Treatment satisfaction in cystic fibrosis: early patient experience with tobramycin inhalation powder

BACKGROUND

This study assessed treatment satisfaction of cystic fibrosis (CF) patients in a routine clinical setting for tobramycin inhalation powder (TIP), the first dry powder-inhaled antibiotic for Pseudomonas aeruginosa infection.

METHODS

CF patients aged 6 years or older treated with at least one cycle of TIP completed a web survey on experience with TIP, including the Treatment Satisfaction Questionnaire for Medication (TSQM). Regression analysis determined the factors associated with TSQM global satisfaction.

RESULTS

Eighty patients (mean age ± standard deviation: 24.4±9.4 years; 57.5% female; mean forced expiratory volume in 1 second ± standard deviation: 67.1%±27.3% predicted) completed the survey. The majority expressed satisfaction with TIP's administration time (100%), time to clean (97.1%), portability (97.1%), and ease of use (94.3%). Effectiveness was significantly associated with TSQM global satisfaction (regression R-squared: 0.54).

CONCLUSION

Patient preferences for TIP were based on administration time and ease of use. Global satisfaction was related to greater patient-perceived effectiveness.

Promising results with image guided intensity modulated radiotherapy for muscle invasive bladder cancer

AIM

To describe the feasibility of image guided intensity modulated radiotherapy (IG-IMRT) using daily soft tissue matching in the treatment of bladder cancer.

METHODS

Twenty-eight patients with muscle-invasive carcinoma of the bladder were recruited to a protocol of definitive radiation using IMRT with accelerated hypofractionation with simultaneous integrated boost (SIB). Isotropic margins of .5 and 1 cm were used to generate the high risk and intermediate risk planning target volumes respectively. Cone beam CT (CBCT) was acquired daily and a soft tissue match was performed. Cystoscopy was scheduled 6 weeks post treatment.

RESULTS

The median age was 83 years (range 58-92). Twenty patients had stage II or III disease, and eight were stage IV. Gross disease received 66 Gy in 30 fractions in 11 patients (ten with concurrent chemotherapy) or 55 Gy in 20 fractions for those of poorer performance status or with palliative intent. All patients completed radiation treatment as planned. Three patients ceased chemotherapy early due to toxicity. Six patients (21 %) had acute Grade ≥ 2 genitourinary (GU) toxicity and six (21 %) had acute Grade ≥ 2 gastrointestinal (GI) toxicity. Five patients (18 %) developed Grade ≥2 late GU toxicity and no ≥2 late GI toxicity was observed. Nineteen patients underwent cystoscopy following radiation, with complete response (CR) in 16 cases (86 %), including all patients treated with chemoradiotherapy. Eight patients relapsed, four of which were local relapses. Of the patients with local recurrence, one underwent salvage cystectomy. For patients treated with definitive intent, freedom from locoregional recurrence (FFLR) and overall survival (OS) was 90 %/100 % for chemoradiotherapy versus 86 %/69 % for radiotherapy alone.

CONCLUSION

IG- IMRT using daily soft tissue matching is a feasible in the treatment of bladder cancer, enabling the delivery of accelerated synchronous integrated boost with good early local control outcomes and low toxicity.

Comparison of Single-fraction and Multi-fraction Stereotactic Radiotherapy for Patients with 18F-fluorodeoxyglucose Positron Emission Tomography-staged Pulmonary Oligometastases

AIM

To compare outcomes of single-fraction and multi-fraction stereotactic ablative body radiotherapy (SABR) for pulmonary metastases.

MATERIALS AND METHODS

A retrospective review from two academic institutions of patients with one to three pulmonary metastases staged with (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans. For single-fraction SABR, 26 Gy was prescribed for peripheral targets and 18 Gy for central targets. In the multi-fraction cohort, 48 Gy/4 or 50 Gy/5 was prescribed for peripheral targets and 50 Gy/5 was prescribed for central targets. Three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans were delivered using heterogeneity corrections. Conformity indices at an intermediate dose (R50%) and at a high dose (R100%) were used to assess a relationship with the planning target volume (PTV). Overall survival, local and distant progression and toxicity rates were analysed from the date of treatment completion.

