Frequency of patients' consulting in general practice and workload generated by frequent attenders: comparisons between practices.

BACKGROUND: Patients who attend frequently may present a problem for general practitioners (GPs) in several ways. The frequency of patients' consulting, comparisons between practices, and the effect of frequent consulting on the clinical workload have not been quantified previously. AIMS: To examine the distribution of the number of consultations per patient in four general practices. To estimate the clinical workload generated by frequent attenders. To model the data to demonstrate the contribution of age, sex, and practice on the likelihood of attending frequently. METHOD: Analysis and modelling of a validated data set of date records of consultations collected routinely over a 41-month period from four practices in and around Leeds, representing 44,146 patients and 470,712 consultations. RESULTS: A minority of patients consulted with extreme frequency. All practices had similar distributions but varied with respect to the numbers of frequent attenders, and the frequencies of their consulting. The most frequent 1% of attenders accounted for 6% of all consultations, and the most frequent 3% for 15% of all consultations. Females and older people were more likely to be frequent attenders. CONCLUSION: Frequent attenders have an important effect on GPs clinical workload. Between one in six and one in seven consultations are with the top 3% of attenders. Further research is needed to explain the behaviour underpinning frequent attendance in order to identify appropriate management strategies; such strategies could have an important effect on clinical workload.

Abdominal migraine: a cause of abdominal pain in adults?

Eighty-five patients with non-organic abdominal pain, were interviewed with the help of a questionnaire. Those who responded to a high fibre diet were excluded from the study. Twenty-seven patients had multiple pains and 58 described a single pain, which was intermittent in 39. A detailed analysis of the symptoms and family history of the latter group suggested that in 19 patients the symptoms might have been caused by abdominal migraine. Six of these 19 had typical migraine-associated symptoms during the attack, characteristic abdominal pain and a family or personal history of classical migraine. Abdominal migraine should be considered in patients with non-organic abdominal pain where symptoms are not typical of irritable bowel syndrome and when organic disease has been excluded.

A case/control study of adult haematological malignancies in relation to overhead powerlines.

A population based case control study of adult haematological malignancy and distance from, and magnetic fields associated with, overhead (OH) power lines has been carried out in the North West and Yorkshire regions of England. Three-thousand, one hundred and forty-four cases with histologically proven disease were entered into the study. One control per case, matched for age, sex, year of diagnosis and health district of residence, was selected from hospital discharges. Seven per cent of cases and controls lived near to OH power lines as defined by the study protocol. The measure of exposure used was the calculated magnetic field strength at each of these addresses due to maximum load currents carried by OH power lines in the 5 years preceding diagnosis. The odds ratio (OR) for living within 50 m of an OH line was 1.29 with a 95% Confidence Interval (CI) of 0.99-1.68 but a chi 2 test for trend with distance was not statistically significant. The analysis of calculated magnetic fields, did not produce any statistically odds ratios. The OR for magnetic fields greater than or equal to 0.1 mG was 1.03 (95% CI 0.81 1.32). Analysis of magnetic fields greater than or equal to 3.0 mG gave an OR of 1.87 (95% CI 0.79 4.42), but this result is based on small numbers. No evidence was found for confounding by the type of dwelling which was used as a partial surrogate for socio-economic status.

Childhood cancer and overhead powerlines: a case-control study.

A case-control study has been carried out to examine the occurrence of childhood cancer in relation to the proximity of overhead power lines to a child's home address at birth and to the calculated magnetic field at the address. The study included 374 cases diagnosed in the Yorkshire Health Region between 1970 and 1979, together with 588 matched controls. Magnetic-field strengths at the birth addresses due to the load currents of overhead power lines were calculated on the basis of line-network maps and load records. The results indicate no association between the occurrence of childhood malignancies and either the proximity or the magnetic fields of overhead lines, although the statistical power of the study was limited by the small numbers of children living close to overhead power lines.

Who should teach medical statistics, when, how and where should it be taught?

As far as we can tell, there is no single answer to any of these questions. This paper describes some of the approaches adopted in the teaching of medical statistics in the U.K. medical schools. It is suggested that collaboration between non-statistically qualified teachers and medical statisticians is beneficial, with an emphasis in the application of statistical principles to interesting and 'relevant' medical topics. A block of 'laboratory based' teaching in the early years may be followed by occasional, clinically focused sessions later in the undergraduate course. Research oriented courses, made available when postgraduates have a real and pressing need for information, are thought likely to be most valuable and rewarding for students and statisticians. It is thought that the use of information technology to improve the communication of concepts and 'facts' during lectures, and for ad hoc enquiries by students, is likely to make the most of the limited teaching resources. The future is thought to be in the greater use of small group or individualized teaching which confirms or tests the knowledge gained from students use of I.T. supported activities. Unless lecturers collaborate in evaluative studies which compare different teaching methods, it will never be possible to provide valid generalizable advice to teachers of medical statistics.

