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Biomedical subjects

K R Muir

Publications and source records attributed to K R Muir.

At least 37 records · Page 2Linked to original sources
PubMed1998

Binomial cokriging for estimating and mapping the risk of childhood cancer.

The incidences of human diseases vary from place to place, and this is also likely to be so for the risk of people developing many of them. We have analysed the spatial distribution of childhood cancer in the West Midland Health Authority Region of England from 1980 to 1984. This is a rare disease which is considered to be noncontagious. The observed frequencies of the disease in the electoral wards have been converted to proportions that estimate the risk of a child's developing it. The spatial autocorrelation of the risk, expressed in the variogram, was determined in a novel way from the proportions within electoral wards by treating them as binomial variables dependent on the risk and the numbers of children in the wards. The observed variogram was modelled by Whittle's elementary two-dimensional correlation. Covariances of the proportion and cross covariances between the proportion and the risk were derived, and from the latter and the proportions the risk was estimated in two ways by a form of cokriging: ordinary and conditional unbiased cokriging. The variogram of the risk shows strong autocorrelation, and the kriged estimates, when mapped, have a distribution that is far from even. There are patches where the estimated risk is large, especially in the rural south west and the suburban north east; and there are other patches, notably the more densely populated areas, where it is small.

Adolescent↗
PubMed1998

The geographical assignment of cancer units: patient accessibility as an optimal allocation problem.

The seminal report A Policy Framework for Commissioning Cancer Services provides the foundation for a major reorganisation of cancer service provision in England and Wales. One central recommendation of the report, the establishment of a tier of specialised cancer units in each Health Authority Region has raised the fundamental question of where those units are to be located. In particular, a declared objective of the report is for services to be planned to maximise their accessibility to patients. This paper demonstrates a classical method (location-allocation modelling) by which the accessibility criterion can be used to determine the optimal number, location and capacity of units for a given cancer site. The method is illustrated with reference to cervical cancer in Trent Health Authority Region. The implications of the method for the guidance of access-related decisions on the placement of cancer services are considered, and the wider relevance of the method to the organisation of service provision in other branches of medicine is suggested.

Algorithms↗
PubMed1997

The need for specialist review of pathology in paediatric cancer.

A retrospective histopathological review of 2104 cases of solid tumour was carried out to assess the variability in diagnosis of childhood cancer. Cases were subject to three independent, concurrent opinions from a national panel of specialist pathologists. The conformity between them was analysed using the percentage of agreement and the kappa statistic (kappa), a measure of the level of agreement beyond that which could occur by chance alone, and weighted kappa (w kappa), which demonstrates the degree of variation between opinions. The major groupings of the Birch-Marsden classification were used within which tumours were assigned for kappa analysis according to the clinical significance of the differential diagnoses. The mean agreement for all tumours together was 90%; kappa = 0.82, w kappa = 0.82. Retinoblastoma achieved the highest kappa value (1.0) and lymphoma the lowest (0.66). Of the cases, 16.5% had their original diagnoses amended and the panel confirmed the original diagnosis of paediatric pathologists in 89% of cases compared with 78% for general pathologists. The varying levels of agreement between experts confirm the difficulty of diagnosis in some tumour types, suggesting justification for specialist review in most diagnoses. Specialist training in paediatric pathology is also recommended.

Child↗
PubMed1997

Continued inadequacies in data sources for the evaluation of cancer services.

There is a need to evaluate cancer services and provide a baseline on current treatment success and organization. This study shows that this process may be severely hindered by case note destruction or inaccessibility and incomplete information. This is an ongoing problem that needs to be addressed now.

Breast Neoplasms↗
PubMed1997

Conservatively managed tibial shaft fractures in Nottingham, UK: are pain, osteoarthritis, and disability long-term complications?

