Internal consistency and validity of the Stroke Impact Scale 2.0 (SIS 2.0) and SIS-16 in an Australian sample

Background and Purpose: The impact of stroke is multidimensional however standard stroke measures do not discriminate well when stroke patients are less physically impaired. The Stroke Impact Scale 2.0 (SIS 2.0) is a multidimensional measure of the impact of stroke but its' psychometric properties require further testing. The SIS-16 is a measure of physical functioning designed to be more sensitive to differences in physical functioning than current stroke outcome measures but there is only preliminary information detailing its' reliability and validity. The current study examined the internal consistency and validity of the SIS 2.0 and SIS-16 in an Australian sample of stroke patients. Methods: The SIS 2.0, SIS-16, World Health Organization Bref-Scale (WHOQOL-BREF) and Zung's Self-Rating Depression Scale (SDS) were completed by 74 stroke patients in rural Victoria, Australia. Results: The item convergent validity index indicated good item convergence of the SIS-16 and SIS 2.0 domains. The item discriminant validity index had only adequate divergence for most SIS 2.0 domains. Internal consistencies of the SIS-16 and SIS 2.0 domains were acceptable ( = 0.87–0.95). Correlations between the SIS-16 and SIS 2.0 and the WHOQOL-BREF and SDS supported the convergent and discriminant validity of the SIS-16 and all the dimensions of the SIS 2.0 except Participation which lacked discriminant validity. Conclusions: The SIS 2.0 and SIS-16 had good psychometric properties with support for the internal consistency and validity of both measures.     

The SF-36: A simple, effective measure of mobility-disability for epidemiological studies

Background  Mobility disability is a major problem in older people. Numerous scales exist for the measurement of disability but often these do not permit comparisons between study groups. The physical functioning (PF) domain of the established and widely used Short Form-36 (SF-36) questionnaire asks about limitations on ten mobility activities. Objectives  To describe prevalence of mobility disability in an elderly population, investigate the validity of the SF-36 PF score as a measure of mobility disability, and to establish age and sex specific norms for the PF score. Methods  We explored relationships between the SF-36 PF score and objectively measured physical performance variables among 349 men and 280 women, 59–72 years of age, who participated in the Hertfordshire Cohort Study (HCS). Normative data were derived from the Health Survey for England (HSE) 1996. Results  32% of men and 46% of women had at least some limitation in PF scale items. Poor SF-36 PF scores (lowest fifth of the gender-specific distribution) were related to: lower grip strength; longer timed-up-and-go, 3m walk, and chair rises test times in men and women; and lower quadriceps peak torque in women but not men. HSE normative data showed that median PF scores declined with increasing age in men and women. Conclusion  Our results are consistent with the SF-36 PF score being a valid measure of mobility disability in epidemiological studies. This approach might be a first step towards enabling simple comparisons of prevalence of mobility disability between different studies of older people. The SF-36 PF score could usefully complement existing detailed schemes for classification of disability and it now requires validation against them.     

The Validity of the Canadian Occupational Performance Measure (COPM) When Used in a Sub-Acute Rehabilitation Setting with Older Adults

This study investigated the validity of the Canadian Occupational Performance Measure (COPM) when included as one of the scales used by therapists with older adults on an inpatient sub-acute rehabilitation setting. Quantitative data from 36 participants in a sub-acute rehabilitation setting was obtained via the COPM, the Functional Independence Measure (FIM) and the Short Form 36 Health Survey (SF-36) using a pre-post methodology. Pearson's r correlations and linear regression analyses were computed. The COPM Performance admission score was significantly correlated with the FIM Total and FIM Physical admission scores (p <.05) while the COPM Satisfaction admission score was significantly correlated with the FIM Total and FIM Physical admission scores (p <.05). The COPM Performance discharge score was significantly associated with the FIM Total, FIM Physical, and SF-36 Physical Health discharge scores (p <.01) while the COPM Satisfaction discharge scores was significantly associated with the FIM Total, FIM Physical, and SF-36 Physical Health discharge scores (p <.01) respectively. Linear regression analyses determined that the COPM's Performance admission score uniquely explained 8.4% of the SF-36 Physical Health discharge score's total variance (p <.05). The results contribute to the COPM's evidence base, supporting its convergent validity and predictive validity.     

