Improved responsiveness and reduced sample size requirements of PROMIS physical function scales with item response theory

INTRODUCTION: The Health Assessment Questionnaire Disability Index (HAQ) and the SF-36 PF-10, among other instruments, yield sensitive and valid Disability (Physical Function) endpoints. Modern techniques, such as Item Response Theory (IRT), now enable development of more precise instruments using improved items. The NIH Patient Reported Outcomes Measurement Information System (PROMIS) is charged with developing improved IRT-based tools. We compared the ability to detect change in physical function using original (Legacy) instruments with Item-Improved and PROMIS IRT-based instruments. METHODS: We studied two Legacy (original) Physical Function/Disability instruments (HAQ, PF-10), their item-improved derivatives (Item-Improved HAQ and PF-10), and the IRT-based PROMIS Physical Function 10- (PROMIS PF 10) and 20-item (PROMIS PF 20) instruments. We compared sensitivity to detect 12-month changes in physical function in 451 rheumatoid arthritis (RA) patients and assessed relative responsiveness using P-values, effect sizes (ES), and sample size requirements. RESULTS: The study sample was 81% female, 87% Caucasian, 65 years of age, had 14 years of education, and had moderate baseline disability. All instruments were sensitive to detecting change (\u3c 0.05) in physical function over one year. The most responsive instruments in these patients were the Item-Improved HAQ and the PROMIS PF 20. IRT-improved instruments could detect a 1.2% difference with 80% power, while reference instruments could detect only a 2.3% difference (P \u3c 0.01). The best IRT-based instruments required only one-quarter of the sample sizes of the Legacy (PF-10) comparator (95 versus 427). The HAQ outperformed the PF-10 in more impaired populations; the reverse was true in more normal populations. Considering especially the range of severity measured, the PROMIS PF 20 appears the most responsive instrument. CONCLUSIONS: Physical Function scales using item improved or IRT-based items can result in greater responsiveness and precision across a broader range of physical function. This can reduce sample size requirements and thus study costs

Better assessment of physical function: item improvement is neglected but essential

INTRODUCTION: Physical function is a key component of patient-reported outcome (PRO) assessment in rheumatology. Modern psychometric methods, such as Item Response Theory (IRT) and Computerized Adaptive Testing, can materially improve measurement precision at the item level. We present the qualitative and quantitative item-evaluation process for developing the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function item bank. METHODS: The process was stepwise: we searched extensively to identify extant Physical Function items and then classified and selectively reduced the item pool. We evaluated retained items for content, clarity, relevance and comprehension, reading level, and translation ease by experts and patient surveys, focus groups, and cognitive interviews. We then assessed items by using classic test theory and IRT, used confirmatory factor analyses to estimate item parameters, and graded response modeling for parameter estimation. We retained the 20 Legacy (original) Health Assessment Questionnaire Disability Index (HAQ-DI) and the 10 SF-36\u27s PF-10 items for comparison. Subjects were from rheumatoid arthritis, osteoarthritis, and healthy aging cohorts (n = 1,100) and a national Internet sample of 21,133 subjects. RESULTS: We identified 1,860 items. After qualitative and quantitative evaluation, 124 newly developed PROMIS items composed the PROMIS item bank, which included revised Legacy items with good fit that met IRT model assumptions. Results showed that the clearest and best-understood items were simple, in the present tense, and straightforward. Basic tasks (like dressing) were more relevant and important versus complex ones (like dancing). Revised HAQ-DI and PF-10 items with five response options had higher item-information content than did comparable original Legacy items with fewer response options. IRT analyses showed that the Physical Function domain satisfied general criteria for unidimensionality with one-, two-, three-, and four-factor models having comparable model fits. Correlations between factors in the test data sets were \u3e 0.90. CONCLUSIONS: Item improvement must underlie attempts to improve outcome assessment. The clear, personally important and relevant, ability-framed items in the PROMIS Physical Function item bank perform well in PRO assessment. They will benefit from further study and application in a wider variety of rheumatic diseases in diverse clinical groups, including those at the extremes of physical functioning, and in different administration modes

Varying the item format improved the range of measurement in patient-reported outcome measures assessing physical function

BACKGROUND: Physical function (PF) is a core patient-reported outcome domain in clinical trials in rheumatic diseases. Frequently used PF measures have ceiling effects, leading to large sample size requirements and low sensitivity to change. In most of these instruments, the response category that indicates the highest PF level is the statement that one is able to perform a given physical activity without any limitations or difficulty. This study investigates whether using an item format with an extended response scale, allowing respondents to state that the performance of an activity is easy or very easy, increases the range of precise measurement of self-reported PF. METHODS: Three five-item PF short forms were constructed from the Patient-Reported Outcomes Measurement Information System (PROMIS(R)) wave 1 data. All forms included the same physical activities but varied in item stem and response scale: format A ( Are you able to ... ; without any difficulty / unable to do ); format B ( Does your health now limit you ... ; not at all / cannot do ); format C ( How difficult is it for you to ... ; very easy / impossible ). Each short-form item was answered by 2217-2835 subjects. We evaluated unidimensionality and estimated a graded response model for the 15 short-form items and remaining 119 items of the PROMIS PF bank to compare item and test information for the short forms along the PF continuum. We then used simulated data for five groups with different PF levels to illustrate differences in scoring precision between the short forms using different item formats. RESULTS: Sufficient unidimensionality of all short-form items and the original PF item bank was supported. Compared to formats A and B, format C increased the range of reliable measurement by about 0.5 standard deviations on the positive side of the PF continuum of the sample, provided more item information, and was more useful in distinguishing known groups with above-average functioning. CONCLUSIONS: Using an item format with an extended response scale is an efficient option to increase the measurement range of self-reported physical function without changing the content of the measure or affecting the latent construct of the instrument