RESULTS

Between February 2010 and June 2013, 65 patients with 85 pulmonary metastases were reviewed. The median follow-up was 2.1 years. Metastases most commonly originated from colorectal cancer (31%), followed by non-small cell lung cancer (25%). 3D-CRT was used in 52 targets, IMRT in 21 and VMAT in 12. 3D-CRT showed a lower median R50% (P=0.01), but a higher median R100% than IMRT/VMAT (P=0.04). The R50% index was inversely correlated to the PTV with all techniques (P=0.01). Overall survival at 1 and 2 years in all patients was 93% (95% confidence interval 87-100%) and 71% (95% confidence interval 58-86%), respectively. The 2 year freedom from local and distant progression was 93% (95% confidence interval 86-100%) and 38% (95% confidence interval 27-55%), respectively. There were no significant differences between overall survival (P=0 .14), time to distant progression (P=0.06) or toxicity rates (P=0.75) between single- and multi-fraction cohorts.

CONCLUSION

We report comparable local control, overall survival and toxicity rates between single-fraction and multi-fraction SABR treatments in patients with FDG-PET-staged pulmonary oligometastases. We propose a guideline for R50% conformity incorporating 3D-CRT/IMRT/VMAT techniques with heterogeneity corrected planning algorithms.

The need to clot: a review of current management strategies for adverse bleeding events with new oral anticoagulants

The new factor Xa inhibitors and direct thrombin inhibitors have offered alternatives to traditional anticoagulants, with benefits of no routine monitoring, less drug interactions, and oral administration. Current approved uses of these agents include prophylaxis of stroke in non-valvular atrial fibrillation and prevention of venous thromboembolism (VTE) following hip and knee arthroplasty. However, concern over bleeding risk in the context of having no specific antidotes available is a topic of focus for many physicians in an acute care setting. This manuscript examines the recent literature in the management of acute bleeding and the various methods of reversing anticoagulation in this setting. Literature published over the last 18 months (2011/07/01-present) was gathered from PubMed, Ovid, and Medline under a combined search strategy covering bleeding, reversal, and new oral anticoagulants, both factor Xa and direct thrombin inhibitors. The use of prothrombin complex concentrate, fresh frozen plasma, activated recombinant factor VII, activated prothrombin complex concentrate, as well as adjuncts of charcoal, hemodialysis, and antifibrinolytics are discussed. Recommendations are based on the determination of the severity of the bleed and physiological markers of anticoagulation, and involve the use of prothrombin complex concentrate, activated recombinant factor VII, and adjunctive therapy as appropriate.

Patient empowerment in long-term conditions: development and preliminary testing of a new measure

Background

Patient empowerment is viewed by policy makers and health care practitioners as a mechanism to help patients with long-term conditions better manage their health and achieve better outcomes. However, assessing the role of empowerment is dependent on effective measures of empowerment. Although many measures of empowerment exist, no measure has been developed specifically for patients with long-term conditions in the primary care setting. This study presents preliminary data on the development and validation of such a measure.

Methods

We conducted two empirical studies. Study one was an interview study to understand empowerment from the perspective of patients living with long-term conditions. Qualitative analysis identified dimensions of empowerment, and the qualitative data were used to generate items relating to these dimensions. Study two was a cross-sectional postal study involving patients with different types of long-term conditions recruited from general practices. The survey was conducted to test and validate our new measure of empowerment. Factor analysis and regression were performed to test scale structure, internal consistency and construct validity.

Results

Sixteen predominately elderly patients with different types of long-term conditions described empowerment in terms of 5 dimensions (identity, knowledge and understanding, personal control, personal decision-making, and enabling other patients). One hundred and ninety seven survey responses were received from mainly older white females, with relatively low levels of formal education, with the majority retired from paid work. Almost half of the sample reported cardiovascular, joint or diabetes long-term conditions. Factor analysis identified a three factor solution (positive attitude and sense of control, knowledge and confidence in decision making and enabling others), although the structure lacked clarity. A total empowerment score across all items showed acceptable levels of internal consistency and relationships with other measures were generally supportive of its construct validity.

