Katja Rüdell

Validity of instruments to measure physical activity may be questionable due to a lack of conceptual frameworks: a systematic review

BackgroundGuidance documents for the development and validation of patient-reported outcomes (PROs) advise the use of conceptual frameworks, which outline the structure of the concept that a PRO aims to measure. It is unknown whether currently available PROs are based on conceptual frameworks. This study, which was limited to a specific case, had the following aims: (i) to identify conceptual frameworks of physical activity in chronic respiratory patients or similar populations (chronic heart disease patients or the elderly) and (ii) to assess whether the development and validation of PROs to measure physical activity in these populations were based on a conceptual framework of physical activity.MethodsTwo systematic reviews were conducted through searches of the Medline, Embase, PsycINFO, and Cinahl databases prior to January 2010.ResultsIn the first review, only 2 out of 581 references pertaining to physical activity in the defined populations provided a conceptual framework of physical activity in COPD patients. In the second review, out of 103 studies developing PROs to measure physical activity or related constructs, none were based on a conceptual framework of physical activity.ConclusionsThese findings raise concerns about how the large body of evidence from studies that use physical activity PRO instruments should be evaluated by health care providers, guideline developers, and regulatory agencies.

Do 'alternative' help-seeking strategies affect primary care service use? A survey of help-seeking for mental distress

BackgroundEpidemiological studies suggest that only some distressed individuals seek help from primary care and that pathways to mental health care appear to be ethnically patterned. However few research studies examine how people with common mental disorder manage their mental distress, which help-seeking strategies they employ and whether these are patterned by ethnicity? This study investigates alternative help-seeking strategies in a multi-ethnic community and examines the relationship with primary care use.MethodsParticipants were recruited from four GP practice registers and 14 community groups in East London. Of 268 participants, 117 had a common mental disorder according to a valid and structured interview schedule (CIS-R). Participants were of Bangladeshi, black Caribbean and White British ethnic background. For those with a common mental disorder, we examined self-reported help-seeking behaviour, perceived helpfulness of care givers, and associations with primary care service use.ResultsWe found that alternative help-seeking such as talking to family about distress (OR 15.83, CI 3.9–64.5, P < .001), utilising traditional healers (OR 8.79, CI 1.98–38.93, p = .004), and severity of distress (1.11, CI 1.03–1.20, p = .006) was positively associated with primary care service use for people with a common mental disorder. Ethnic background influenced the choice of help-seeking strategies, but was less important in perceptions of their helpfulness.ConclusionPrimary care service use was strongly correlated with lay and community help-seeking. Alternative help-seeking was commonly employed in all ethnic groups. A large number of people believed mental distress could not be resolved or they did not know how to resolve it. The implications for health promotion and integrated care pathways are discussed.

The PROactive innovative conceptual framework on physical activity.

Although physical activity is considered an important therapeutic target in chronic obstructive pulmonary disease (COPD), what “physical activity” means to COPD patients and how their perspective is best measured is poorly understood. We designed a conceptual framework, guiding the development and content validation of two patient reported outcome (PRO) instruments on physical activity (PROactive PRO instruments). 116 patients from four European countries with diverse demographics and COPD phenotypes participated in three consecutive qualitative studies (63% male, age mean±sd 66±9 years, 35% Global Initiative for Chronic Obstructive Lung Disease stage III–IV). 23 interviews and eight focus groups (n = 54) identified the main themes and candidate items of the framework. 39 cognitive debriefings allowed the clarity of the items and instructions to be optimised. Three themes emerged, i.e. impact of COPD on amount of physical activity, symptoms experienced during physical activity, and adaptations made to facilitate physical activity. The themes were similar irrespective of country, demographic or disease characteristics. Iterative rounds of appraisal and refinement of candidate items resulted in 30 items with a daily recall period and 34 items with a 7-day recall period. For the first time, our approach provides comprehensive insight on physical activity from the COPD patients’ perspective. The PROactive PRO instruments’ content validity represents the pivotal basis for empirically based item reduction and validation. Conceptual framework as basis of PROactive PRO instruments to assess physical activity from COPD patient perspective http://ow.ly/ytJoS

Quality of Life and Utility Measurement in a Large Clinical Trial Sample of Patients with Mild to Moderate Alzheimer's Disease: Determinants and Level of Changes Observed.

