Biomedical subjects
Publications and source records attributed to A M Garratt.
Explore the source record for details and available documents.
OBJECTIVE: To review evidence relating to the measurement properties for all disease-specific, multi-item, patient-assessed health instruments in patients with ankylosing spondylitis (AS). METHODS: Systematic literature searches were made to identify instruments, using predefined criteria relating to reliability, validity, responsiveness and precision. RESULTS: Twelve AS-specific and three arthritis-specific instruments met the inclusion criteria. Three AS-specific instruments that measure health-related quality of life (HRQL) were reviewed. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Dougados Functional Index (DFI) had the greatest amount of evidence for reliability, validity and responsiveness across a range of settings. Four instruments lacked evidence for test-retest or internal consistency reliability. Most were assessed for validity through comparisons with other instruments, global judgements of health, mobility or clinical and sociodemographic variables. Most were assessed for responsiveness through mean score changes. Three instruments lacked evidence of responsiveness. CONCLUSION: This review provides a contribution to AS assessment. AS-specific multi-item measures specific to the assessment of pain, stiffness, fatigue and global health were not identified; where assessed, these domains were largely measured with single-item visual analogue scales. Single items may provide a limited reflection of these important domains. The BASFI and DFI remain the instruments of choice for functional assessment. HRQL is recommended as a core assessment domain. Further concurrent evaluation is recommended.
OBJECTIVE: To review evidence relating to the measurement properties of multi-item generic patient or self-assessed measures of health in older people. METHODS: Systematic literature searches to identify instruments. Pre-defined criteria relating to reliability, validity and responsiveness. RESULTS: 122 articles relating to 15 instruments met the inclusion criteria. The most extensive evidence was found for the SF-36, COOP Charts, EQ-5D, Nottingham Health Profile (NHP) and SIP. Four instruments have evidence of both internal consistency and test-retest reliability--NHP, SF-12, SF-20, SF-36. Four instruments lack evidence of reliability--HSQ-12, IHQL, QWB, SQL. Most instruments were assessed for validity through comparisons with other instruments, global judgements of health, or clinical and socio-demographic variables. Five instruments lack evidence of responsiveness--GQL, HSQ-12, IHQL, QLI and QWB. CONCLUSION: There is good evidence for reliability, validity and responsiveness for the SF-36, EQ-5D and NHP. There is more limited evidence for the COOP, SF-12 and SIP. The SF-36 is recommended where a detailed and broad ranging assessment of health is required, particularly in community dwelling older people with limited morbidity. The EQ-5D is recommended where a more succinct assessment is required, particularly where a substantial change in health is expected. Instrument content should be assessed for relevance before application. The concurrent evaluation of generic instruments in older people is recommended.
OBJECTIVE: To describe the development and evaluation of the OutPatient Experiences Questionnaire (OPEQ) for somatic outpatients. DESIGN: Literature review, patient interviews, pretesting of questionnaire items, and a cross sectional survey. SETTING: Postal survey of adult outpatient clinics at 52 hospitals in all five regions of Norway during 2003 and 2004. SUBJECTS: 35,719 patients who had attended an outpatient clinic within the previous 3 weeks. RESULTS: 19,266 patients (53.9%) responded to the questionnaire. Low levels of missing data suggest that the questionnaire is acceptable to patients. Factor analysis of items applicable to all patients produced three factors: clinic access (two items), communication (six items), and organisation (four items). The remaining items contributed to the hypothesised scales of hospital standards (three items), information (six items), and pre-visit communication (three items). With the exception of the pre-visit communication scale, the levels of Cronbach's alpha were >0.7. With the exception of the hospital standards scale, all produced test-retest correlations that exceeded 0.7. Most of the results of validity testing were as hypothesised. Correlations between the OPEQ scores ranged from 0.30 (clinic access and hospital standards) to 0.73 (communication and information). As hypothesised, scores were significantly related to patient responses to questions about overall satisfaction, general health and age. CONCLUSIONS: The OPEQ is a self-administered questionnaire that includes the most important aspects of patient experience from an outpatient perspective. It has good evidence for internal consistency, test-retest reliability, and validity.