Conclusion

Initial analyses suggest that the new empowerment measure meets basic psychometric criteria. Reasons concerning the failure to confirm the hypothesized factor structure are discussed alongside further developments of the scale.

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.

What patients want from primary care consultations: a discrete choice experiment to identify patients' priorities

PURPOSE

The consultation is fundamental to the delivery of primary care, but different ways of organizing consultations may lead to different patient experiences in terms of access, continuity, technical quality of care, and communication. Patients' priorities for these different issues need to be understood, but the optimal methods for assessing priorities are unclear. This study used a discrete choice experiment to assess patients' priorities.

METHODS

We surveyed patients from 6 family practices in England. The patients chose between primary care consultations differing in attributes such as ease of access (wait for an appointment), choice (flexibility of appointment times), continuity (physician's knowledge of the patient), technical quality (thoroughness of physical examination), and multiple aspects of patient-centered care (interest in patient's ideas, inquiry about patient's social and emotional well-being, and involvement of patient in decision making). We used probit models to assess the relative priority patients placed on different attributes and to estimate how much they were willing to pay for them.

RESULTS

Analyses were based on responses from 1,193 patients (a 53% response rate). Overall, patients were willing to pay the most for a thorough physical examination ($40.87). The next most valued attributes of care were seeing a physician who knew them well ($12.18), seeing a physician with a friendly manner ($8.50), having a reduction in waiting time of 1 day ($7.22), and having flexibility of appointment times ($6.71). Patients placed similar value on the different aspects of patient-centered care ($12.06-$14.82). Responses were influenced by the scenario in which the decision was made (minor physical problem vs urgent physical problem vs ambiguous physical or psychological problem) and by patients' demographic characteristics.

CONCLUSIONS

Although patient-centered care is important to patients, they may place higher priority on the technical quality of care and continuity of care. Discrete choice experiments may be a useful method for assessing patients' priorities in health care.

Making sense of patient priorities: applying discrete choice methods in primary care using 'think aloud' technique

BACKGROUND

Delivering effective health care within limited budgets requires an understanding of patient priorities. Discrete choice experiments (DCEs) provide patients with choices, where each choice differs in terms of certain attributes (such as waiting times, quality of care). Although this technique has significant potential in examining priorities, its use raises practical and conceptual issues. This paper describes the development of a DCE evaluating patient priorities in primary care.

METHODS

Twenty patients completed a DCE using a 'think aloud' protocol, where they verbalized their thinking while making choices. The analysis examined their decision-making processes.

RESULTS

There was evidence that patients reinterpreted some attributes, and related some to others outside the task. The cost attribute was interpreted in a variety of ways, dominating some patients' decision-making, being seen as irrelevant by others and being interpreted appropriately by some. The deree to which patients exhibited trading in line with theoretical assumptions also varied. Some choices in the hypothetical task were restricted by their previous experience, but more frequently patients tested the boundaries of the task in ways which directly reflected the primary care context.

CONCLUSION

Patient interpretation of the discrete choice task was varied and some went beyond the formal boundaries of the task to make their choices. This highlights the importance of piloting attributes, providing clear instructions about the task and developing models of patient decision-making so that responses can be interpreted correctly.

Governing the ethical consumer: identity, choice and the primary care medical encounter

Government policy promoting consumerism in healthcare can be seen as offering up certain preferred identities to which its citizens are encouraged to aspire. Whilst many commentators reject the notion that health services users should be conceived of as consumers, this paper outlines the relevance of the concept to our understanding of the ways in which individuals manage their health and service use. The paper examines the identity work undertaken by individuals in relation to decisions about healthcare preferences and assesses the extent to which this is compatible with the identities promoted in Government policy. We suggest that in circumstances where individuals feel both a sense of personal entitlement and a desire to be supportive of the needs of other members of the community, 'doing' ethical consumer can be fraught with discomfort and anxiety. These anxieties are exacerbated in a context where citizenship is increasingly being defined in terms of consumer identities, and making good (health) choices might be seen as distinguishing the civilised from the marginalised.