Psychometric properties of the WHODASII in rehabilitation patients

Background To evaluate function and disability, the WHO has developed the WHO Disability Assessment Schedule II (WHODASII), an instrument arising from the same conceptual basis as the International Classification of Functioning, Disability, and Health (ICF). Objectives The general objective of this study was to investigate whether the WHODASII––German version—is a valid instrument to measure functioning and disability across various conditions. Specific aims were (1) to assess its psychometric properties (reliability, validity, and sensitivity to change) based on the traditional test theory and (2) to compare its sensitivity to change after a rehabilitative intervention to the Short Form 36 (SF-36). Research design This was a multi-center study with convenience samples of patients with different chronic conditions undergoing rehabilitation. Patients completed the WHODASII and the SF-36 before and after a rehabilitation treatment. Health professionals rated in cooperation with the patients the pain of the patients based on the ICF category “sensation of pain.” Results 904 patients were included in the study. The Cronbach’s range from 0.70 to 0.97 for the different subscales of WHODASII. With exception of the subscale Activities, the exploratory-factor structure of the WHODASII corresponds highly with the original structure. The effect size (ES) of the WHODASII total score ranged from 0.16 to 0.69 depending on the subgroup. The ES of the SF-36 summary scores ranged from 0.03 to 1.40. Conclusions The WHODAS II (German version) is a useful instrument for measuring functioning and disability in patients with musculoskeletal diseases, internal diseases, stroke, breast cancer, and depressive disorder. The results of this study support the reliability, validity, dimensionality, and responsiveness of the German version of the WHODASII. However, the reproducibility in test–retest samples of stable patients, as well as the question to what extent a summary score can be constructed, requires further investigation.     

Screening behaviors for diabetic foot risk and their influencing factors among general practitioners: a cross-sectional study in Changsha,China

Background

Stroke is one of the leading causes of death and the main cause of long-term disability in the United States. The significant risk factors of stroke among Hispanics are well-documented. The majority of stroke survivors return home following a stroke and are cared for by family caregivers. Due to the abrupt nature of strokes, caregivers experience unexpected changes and demands that oftentimes lead to caregiver burden and depression. Given the significant risk factors for stroke in Hispanics and the influence of culture in family norms and family management, we developed a telephone and online problem-solving intervention for Spanish-speaking stroke caregivers. This study tests the impact of a telephone and online problem-solving intervention for Spanish-speaking stroke caregivers on caregiver outcomes.

Methods

The design is a two-arm parallel randomized clinical trial with repeated measures. We will enroll 290 caregivers from 3 Veterans Affairs (VA) medical centers. Participants randomized into the intervention arm receive a problem-solving intervention that uses telephone and online education and care management tools on the previously developed and nationally available RESCUE en Español Caregiver website. In the usual care group, participants receive the information and/or support caregivers of veterans with stroke normally receive through existing VA resources (e.g., stroke-related information and support). The primary outcome is change in caregiver’s depressive symptoms at 1- and 12-weeks post-intervention. Secondary outcomes include changes in stroke caregivers’ burden, self-efficacy, problem-solving, and health-related quality of life (HRQOL) and veterans’ functional abilities. We will also determine the budgetary impact, the acceptability of the intervention and participation barriers and facilitators for Spanish-speaking stroke caregivers.

Discussion

This is an ongoing study. It is the first known randomized controlled trial testing the effect of a telephone and online problem-solving intervention in Spanish for caregivers of veterans post-stroke. If successful, findings will support an evidence-based model that can be transported into clinical practice to improve the quality of caregiving post-stroke.

Trial registration

ClinicalTrials.gov: NCT03142841— Spanish Intervention for Caregivers of Veterans with Stroke (RESCUE Español). Registered on February 23, 2018. Protocol version 8. 08.11.2022.