Personal non-commercial use only

ABSTRACT. Objective. Patient-reported outcome (PRO) questionnaires record health information directly from research participants because observers may not accurately represent the patient perspective. Patient-reported Outcomes Measurement Information System (PROMIS) is a US National Institutes of Health cooperative group charged with bringing PRO to a new level of precision and standardization across diseases by item development and use of item response theory (IRT). Methods. With IRT methods, improved items are calibrated on an underlying concept to form an item bank for a "domain" such as physical function (PF). The most informative items can be combined to construct efficient "instruments" such as 10-item or 20-item PF static forms. Each item is calibrated on the basis of the probability that a given person will respond at a given level, and the ability of the item to discriminate people from one another

Care planning: a neoliberal three card trick

Introduction The three card game, sometimes called find the queen, is a classic confidence trick, typically taking place on an impromptu table top, set up on pavement or street corner. The tricksters usually operate in teams, pulling in punters and ‘losing’ games with their fellows to persuade prospective speculators the game is winnable. For our titular purposes the three card trick serves as a metaphor for broader deceits. We are concerned with how well-meaning mental health nurses can enter into a set of apparently rational practices, insisted upon by policy and protocol, seemingly motivated by ideals of care and protection from harm, yet functioning to destroy the very essence of what it might mean to be a caring, progressive practitioner by contributing to a mutuality of alienation that, at the relational level, is the opposite of what services intend to achieve. This may prove to be the case because an external confidence trickster (neoliberalism) is actually in charge, and the real function of the game serves other ends. The whole point of the game is that genuine players can never win, and for the trickster to triumph it is necessary that these punters are willing, gullible and in most circumstances accept losses without too much fuss. When the losers do not go quietly this is referred to in the argot of the con as ‘squawking’, and personnel are deployed on the periphery to ensure any squawk is minimised. Various strategies can be used to ‘cool out the mark’, and are analogous to the means by which people are assisted to adjust to life’s disappointments in other contexts, including encounters with priests or sundry psy-professionals (Goffman 1952; McKeown et al. 2013). This commentary paper seeks to provoke nursing out of its state of gullibility and self-deception even if this involves painful reflection on the losses inherent in our collective game of mental health care. If we are to defend the importance of mental health nursing we must think more critically about our complicity within oppressive systems of control and do something about it. There is a lengthy critical tradition to draw on. We urge mental health nurses to squawk, asserting a more recalcitrant and rebellious standpoint, preferably in alliance with service users, refusers and survivors. Acknowledging the constraints upon nursing’s agency, deficits of power, and structural disadvantage need not default to impotence and inaction: collective resistance is always possible, however difficult the circumstances

Fibroblasts from different sites may promote or inhibit recruitment of flowing lymphocytes by endothelial cells

We examined the hypothesis that stromal fibroblasts modulate the ability of endothelial cells (EC) to recruit lymphocytes in a site-specific manner. PBL were perfused over HUVEC that had been cultured with fibroblasts isolated from the inflamed synovium or the skin of patients with rheumatoid arthritis or osteoarthritis, or from normal synovium, with or without exposure to the inflammatory cytokines TNF-a+IFN-c. Fibroblasts from inflamed synovium, but no others, caused unstimulated HUVEC to bind flowing lymphocytes. This adhesion was supported by a4b1-VCAM-1 interaction and stabilised by activation of PBL through CXCR4–CXCL12. Antibody neutralisation of IL-6 during co-culture effectively abolished the ability of EC to bind lymphocytes. Cytokine-stimulated EC supported high levels of lymphocyte adhesion, through the presentation of VCAM-1, E-selectin and chemokine(s) acting through CXCR3. Interestingly, co-culture with dermal fibroblasts caused a marked reduction in cytokine-induced adhesion, while synovial fibroblasts had variable effects depending on their source. In the dermal co-cultures, neutralisation of IL-6 or TGF-b caused partial recovery of cytokine-induced lymphocyte adhesion; this was complete when both were neutralised. Exogenous IL-6 was also found to inhibit response to TNF-a+IFN-c. Normal stromal fibroblasts appear to regulate the cytokine-sensitivity of vascular endothelium, while fibroblasts associated with chronic inflammation bypass this and develop a directly inflammatory phenotype. Actions of IL-6 might be pro-inflammatory or anti-inflammatory, depending on the local milieu

Financial considerations in the conduct of multi-centre randomised controlled trials: evidence from a qualitative study.

National Coordinating Centre for Research Methodology; Medical Research Council, UK Department of Health; Chief Scientist OfficeNot peer reviewedPublisher PD