PubMed Health⌕ Search

Biomedical subjects

C Jenkinson

Publications and source records attributed to C Jenkinson.

At least 37 records · Page 2Linked to original sources
PubMed2001

Determining minimally important differences for the PDQ-39 Parkinson's disease questionnaire.

OBJECTIVE: To determine minimally important differences for dimensions of the PDQ-39, a 39-item Parkinson's disease questionnaire. A minimally important difference is defined as the smallest change between two scores that is subjectively meaningful to patients. Data on minimally important differences are essential for the calculation of sample sizes in trials and surveys. METHODS: We conducted a postal survey of randomly selected members of 13 local branches of the Parkinson's Disease Society, asking them to complete the PDQ-39 on two occasions, 6 months apart. On the first occasion respondents received the PDQ-39, demographic questions and a request to provide their name and address if they were willing to take part in the follow-up survey. After 6 months, we sent those who had agreed another copy of the questionnaire and also asked them to indicate how much change they had experienced since baseline in overall health and in each of the eight domains of the questionnaire. RESULTS: We calculated minimally important difference for each dimension and the index score for those reporting minor change since baseline. The minimally important difference varied across dimensions. CONCLUSIONS: These results indicate the minimum magnitude of change that should be sought when designing studies to evaluate change over time in Parkinson's disease. Since minimally important differences differ across dimensions, those designing studies in which sample size calculations are based on the PDQ-39 as an outcome measure should select the dimension which is the primary variable of interest.

Adult↗
PubMed2001

An assessment of the construct validity of the SF-12 summary scores across ethnic groups.

BACKGROUND: The aim of the study was to determine the construct validity of the 12-item Short Form health survey questionnaire (SF-12) across ethnic groups in a large community sample of the United Kingdom. METHODS: A postal survey was carried out in English using a questionnaire booklet, containing the SF-12 and a number of other items relating to experiences of chronic illness and utilization of health care services. The dataset was the National Survey of NHS Patients. The sample consisted of 1000 residents within each Health Authority in England who were randomly selected from the electoral registers, giving an initial sample of 100000. RESULTS: A total of 61 426 (61.4 per cent) questionnaires were returned; 94.3 per cent of respondents classified themselves as white and 5.7 per cent classified themselves as members of other ethnic groups. Construct validity of the SF-12 was assessed by comparing results from the two summary scores (the Mental Health Component Summary (MCS) score and the Physical Health Component Summary (PCS) score) with overall self-assessed health and limiting longstanding illness. Although there were generally consistent patterns of association between overall self-assessed health or limiting longstanding illness and the MCS and PCS scores in all the ethnic groups, there were significant differences between the MCS and PCS scores of Indians, Pakistanis and Bangladeshis who understood English fluently and those who did not. Furthermore, there were differences in the completion rates of the SF-12 between ethnic groups and a reversal of the general pattern of increasing MCS scores with increasing age in Bangladeshis. CONCLUSION: The results indicate that the use of the SF-12 to measure the health of ethnic minorities seems acceptable in most instances, but may prove problematic in those instances where respondents complete the questionnaire via an untrained translator, such as a friend or family member. The systematic differences in MCS and PCS scores between ethnic minorities who understood English fluently and those who did not suggest that the meaning of specific SF-12 items may change when informally translated. Future research using the SF-12 to measure the health status of ethnic minorities in the United Kingdom via postal surveys must include questions on whether respondents completed the questionnaires via informal translations. In general, those wishing to measure the health of members of ethnic groups who are unable to read English might consider using different techniques to gain the information from these groups.

Adult↗
PubMed2001

Long-term benefits in self-reported health status of nasal continuous positive airway pressure therapy for obstructive sleep apnoea.

Doubt has been expressed about the efficacy of nasal continuous positive airways pressure (NCPAP) therapy for sleep apnoea. Recent evidence from a randomized controlled trial of 1 month duration, suggested that NCPAP therapy can have a substantial impact on subjective and clinical outcomes in the short term, but data was not available to determine whether these effects were sustained over the long term. This study, an extension of the original trial, examined whether the beneficial impacts of NCPAP continued over the longer term. Patients were followed-up 1 month after being placed on active or sub-therapeutic NCPAP. They completed health status measures and a clinical test of sleepiness. After this period, all patients were placed on NCPAP and followed up 5 months later. The beneficial impact of NCPAP on sleep apnoea was sustained on all measures at follow-up. Furthermore, those who had initially been in the sub-therapeutic arm gained scores after 5 months of NCPAP similar to those of the active group. The impact of NCPAP appears sustained in the longer term. Subjective health status instruments have been advocated as important outcome points in randomized trials. This study would support such a use, and shows the important role of patient report in the evaluation of health care.