OBJECTIVES: To identify patient-assessed health instruments specific to the knee and review evidence for reliability, validity and responsiveness. METHODS: Instruments were identified through systematic searches of the literature. Information relating to instrument content, patient population, reliability, validity and responsiveness was extracted from published papers. RESULTS: The 16 instruments that met the inclusion criteria varied in length from 4 to 42 items. The majority form a single index; six produce a profile of scores. Eight have been evaluated in patients with a variety of knee problems. All instruments have satisfactory internal or test-retest reliability. However, there is limited empirical support for the health domains of six instruments. Patients informed the development of items within just five instruments. Few authors gave explicit consideration to the size of expected relationships in tests of construct validity. Eleven instruments have evidence for responsiveness to changes in health. The minimally important difference was not determined for any of the instruments. CONCLUSIONS: In the absence of comparative evidence, the large number of patient-assessed instruments for knee problems makes instrument selection difficult. The Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Pain Scale and Oxford Knee Score have good evidence for reliability, content validity and construct validity. The KOOS and Oxford instruments also have evidence for responsiveness. The instruments have not been evaluated for all knee problems, and instrument appropriateness, including content relevance, must be assessed before application. The comparative evaluation of instruments is recommended.
OBJECTIVE: To evaluate the measurement properties of an evidence-based selection of measures of spinal mobility in patients with ankylosing spondylitis (AS). METHODS: Measurements of spinal mobility were taken by trained observers within a UK rheumatology centre. Inter-observer reliability was assessed. Intra-observer reliability was assessed in patients reporting no change in AS-specific health at 2 weeks. Validity was assessed and scores were correlated with responses to health transition questions. Responsiveness was evaluated for patients reporting change in health at 6 months. RESULTS: Reliability estimates support the use of all measures in individual evaluation (intraclass correlation>0.90). Correlations between measures of spinal mobility were in the hypothesized direction; the largest was between the modified Schober index (15 cm) (MSI) and the other measures. As hypothesized, small to moderate levels of correlation were found between mobility measures and patient-assessed health status. There was no significant linear relationship between mobility measures and self-reported health transition. Fingertip-to-floor distance following trunk forward flexion (FFD) was the most responsive mobility measure but was not as responsive as two AS-specific patient-assessed instruments, the Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). The MSI and cervical rotation (Crot) also had evidence of responsiveness. Low levels of responsiveness were found for the remaining measures. CONCLUSION: All mobility measures had adequate levels of reliability and validity. The MSI had a strong relationship with all mobility measures, and the FFD and Crot were the most responsive to self-perceived changes in health at 6 months. The MSI, FFD and Crot are recommended for clinical practice and research.
AIMS: To identify generic measures of health-related quality of life (HRQL) for children and adolescents developed for use within general populations. Instruments are evaluated on the basis of evidence relating to their reliability and validity. METHODS: Systematic literature searches were used to identify instruments, which were then assessed against predefined criteria. Information relating to instrument content, population, reliability and validity was extracted from published papers. RESULTS: Sixteen instruments were identified that had been evaluated among a general population of children or adolescents. Four instruments had reported data on both internal consistency and test-retest reliability. All except two instruments had undergone some degree of construct validation. CONCLUSIONS: The evidence suggests that the Child Health Questionnaire (CHQ) has been the most extensively evaluated for younger populations but is available as a parent-completed measure only. The new version of the Child Health and Illness Profile (CHIP-CE) is particularly promising and has parallel child- and parent-completed versions for young ages. The weight of evidence suggests that versions of these two instruments are suitable for older children. The Warwick Child Health and Morbidity Profile could be used where information on morbidity and health service contacts is required. Once basic psychometric criteria are fulfilled, instruments should be chosen by assessing their content and design in the light of the prospective application.