What are the key attributes of primary care for patients? Building a conceptual 'map' of patient preferences

BACKGROUND

Responding to the preferences of patients is a key focus of current health policy and is especially important in primary care. Responding effectively to patient preferences requires a clear understanding of the way in which patients assess primary care services.

OBJECTIVE

This study was designed to provide a 'map' of the content and structure of the key attributes of patient preferences concerning primary care.

DESIGN

The development of the 'map' used secondary research methods. Electronic databases were searched for published conceptual reviews of patient preferences, which were used to develop a basic 'map' through content analysis. A search for recently published primary empirical studies of patient preferences was conducted to extend and develop the 'map'. The 'map' was tested by taking a random sample of patient assessment instruments and categorizing the item content.

RESULTS

Seven major categories and multiple subcategories were described. The major categories were access, technical care, interpersonal care, patient-centredness, continuity, outcomes, and hotel aspects of care. The coverage of these attributes in a selection of patient assessment instruments varied widely, and the coding of a proportion of items in the patient assessment instruments according to the 'map' was problematic.

CONCLUSIONS

The conceptual 'map' can be used to plan comprehensive assessment of patient preferences in primary care. It also raises many theoretical issues concerning the nature of attributes and their interrelationships. The implications for the measurement of patient preferences are discussed.

Treatment of paediatric atopic dermatitis with pimecrolimus (ElidelR, SDZ ASM 981): impact on quality of life and health-related quality of life

AIM

To report on quality of life (QoL) and health-related quality of life (HRQL) impacts of pimecrolimus (Elidel, Novartis A.G., Basel, Switzerland, SDZ ASM 981) 1% cream in the long-term treatment of paediatric atopic dermatitis.

METHODS

QoL and HRQL data are presented from two 12-month international clinical trials evaluating the efficacy and safety of pimecrolimus 1% cream. Both trials were randomized and double blinded and compared two treatment strategies, one involving the use of emollients, pimecrolimus and topical corticosteroids, the other is 'usual care' (emollients plus topical corticosteroids) with a vehicle cream to maintain study blinding. The first trial (the infant trial) involved patients between ages 3 months and 2 years, whereas the children trial included patients aged 2-17 years. In both trials, QoL of the affected child's parent was evaluated with the parent's index of quality of life in atopic dermatitis (PIQoL-AD). HRQL was assessed in the children trial only with the children's dermatology life quality index (CDLQI). QoL and HRQL assessments were conducted at baseline, 6 weeks, 6 months and 12 months.

RESULTS

Generalized linear modelling of PIQoL-AD scores at each post-baseline visit showed a greater impact on parent's QoL for pimecrolimus compared with control at all time-points in both trials. HRQL scores showed a greater improvement from baseline for children in the pimecrolimus group compared with those in the control group at all time-points.

CONCLUSIONS

The results show a beneficial impact of pimecrolimus on parents' QoL in paediatric atopic dermatitis, confirming findings from earlier shorter term trials. There was also a clear benefit to the HRQL of the children treated.

GP job satisfaction in view of contract reform: a national survey

BACKGROUND

Job satisfaction has been associated with intentions to quit and aspects of quality of care. In 2001, GP job satisfaction in England had fallen to its lowest point for over a decade.

AIM

To assess GP job satisfaction and stressors immediately prior to implementation of the 2004 contract.

DESIGN OF STUDY

National survey of a random sample of GPs.

SETTING

England.

METHOD

One thousand, nine hundred and fifty principal and salaried GPs surveyed in February 2004 were compared with 1828 principals surveyed in 1998 and 1841 principal and salaried GPs surveyed in 2001. Job satisfaction and stressor scores were adjusted for 2004 age-sex distributions. Determinants of overall satisfaction were examined through ordinary least squares regression.

RESULTS

The 2004 response rate was 53%. GPs were most dissatisfied with hours of work, recognition for good work and remuneration, and experienced most pressure from paperwork, increasing workloads and having insufficient time. The majority of doctors were satisfied with their job overall. Satisfaction was higher than in 2001 and approximately the same as in 1998. Overall stress in 2004 was lower than in 2001 but still higher than in 1998. After allowing for personal, practice and job characteristics, higher satisfaction was associated with lower job stress, involvement in decision making, increasing job interest and ability to meet conflicting demands.

