrent Genital Herpes Quality of Life Questionnaire (RGHQoL), a condition-specific quality of life (QoL) instrument. The theoretical foundation for the measure is the needs-based model of QoL and the content of the instrument was derived from in-depth qualitative interviews with relevant patients in the UK. Versions of the RGHQoL were required for the UK, USA, Italy, Germany, France and Denmark for use in international clinical trials. The results indicate that the final 20 item measure has good reliability, internal consistency and validity for all language versions. A small responsiveness study in Denmark suggested that the measure is sensitive to changes in QoL associated with the initiation of suppression treatment for recurrent genital herpes (RGH). It is concluded that the RGHQoL is a valuable instrument for inclusion in clinical trials. The psychometric properties of the instrument are such that it may also be used to monitor the progress of individual patients.

Development and validation of a needs-based quality of life instrument for osteoarthritis.

OBJECTIVE To develop and validate a disease-specific quality of life (QOL) measure for osteoarthritis (OA), the OAQoL, using the needs-based conceptual model. METHODS In the first phase of this study, in-depth, semistructured interviews were conducted with 44 OA patients to explore the issues associated with impact of OA and to derive items for a draft OAQoL questionnaire. In phase 2, 17 OA patients were interviewed on the relevance, clarity, and ease of completion of the measure in structured interviews. In phase 3, the draft questionnaire was mailed to 635 patients to test the psychometric properties of the questionnaire using Rasch analysis. Test-retest assessment of the revised questionnaire was performed in phase 4 by mailing the questionnaire to an additional 201 participants, with a second questionnaire repeated 2 weeks later. RESULTS A 38-item draft measure was devised during phase 1 and mailed in phase 2. Rasch analysis of the draft questionnaire (n = 259) indicated initial misfit, which was rectified with the removal of 13 problematic items (chi(2)[75] = 83.602, P = 0.232). For the test-retest assessment (n = 60), 3 additional items were removed, leaving a 22-item OAQoL that demonstrated good fit to the Rasch model (chi(2)[44] = 44.559, P = 0.533) with excellent test-retest correlation (rho = 0.925, P < 0.001; z = -0.06, P = 0.995). CONCLUSION The OAQoL is a simple and easy to use 22-item unidimensional questionnaire developed specifically to assess the impact of OA on QOL. The measure has been developed as a true patient-based questionnaire and demonstrates good psychometric properties, including test-retest reliability.

International development of the Quality of Life in Depression Scale (QLDS)

BACKGROUND The Quality of Life in Depression Scale (QLDS) employs the needs-based model of quality of life (QoL) and was developed in the UK and The Netherlands as an outcome measure for clinical trials. This paper describes the production and psychometric assessment of nine new language versions for Canada (French and English), Denmark, France, Germany, Italy, Morocco, Spain and the US. METHODS Three adaptation stages were employed; production of conceptually equivalent translations, field-test interviews and assessment of reliability and construct validity by survey of patients with major depression. RESULTS Few problems were experienced with producing conceptually equivalent translations, except in Morocco. Patients in the field-test interviews found the instrument to have appropriate content and to be easy to complete. Internal consistency and test-retest reliability were excellent for all language versions and scores were found to relate appropriately to measures of depression severity and health status. LIMITATIONS Further investigation is required of the ability of the measure to assess individuals at the extremes of the QoL continuum. Data collected with the Arabic QLDS should not be combined with those from other countries. CONCLUSIONS The QLDS is the first instrument designed to assess QoL in depression based on a coherent model of the construct. Each language version has been shown to be well accepted by respondents and to have excellent psychometric properties. As the instrument is now available in a large number of languages, the QLDS is the QoL instrument of choice for inclusion in clinical trials of interventions for depression.

Quality of life of children with atopic dermatitis and their families.

Purpose of the reviewOver the last few years major advances have been made in the conceptualization of quality of life and new instruments have been developed for assessing the construct in paediatric atopic dermatitis. This review looks at these developments and reports on recently published articles on the impact of the condition on affected children and other members of their family. Recent findingsDuring the period of the review only one article addressing the impact of treatment for paediatric atopic dermatitis on quality of life could be found. This showed the benefits to the quality of life of parents of treating their children with pimecrolimus cream. SummaryGiven the prevalence of paediatric atopic dermatitis and its impact on affected children and their families it is surprising that so little attention has been devoted to the impact of treatment on quality of life. Where standardized measures are included in studies they generally assess outcomes that are of interest to physicians rather than to patients and their carers.