     

A Study of the Construct Validity of the Health Utilities Index Mark 3 (HUI3) in Patients with Schizophrenia

This study assessed the construct validity of the Health Utilities Index Mark 3 (HUI3) in patients with schizophrenia. Patients with schizophrenia recruited from a tertiary mental hospital in Singapore completed the HUI3, the Short-Form 36 Health Survey (SF-36) and the Schizophrenia Quality of Life Scale (SQLS). Patients were assessed for presence and absence of 22 common psychiatric symptoms. Construct validity was assessed using 6 a priori hypotheses. Two hundred and two patients (mean age: 37.8 years, female: 52%) completed the survey. As hypothesized, overall HUI3 utility scores were correlated with SF-36 measures (Spearman’s rho: 0.19 to 0.51), SQLS scales (Spearman’s rho: −0.56 to −0.36), and the number of psychiatric symptoms (Spearman’s rho: −0.49). The HUI3 emotion attribute was moderately correlated with SF-36 mental health (Spearman’s rho: 0.45) and SQLS psychosocial scales (Spearman’s rho: −0.43), and HUI3 pain attribute was strongly correlated with SF-36 bodily pain scale (Spearman’s rho: 0.58). The mean HUI3 overall, emotion, cognition, and speech scores for patients with schizophrenia were 0.07, 0.09, 0.04 and 0.04 points lower than respective age-, sex- and ethnicity-adjusted population norms (p<0.001 for all, ANCOVA). This study provides evidence for the construct validity of the HUI3 in patients with schizophrenia.     

Change in quality of life of people with stroke over time: True change or response shift?

In many studies, assessments of change in self-report measures such as health-related quality of life must account for potential response shift, including reconceptualization and changes in internal standards of measurement. Objective: The objective of our study was to compare healthy controls and individuals with stroke on the extent to which changes in internal standards and reconceptualization of health related quality of life (HRQL) occurs over the first 6 months post-stroke. Methods: Confirmatory factor analysis was used to assess invariance of the SF-36 measurement model over time among 238 individuals with stroke and 392 controls, separately. This procedure assessed changes over time in the factor loadings, variances, and covariances of responses, and compared the extent of change between individuals with stroke and those in the control group. In addition a multisample comparison was made between individuals with stroke and members of the control group at the first evaluation in order to assess invariance of the SF-36 measurement model between the groups. The controls were considered to be a proxy for the stroke cohort prior to the stroke. Results: We found no evidence of reconceptualization and changes in internal standards over time when the groups were assessed separately. There was a significant difference in the factor covariances (reconceptualization) between the two groups at the time of the first evaluation. However, measurement error was also significant for this comparison. Conclusion: This study indicates that the improvement in HRQL over time is real rather than a result of reconceptualization or a recalibration. If response shift does occur with stroke it is likely to be mediated by the event itself and not the recovery process.     

Health-related Quality of Life in Multiple Sclerosis: The Impact of Disability, Gender and Employment Status

Objectives: (1) Evaluate the impact of the patient charateristics of disability, gender and employment status on health-related quality of life (HRQOL) in multiple sclerosis (MS) and (2) Characterize the functional relationship between HRQOL and disability overall, and by gender and employment status. Methods: We assessed the HRQOL of 215 MS outpatients in our clinic using the MSQOL-54 and Fatigue Severity Scale (FSS), and that of 172 healthy controls, using the SF-36 (a subset of MSQOL-54). We compared QOL between MS subgroups defined by disability, gender and employment, and computed the linear and non-linear relationships between disability level measured by the Expanded Disability Status Scale (EDSS) and MSQOL-54 dimensions. Results: QOL of MS patients measured by SF-36 is lower than controls, varying by QOL dimension with the greatest difference emerging for physical aspects of the disease. The relationship of physical disability, measured by EDSS, and all 14 MSQOL-54 dimensions and FSS is negative; for 12 of the 14 dimensions and FSS it is also non-linear. Non-linearity is most pronounced among women, who show a weak EDSS/QOL relatioship at higher levels of physical disability, suggesting women better able to “psychologically buffer” the debilitating aspects of MS. While employed have higher QOL than unemployed, the former are more affected by physical disability. Conclusions: Multiple attributes, including disability, gender and employment status, affect QOL. QOL’s relationship with disability is complex, displaying non-linearity and interacting with patient characteristics. This has implication for QOL research methodology and provides insight into factors affecting patients’ perceptions of well-being.     