CONCLUSIONS

Despite recent initiatives to enhance workforce capacity and working lives for GPs, workload, time pressures and job control remain potential areas of concern. Addressing such issues may be key to maintaining morale as the new contract is implemented.

The Psychometric Properties of the Psoriasis Disability Index in United States Patients

Although it has had only limited psychometric assessment in one country (the UK), the Psoriasis Disability Index (PDI) is a commonly used measure of the impact of psoriasis on patients. This study's objective was to analyze the psychometric properties of the PDI in 1196 US patients. High Cronbach's alpha coefficients suggested that the PDI's internal consistency is good. The validity of the PDI was tested using a global question on disease burden and self-assessed extent of disease and both appeared to be good predictors of the PDI. Large floor effects and the suboptimal response distribution of most items, however, suggested that the PDI is insensitive to mild functional limitation. Factor analyses indicated that the current PDI subscales are suboptimal. In the Rasch analysis, the PDI and its subscales appeared to measure multiple constructs, making the validity of deriving a single overall score questionable. The frequent presence of differential item functioning related to several patient characteristics confirmed the instrument's multidimensionality. These findings suggest that the PDI is not an optimal measure for use in US study populations. The psychometric properties of instruments designed to measure the impact of psoriasis should be tested in populations in which the instrument is to be applied.

International development of the Parents’ Index of Quality of Life in Atopic Dermatitis (PIQoL-AD)

OBJECTIVE

The international development of the Parents' Index of Quality of Life in Atopic Dermatitis (PIQoL-AD), a quality of life (QoL) instrument specific to parents of children with atopic dermatitis (AD) is described.

METHOD

The instrument was developed simultaneously in several countries. Its content was derived from 65 qualitative interviews with parents in the UK, Netherlands and Italy. The measure was then produced for the UK, Netherlands, Italy, Germany, France, US and Spain. Field-test interviews were conducted with approximately 20 patients in each country to assess face and content validity. A two time-point survey was conducted with between 45 and 328 parents in each country to finalise the instrument through application of the Rasch model and to evaluate the psychometric properties of the final instrument.

RESULTS

Application of the Rasch model to the survey data identified the final 28-item version. All language versions had good item fit, test-retest reliability (above 0.85), internal consistency and promising validity.

CONCLUSIONS

The PIQoL-AD is a valuable instrument for inclusion in clinical trials and routine clinical practice. It provides distinct and complementary information to that of existing dermatology-specific measures and has been shown to be responsive to changes in QoL in clinical trials.

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 (alpha = 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.

A new instrument for assessing quality of life in atopic dermatitis: international development of the Quality of Life Index for Atopic Dermatitis (QoLIAD)

BACKGROUND

Atopic dermatitis (AD) is a chronic or chronically relapsing inflammatory skin condition that can have a considerable impact on those affected. There are a number of instruments available to measure outcome in dermatological conditions but none have been developed specifically for AD. In addition, most measure symptoms and/or daily functioning, which are potential influences on quality of life (QoL) rather than assessments of the construct itself.

OBJECTIVES

The aim of the current study was to develop a new instrument specifically designed to measure QoL in adults with AD-the Quality of Life Index for Atopic Dermatitis (QoLIAD).

METHODS

The instrument was developed based on the needs-based model of QoL and was produced in several different countries simultaneously. Its content was derived from 65 in-depth interviews with relevant patients in the U.K., Italy and the Netherlands. The initial version of the measure was produced in U.K. English and translations were produced for the Netherlands, Italy, Germany, France and the U.S.A. using a dual translation panel methodology. A Spanish version was developed using the same adaptation process after the instrument was finalized. Field-test interviews were conducted with approximately 20 patients in each country to assess face and content validity. The instrument [in addition to the Dermatology Life Quality Index (DLQI) and the Psychological General Well-Being Schedule (PGWB)] was then administered to up to 300 AD patients in each country at two time points to finalize the instrument and test its psychometric properties.