OBJECTIVES: To investigate longterm pain and disability subsequent to a tibial shaft fracture treated conservatively. DESIGN AND SETTING: Subjects who had sustained a tibial shaft fracture more than 27 years ago were compared with those who had not. SUBJECTS: 572 fracture patients (identified from the records of the plaster room) aged over 16 at the time of injury were contracted and were compared with 2285 randomly selected subjects matched for age, sex, and general practice. MAIN OUTCOME MEASURES: Self reported knee pain; self reported GP's diagnosis of osteoarthritis; ability to climb stairs, walk 100 yards, to bend, kneel, or stoop; and SF-36 physical functioning score. RESULTS: Subjects were reviewed between 27 and 41 years after tibial shaft fracture (mean 35 years). Fracture patients were more likely to suffer chronic knee pain (odds ratio 1.23; 95% confidence interval (CI) 1.00, 1.51) and report being given a diagnosis of osteoarthritis by their GP (odds ratio 1.46; 95% CI 1.08, 1.97). The ability to climb stairs, walk 100 yards, and bend, kneel, or stoop was less in the fracture group than the other subjects. The SF-36 physical function score was significantly lower in the fracture group. CONCLUSIONS: More than 27 years after a tibial shaft fracture, subjects have more knee pain than the rest of the population. They also have greater difficulty performing everyday physical activities. The excess morbidity may be due to injury factors or treatment factors, and further research is needed to investigate this important association further.

Activities of Daily Living↗
PubMed1996

Coronary heart disease: a review of the role of psychosocial stress and social support.

BACKGROUND: The role of psychosocial factors in the aetiology of coronary heart disease continues to be debated. Despite public perception of a major role for their effect, scientific opinion on their relevance remains divided. This paper reviews the literature on the influence of social support and life stress on coronary heart disease incidence and mortality. METHODS: Observational studies published in English, based on over 100 human subjects from the general population, investigating life stress or social support were considered. Fourteen studies derived from MEDLINE searches on MeSH headings: coronary disease; stress, psychological; social support; social isolation; life change events. An equivalent search of BIDS and studies referenced by papers identified using these sources was carried out. RESULTS AND CONCLUSIONS: The review concludes that both life stress and social support were found to have an influence on coronary heart disease, social support more so than stress. Both have a stronger influence on coronary heart disease mortality than on initial incidence of clinical disease. Measures of the quality of support, in particular emotion support, show the largest effects. The review highlights problems in drawing conclusions from the available literature; in particular, the inconsistency in measures used to define the psychosocial factors. Further studies are needed to investigate interrelationships between stress and social support, and a recommendation is made to adopt pragmatic measures in future studies, which if proven to have an effect, may be open to modification.

Adult↗
PubMed1996

Screening for pain in knee osteoarthritis: which question?

OBJECTIVE: To compare three questions on knee pain with respect to determined prevalence and associations with disability and structural change. METHODS: Postal survey to 4057 men and women aged 40-79 years. Knee pain was defined by three questions: (A) "Have you ever had pain in or around the knee on most days for at least a month? If so, have you experienced any pain during the last year?" (B) "Have you had pain within the last year in or around the knee that occurred on most days for at least a month?" (C) "Have you had knee pain on most days of the last month?" [American College of Rheumatology (ACR) criteria for knee osteoarthritis]. Disability was assessed with the SF-36 health status questionnaire. Radiographs (AP weight bearing and skyline) were obtained on a proportion (n = 459) and graded for maximum osteophyte in any compartment. RESULTS: Prevalence of knee pain for questions A, B, and C were 28.3%, 25.3%, and 19.3% respectively. Highest rates of disability were observed for question C (71.3% compared with 60.9% for question A). There was no major difference between questions in terms of percentage with > or = grade 1 osteophyte or > or = grade 2 osteophyte. Sensitivity and specificity of each question for > or = grade 1 osteophyte did vary, with question A being most sensitive but least specific (58.7% and 59.1%) and question C most specific (72.7%) but least sensitive (45.4%). CONCLUSIONS: Estimates of knee pain and disability are influenced by even minor changes in question content. The ACR criteria question may be a better predictor of disability but is relatively insensitive for use in the community.

Adult↗
PubMed1995

Changing incidence and geographical distribution of malignant paediatric germ cell tumours in the West Midlands Health Authority region, 1957-92.

The West Midlands Regional Children's Tumour Research Group holds high-quality data from 1957 on all childhood cancers in the West Midlands Health Authority region. Since it has been reported that malignant germ cell tumours are increasing in incidence in the north-west of England, we undertook to examine rates in this region and to map the distribution of cases in order to assess any geographical changes in incidence rates. We identified a total of 102 malignant germ cell tumours (MGCTs) between 1957 and 1992. The average age-standardised rate was 1.6 per million per year in the period 1957-74 and 3.6 per million per year during 1975-92, a significant increase (P = 0.0004). Particular increases were noted in older children (10-14 years); P = 0.0002) and in yolk sac (endodermal sinus) tumours (P = 0.004). A small excess was also observed in Asian children when compared with other diagnoses. Geographical analysis showed particularly higher rates at health district level in the West Midlands conurbation as compared with the other areas in the period 1975-92. These factors suggest the possibility that industrial/urban or population effects may be implicated in the observed increase in childhood MGCT and we recommend these areas for further studies.