Comparison of histopathological and flow cytometric parameters in prediction of prognosis in gastric cancer.

Flow cytometric analysis was performed retrospectively on material from 76 patients having potentially curative resection for gastric carcinoma between 1968 and 1984. The prognostic significance of DNA aneuploidy was compared with that of conventional histological grading and staging of the tumour. The presence of DNA aneuploidy was associated with a significantly poorer prognosis when compared with diploid tumours (P less than 0.02), but was not found to be predictive of survival when the presence of lymph node metastases (P less than 0.0001) and resection margin involvement (P less than 0.003) were allowed for using multiple regression analysis. When intestinal and diffuse types of gastric carcinoma were analysed separately, DNA aneuploidy was associated with a significantly shorter survival only in patients with intestinal type tumours.

Symphysis-fundus measurements in Asian and Caucasian women in Bradford.

A study was undertaken to assess the need for a separate chart of symphysis-fundus measurements for the large Asian population of Bradford. 129 measurements from 47 pregnant Asian patients were compared with 193 measurements from 87 pregnant Caucasian patients. There was insufficient evidence to support the production of a separate chart for the Asian population.

Observer variation in histological grading of breast cancer.

A multicentre study was conducted to assess the degree of agreement between pathologists grading breast tumours using the WHO criteria. Satisfactory correlation of grades was found to occur with observer variation of 21.9% on 874 tumours.

Histological grading of breast cancer; significance of grade on recurrence and mortality.

The influence of histological grade on the recurrence and mortality of patients with breast cancer is reported for 829 patients. The effect of the histological grade is also compared with the effect of axillary node involvement and the implications for clinical studies of the management of breast cancer discussed. The prognosis for both recurrence and death becomes increasingly poor as the degree of differentiation decreases, as reflected by the grading allocated to the tumour. This effect is independent of the clinical stage of the cancer at the time of treatment.

Aids and adaptations for the elderly at home: underprovided, underused, and undermaintained.

A random sample of 140 elderly people aged over 75 was selected from the age-sex register of an urban general practice to assess the provision and use of aids and adaptations in their homes. Many of the aids that the elderly had were faulty, including half of the walking aids and 15% of hearing aids, reading spectacles, and dentures, and up to half of the aids were not used. Yet despite this underuse there were many disabled elderly people who required aids for the bath and toilet. When screening of elderly people is carried out in general practice assessment of aids and adaptations should be included to see that they are provided where needed, are used, and are adequately maintained.

Morphometric differences between cytologically benign and malignant serous effusions.

The morphometric differences between benign and malignant serous effusions, as diagnosed by standard cytologic criteria in 95 unselected cases (50 benign and 45 malignant), were studied using the IBAS semi-automated image analysis system, which calculates various parameters from tracings of cellular and nuclear outlines. Fourteen cases were also stained for cytokeratin proteins (with the CAM 5.2 antibody) by the immunoperoxidase technique and reanalyzed for positive cells. Significant differences were found for mean values between cytologically benign and malignant cases for cellular and nuclear areas, perimeters and maximum diameters, but not for two form factors. Some differences were enhanced in the CAM 5.2-stained cases. Real morphometric differences in samples of cells from benign and malignant cases are the basis of cytologic diagnosis. Fully automated diagnostic systems could operate on arbitrary threshold values, but there is considerable overlap in specimen means for all parameters between benign and malignant cases.

False positive results of tests for syphilis and outcome of pregnancy: a retrospective case-control study.

In a retrospective case-control study 64 women yielding a false positive result to a test for syphilis in pregnancy were compared with 128 controls individually matched for age, parity, hospital of delivery, and year of delivery. There were significantly more unsuccessful pregnancies, mainly spontaneous abortions during the first and second trimesters, among women with persistent false positive results. There was no significant difference between groups in the mean birth weights of liveborn infants. The antibodies responsible for the false positive result may indicate the presence of an immunological disturbance. Women who give a false positive result should be carefully managed throughout their pregnancy.

Prognostic significance of DNA aneuploidy and cell proliferation in rectal adenocarcinomas.