Follow-Up Studies↗
PubMed2001

Reduced item set for the amyotrophic lateral sclerosis assessment questionnaire: development and validation of the ALSAQ-5.

OBJECTIVE: The 40 item amyotrophic lateral sclerosis assessment questionnaire (ALSAQ-40) is a subjective health measure designed specifically to assess areas of importance to patients with ALS. It was designed for use in surveys and clinical trials of this patient group, and has been assessed for reliability and validity. Despite its relative brevity there are situations where an even shorter form of the instrument would be desirable. Consequently, this paper reports a process of item reduction which results in a brief five item version of the instrument. METHODS: Data from two surveys of patients with ALS who completed the ALSAQ-40 were analysed to develop a short form ALSAQ. Questionnaire items were correlated with their dimension total scores. Highly correlated items were transformed onto a scale from 0 to 100 and results compared with the parent dimension. RESULTS: Five items were selected that produced results that closely resembled those of the five dimension scores of the ALSAQ-40. CONCLUSIONS: Results on the new measure compared with the parent ("gold standard") ALSAQ-40 suggest that the measure can produce similar results to the longer form but with considerable economy.

Adult↗
PubMed2001

Can item response theory reduce patient burden when measuring health status in neurological disorders? Results from Rasch analysis of the SF-36 physical functioning scale (PF-10).

BACKGROUND: Indices of physical function may have a hierarchy of items. In cases where this can be demonstrated it may be possible to reduce patient burden by asking them to complete only those items which relate directly to their own level of ability. OBJECTIVES: To determine whether statistical procedures, operationalising what is known as item response theory (IRT), can be used to assess the unidimensionality of the 10 item physical functioning domain of the SF-36 in patients with Parkinson's disease and motor neuron disease, and, secondly, to determine whether it would be possible to administer subsets of items to certain patients, on the basis of their replies to other items in the scale, thereby reducing patient burden. METHODS: Rasch analysis, a form of IRT methodology, of the 10 item physical functioning domain (PF-10) in two neurological patient samples was undertaken and the results compared with results of a Rasch analysis of data gained from a population survey (the third Oxford healthy lifestyles survey). RESULTS: Evidence from the analyses suggests that the PF-10 does not form a perfect hierarchy on a unidimensional scale. However, certain items seem to form a hierarchy, and responses to some of them are contingent on responses to the other items. CONCLUSIONS: Rasch analysis of the PF-10 in neurological patients has indicated that certain items of the scale are hierarchically ordered, and consequently not all respondents would need to complete them all: indeed those most severely ill would be required to complete less items than those with only limited disabilities. The implications of this are discussed.

Activities of Daily Living↗
PubMed2001

A Ser311Cys mutation in the human dopamine receptor D2 gene is associated with reduced energy expenditure.

Brain dopaminergic pathways play a major role in the control of movement. Absence of the murine dopamine D2 receptor gene (drd2) produces bradykinesia and hypothermia. A Ser311Cys mutation of the human DRD2 produces a marked functional impairment of the receptor and is associated with higher BMI in some populations. We hypothesized that the Ser311Cys mutation of DRD2 may inhibit energy expenditure. Here we report that total energy expenditure (doubly labeled water) measured in 89 nondiabetic Pima Indians was 244 kcal/ day lower in homozygotes for the Cys311-encoding allele when compared with those heterozygous and homozygous for the Ser311-encoding allele (P = 0.056). The 24-h resting energy expenditure (respiratory chamber) measured in 320 nondiabetic Pimas was also 87 kcal/day lower in homozygotes for the Cys311-encoding allele when compared with those heterozygous and homozygous for the Ser311-encoding allele (P = 0.026). These findings are the first evidence that a genetic mutation is associated with reduced energy expenditure in humans. Because the impact of this mutation on human obesity is small, we suggest that either the energy deficit induced is not large enough to significantly influence body weight in this population and/or that the Cys311-encoding allele is also associated with reduced energy intake.