Adolescent↗
PubMed1995

Distribution of cases of systemic lupus erythematosus at time of first symptom in an urban area.

OBJECTIVES: To determine the geographical distribution of cases of systemic lupus erythematosus (SLE) in a defined geographical area in the East Midlands, UK, and, in particular, to search for spatial variation in cases that may implicate the role of environmental factors in SLE aetiology. METHODS: Six methods of case ascertainment were used. The postcode of the patient's domicile at time of first definite symptom of SLE was used for analysis which included case mapping, probability mapping by electoral ward, and variogram analysis. RESULTS: The study area population of 613,700 contained 200 SLE patients, 188 of whom experienced their first symptom whilst residing in the area. Case mapping revealed 12 SLE patients residing within an area of one square mile, including four men and six patients with RNP antibodies. The use of probability mapping showed five wards in close proximity to each other to have a greater number of SLE cases than would be expected by chance (p < 0.1). The 'cluster' of patients seen on the case map fell into two wards which showed a significant excess of cases only when combined (p = 0.006). The variogram of the incidence rates for each ward did not confirm any structure or pattern to the distribution of cases for the whole area. CONCLUSIONS: Some areas have a greater than expected prevalence of SLE. The normal result from variogram analysis suggests that the cause(s) for these excess number of cases does not have an effect across the whole study area.

Adolescent↗
PubMed1995

Immunophenotypic analysis of childhood Burkitt's lymphoma in the West Midlands 1957-1986.

AIMS: To analyse the immunophenotype of a large number of non-endemic Burkitt's lymphomas to determine whether a B cell phenotype is consistently recognisable using formalin fixed, paraffin wax embedded archival material and a standard panel of commercially available antibodies. METHODS: Archival material was obtained from 30 cases of childhood Burkitt's lymphoma registered with the West Midlands Regional Children's Tumour Research Group. These were analysed by a standard avidin biotin complex immunoperoxidase method using antibodies to CD45, CD43, CD30, CD20, CD15, and immunoglobulin heavy and light chains. RESULTS: There was a high incidence of the CD45RB and CD20 immunophenotypes, with a clearly recognisable B cell lineage even in archival material. IgM was identifiable in 13 of the 23 (56.5%) cases tested. Only three of 17 (18%) cases expressed CD30. Positive membrane staining with CD45RO was observed in two (6.7%) cases. CONCLUSIONS: A B cell lineage can be identified in Burkitt's lymphoma in formalin fixed, paraffin wax embedded material, even in archival tissue. There was a low incidence of membrane staining with CD45RO which is a potential source of diagnostic confusion.

Adolescent↗
PubMed1995

Stress, social support, and stopping smoking after myocardial infarction in England.

STUDY OBJECTIVE: To examine the effect on mortality of stopping smoking after myocardial infarction and the psychosocial factors that influence the decision to stop. DESIGN: Analysis of smokers in a large prospective study. Self completed questionnaires provided information on psychosocial factors. SETTING: Coronary care units at six English hospitals participating in a multicentre clinical trial. SUBJECTS: These comprised consenting myocardial infarction survivors who had been identified as smokers and who completed questionnaires within seven days of infarct at six hospitals participating in the Anglo-Scandinavian study of early thrombolysis. The 532 patients identified have been followed for over five and a half years. The main outcome measure was five year all cause mortality. MAIN RESULTS: Smokers who stopped within one month showed significantly reduced mortality compared with those who persisted, adjusting for other prognostic indicators (odds ratio 0.56, 95% confidence interval 0.33, 0.98). Overall, 74% stopped smoking. Being married, low life stress levels before infarct, and higher social class were associated with stopping smoking but the differentials were small. Of the clinical variables, a final diagnosis of definite myocardial infarction was associated with stopping smoking. All associations remained after multiple logistic regression. CONCLUSION: Smoking cessation can halve the smokers' odds of dying after myocardial infarction and psychosocial factors play a small but important role in the important decision to stop smoking. Health professionals should continue to stress the importance of stopping smoking to all patients as there is little evidence to support specific directing of advice to relatively "stress or "socially isolated" groups.

