N P Hurst

Bio: N P Hurst is an academic researcher. The author has contributed to research in topics: Test validity & Visual analogue scale. The author has an hindex of 3, co-authored 3 publications receiving 1154 citations.

Measuring health-related quality of life in rheumatoid arthritis: validity, responsiveness and reliability of EuroQol (EQ-5D).

Abstract: The EuroQol (EQ-5D) generic health index comprises a five-part questionnaire and a visual analogue self-rating scale. The questionnaire may be used as a health index to calculate a 'utility' value or as a health profile. The validity, reliability and responsiveness of EQ-5D were tested in 233 patients with rheumatoid arthritis stratified by functional class. EQ-5D demonstrated moderate to high correlations with measures of impairment and high correlations with disability measures. Stepwise regression models showed that EQ-5D utility values and visual analogue scores were explained best as a function of pain, disability, disease activity and mood (R2 approximately 70%), although other variables (side-effects, years of education) were required to explain the visual analogue scores. The EQ-5D health index and visual analogue scale are more responsive than any of the other measures, except pain and doctor-assessed disease activity. The reliability of the EQ-5D index and EQ-5D visual analogue scale is as good or better than that of all other instruments except the Health Assessment Questionnaire. Some patients with severe long-standing disease had health states which attracted utility values below zero, i.e. from a societal perspective they were regarded as being in states 'worse than death'. The practical and ethical implications of these utility valuations are discussed, and at present the utility values should be used and interpreted with caution. With this caveat, EQ-5D is simple to use, valid, responsive to change and sufficiently reliable for group comparisons. It is of potential use as an outcome measure in clinical trials, audit and health economic studies, but further work is required on its performance in other clinical contexts and on the interpretation of the utility values.

Comparison of the MOS short form-12 (SF12) health status questionnaire with the SF36 in patients with rheumatoid arthritis

Abstract: SUMMARY Objective. To compare the performance of the MOS SF12 health survey (SF12) with the SF36 in a sample of 233 patients with rheumatoid arthritis (RA) stratified by functional class. Methods. The SF12 and SF36 physical and mental component summary scales (PCS and MCS) were compared for test‐ retest reliability [intra-class correlation coeYcient (RC ) and repeatability], construct validity and responsiveness [standardized response mean (SRM )] to self-reported change in health. Results. Overall, despite its brevity, the SF12 is comparable to the SF36 with only some loss of performance. The SF12-PCS is slightly less reliable (RC= 0.75) and responsive to improvements in health (SRM= 0.52) than the SF36-PCS (RC= 0.81; SRM= 0.61). The SF12-PCS correlates strongly with the SF36-PCS (R= 0.94), SF36 physical function subscale (R= 0.77) and modified Stanford Health Assessment Questionnaire (MHAQ) (R= 0.71), but only weakly with the SF36 mental health subscale (R= 0.22). SF12-PCS discriminated well between Steinbrocker functional classes; patients in functional classes 1‐4, respectively, have SF12-PCS scores 1s ,2 s, 2.4s and 2.7s below the population norm (ANOVA, F= 35.8, P< 0.000). The SF12-MCS is relatively unresponsive to reported improvement in RA (SRM= 0.31), but is reliable (RC= 0.71) and correlates well with the SF36-MCS (R= 0.71). SF12-MCS correlates more closely than the SF36-MCS with the SF36 mental health subscale (R= 0.86) and Hospital Anxiety and Depression (HAD) scale (R= 0.76). In ANOVA models, only the HAD (R2 = 57%) score contributes significantly to variance in SF12-MCS (F= 254.8; P< 0.000), but both the HAD (R2 = 24%) and MHAQ (R2 = 10%) scores contribute to variance in the SF36-MCS (F= 50.9; P< 0.000). Thus, the SF12-MCS has better construct validity for mental health than SF36-MCS in RA subjects. Missing responses to items were high amongst patients in functional class 4 (34%). Conclusion. The SF12 is a reliable, valid and responsive measure of health status in the majority of RA patients, and meets standards required for comparing groups of patients. Its application in the most severely disabled subjects is uncertain.

Measuring health status in British patients with rheumatoid arthritis: reliability, validity and responsiveness of the short form 36-item health survey (SF-36).