Comparison of WHOQOL-BREF and SF-36 in patients with HIV infection

The purpose of the study was to evaluate the reliability and validity of the two generic instruments, the WHOQOL and the SF-36, for assessing health-related quality of life in 224 patients with HIV infection. The internal consistency ranged from 0.75 to 0.86 across the WHOQOL-BREF domains and from 0.72 to 0.93 across the SF-36 scales. The scores of all WHOQOL-BREF domains and SF-36 scales correlated positively with the measure of happiness, Sat-HRQOL and self-perceived health status, and correlated negatively with the number and intensity of symptoms. Patients with higher CD4 cell counts scored significantly higher on G4 (general health), three WHOQOL-BREF domains, seven SF-36 scales, and PCS (physical component summary). Patients with fewer symptoms and with less intensity of symptoms had significantly higher scores on all four domains of WHOQOL-BREF, eight scales, PCS, and MCS (mental component summary) of the SF-36 scale. The correlations between the physical, psychological, and social domains of the WHOQOL-BREF and PF (physical functioning), MH (mental health), and SF (social functioning) of the SF-36 were 0.51, 0.75, and 0.54, respectively. There is also good correlation between PCS of the SF-36 and the physical domain of the WHOQOL-BREF (r = 0.48), and between MCS and all four domains of the WHOQOL-BREF (r range = 0.60–0.75). The WHOQOL-BREF domains showed fewer floor or ceiling effect than the SF-36 scales. We concluded that both the WHOQOL-BREF and the SF-36 are reliable and valid health related quality-of-life instruments in patients with HIV infection.     

农村脑卒中患者家庭陪护人生命质量的研究

目的了解脑卒中致农村家庭负担，为今后降低脑卒中对家庭的危害性提供依据。方法以SF-36量表作为测量工具，采用人户的方式对71名脑卒中的家庭陪护人进行调查。结果脑卒中患者及其家庭陪护人在8个维度的评分比较，经t检验，差别均无统计学意义（P〉0．05）。男女性家庭陪护人在8个维度的评分上均低于四川省40～59岁农村人口，差别有统计学意义（P〈0．01）。结论脑卒中在严重影响患者自身生命质量的同时，给农村家庭造成的负担不容忽视。     

Psychometric properties of the Japanese version of the quality of life-Cancer Survivors Instrument

The purpose of this study was to describe the psychometric properties of the Japanese version of the Quality of Life-Cancer Survivors Instrument (QOL-CS-J) developed in the U.S. This study was conducted as a mail survey to survivors of more than 5 years post curative resection for non-small-cell lung cancer (NSCLC) and who had participated in an earlier survey. This survey included the medical and demographic factors, the QOL-CS scores, and the Medical Outcome Study 36-Item Short Form (SF-36). A total of 113 survivors completed the survey. To confirm the reliability, the Cronbach’s α coefficient of each subscale was calculated as an internal consistency (α = 0.65–0.89). To confirm the validity of the trial as conducted, Pearson’s correlation coefficients between the subscales of the QOL-CS and the subscales of the SF-36 were calculated. There were moderate correlations between associated subscales including QOL-CS physical to SF-36 bodily pain (r = 0.45) and vitality (r = 0.52), QOL-CS psychological to SF-36 mental health (r = 0.55), QOL-CS social to SF-36 general health perception (r = 0.31) and mental health (r = 0.47), and QOL-CS total to each subscale of SF-36 (r = 0.25–0.64). Findings demonstrated that the QOL-CS-J adequately measured the QOL in long-term NSCLC survivors.     