Adult↗
PubMed2000

The amyotrophic lateral sclerosis assessment questionnaire (ALSAQ-40): tests of data quality, score reliability and response rate in a survey of patients.

OBJECTIVES: To evaluate response rate, data quality, and score reliability of the 40 item Amyotrophic Lateral Sclerosis Assessment Questionnaire in a survey of MND patients. DESIGN: A survey of members of the MND Association of the UK, of which half were randomly allocated to receive a survey instrument from the MND Association and the other half allocated to receive the MND Association survey instrument and also the ALSAQ-40 questionnaire. SAMPLE: Five hundred patients were randomly selected from the membership lists of the MND Association, of whom 250 received the MND Association Survey and the ALSAQ-40. RESULTS: Response rate to the survey was 59.2%. Over half of the respondents received the ALSAQ-40. Data for individual items were analysed and found to be distributed across all response categories. All items were found to be highly associated with the scales to which they contribute. Internal consistency reliability of all the five scales of the ALSAQ-40 was also found to be high. CONCLUSION: Inclusion of the ALSAQ-40 into the survey did not have an adverse effect upon response rates. Furthermore, the ALSAQ-40 was shown to have highly desirable psychometric properties. This paper provides further evidence of the reliability and validity of the measure.

Adult↗
PubMed2000

The ALS Health Profile Study: quality of life of amyotrophic lateral sclerosis patients and carers in Europe.

The measurement of functioning and well-being from the perspective of the patient has in recent years become central to the assessment of health and the evaluation of treatment regimes. The past decade has seen an enormous growth in the application of measures designed to assess quality of life in a vast array of medical specialties. However, the use of such measures in neurology has been relatively limited, and this has certainly been the case in amyotrophic lateral sclerosis (ALS). The European ALS Health Profile Study is a longitudinal survey of patients diagnosed with ALS or other motor neurone diseases in which patients are asked to complete questionnaires concerning their subjective health status. Data from clinical assessments are also collected. It is intended that the information collected will provide more systematic and detailed evidence of the impact of the disease from the perspective of the patient. This contribution documents results from baseline assessment obtained from data supplied by clinicians, carers and patients themselves. Three outcome measures are assessed in this paper: the SF-36, a generic measure of well being and functioning, the ALS Functional Rating Scale and the Carer Strain Index. The evidence presented here suggests that these measures provide a meaningful and valid picture of the impact of the disease. The data indicate that ALS has substantial adverse effects both upon the functioning and well being of patients and carers, as well as an association between the emotional health status of patients and carers, and between the physical health status of patients and carers.

Adult↗
PubMed2000

Validating self-rated health in different ethnic groups.

BACKGROUND: Subjective accounts of health status are increasingly utilized in social surveys and medical research to assess functioning and well-being. Despite the fact that substantial research evidence suggests that self-rated health is meaningful and provides valid and reliable data, some authors have raised concerns that different social groups may interpret the notion of health in different ways, and hence complete health measures in systematically different ways. This study evaluates the validity of using self-rated health status to measure health status in different ethnic groups. METHODS: Logistic regression models were used to examine the association of self-rated health with more objective measures of morbidity in different ethnic groups. SAMPLE: Two sources of data were used--the Health Survey for England (HSE) 1991-96 combined file and the Fourth National Survey of Ethnic Minorities (Ethmins4). MEASURES OF HEALTH: Hypertension, presence of cardiovascular disease or diabetes, limiting health and number of visits to a doctor. Self-rated health was measured on 5-point scale ranging from excellent to very poor. RESULTS: Poorer self-rated health was associated with greater morbidity within each ethnic group. Furthermore, there was little evidence that the association of self-rated health with more objective measures of morbidity differed between ethnic groups. CONCLUSION: The evidence reported here suggests that the use of a single item measure of self-rated health to measure health status in different ethnic groups is valid. Further research might usefully explore the validity of using more comprehensive profile measures of health status in different ethnic groups.

