Donna L. Lamping

OBJECTIVE: To develop a patient-based measure of walking ability in MS. METHODS: Twelve items describing the impact of MS on walking (12-Item MS Walking Scale [MSWS-12]) were generated from 30 patient interviews, expert opinion, and literature review. Preliminary psychometric evaluation (data quality, scaling assumptions, acceptability, reliability, validity) was undertaken in the data generated by 602 people from the MS Society membership database. Further psychometric evaluation (including comprehensive validity assessment, responsiveness, and relative efficiency) was conducted in two hospital-based samples: people with primary progressive MS (PPMS; n = 78) and people with relapses admitted for IV steroid treatment (n = 54). RESULTS: In all samples, missing data were low (< or =3.8%), item test-retest reproducibility was high (> or =0.78), scaling assumptions were satisfied, and reliability was high (> or =0.94). Correlations between the MSWS-12 and other scales were consistent with a priori hypotheses. The MSWS-12 (relative efficiency = 1.0) was more responsive than the Functional Assessment of Multiple Sclerosis mobility scale (0.72), the 36-Item Short Form Health Survey physical functioning scale (0.33), the Expanded Disability Status Scale (0.03), the 25-ft Timed Walk Test (0.44), and Guy's Neurologic Disability Scale lower limb disability item (0.10). CONCLUSIONS: The MSWS-12 satisfies standard criteria as a reliable and valid patient-based measure of the impact of MS on walking. In these samples, the MSWS-12 was more responsive than other walking-based scales.

STUDY DESIGN: The Quebec Back Pain Disability Scale is a 20-item self-administered instrument designed to assess the level of functional disability in individuals with back pain. The scale was administered as part of a larger questionnaire to a group of 242 back pain patients. Follow-up data were obtained after several days and after 2 to 6 months. OBJECTIVES: The goal of this study was to determine whether the Quebec scale is a reliable, valid, and responsive measure of disability in back pain, and to compare it with other disability scales. SUMMARY OF BACKGROUND DATA: A number of functional disability scales for back pain are being used, but their conceptual validity is uncertain. Unlike most published instruments, the Quebec scale was constructed using a conceptual approach to disability assessment and empirical methods of item development, analysis, and selection. METHODS: The authors calculated test-retest and internal consistency coefficients, evaluated construct validity of the scale, and tested its responsiveness against a global index of change. Direct comparisons with the Roland, Oswestry, and SF-36 scales were carried out. RESULTS: Test-retest reliability was 0.92, and Cronbach's alpha coefficient was 0.96. The scale correlated as expected with other measures of disability, pain, medical history, and utilization variables, work-related variables, and socio-demographic characteristics. Significant changes in disability over time, and differences in change scores between patients that were expected to differ in the direction of change, were found. CONCLUSIONS: The Quebec scale can be recommended as an outcome measure in clinical trials, and for monitoring the progress of individual patients participating in treatment or rehabilitation programs.

OBJECTIVES: To develop and validate a psychometrically rigorous measure of health-related quality of life (HRQoL) for people with dementia: DEMQOL. DATA SOURCES: Literature review. Expert opinion. Interviews and questionnaires. REVIEW METHODS: Gold standard psychometric techniques were used to develop DEMQOL and DEMQOL-Proxy. A conceptual framework was generated from a review of the literature, qualitative interviews with people with dementia and their carers, expert opinion and team discussion. Items for each component of the conceptual framework were drafted and piloted to produce questionnaires for the person with dementia (DEMQOL) and carer (DEMQOL-Proxy). An extensive two-stage field-testing was then undertaken of both measures in large samples of people with dementia (n = 130) and their carers (n = 126) representing a range of severity and care arrangements. In the first field test, items with poor psychometric performance were eliminated separately for DEMQOL and DEMQOL-Proxy to produce two shorter, more scientifically robust instruments. In the second field test, the item-reduced questionnaires were evaluated along with other validating measures (n = 101 people with dementia, n = 99 carers) to assess acceptability, reliability and validity. RESULTS: Rigorous evaluation in two-stage field testing with 241 people with dementia and 225 carers demonstrated that in psychometric terms: (1) DEMQOL is comparable to the best available dementia-specific HRQoL measures in mild to moderate dementia, but is not appropriate for use in severe dementia [Mini Mental State Examination (MMSE) <10]; and (2) DEMQOL-Proxy is comparable to the best available proxy measure in mild to moderate dementia, and shows promise in severe dementia. In addition, the DEMQOL system has been validated in the UK in a large sample of people with dementia and their carers, and it provides separate measures for self-report and proxy report, which allows outcomes assessment across a wide range of severity in dementia. CONCLUSIONS: The 28-item DEMQOL and 31-item DEMQOL-Proxy provide a method for evaluating HRQoL in dementia. The new measures show comparable psychometric properties to the best available dementia-specific measures, provide both self- and proxy-report versions for people with dementia and their carers, are appropriate for use in mild/moderate dementia (MMSE >/= 10) and are suitable for use in the UK. DEMQOL-Proxy also shows promise in severe dementia. As DEMQOL and DEMQOL-Proxy give different but complementary perspectives on quality of life in dementia, the use of both measures together is recommended. In severe dementia, only DEMQOL-Proxy should be used. Further research with DEMQOL is needed to confirm these findings in an independent sample, evaluate responsiveness, investigate the feasibility of use in specific subgroups and in economic evaluation, and develop population norms. Additional research is needed to address the psychometric challenges of self-report in dementia and validating new dementia-specific HRQoL measures.

BACKGROUND AND PURPOSE: Health-related quality of life (HRQL) is a key outcome in stroke clinical trials. Stroke-specific HRQL scales (eg, SS-QOL, SIS) have generally been developed with samples of stroke survivors that exclude people with aphasia. We adapted the SS-QOL for use with people with aphasia to produce the Stroke and Aphasia Quality of Life Scale (SAQOL). We report results from the psychometric evaluation of the initial 53-item SAQOL and the item-reduced SAQOL-39. METHODS: We studied 95 people with long-term aphasia to evaluate the acceptability, reliability, and validity of the SAQOL and SAQOL-39 using standard psychometric methods. RESULTS: A total of 83 of 95 (87%) were able to complete the SAQOL by self-report; their results are reported here. Results supported the reliability and validity of the overall score on the 53-item SAQOL, but there was little support for hypothesized subdomains. Using factor analysis, we derived a shorter version (SAQOL-39) that identified 4 subdomains (physical, psychosocial, communication, and energy). The SAQOL-39 demonstrated good acceptability, internal consistency (Cronbach's alpha=0.74 to 0.94), test-retest reliability (intraclass correlation coefficient=0.89 to 0.98), and construct validity (corrected domain-total correlations, r=0.38 to 0.58; convergent, r=0.55 to 0.67; discriminant, r=0.02 to 0.27 validity). CONCLUSIONS: The SAQOL-39 is an acceptable, reliable, and valid measure of HRQL in people with long-term aphasia. Further testing is needed to evaluate the responsiveness of the SAQOL-39 and to investigate its usefulness in evaluative research and routine clinical practice.