Reliability and validity of the social integration survey (SIS) in patients with schizophrenia

Introduction Schizophrenia-related impairments impact functional status and health-related quality of life. The Social Integration Survey (SIS) measures social functioning outcomes in schizophrenia from patient and informant perspectives. Methods A total of 129 patient/informant dyads at eight US sites participated. Patients were at least 18 years old, with schizophrenia or schizoaffective disorder for 1 year or more, residing in the community. Informants were at least 21 years old, cared for patient at least 1 month, with contact at least twice weekly. The SIS, PSP, PETiT, QLS, CGI-S, and PANSS were completed. Individual item performance, subscale development, reliability, and validity were examined. Results Items were easily understood and responses well-distributed for patients and informants. Four of five subscales identified were internally consistent (alphas ≥0.68) and stable over time. Inter-rater reliability was low. SIS scores were not strongly correlated with other measures, except PETiT Quality of Life. The SIS differentiated on social functioning at varying levels of symptom severity (P < 0.05). Conclusions Patient and informant-completed versions showed adequate internal consistency, test–retest reliability, and discriminant validity. Lack of correspondence between patient and informant responses and construct validity require further examination. Work-related items were inapplicable for most patients, but would be for those with higher functioning.     

Changing to an Outcome-focused Program Improves Return to Work Outcomes

Objectives: The purposes of this study were to: (1) evaluate the effectiveness of changing a Return to Work (RTW) program’s focus to one that was “outcome-focused”, and (2) to determine which factors collected in the facility’s database were most predictive of RTW. Methods: A total of 13,428 client files were extracted from Millard Health’s database which included data on two cohorts of subjects: those in the program before and after the change in focus had been made. This was to determine whether significant improvements in outcomes were achieved. Variables that were hypothesized to be predictive of RTW were selected based on previous published literature. Analyses included ANOVA’s, logistic regression analysis and Pearson correlation. Results: Statistically significant improvements in RTW, total temporary disability claims, client satisfaction, efficiency of services and scores on the Perceived Disability Index (PDI), Short Form-36 (SF-36) and Visual Analogue Scale (VAS) for perceived pain were found. Variables that were predictive of RTW included: more efficient services, completion of a worksite visit, having the worker participate in the visit, availability of modified duties from the employer, fewer absences from the program and better scores on the PDI, SF-36 and VAS. The most predictive variable of RTW was sores on the PDI indicating lower levels of perceived disability. Conclusions: Changing to an outcome-focused program improved various outcomes in this RTW program. Several factors predict the outcome of RTW and these should be considered in treatment planning.     

Is Psychometric Scoring of the McNew Quality of Life After Myocardial Infarction Questionnaire Superior to the Clinimetric Scoring? A Comparison of the Two Approaches

Objective: ‘Clinimetric’ and ‘psychometric’ approaches are currently used to develop health related quality of life questionnaires. The Quality of Life after Myocardial Infarction questionnaire (QLMI) was originally developed using ‘clinimetric’ criteria; it was subsequently modified (McNew QLMI) and a new domain structure was defined using factor analysis. The objective of this study was to compare the measurement properties of the McNew QLMI scores when both approaches for scoring are used. Methods: The McNew QLMI and SF-36 were administered to patients 2 weeks and 2 months after myocardial infarction. Two sets of scores for the McNew QLMI were computed using the original ‘clinimetric’ and the subsequent ‘psychometrically’ derived scoring systems. Reliability statistics for the two sets of domains were compared and construct validity was assessed by establishing a priori hypotheses on the expected correlation between each score and the dimensions of the SF-36. Results: Both sets of scores had similar reliability (Cronbach’s α between 0.64 and 0.93) and responsiveness (SRMs between 0.17 and 0.87) while validity was better for the ‘clinimetric’ set of scores (concordance between observed and expected correlations was moderate for the ‘clinimetric’ scores and fair for the ‘psychometric’ scores). Conclusion: Since overall measurement properties of the ‘clinimetrically’ scored McNew QLMI are better than the ‘psychometrically’ scored version, we suggest that either the original ‘clinimetric’ system is used or that an improved ‘psychometric’ version is developed.     