England↗
PubMed2000

The new UK National Statistics Socio-Economic Classification (NS-SEC); investigating social class differences in self-reported health status.

BACKGROUND: The new UK National Statistics Socio-Economic Classification (NS-SEC) is theoretically based on differences in employment relations and conditions. Differences in employment relations could account for some of the often observed social class differences in health in the United Kingdom. This study investigates the associations of the NS-SEC with a well-validated health outcome measure--the Short Form health survey (SF-36). METHODS: Data from the Oxford Healthy Lifestyles Survey III (OHLS III, n = 6,454), a cross-sectional survey of adult men and women aged 18-64 randomly selected from the counties of Berkshire, Buckinghamshire, Northamptonshire and Oxfordshire, were analysed. The associations of the NS-SEC with the SF-36 physical and mental summary scores are investigated in a series of regression models controlling for age, lifestyle factors, housing and neighbourhood conditions. RESULTS: There are significant social class differences in the SF-36 physical and mental summary scores after controlling for age. When lifestyle, housing and neighbourhood conditions are controlled for, these differences reduce to non-significance. CONCLUSION: The NS-SEC shows significant social class differences in health, further evidence for its construct validity. Social class differences in housing, neighbourhood and lifestyle factors appear to have a large role in understanding class differences in health. As it is grounded in theory, the NS-SEC is likely to prove a valuable tool for explanations of inequalities in health.

Adolescent↗
PubMed2000

Racial group, socioeconomic status, and the development of persistent proteinuria in systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) patients of Afro-Caribbean and Asian origin living in the United Kingdom have a more severe spectrum of disease compared with the white population but whether this is attributable to genetic host factors or environmental factors is unclear. This study examines time from first symptom to onset of persistent proteinuria, as a marker of renal disease, to assess which factors are important. METHODS: The 189 patients studied were ascertained using multiple methods and included 161 white, 22 Afro-Caribbean and six Asian patients. Time of first observation of persistent proteinuria (>/=0.5 g/day) was taken as onset of renal SLE. Initial univariate analysis to determine which factors are associated with onset of renal disease was followed by using a Cox's proportional hazards regression model enabling analysis of several prognostic factors at the same time. Variables included three measures of socioeconomic status, ethnic group and the presence or absence of different autoantibodies. RESULTS: There was no effect from any socioeconomic variable. Using forwards stepwise selection, the following had independent effects (p<0.05) on the development of renal SLE: Afro-Caribbean race (hazard rate ratio 4.4 (1.9-10.2), compared with white population); and the presence of IgG anti-cardiolipin antibodies (hazard rate ratio 2.6 (1.2-5.7)). CONCLUSION: Differing socioeconomic factors do not explain the increased frequency of lupus nephritis in Afro-Caribbean patients with SLE, but rather there are important genetic or other host differences. The independent effect of IgG anti-cardiolipin antibodies warrants further investigation.

Adolescent↗
PubMed2000

The London handicap scale: a re-evaluation of its validity using standard scoring and simple summation.

OBJECTIVE: To assess the validity of the London handicap scale (LHS) using a simple unweighted scoring system compared with traditional weighted scoring METHODS: 323 patients admitted to hospital with acute stroke were followed up by interview 6 months after their stroke as part of a trial looking at the impact of a family support organiser. Outcome measures included the six item LHS, the Dartmouth COOP charts, the Frenchay activities index, the Barthel index, and the hospital anxiety and depression scale. Patients' handicap score was calculated both using the standard procedure (with weighting) for the LHS, and using a simple summation procedure without weighting (U-LHS). Construct validity of both LHS and U-LHS was assessed by testing their correlations with the other outcome measures. RESULTS: Cronbach's alpha for the LHS was 0.83. The U-LHS was highly correlated with the LHS (r=0.98). Correlation of U-LHS with the other outcome measures gave very similar results to correlation of LHS with these measures. CONCLUSION: Simple summation scoring of the LHS does not lead to any change in the measurement properties of the instrument compared with standard weighted scoring. Unweighted scores are easier to calculate and interpret, so it is recommended that these are used.