Abstract: SUMMARY The objective was to assess the performance of the SF-36 health survey (SF-36) in a sample of patients with rheumatoid arthritis (RA) stratified by functional class. The eight SF-36 subscales and the two summary scales (the physical and mental component scales) were assessed for test‐retest reliability, construct validity and responsiveness to self-reported change in health. In 233 patients with RA, the SF-36 scales were: reliable (intra-class correlation coeYcients 0.76‐0.93); correlated with American College of Rheumatology (ACR) core disease activity measures [Spearman r =’ 0.12 (erythrocyte sedimentation rate) to ’0.89 (Modified Health Assessment Questionnaire)]; and responsive to improvements in health (standardized response means 0.27‐0.9). The distribution of scores on four of the eight subscales (physical function, role limitations‐physical, role limitations‐emotional and social function) was clearly non-Gaussian. Very marked floor eVects were noted with the physical function scale, and both ceiling and floor eVects with the other three subscales. The two SF-36 physical and mental component summary scales are reliable, valid and responsive measures of health status in patients with RA. Six of the eight subscales meet standards required for comparing groups of patients, and the physical function and general health scales may be suitable for monitoring individuals. The two scales measuring role limitations have poor measurement characteristics. The SF-36 pain and physical function scales may be suitable for use as patient self-assessed measures of pain and physical function within the ACR core disease activity set.

EQ-5D: a measure of health status from the EuroQol Group.

Abstract: Established in 1987, the EuroQol Group initially comprised a network of international, multilingual and multidisciplinary researchers from seven centres in Finland, the Netherlands, Norway, Sweden and the UK. Nowadays, the Group comprises researchers from Canada, Denmark, Germany, Greece, Japan, New Zealand, Slovenia, Spain, the USA and Zimbabwe. The process of shared development and local experimentation resulted in EQ-5D, a generic measure of health status that provides a simple descriptive profile and a single index value that can be used in the clinical and economic evaluation of health care and in population health surveys. Currently, EQ-5D is being widely used in different countries by clinical researchers in a variety of clinical areas. EQ-5D is also being used by eight out of the first 10 of the top 50 pharmaceutical companies listed in the annual report of Pharma Business (November/December 1999). Furthermore, EQ-5D is one of the handful of measures recommended for use in cost-effectiveness analyses by the Washington Panel on Cost Effectiveness in Health and Medicine. EQ-5D has now been translated into most major languages with the EuroQol Group closely monitoring the process.

A Comparative Review of Generic Quality-of-Life Instruments

Abstract: The assessment of health-related quality of life (HR-QOL) is an essential element of healthcare evaluation Hundreds of generic and specific HR-QOL instruments have been developed Generic HR-QOL instruments are designed to be applicable across a wide range of populations and interventions Specific HR-QOL measures are designed to be relevant to particular interventions or in certain subpopulations (eg individuals with rheumatoid arthritis) This review examines 7 generic HR-QOL instruments: (i) the Medical Outcomes Study 36-Item Short Form (SF-36) health survey; (ii) the Nottingham Health Profile (NHP); (iii) the Sickness Impact Profile (SIP); (iv) the Dartmouth Primary care Cooperative Information Project (COOP) Charts; (v) the Quality of Well-Being (QWB) Scale; (vi) the Health Utilities Index (HUI); and (vii) the EuroQol Instrument (EQ-5D) These instruments were selected because they are commonly used and/or cited in the English language literature The 6 characteristics of an instrument addressed by this review are: (i) conceptual and measurement model; (ii) reliability; (iii) validity; (iv) respondent and administrative burden; (v) alternative forms; and (vi) cultural and language adaptations Of the instruments reviewed, the SF-36 health survey is the most commonly used HR-QOL measure It was developed as a short-form measure of functioning and well-being in the Medical Outcomes Study The Dartmouth COOP Charts were designed to be used in everyday clinical practice to provide immediate feedback to clinicians about the health status of their patients The NHP was developed to reflect lay rather than professional perceptions of health The SIP was constructed as a measure of sickness in relation to impact on behaviour The QWB, HUI and EQ-5D are preference-based measures designed to summarise HR-QOL in a single number ranging from 0 to 1 We found that there are no uniformly ‘worst’or ‘best’ performing instruments The decision to use one over another, to use a combination of 2 or more, to use a profile and/or a preference-based measure or to use a generic measure along with a targeted measure will be driven by the purpose of the measurment In addition, the choice will depend on a variety of factors including the characteristics of the population (eg age, health status, language/culture) and the environment in which the measurement is undertaken (eg clinical trial, routine physician visit) We provide our summary of the level of evidence in the literature regarding each instrument’s characteristics based on the review criteria The potential user of these instruments should base their instrument selection decision on the characteristics that are most relevant to their particular HR-QOL measurment needs