AIMS: To identify available disease-specific measures of health-related quality of life (HRQL) for diabetes and to review evidence for the reliability, validity and responsiveness of instruments. METHODS: Systematic searches were used to identify instruments. Instruments were assessed against predefined inclusion and exclusion criteria. Letters were sent to authors requesting details of further instrument evaluation. Information relating to instrument content, patients, reliability, validity and responsiveness to change was extracted from published papers. RESULTS: The search produced 252 references. Nine instruments met the inclusion criteria: Appraisal of Diabetes Scale (ADS), Audit of Diabetes-Dependent Quality of Life (ADDQoL), Diabetes Health Profile (DHP-1, DHP-18), Diabetes Impact Measurement Scales (DIMS), Diabetes Quality of Life Measure (DQOL), Diabetes-Specific Quality of Life Scale (DSQOLS), Questionnaire on Stress in Diabetic Patients-Revised (QSD-R), Diabetes-39 (D-39) and Well-being Enquiry for Diabetics (WED). The shortest instrument (ADS) has seven items and the longest (WED) has 50 items. The ADS and ADDQoL are single-index measures. The seven multidimensional instruments have dimensions covering psychological well-being and social functioning but vary in the remainder of their content. The DHP-1 and DSQOLS are specific to Type 1 diabetes patients. The DHP-18 is specific to Type 2 diabetes patients. The DIMS and DQOL have weaker evidence for reliability and internal construct validity. Patients contributed to the content of the ADDQoL, DHP-1/18, DQOL, DSQOLS, D-39, QSD-R and WED. The authors of the ADDQoL, DHP-1/18, DQOL, DSQOLS gave explicit consideration to content validity. The construct validity of instruments was assessed through comparisons with instruments measuring related constructs and clinical and sociodemographic variables. None of the instruments has been formally assessed for responsiveness to changes in health. CONCLUSIONS: Five of the diabetes-specific instruments have good evidence for reliability and internal and external construct validity: the ADDQoL, DHP-1/18, DSQOLS, D-39 and QSD-R. Instrument content should be assessed for relevance before application. The instruments should be evaluated concurrently for validity and responsiveness to important changes in health.
OBJECTIVE: To assess the acceptability and measurement properties of four ankylosing spondylitis (AS)-specific, patient-assessed measures of health outcome: AS Quality of Life Questionnaire (ASQoL), Bath AS Disease Activity Index (BASDAI), the Body Chart and the Revised Leeds Disability Questionnaire (RLDQ). METHODS: Instruments were administered by means of a self-completed questionnaire to patients recruited from across the United Kingdom (UK). Instruments were assessed for data quality and scaling assumptions. Where appropriate, dimensionality was assessed using principle component analysis (PCA). Internal consistency reliability was tested using Cronbach's alpha. Test-retest reliability was assessed in those patients reporting no change in AS-specific health at 2 weeks. The convergent validity of the instruments was assessed and scores were correlated with responses to the health transition questions. Responsiveness was assessed for patients reporting change in health at 6 months. RESULTS: The BASDAI and Body Chart have low self-completion rates. Item responses for the RLDQ were skewed towards higher levels of functional ability. PCA supported instrument unidimensionality. Cronbach's alpha ranged from 0.87 (BASDAI) to 0.93 (RLDQ). Test-retest reliability estimates support the use of the ASQoL and RLDQ in individual evaluation (>0.90). Correlations between instruments were in the hypothesized direction; the largest was between the ASQoL and BASDAI (0.79). The BASDAI had the strongest linear relationship, with responses to both specific and general health transition questions (P<0.01). With the exception of the Body Chart, instruments had a stronger relationship with general health transition. The BASDAI was the most responsive instrument. The Body Chart and RLDQ had low levels of responsiveness. CONCLUSION: The instruments have undergone a comprehensive comparative evaluation to assess the measurement properties required for patient-assessed measures of health outcome. Adequate levels of reliability and validity were found for all instruments. The BASDAI and the ASQoL were the most responsive to self-perceived change in health, but the BASDAI had low levels of self-completion.