Disability Evaluation↗
PubMed2000

Randomised prospective parallel trial of therapeutic versus subtherapeutic nasal continuous positive airway pressure on simulated steering performance in patients with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) impairs vigilance and may lead to an increased rate of driving accidents. In uncontrolled studies accident rates and simulated steering performance improve following treatment with nasal continuous positive airway pressure (NCPAP). This study seeks to confirm the improvement in steering performance in a randomised controlled trial using subtherapeutic NCPAP as a control treatment. METHODS: Fifty nine men with OSA (Epworth Sleepiness Score (ESS) of > or =10, and > or =10/h dips in SaO(2) of >4% due to OSA) received therapeutic or subtherapeutic NCPAP ( approximately 1 cm H(2)O) for one month. Simulated steering performance over three 30-minute "drives" was quantified as: standard deviation (SD) of road position, deterioration in SD across the drive, length of drive before "crashing", and number of off-road events. The reaction times to peripheral target stimuli during the drive were also measured. RESULTS: Subtherapeutic NCPAP did not improve overnight >4% SaO(2) dips/h compared with baseline values, thus acting as a control. The SD of the steering position improved from 0.36 to 0.21 on therapeutic NCPAP, and from 0.35 to 0.30 on subtherapeutic NCPAP (p = 0.03). Deterioration in SD of the steering position improved from 0.18 to 0.06 SD/h with therapeutic NCPAP and worsened from 0.18 to 0.24 with subtherapeutic NCPAP (p = 0.04). The reaction time to target stimuli was quicker after therapeutic than after subtherapeutic NCPAP (2.3 versus 2.7 seconds, p = 0.04). CONCLUSIONS: Therapeutic NCPAP improves steering performance and reaction time to target stimuli in patients with OSA, lending further support to the hypothesis that OSA impairs driving, increases driving accident rates, and that these improve following treatment with NCPAP.

Accidents, Traffic↗
PubMed2000

Self-report quality of life measure for people with schizophrenia: the SQLS.

BACKGROUND: Quality of life is the subject of growing interest and investigation. AIMS: To develop and validate a short, self-report quality of life questionnaire (the Schizophrenia Quality of Life Scale, SQLS). METHOD: People with schizophrenia in Liverpool were recruited via the NHS. Items, generated from in-depth interviews, were developed into an 80-item self-report questionnaire. Data were factor analysed, and a shorter form measure was tested for reliability and validity. This measure was administered together with other self-report measures--SF-36, GHQ-12 and HADS--to assess validity. RESULTS: Data were analysed to produce a final 30-item questionnaire, comprising three scales ('psychosocial', 'motivation and energy', and 'symptoms and side-effects') addressing different SQLS dimensions. Internal consistency reliability of the scale was found to be satisfactory. There was a high level of association with relevant SF-36, GHQ-12 and HADS scores. CONCLUSIONS: The SQLS was completed within 5-10 minutes. It possesses internal reliability and construct validity, and promises to be a useful tool for the evaluation of new treatment regimes for people with schizophrenia.

Adolescent↗
PubMed2000

Outcome measures for adult critical care: a systematic review.