Test-Retest Reliability and Minimal Detectable Change on Balance and Ambulation Tests, the 36-Item Short-Form Health Survey, and the Unified Parkinson Disease Rating Scale in People With Parkinsonism

Abstract: Background and Purpose: Distinguishing between a clinically significant change and change due to measurement error can be difficult. The purpose of this study was to determine test-retest reliability and minimal detectable change for the Berg Balance Scale (BBS), forward and backward functional reach, the Romberg Test and the Sharpened Romberg Test (SRT) with eyes open and closed, the Activities-specific Balance Confidence (ABC) Scale, the Six-Minute Walk Test (6MWT), comfortable and fast gait speed, the Timed “Up & Go” Test (TUG), the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and the Unified Parkinson Disease Rating Scale (UPDRS) in people with parkinsonism. Subjects: Thirty-seven community-dwelling adults with parkinsonism (mean age=71 years) participated. The Hoehn and Yahr Scale median score of 2 was on the lower end of the scale; however, the scores ranged from 1 to 4. Methods: Subjects were tested twice by the same raters, with 1 week between tests. Test-retest reliability was calculated using intraclass correlation coefficients (ICCs). Minimal detectable change was calculated using a 95% confidence interval (MDC95). Results: The ICCs for test-retest reliability were above .90 for the BBS, ABC Scale, SRT with eyes closed, 6MWT, and comfortable and fast gait speeds. The MDC95 values for those functional tests were: BBS=5/56, ABC Scale=13%, SRT with eyes closed=19 seconds, 6MWT=82 m, comfortable gait speed=0.18 m/s, and fast gait speed=0.25 m/s. The ICCs for test-retest reliability of SF-36 scores were above .80, with the exception of the social functioning subscale. The MDC95 values for the SF-36 ranged between 19% and 45%. The MDC95 values for the UPDRS Activities of Daily Living section, Motor Examination section, and total scores were 4/52, 11/108, and 13/176, respectively. Discussion and Conclusion: Minimal detectable change values are useful to therapists in rehabilitation and wellness programs in determining whether change during or after intervention is clinically significant. High test-retest reliability of scores for the BBS, ABC Scale, SRT with eyes closed, 6MWT, and gait speed make them trustworthy functional assessments in people with parkinsonism. The SF-36 and UPDRS provide quality-of-life and disease severity rating values in the ongoing assessment of people with parkinsonism.

Lymphoma in rheumatoid arthritis: the effect of methotrexate and anti-tumor necrosis factor therapy in 18,572 patients.

Abstract: Objective The risk of lymphoma is increased in patients with rheumatoid arthritis (RA), and spontaneous reporting suggests that methotrexate (MTX) and anti–tumor necrosis factor (anti-TNF) therapy might be associated independently with an increased risk of lymphoma. However, data from clinical trials and clinical practice do not provide sufficient evidence concerning these issues because of small sample sizes and selected study populations. The objective of this study was to determine the rate of and standardized incidence ratio (SIR) for lymphoma in patients with RA and in RA patient subsets by treatment group. Additionally, we sought to determine predictors of lymphoma in RA. Methods We prospectively studied 18,572 patients with RA who were enrolled in the National Data Bank for Rheumatic Diseases (NDB). Patients were surveyed biannually, and potential lymphoma cases received detailed followup. The SEER (Survey, Epidemiology, and End Results) cancer data resource was used to derive the expected number of cases of lymphoma in a cohort that was comparable in age and sex with the RA cohort. Results The overall SIR for lymphoma was 1.9 (95% confidence interval [95% CI] 1.3–2.7). The SIR for biologic use was 2.9 (95% CI 1.7–4.9) and for the use of infliximab (with or without etanercept) was 2.6 (95% CI 1.4–4.5). For etanercept, with or without infliximab, the SIR was 3.8 (95% CI 1.9–7.5). The SIR for MTX was 1.7 (95% CI 0.9–3.2), and was 1.0 (95% CI 0.4–2.5) for those not receiving MTX or biologics. Lymphoma was associated with increasing age, male sex, and education. Conclusion Lymphomas are increased in RA. Although the SIR is greatest for anti-TNF therapies, differences between therapies are slight, and confidence intervals for treatment groups overlap. The increased lymphoma rates observed with anti-TNF therapy may reflect channeling bias, whereby patients with the highest risk of lymphoma preferentially receive anti-TNF therapy. Current data are insufficient to establish a causal relationship between RA treatments and the development of lymphoma.