DNA content and cell proliferation were studied retrospectively in 125 patients presenting from 1974-1981 with rectal adenocarcinoma. The presence of DNA aneuploidy or a high level of cell proliferation were associated with a poor prognosis and when combined were the best predictor of survival after Dukes's stage excluding all other pathological assessments investigated. High cell turnover was significantly associated with an infiltrative pattern of growth, an observation that might explain the poorer prognosis of this pattern in rectal adenocarcinomas.

DNA content and prognosis of non-Hodgkin's lymphoma.

Ninety cases of non-Hodgkin's lymphoma diagnosed prior to the use of modern therapeutic regimens (1963-67) and 88 cases treated with such chemotherapy (1980-85) were studied using conventional morphology and flow cytometry. DNA aneuploidy as determined by flow cytometry was more common among high grade (38%) than low grade (19%) tumours (P less than 0.01). Measurements of proliferative index (S + G2 phase cells) revealed significantly increased values for high grade as compared with low grade lymphomas (P less than 0.001). In the first group of cases (1963-67) the relationship between histological grade and survival just failed to reach statistical significance over the long term (20 yr) (P = 0.1) but proved significant over 3 yr (P = 0.012). Differences in ploidy and proliferative index status were not associated with survival. In the second patient group (1980-85) attainment of complete remission following chemotherapy was associated with the presence of DNA aneuploidy in high grade tumours (P less than 0.05). The limited follow up of this group precluded assessment of survival in relation to ploidy.

The diagnosis and treatment of adults with obstructive airways disease in general practice.

Two hundred and one patients diagnosed by their general practitioners as having asthma and 113 as having chronic bronchitis were compared by symptomatology and airways reversibility. Though the majority of patients given these two diagnoses could be separated by symptom complex, in about one-third such differentiation was difficult. There was no significant difference in bronchodilator reversibility between the asthmatics and chronic bronchitics. Nine out of 15 (60%) asthmatics and four out of 18 (22%) chronic bronchitics responded by 15% or more to a course of oral corticosteroid drugs. The majority of corticosteroid responders had been undertreated. The problems arising from the poor correlation between airways reversibility and symptomatic diagnosis are discussed.

Primary biliary cirrhosis and chronic active hepatitis: an examination of clinical, biochemical, and histopathological features in differential diagnosis.

Seventy four liver biopsies from 59 patients were reviewed by two observers and histologically graded in the absence of clinical information, firstly, to assess the level of agreement with previous diagnoses; secondly, to identify differences between primary biliary cirrhosis and chronic active hepatitis; and, thirdly, to assess the specificity of Shikata orcein staining and antimitochondrial antibody positivity and titre for primary biliary cirrhosis. Thirty six patients with adequate histology were initially selected as typical of primary biliary cirrhosis or chronic active hepatitis; agreement both between observers and with original diagnoses was reached in 26 (72%) (15 with primary biliary cirrhosis (group 1), 11 with chronic active hepatitis (group 2)). In 19 diagnostically difficult patients in whom clinical and original histological findings had been at variance, histological agreement between observers was reached in 17 (group 3) and original underdiagnosis of primary biliary cirrhosis was suggested. The main clinical and histological differences between groups 1 and 2 are discussed in this paper. Although a high grade of positivity for copper associated protein in the Shikata orcein stain was seen only in primary biliary cirrhosis, a high titre of antimitochondrial antibody positivity was not unique to this condition.

Blood group as a prognostic indicator in breast cancer.

A retrospective analysis of 1001 patients with invasive breast cancer showed a difference in survival between patients with different blood groups. Analysis of time from operation to local recurrence and to general recurrence reinforced this finding. The difference between blood groups became increasingly significant after accepted prognostic factors were allowed for. Patients at particularly high risk of early death or general recurrence were those with blood groups B and AB, those with group AB having a greater relative local recurrence rate.

Coronary artery luminal diameter in aortic stenosis.

The coronary artery luminal diameters in 32 patients with aortic stenosis (AS) were compared with those of 24 control subjects without left ventricular (LV) hypertrophy by means of a derived index. Patients with AS had significantly larger coronary arteries than the control subjects (p less than 0.01). The increase in coronary luminal diameter had a weak correlation to LV wall thickness (r = 0.32) and LV mass (r = 0.34). Among 21 patients with AS and normal coronary angiograms, those with angina had higher peak LV pressures (224 +/- 8 vs 196 +/- 7 mm Hg) and greater peak systolic gradients (103 +/- 9 vs 74 +/- 10 mm Hg) than those without angina (p less than 0.05). However, there was no significant difference in coronary artery diameters, peak LV stress or LV tension at rest between patients with and without angina.