OBJECTIVES: 1. To identify generic and disease specific measures of impairment, functional status and health-related quality of life that have been used in adult critical care (intensive and high-dependency care) survivors. 2. To review the validity, reliability and responsiveness of the measures in adult critical care survivors. 3. To consider the implications for future policy and to make recommendations for further methodological research. 4. To review what is currently known of the outcome of adult critical care. METHODS DATA SOURCES: Searches of electronic databases (MEDLINE, EMBASE, CINAHL, PsycLIT, The Cochrane Library and SIGLE) from 1970 to August 1998. Manual searches of five journals (1985-98) not indexed in electronic databases and relevant conference proceedings (1993-98). Reference lists of six existing reviews, plus snowballing from reference lists of all relevant articles identified. STUDY SELECTION: Randomised trials, non-randomised trials (cohort studies) and case series that included data on outcomes after discharge from adult (16 years and over) critical care. DATA EXTRACTION AND SYNTHESIS: If reported, the following data were extracted from each paper: patient characteristics (age, gender, severity of illness, diagnostic category) number of patients eligible for study, follow-up period, number of deaths before follow-up, number and proportion of survivors included in follow-up method of presentation of outcome data - proportion normal as defined by reference values, or aggregate value (e.g. mean or median), or aggregate values plus an indication of variance (e.g. standard deviation or inter-quartile range). Evidence for three measurement properties was sought for each outcome measure that had been used in at least two studies - their validity, reliability and responsiveness in adult critical care. If the authors did not report these aspects explicitly, an attempt was made to use the data provided to provide these measurement properties. For measures that were used in at least ten studies, information on actual reported outcomes were also extracted. RESULTS: MEASURES USED IN CRITICAL CARE: Measures of impairment were largely confined to the respiratory system so are almost certainly not appropriate for many critical care survivors. They can be categorised as respiratory volumes (e.g. vital capacity), gas flow within the respiratory system (e.g. forced expiratory volume in 1 second (FEV1)), pulmonary diffusing capacity (e.g. carbon monoxide diffusing capacity) and visualisation of the upper airway (e.g. bronchoscopy). Multiple tests are often performed. Eight measures of physical functional status were used, five generic and three disease-specific. The most frequently used generic measures were multi-item scales. Two single-item global measures attempted to capture a person's overall activity level or functional status. Five multi-item measures of mental functional status were used, four generic and one specific to trauma patients. The generic measures were either confined to assessing depressive symptoms or also encompassed a measure of anxiety. Measures of neuropsychological functioning relate to a person's cognition, attention, ability to process information and memory. Apart from one single-item measure, which focused on communication level, six multi-item measures were used with critical care survivors. Such measures are particularly appropriate for use with survivors of head injury or other neurological insult and, in that sense, they are disease-specific rather than generic measures. Single item measures of recovery were frequently used but researchers often invented their own, so there was little consistency in the wording. These measures had five principal foci - return to work, return to own home, degree of recovery, productivity and chronic health status. One multi-item scale was also used. (ABSTRACT TRUNCATED)

Adult↗
PubMed1999

Comparison of therapeutic and subtherapeutic nasal continuous positive airway pressure for obstructive sleep apnoea: a randomised prospective parallel trial.

BACKGROUND: Nasal continuous positive airway pressure (NCPAP) is widely used as a treatment for obstructive sleep apnoea. However, to date there are no randomised controlled trials of this therapy against a well-matched control. We undertook a randomised prospective parallel trial of therapeutic NCPAP for obstructive sleep apnoea compared with a control group on subtherapeutic NCPAP. METHODS: Men with obstructive sleep apnoea, defined as an Epworth sleepiness score of 10 or more and ten or more dips per h of more than 4% SaO2 caused by obstructive sleep apnoea on overnight sleep study, were randomly assigned therapeutic NCPAP or subtherapeutic NCPAP (about 1 cm H2O) for 1 month. Primary outcomes were subjective sleepiness (Epworth sleepiness score), objective sleepiness (maintenance of wakefulness test), and SF-36 questionnaire measurements of self-reported functioning and well-being. FINDINGS: 107 men entered the study: 53 received subtherapeutic NCPAP and 54 therapeutic NCPAP. Use of NCPAP by the two treatment groups was similar: 5.4 h (therapeutic) and 4.6 h (subtherapeutic) per night. Subtherapeutic NCPAP did not alter the overnight number of SaO2 dips per h compared with baseline, and thus acted as a control. Therapeutic NCPAP was superior to subtherapeutic NCPAP in all primary outcome measures. The Epworth score was decreased from a median of 15.5 to 7.0 on therapeutic NCPAP, and from 15.0 to 13.0 on subtherapeutic NCPAP (between treatments, p<0.0001). Mean maintenance-of-wakefulness time increased from 22.5 to 32.9 min on therapeutic NCPAP and, not significantly, from 20.0 to 23.5 min on subtherapeutic NCPAP (between treatments p<0.005). Effect sizes for SF-36 measures of energy and vitality were 1.68 (therapeutic) and 0.97 (subtherapeutic) NCPAP (between treatments p<0.0001). For mental summary score, the corresponding values were 1.02 and 0.4 (between treatments p=0.002). INTERPRETATION: Therapeutic NCPAP reduces excessive daytime sleepiness and improves self-reported health status compared with a subtherapeutic control. Compared with controls, the effects of therapeutic NCPAP are large and confirm previous uncontrolled clinical observations and the results of controlled trials that used an oral placebo.

Adult↗