OBJECTIVE: To assess the acceptability and measurement properties of two generic measures of health-related quality of life (HRQL): the EuroQol and the Short Form 12-item Health Survey Questionnaire (SF-12) in ankylosing spondylitis (AS). METHODS: Instruments were administered by means of a self-completed questionnaire to AS patients recruited from across the United Kingdom. Instruments were assessed for data quality and scaling assumptions. Test-retest reliability was assessed in those patients reporting no change in general health at 2 weeks. The convergent validity of both instruments was assessed and scores were correlated with responses to health transition questions. Responsiveness was assessed for patients reporting change in health at 6 months. RESULTS: The instruments had high completion rates. Although slightly skewed towards better levels of health, scores covered the available range for both sections of the EuroQol [EQ-5D and EQ-visual analogue scale (EQ-VAS)]. Score distributions approximated normality for the SF-12. Test-retest reliability estimates support the use of both instruments in group evaluation and the SF-12 Physical Component Summary score (PCS) in individual evaluation (>0.90). Correlations between instruments were in the hypothesized direction and were of a moderate level. The EQ-VAS had the strongest linear relationship, with responses to both specific and general health transition questions (P<0.01). The EQ-VAS and SF-12 PCS were the most responsive instruments. The EQ-5D was the least responsive instrument. CONCLUSION: The instruments have undergone a comprehensive comparative evaluation to assess the measurement properties required for patient-assessed measures of health outcome in AS. Adequate levels of acceptability, reliability and validity were found for both instruments. Although evidence supporting instrument responsiveness was strong for the EQ-VAS and SF-12 PCS, it was very weak for the EQ-5D and SF-12 Mental Component Summary Scale (MCS). The EQ-VAS and SF-12 PCS can both be recommended for use in group evaluation, and the SF-12 PCS is recommended in routine practice or research. However, the lower reliability of the SF-12 MCS and the limited ability of both the EQ-5D and SF-12 MCS to detect change in health may restrict these roles.
STUDY DESIGN: A longitudinal study using patient questionnaires was performed. OBJECTIVE: To compare the discriminatory power and responsiveness of the Aberdeen Back Pain Scale (ABPS), the Roland Disability Questionnaire (RDQ), and the EuroQol in patients with low back pain. SUMMARY OF BACKGROUND DATA: A number instruments specific to low back pain have not been compared for measurement properties. The EuroQol is a widely used generic instrument that has not been compared with specific instruments in patients with back pain. METHODS: A questionnaire incorporating the Aberdeen Back Pain Scale, the Roland Disability Questionnaire, and the EuroQol was completed by patients taking part in a clinical trial of exercise treatments for back pain. Patients completed follow-up questionnaires at 6 weeks, 6 months, and 1 year. The discriminatory power of these instruments was assessed against variables relating to activity limitations, medication, and comorbidity. Responsiveness was assessed using standardized response means. RESULTS: The questionnaire was completed by 187 patients taking part in the clinical trial. The Aberdeen instrument was found to be the most powerful at discriminating between different groups of patients on variables relating to activity limitations, medication, and comorbidity. The specific instruments demonstrated good levels of responsiveness, with the Aberdeen instrument producing the largest standardized response means. The Aberdeen instrument was more responsive to the smaller changes experienced by the control group, but was less powerful than the Roland at measuring differences in the levels of change between the two groups of patients at two of the three follow-up assessments in the trial. The EuroQol demonstrated a moderate level of responsiveness. CONCLUSIONS: The two specific instruments are capable of greater levels of discrimination between groups of patients, and are more responsive over time than the generic EuroQol. The Aberdeen instrument performed most satisfactorily in relation to these criteria, but the Roland instrument was more sensitive to differences between the two groups in the clinical trial. The measurement properties of these two instruments reflect their origin: The Aberdeen instrument is based on clinical questions, whereas the Roland instrument is based on the generic Sickness Impact Profile. Instrument content should be carefullyconsidered when selecting instruments for applications, including clinical trials.
The study assesses the reliability, validity and responsiveness of the UK version of the Seattle Angina Questionnaire (SAQ-UK). The instrument was anglicised and administered by self-completed postal questionnaire to 959 patients recruited from general practices in the North East of England. A total of 655 (68.3%) patients returned a completed questionnaire. Principal component analysis produced three important dimensions: physical limitations, anginal frequency and perception and treatment satisfaction. Four items that performed poorly were removed from the instrument. The removal of items greatly increased the number of computable scale scores. Estimates of internal reliability for the three dimensions ranged from 0.83-0.92. Estimates of test-retest reliability were above accepted standards. The correlation between the SAQ-UK scores and the SF-12, EuroQol and health transition was evidence for the validity of the instrument. The SAQ-UK produced responsiveness statistics that were comparable to the parent instrument and was more responsive to improvements in health than the generic instruments. The SAQ-UK is recommended as a measure of health outcome for the evaluation of angina management.