OBJECTIVE To evaluate the performance (in terms of responsiveness to change, associations with other criterion standards, and indicators of Alzheimers disease [AD] severity) of a quality-of-life measure (Quality of Life in Alzheimers Disease [QOL-AD]) and a health utility measure (Health Utilities Index Mark 3 [HUI-3]) from two recently completed clinical trials of a new drug for AD. METHODS Change from baseline scores was calculated, and treatment effects were analyzed using mixed models for repeated measures. Three separate models were then estimated to examine the association between the quality-of-life/utility end points and the clinical and other health outcome end points measured during the trials, including cognition, function, behavior, and dependence. RESULTS The performance of the two measures differed. Subject-assessed QOL-AD was found to be weakly associated with clinical measures of cognition, and with caregiver reports of function, behavior, and dependence, and showed little movement over time and did not appear to differ by baseline AD severity. Proxy-assessed QOL-AD scores were consistently lower than subject-assessed scores, and the level of decline in QOL-AD was greater using proxy-assessed QOL-AD. Proxy-assessed HUI-3 scores were more strongly associated with clinical measures of cognition, function, behavior, and dependence than the subject- and proxy-assessed QOL-AD scores. Larger proportionate changes over 78 weeks were observed with HUI-3 scores and greater separation in HUI-3 scores by baseline severity. CONCLUSIONS Subject-assessed QOL-AD is less likely than proxy-assessed QOL-AD to respond to changes in clinical measures used to track progression in clinical trials of subjects with mild to moderate AD. Proxy-assessed HUI-3 assessments were more in line with other outcome assessments and could therefore be better outcome measures to evaluate clinical progression in mild to moderate AD.

Psychometric Properties of the Dependence Scale in Large Randomized Clinical Trials of Patients With Mild and Moderate Alzheimer’s Disease

Objective: The need for assistance from others is a hallmark concern in Alzheimer’s disease (AD). The psychometric properties of the Dependence Scale (DS) for measuring treatment benefit were investigated in large randomized clinical trials of patients with mild to moderate AD. Methods: Reliability, validity, and responsiveness of the DS were examined. Path models appraised relationships and distinctiveness of key AD measures. The responder definition was empirically derived. Results: Generally acceptable reliability (α ≥ .65), significant (P < .001) known-groups tests, and moderate to strong correlations (r ≥ .31) confirmed the DS psychometric properties. Path models supported relationships and distinctiveness of key AD measures. A DS change of ≤1 point for patients with limited home care and ≤2 points for patients with assisted living care best described stability of the level of dependence on caregivers. Conclusion: The DS is a psychometrically robust measure in mild to moderate AD. The empirically derived responder definition aids in the interpretation of DS change.

Literature review to assemble the evidence for response scales used in patient-reported outcome measures

BackgroundIn the development of patient-reported outcome (PRO) instruments, little documentation is provided on the justification of response scale selection. The selection of response scales is often based on the developers’ preferences or therapeutic area conventions. The purpose of this literature review was to assemble evidence on the selection of response scale types, in PRO instruments. The literature search was conducted in EMBASE, MEDLINE, and PsycINFO databases. Secondary search was conducted on supplementary sources including reference lists of key articles, websites for major PRO-related working groups and consortia, and conference abstracts. Evidence on the selection of verbal rating scale (VRS), numeric rating scale (NRS), and visual analogue scale (VAS) was collated based on pre-determined categories pertinent to the development of PRO instruments: reliability, validity, and responsiveness of PRO instruments, select therapeutic areas, and optimal number of response scale options.ResultsA total of 6713 abstracts were reviewed; 186 full-text references included. There was a lack of consensus in the literature on the justification for response scale type based on the reliability, validity, and responsiveness of a PRO instrument. The type of response scale varied within the following therapeutic areas: asthma, cognition, depression, fatigue in rheumatoid arthritis, and oncology. The optimal number of response options depends on the construct, but quantitative evidence suggests that a 5-point or 6-point VRS was more informative and discriminative than fewer response options.ConclusionsThe VRS, NRS, and VAS are acceptable response scale types in the development of PRO instruments. The empirical evidence on selection of response scales was inconsistent and, therefore, more empirical evidence needs to be generated. In the development of PRO instruments, it is important to consider the measurement properties and therapeutic area and provide justification for the selection of response scale type.

Response scale selection in adult pain measures: results from a literature review

BackgroundThe purpose of this literature review was to examine the existing patient-reported outcome measurement literature to understand the empirical evidence supporting response scale selection in pain measurement for the adult population.MethodsThe search strategy involved a comprehensive, structured, literature review with multiple search objectives and search terms.ResultsThe searched yielded 6918 abstracts which were reviewed against study criteria for eligibility across the adult pain objective. The review included 42 review articles, consensus guidelines, expert opinion pieces, and primary research articles providing insights into optimal response scale selection for pain assessment in the adult population. Based on the extensive and varied literature on pain assessments, the adult pain studies typically use simple response scales with single-item measures of pain—a numeric rating scale, visual analog scale, or verbal rating scale. Across 42 review articles, consensus guidelines, expert opinion pieces, and primary research articles, the NRS response scale was most often recommended in these guidance documents. When reviewing the empirical basis for these recommendations, we found that the NRS had slightly superior measurement properties (e.g., reliability, validity, responsiveness) across a wide variety of contexts of use as compared to other response scales.ConclusionsBoth empirical studies and review articles provide evidence that the 11-point NRS is likely the optimal response scale to evaluate pain among adult patients without cognitive impairment.