BACKGROUND: Magnetic resonance imaging (MRI) of the knee for meniscus and ligament injuries is an accurate diagnostic test. Early and accurate diagnosis of patients with knee problems may prevent the onset of chronic problems such as osteoarthritis, a common cause of disability in older people consulting their GP. AIM: To assess the effect of early access to MRI, compared with referral to an orthopaedic specialist, on GPs' diagnoses and treatment plans for patients with knee problems. DESIGN OF STUDY: A multi-centre, pragmatic, randomised controlled trial. SETTING: Five hundred and fifty-three patients with knee problems were recruited from 163 general practices across the UK from November 2002 to October 2004. METHOD: Eligible patients were randomised to MRI or consultation with an orthopaedic specialist. GPs made a concomitant provisional referral to orthopaedics for patients who were allocated to imaging. GPs recorded patients' diagnoses, treatment plans, and their confidence in these decisions at trial entry and follow-up. Data were analysed as intention to treat. RESULTS: There was no significant difference between MRI and orthopaedic groups for changes in diagnosis (P = 0.79) or treatment plans (P = 0.059). Significant changes in diagnostic and therapeutic confidence were observed for both groups with a greater increase in diagnostic confidence (P<0.001) and therapeutic confidence (P = 0.002) in the MRI group. There was a significant increase in within-group changes in diagnostic and therapeutic confidence. CONCLUSION: Access to MRI did not significantly alter GPs' diagnoses or treatment plans compared with direct referral to an orthopaedic specialist, but access to MRI significantly increased their confidence in these decisions.

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.

Background The aim of this study was to gain population norms for the COOP Charts in a large community sample, and to explore the construct validity, and whether the inclusion of the illustrations influences response rates.Methods A postal survey was carried out using a questionnaire booklet, containing the COOP Charts and a number of other items concerned with lifestyles and illness, sent to 6007 randomly selected subjects over the age of 18 years. Respondents were randomized to receiving the questionnaire booklet with a copy of the COOP Charts including illustrations, or the same booklet but including the COOP items without illustrations. The sample was drawn from the Family Health Services Authority (FHSA) computerized register for Oxfordshire. Outcome measures were scores for the eight dimensions of the COOP Charts.Results The survey achieved an adjusted response rate of 56.72 per cent. There was no difference in response rate or scores on the eight dimensions of the COOP Charts when broken down by those who received the illustrated Charts or simply the items from the measure without illustrations. Normative data for the COOP Charts are reported, broken down by age, sex, social class and whether respondent reported chronic illness or not.Conclusion The illustrations included in the original charts do not appear to influence response rates, or responses given to the questions. The evidence suggests that items of the COOP Charts provide a short and comprehensive survey of health status. The normative data provided in this paper may further facilitate their validation and use.

Questionnaires are often used to collect primaryquantitative data from patients and healthcareprofessionals. The aim is to gather valid, reliable,unbiased and discriminatory data from a represen-tative sample of respondents. However, theinformation yielded is subject to error and biasfrom a range of sources. Close attention to issuesof questionnaire design and survey administrationcan reduce these errors.

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.

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.

EDITOR,—Charlotte Paterson should be commended for piloting her patient generated outcome measure in a primary care setting.1 The “measure yourself medical outcome profile” (MYMOP) has potential for routine use, not least because it is simple to use. Also, the authors' tests of validity and responsiveness indicate that it correlates with health status and perceived improvements in health. Three important questions remain unanswered, however. Firstly, does the MYMOP really measure outcomes that matter to patients—that is, that have meaning and …

role, they must be continually updated to take account of changes in medical knowledge and practice.2 At the same time, guidelines must honestly reflect the many uncertainties in management and not attempt to simplify healthy variation in practice.3 In two separate studies in South East Thames region looking at a total of 1600 patients with head injury attending accident and emergency departments, 16 skull fractures would have been missed if the criteria for ordering skull radiography had been adhered to. To avoid "laundry lists" or "cookbook medicine,"4 criteria should be restricted to elements that are essential or critical to management; that surely must include the mechanism of injury in patients presenting with the common diagnosis of mild head injury. If the criteria are to be effective they need to be considered in all cases of head injury by doctors in accident and emergency departments. Handwritten notes from local departments suggest that this is not the case. With use of a specially designed form for head injury the quality of documentation and hence consideration of the criteria have been considerably improved. Such a method of documentation has been used in nine accident and emergency departments in South East Thames region and is being evaluated. The doctors in Manchester seem to support the view that guidelines are not intended to replace clinical judgment' and have shown that practising medicine in the 1990s remains an art.

Plasma sodium and osmolality were determined in 80 adult epileptic patients receiving chronic treatment with carbamazepine and in 50 control patients treated with other anticonvulsant drugs. Mean plasma osmolality was significantly lower in the carbamazepine-treated patients but mean plasma sodium did not differ in the two groups. Hyponatraemia was found in five of the carbamazine-treated patients and hypo-osmolality in six. None of the control patients had hyponatraemia and only one had a borderline low osmolality. Three of the 13 patients receiving carbamazepine alone were hyponatraemic. Plasma sodium concentration correlated negatively with both daily carbamazepine dose and serum carbamazepine level. Free water clearance after an oral water load was determined in six patients on carbamazepine alone and in six normal subjects not receiving drug therapy. The capacity of some of the patients to excrete the water load was found to be grossly impaired.