RESULTS

The initial version of the QoLIAD had 56 items that reflected the areas of need fulfillment identified in the qualitative interviews as having been affected by AD: mental and emotional stimulation, physical and emotional stability, security, sharing and belonging, self-esteem, personal development and fulfillment. Comments from patients in field-test interviews resulted in the removal of 14 items, to leave a 42-item instrument that was considered relevant and acceptable. The number of patients participating in the survey were 286 in the U.K., 46 in the Netherlands, 213 in France, 187 in Germany, 178 in the U.S.A. and 83 in Spain. Application of the Rasch model to these data identified the final 25-item QoLIAD. Unidimensionality was confirmed, with deviation of the total scale from the Rasch model evident at a single time point in one country only (the U.K.). All language versions, with the exception of the Dutch measure, had test-retest reliability coefficients in excess of 0.85. The test-retest in the Netherlands was 0.80. However, this country had the smallest sample size and the corresponding reliability for the DLQI was only 0.40. The QoLIAD had adequate internal consistency and the initial indications of construct validity were good. The levels of association with the DLQI indicated that the two instruments measure related but distinct constructs.

CONCLUSIONS

The QoLIAD is a practical, reliable, valid and culturally applicable instrument for measuring the impact of AD and its treatment on QoL in clinical trials or in routine clinical practice.

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

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.

OBJECTIVES

To develop a new instrument specifically designed to measure QoL in psoriasis-the Psoriasis Index of Quality of Life (PSORIQoL).

METHODS

The content of the instrument was derived from qualitative interviews with 62 psoriasis patients in the U.K., Italy and the Netherlands. Content analysis of the interview transcripts from the three countries identified potential items for the questionnaire. All further stages of the project were conducted in the U.K. only. Face and content validity were determined by means of a focus group held with seven psoriasis patients and face-to-face interviews with a further 21 patients. A new draft version of the PSORIQoL, together with the Dermatology Life Quality Index (DLQI) and the General Well-Being Index (GWBI), were completed by a new sample of psoriasis patients contacted by mail, in order to determine construct validity. A subsample of the respondents completed a similar package 2 weeks later, to assess reproducibility (reliability).

RESULTS

The first version of the PSORIQoL consisted of 61 items covering the needs identified in the interviews as having been affected by psoriasis or its treatment. These included fear of negative reactions from others, self-consciousness and poor self-confidence, problems with socialization, physical contact and intimacy, limitations on personal freedom and impaired relaxation, sleep and emotional stability. Following the focus group and field-test interviews, a new draft measure consisting of 45 items was completed by 148 patients, 88 of whom completed and returned a similar package 2 weeks later. Application of Rasch analysis identified a final 25-item version of the PSORIQoL. This version had a test-retest reliability coefficient of 0.89, indicating good reproducibility. The levels of association with the DLQI and PGWB indicated that the PSORIQoL measures a related but distinct construct.

CONCLUSIONS

The PSORIQoL appears to be a practical, reliable and valid instrument for measuring the impact of psoriasis on QoL. It remains necessary to establish the instrument's responsiveness to changes in QoL associated with treatment.

Health status measurement in Parkinson's disease: validity of the PDQ-39 and Nottingham Health Profile

We assessed the feasibility and psychometric properties of two commonly used health status questionnaires in Parkinson's disease (PD): the generic Nottingham Health Profile (NHP) and the disease-specific 39-item Parkinson's disease Questionnaire (PDQ-39), from a cross-sectional postal survey of PD patients (N = 81), using traditional and Rasch measurement methodologies. Overall response rate was 88%. Both questionnaires were found feasible, although the NHP performed less well. The PDQ-39 had fewer floor effects and was better able to separate respondents into distinct groups than the NHP, whereas the latter exhibited less ambiguous dimensionality and better targeting of respondents with non-extreme scores. Reliability and validity indices were similar, and potential differential item functioning by age and gender groups was found for both questionnaires. PDQ-39 response alternatives indicated ambiguity. With few exceptions, questionnaire scales were unable to meet recommended standards fully. While preliminary, this study illustrates the need for thorough evaluation of outcome measures and has implications beyond the questionnaires used here. Although promising, both questionnaires warrant further developmental work and stronger support of measurement validity before they could be considered fully suitable for valid use in PD, in particular in earlier stages of the disease.