Aged↗
PubMed1994

Neonatal tumours: a thirty-year population-based study.

Estimates of the incidence and outcome of tumours in neonates are uncertain and most reports relate to selected experience in single centres. The definition of neonatal tumour is also unclear and histology is not always an accurate predictor of outcome. This report documents the incidence, clinical features, and outcome of neonatal tumours (birth-3 months) in a population-based paediatric register over a 30-year period from 1960-89. Case note and pathology review identified 170 cases for analysis, of which 21 were leukaemias, 14 CNS tumours, and 135 solid tumours of differing types. Fifty-eight percent were diagnosed in the first month and mature teratoma was the most common diagnosis (29%). Overall incidence increased over the period of the study. Important family medical history was identified in 16% of cases and 15% of patients had associated congenital abnormalities. Overall survival at 1 year was 55%, with leukaemia having the poorest prognosis. Treatment strategies must be individualised but many patients may have a better prognosis than expected and would benefit from assessment at a designated paediatric oncology centre.

Age Distribution↗
PubMed1994

Thirty years of retinoblastoma (1960-89): changing patterns of incidence.

This study of a 30-year population-based dataset investigates further an earlier observation that the incidence of sporadic bilateral retinoblastoma appeared to be increasing in recent years in the West Midlands Health Authority Region (WMHAR). Stringent measures were applied to ensure complete ascertainment of all cases of retinoblastoma in children in the region, resulting in a total of 117 cases diagnosed during the period 1960-89 in the WMHAR. Hospital case notes were abstracted and follow-up data obtained. Incidence rates were calculated. The overall incidence remained constant over the 30-year period, but that of sporadic bilateral tumours increased, with a corresponding decline in familial cases. There was a statistically significant excess seen in Asian children.

Age Distribution↗
PubMed1993

Carcinoid tumours of the appendix in children 1957-1986: incidence, treatment and outcome.

Forty carcinoid tumours of the appendix were identified in children under 15 years of age between 1957 and 1986 from the records of the West Midlands Regional Children's Tumour Research Group. A significant excess of girls was observed (P = 0.02). All tumours were discovered incidentally and two patients underwent further surgery. Twenty-two of the 29 confirmed locations (76 per cent) were at the tip of the appendix and 34 of the 40 tumours (85 per cent) had invaded beyond the appendiceal submucosa. The reported incidence rate of 1.14 per million children per year remained constant throughout the study period. No recurrences, metastases or deaths from tumour were detected. Appendicectomy alone is confirmed as usually curative, although right hemicolectomy is occasionally necessary. Caution during routine appendicectomy is recommended to avoid possible tumour damage, as is consistent histological examination of all appendices in the paediatric age group. The importance of long-term follow-up is emphasized.

Adolescent↗
PubMed1993

Thirty-year population-based review of childhood renal tumours with an assessment of prognostic features including tumour DNA characteristics.

We have reviewed all paediatric kidney tumours seen in the West Midlands Health Authority Region over a 30-year period. There were 205 cases confirmed after a review of the pathology by three paediatric pathologists. Seven were cases of bone metastasising renal tumour (clear cell sarcoma), 5 were rhabdoid tumours, 2 were renal cell carcinomas, and 13 were mesoblastic nephromas. In 3 cases, it was not possible to define further the histological diagnosis. The remaining 175 cases were considered to be Wilms' tumour (86%), which is equivalent to an incidence of 5.7/10(6)/year. In the cases of Wilms' tumour, there were 91 boys and 84 girls (1.1:1). The majority of patients were Caucasian with only 7% of non-Caucasian origin. At presentation, 78% of the patients were less than 5 years old. All of these patients except 9 had surgery as part of their treatment, 154 children had total nephrectomy, 3 had partial nephrectomy, and 9 had other surgical procedures. The majority also received chemotherapy and radiotherapy. Sex, chemotherapy, and stage all had prognostic significance in univariate analysis. The actuarial survival at 10 years increased from 17% for patients treated in the first decade of the study to 78% for patients treated in the third. DNA characteristics were investigated using flow cytometry in paraffin-embedded material and adequate information was obtained in 73 cases of Wilms' tumour. Only 7 had aneuploid tumours. Univariate survival analysis of these 73 results showed that stage, sex, the percentage of cells in the synthetic phase and the proliferative index from the DNA investigations had predictive value.

Actuarial Analysis↗