Do the SF-36 and WHOQOL-BREF Measure the Same Constructs? Evidence from the Taiwan Population*

Background: The SF-36 and WHOQOL-BREF are available for international use, but it is not clear if they measure the same constructs. We compared the psychometric properties and factor structures of these two instruments. Methods: Data were collected from a national representative sample (n=11,440) in the 2001 Taiwan National Health Interview Survey, which included Taiwan versions of the SF-36 and WHOQOL-BREF. We used Cronbach’s alpha coefficient to estimate scale reliability. We conducted exploratory factor analysis to determine factor structure of the scales, and applied multitrait analysis to evaluate convergent and discriminant validity. We used standardized effect size to compare known-groups validity for health-related variables (including chronic conditions and health care utilization) and self-reported overall quality of life. Structural equation modeling was used to analyze relationships among the two SF-36 component scales (PCS and MCS) and the four WHOQOL subscales (physical, psychological, social relations, and environmental). Results: Cronbach’s alpha coefficients were acceptable (⩾0.7) for all subscales of both instruments. The factor analysis yielded two unique factors: one for the 8 SF-36 subscales and a second for the 4 WHOQOL subscales. Pearson correlations were weak (<0.3) among subscales of both instruments. Correlations for subscales hypothesized to measure similar constructs differed little from those measuring heterogeneous subscales. Effect sizes suggested greater discrimination by the SF-36 for health status and services utilization known groups, but greater discrimination by the WHOQOL for QOL-defined groups. Structural equation modeling suggested that the SF-36 PCS and MCS were weakly associated with WHOQOL. Conclusions: In this Taiwan population sample, the SF-36 and WHOQOL-BREF appear to measure different constructs: the SF-36 measures health-related QOL, while the WHOQOL-BREF measures global QOL. Clinicians and researchers should carefully define their research questions related to patient-reported outcomes before selecting which instrument to use. * Presented in part at (1) 11th Annual Conference of the International Society for Quality of Life Research. Hong Kong, China, 2004. (2) 2004 Quality of Life Symposium – Conceptualization and Measurement issues in QOL. Tai-Chuan, Taiwan, 2004     

Quality of Life of Post-stroke Patients

IntroductionStroke is a disease whose consequences have a considerable impact on the quality of the patient’s life. It is a widespread disease that has a disabling impact on life and, in addition to physical changes, brings about a number of psychological and cognitive processes.GoalThe goal of the study was to identify and describe the quality of life of post-stroke patients.MethodologyThe study design was quantitative. A questionnaire of the authors’ own design and the SF-36 questionnaire were used to obtain the data.ResultsSignificant differences in patient quality of life were identified in relation to patient gender. Moreover, the quality of life in all individual SF-36 dimensions, except for mental health, deteriorated with age. With regard to occupational placement, employed respondents gave the highest evaluation of quality of life according to SF-36 and old-age pensioners the lowest. The analysis shows that quality of life in individual dimensions is positively influenced by respondents’ higher education. The evaluation in individual dimensions improves with the time that has passed since the stroke.ConclusionThe quality of life of post-stroke patients deteriorates with age. The deteriorating level of patient quality of life in older age requires programmes that include assessments and interventions that lead to the treatment of these patients.     

Validity and Reliability of the Fear-Avoidance Beliefs Questionnaire (FABQ) in Workers with Upper Extremity Injuries