Reliability and validity of the SF-36 Health Survey Questionnaire was assessed in older rehabilitation patients, comparing cognitively impaired with cognitively normal subjects. The SF-36 was administered by face-to-face interview to 314 patients (58-93 years) in the day hospital and rehabilitation wards of a department of medicine for the elderly. Reliability was measured using Cronbach's alpha (for internal consistency) on the main sample and intraclass correlation coefficients on a test-retest sample; correlations with functional independence measure (FIM) were examined to assess validity. In 203 cognitively normal patients (Mini-Mental State Examination > or =24), Cronbach's alpha scores on the eight dimensions of the SF-36 ranged from 0.545 (social function) to 0.933 (bodily pain). The range for the 111 cognitively impaired patients was 0.413-0.861. Cronbach's alpha values were significantly higher (i.e. reliability was better) in the cognitively normal group for bodily pain (P = 0.003), mental health (P = 0.03) and role emotional (P = 0.04). In test-retest studies on a further 67 patients, an intraclass correlation coefficient of 0.7 was attained for five out of eight dimensions in cognitively normal patients, and four out of eight dimensions in the cognitively impaired. Only the physical function dimension in the cognitively normal group attained the criterion level (r > 0.4) for construct validity when correlated with the FIM. In this group of older physically disabled patients, levels of reliability and validity previously reported for the SF-36 in younger subjects were not attained, even on face-to-face testing. Patients with coexistent cognitive impairment performed worse than those who were cognitively normal.
Measurement of health-related quality of life (HRQL) is becoming more important in studies of patients with inflammatory bowel disease. The McMaster IBDQ is the most widely used HRQL instrument for these patients. However, its use with patients in the United Kingdom has not been validated. This study develops and validates a UK version of the McMaster IBDQ (UK IBDQ). The UK IBDQ was tested with two samples of patients for its reliability, validity, reproducibility, and responsiveness. The first sample consisted of 180 patients participating in a randomized clinical trial. The second was recruited from members of the National Association for Colitis and Crohns Disease. Reliability of the subscales and the summary score of the UK IBDQ is demonstrated by Cronbach's alpha and item-total correlations. Their validity is demonstrated by their correlations with SF-36 subscales and an empirical index of disease activity. Good intraclass correlations and responsiveness ratios show their reproducibility and responsiveness. The findings support the reliability, validity, reproducibility, and responsiveness of the UK IBDQ and its acceptability to patients in UK.
UNLABELLED: The assessment of quality of life is becoming increasingly important in clinical research. Its importance in dentistry has been realised only relatively recently. Health-related quality of life is concerned with the aspects of quality of life that relate specifically to an individual's health. This may be measured using two groups of instruments: (i) generic measures, which provide a summary of health-related quality of life and sometimes generate a single index measure of health or (ii) condition-specific measures, which focus on a particular condition, disease, population or problem and are potentially more responsive to small, but clinically important, changes in health. OBJECTIVES: The aim of this study was to develop a condition-specific quality of life measure for those patients with severe dentofacial deformity who were requesting orthognathic treatment and to assess the reliability of this instrument. METHOD: Instrument content was derived through a literature review and interviews with clinicians and patients. The resulting instrument was tested for internal consistency and test-retest reliability. RESULTS AND CONCLUSION: The instrument was found to divide into four clinically meaningful domains. Internal consistency and test-retest reliability were good. Patient acceptance of the questionnaire was also encouraging.