Introduction Fear Avoidance Beliefs (FAB) have been associated with increased pain, dysfunction and difficulty returning to work in Upper Extremity (UE) injures. The FABQ is used to assess FAB, but its measurement properties have not been established in UE. The purpose of this study is to evaluate the reliability and validity of the FABQ to screen UE compensated injured workers for FAB. Methods Consenting workers attending a specialty clinic completed a modified FABQ, QuickDASH (Disability), SPADI Pain Score and von Korff Chronic Pain Grade (Pain), SF-36v2 (General Health), and Work Instability Scale (Job Instability). A sub-sample of workers (n = 48) completed the FABQ 2 weeks later for test–retest reliability. Results 187 workers; 54.0% male; mean age 45.2 (sd 9.68); 56% were currently working. Mean subscale scores (FABQ-Work [FABQ-W]/FABQ-Physical Activity [FABQ-PA]) were 35/42 and 20/24. Ceiling effects (23%/38%) existed in both subscales. Cronbach’s alphas were 0.75/0.78. Test–retest analysis (ICC(2,1)) was lower than desired (0.52/0.59). Construct validation was supported by a moderate correlation between FABQ-W/FABQ-PA and QuickDASH Work Module (0.51/0.42) and WIS (0.46/0.38) in those currently working. Low correlations were found between the subscales measures of pain (SPADI: 0.24/0.23; Chronic Pain Grade: 0.25/0.25), and SF-36 MCS (−0.25/−0.30). Conclusions Although FAB is an important concept to measure in compensated UE injured workers, the FABQ had limitations in this population as there was a high ceiling effect, and lower than desired reliability for individual discrimination. A priori hypotheses around construct validity were rejected for 16/22 concepts tested.     

A patient-based questionnaire to assess outcomes of foot surgery: Validation in the context of surgery for hallux valgus

Background: A patient-based outcome measure with good measurement properties is urgently needed for use in clinical trials of foot surgery. Methods: We evaluated an existing foot pain and disability questionnaire (the Manchester Foot Pain and Disability Questionnaire) for its suitability as an outcome measure in the context of hallux valgus corrective surgery. Interviews with patients led to initial changes, resulting in 20 candidate questionnaire items with five response categories each. These were tested in a prospective study of 100 patients (representing 138 foot operations) undergoing hallux valgus corrective surgery. Analysis of underlying factor structure, dimensionality, internal reliability, construct validity and responsiveness of the questionnaire items in relation to (i) SF-36 general health survey and (ii) American Orthopaedic Foot & Ankle Society (AOFAS) hallux clinical scale resulted in a final 16 item questionnaire (the ‘Manchester-Oxford Foot Questionnaire’ (MOXFQ)), consisting of three domains/scales: ‘Walking/standing’ (seven items), ‘Pain’ (five items) and ‘Social interaction’ (four items) each having good measurement properties. All three domains were unidimensional. Conclusions: The new 16-item MOXFQ has good measurement properties in the context of outcomes assessment of surgery for hallux valgus. Future studies should assess the MOXFQ in the context of surgery for other foot and ankle conditions.     

Performance of the Swedish SF-36 version 2.0

OBJECTIVES: To evaluate the performance of the first non-English (Swedish) SF-36 version 2.0 (V2) regarding scaling assumptions, reliability and validity, with special emphasis on the effects of extending the response scales of the two role functioning scales, role physical (RP) and role emotional (RE), from a dichotomous to a five-step format. METHODS: Questionnaires were mailed to a non-stratified, random national sample of 3000 18-75 year old Swedish residents in 1998-1999. Methods traditionally used in evaluating the original US SF-36 version 1.0 (V1) and other international versions were applied. RESULTS: A total of 73% of the questionnaires were returned. Scaling assumptions were satisfactorily met and generally enhanced compared with V1, particularly regarding the role functioning scales. Floor/ceiling effects were reduced and reliability estimates increased for the role scales. The factor structure was replicated and the relative validity of the role scales as measures of their components increased. Overall, the tests of the criterion-based validity using known groups comparisons produced results supporting hypotheses: scales from the physical domain distinguished best between groups expected to differ in physical health; and scales comprising the mental domain distinguished best between groups expected to differ in mental health. Furthermore, hypothesized differences in mean scale scores as a function of age and social risk factors were confirmed. CONCLUSIONS: The changes to the response formats of the role functioning scales have improved their precision, reliability and validity without jeopardizing the underlying structure of the original SF-36. These changes will likely further enhance the responsiveness of the SF-36.