The study compares the psychometric properties of four different approaches to patient-assessed health outcomes in asthma, including the Asthma Quality of Life Questionnaire (AQLQ), Newcastle Asthma Symptoms Questionnaire (NASQ), SF-12 and EuroQol. The instruments were administered by means of a self-completed postal questionnaire to 394 patients recruited from general practices in the North East of England. Patients completed a follow-up questionnaire at 6 months. The levels of missing data were assessed and instrument scores compared using correlational analysis. Scores were related to self-reports of smoking behaviour, socioeconomic status and health transition. Responsiveness was assessed using standardized response means. Two hundred and thirty-five patients took part in the study giving a response rate of 59.6%. There was a relatively large amount of missing data for the individualized section of the AQLQ. Correlational analysis provided evidence of convergent validity between the specific instruments; the largest correlation was found between NASQ scores and the asthma symptoms scale of the AQLQ (r = 0.84). The NASQ was found to be the most powerful at discriminating between smokers and non-smokers. All four instruments were linearly related to self-reported asthma transition (P<0.05); the specific instruments having the strongest association. The specific instruments showed good levels of responsiveness with the NASQ producing a large SRM of 0.82. SRMs for the AQLQ were of a moderate to large size (0.32-0.77) and the SRMs for the SF-12 and EuroQol were of a small size. The two specific instruments are capable of greater levels of discrimination between groups of patients and are more responsive to changes in health than the generic SF-12 and EuroQol. The greater responsiveness of the NASQ is probably due to its focus being restricted to symptoms of asthma compared to the broader focus of the AQLQ domains. The NASQ has a strong relationship with the AQLQ and is a more practical instrument that is more acceptable to patients. However, the AQLQ does measure broader patient concerns. The SF-12 and EuroQol have greater potential to capture side-effects and have wider scope for application in economic evaluation.
PURPOSE: We set out to assess the new Aberdeen Varicose Veins Questionnaire (Aberdeen Questionnaire) for the properties necessary for a valid measure of health outcome, to determine quality of life of patients with varicose veins, and to determine the effect of surgery on quality of life. METHODS: A prospective consecutive cohort of 137 patients undergoing varicose vein surgery completed the self-administered SF-36 and Aberdeen Questionnaire and 25 questions relating to the symptoms and concerns of patients with varicose veins. Follow-up was done by repeated questionnaires 6 weeks after surgery. The Aberdeen Questionnaire was assessed for reliability, validity, responsiveness, and practicality. Quality of life of patients with varicose veins was compared with an age- and sex-matched sample of the general population. RESULTS: Reliability estimates for the 8 scales short-form health survey (SF-36) and the Aberdeen Questionnaire were all above 0.7 (Cronbach's alpha). The Aberdeen Questionnaire had a highly significant correlation (r = 0. 74, P <.0001) with the patients' symptoms and concerns questionnaire, which is evidence of its validity. Patients with varicose veins score lower than United Kingdom norms (P <.001) in the physical domains of the SF-36, indicating worse health. After surgery, the SF-36 scores improved in all 8 domains of health, reaching significance in "Mental Health" (P <.05) and approaching significance in "General Health" (P =.066). The Health Transition Item of the SF-36 and the Aberdeen Questionnaire both showed a highly significant improvement in health (P <.001). CONCLUSION: The Aberdeen Questionnaire is a valid measure of quality of life for patients with varicose veins. Persons with varicose veins have a reduced quality of life compared with the general population, and this discrepancy is significantly improved at 6 weeks by operating on them.
OBJECTIVE: To assess clinical status and changes in health related quality of life after two years in women randomised to medical management or transcervical resection of the endometrium (TCRE) for treatment of heavy menstrual loss. DESIGN: Two-year follow up using postal questionnaires and operative databank review. SETTING: Gynaecology department of a large UK teaching hospital. PARTICIPANTS: Women who had joined a randomised comparison of medical treatment with TCRE for heavy menstrual loss two years previously. MAIN OUTCOME MEASURES: Women's satisfaction with treatment, gynaecological symptoms, changes in health related quality of life, and additional treatments received at two years. RESULTS: Women allocated medical treatment were significantly less likely to be totally or generally satisfied (57% vs 79%, difference -22%, 95% CI -36, -9%), to find their management acceptable (77% vs 93%, difference -16%, 95% CI -26, -4%), or to recommend their allocated treatment (24% vs 78%, difference -54%, 95% CI -61, -33%). In the medical cohort 59% of women had undergone TCRE, hysterectomy or both, whereas 17% in the TCRE cohort had undergone further surgery. Bleeding and pain scores were similar in the groups and highly significantly better than at recruitment. Short Form-36 health survey scores were significantly improved from baseline for five of the eight health scores in the medical arm, and seven in the TCRE arm. CONCLUSIONS: The results at two years consolidate the findings and conclusions based on the four-month follow up data. A policy of early TCRE is effective and safe and does not result in an increase in hysterectomies. It should not be routinely withheld in an effort to try alternative medical therapies.