List sizes and use of time in general practice.

The claim that list sizes in general practice should continue to fall towards a national average of 1700 patients rests heavily on the assumption that the extra time available to doctors would be used mainly for longer consultations, resulting in better standards of care. Evidence suggests, however, that the time is more likely to be used to increase rates of consultation in surgeries and home visits and to reduce the length of the working week. A national, random sample of 2104 principals in general practice in England and Wales were questioned about their allocation and use of time. The response rate was 67%, and no large biases in response were detected. The smaller their personal list size the less time general practitioners spent on all aspects of their work and the higher their rates of consultation and home visiting. The effects of further reductions in list sizes would be haphazard, being differentially distributed across the range of list sizes. Longer consultations would probably result, but most of the extra time would probably be used in higher rates of consultation in surgeries and home visits and some would be taken as free time.     

How can good general practitioner care be achieved?

It has been shown that to provide a high standard of care general practitioners probably need to book consultations at intervals of at least 10 minutes. In this study the maximum list size for which a general practitioner might be expected to provide a high standard of care was determined from calculations of the time spent consulting, based on various consultation rates and list sizes and assuming that consultations were 10 minutes long. If good quality care is to be provided and is to include the range of services suggested in the government''s recent green paper average list sizes should probably be no more than 1750, and lower in areas of high demand and high need. In addition to this, minimum standards could be determined for such measures as facilities available in surgeries, practice records, and accessibility of doctors to ensure that basic services were offered by all general practitioners.     

List size and patient contact in general medical practice.

One hundred and ninety nine general practitioners collected data on consultations with patients for a representative sample of recording days. The number of consultations and amount of time spent in patient contact were positively correlated with the number of registered patients (list size), whereas the consultation rate and the amount of time spent with each patient were negatively correlated. These relations, however, were not too strong, and there was considerable variation among doctors, particularly for those with lower list sizes. These findings have implications for issues concerning quality of care and the potential effects of reductions in patient list size.     

Quality of obstetric care provided for Asian immigrants in Leicestershire.

Between 1976 and 1981 some 939 perinatal deaths occurred to women living in Leicestershire, of which 128 (14%) were to Asian women. The qualifications of the general practitioners, the gestation at which women start antenatal care, and perinatal death were used as structural, process, and outcome measures for evaluating the services provided to Asian immigrants within this population. Perinatal deaths were divided into four groups: congenital malformation, macerated stillbirth, asphyxia in labour, and immaturity. Asian mothers had one and a half times the risk of perinatal mortality when social class, parity, height, legitimacy, and the general practitioner''s qualifications were taken into account. Asian and non-Asian mothers with general practitioners who were not on the obstetric list had more than twice the risk of a perinatal death when a similar adjustment was made. Recommendations include priority allocation of community midwives to practitioners not on the obstetric list, the establishment of postgraduate courses for such doctors, and the continued evaluation of the effect of such proposals on perinatal mortality.     

Grampian Health Board's joint drug formulary.

OBJECTIVE--To develop a model for creating a joint general practice-hospital formulary, using the example of ulcer healing drugs. DESIGN--A joint formulary development group produced draft guidelines based on an earlier hospital formulary, which were sent to interested local general practitioners for consultation. Revised guidelines were then drawn up and forwarded to the health board''s medicines committee for approval and distribution. SETTING--Grampian Health Board. SUBJECTS--Nine members of joint formulary development group plus local general practitioners who were invited to comment on a list of 11 ulcer healing drugs. MAIN OUTCOME MEASURE--Degree of coincidence of drugs selected by hospital doctors and general practitioners. RESULTS--The ulcer healing drugs selected by the panel of general practitioners and by hospital doctors were highly coincident. The cost of one day''s treatment with drugs varied considerably between hospital and general practice--for example, one drug cost 46p in hospital and 1 pounds in general practice and another cost 1.26 pounds in hospital and 1.01 pounds in general practice. Overall, six drugs cost more in hospital and five cost more in general practice. CONCLUSIONS--A joint formulary for use in hospitals and general practice in a health board can be devised fairly simply by consultation as virtually the same drugs are used in both types of practice. It should influence the health board''s expenditure on drugs and affect the choice of drugs when a patient is discharged from hospital or is referred to any hospital in the region.     

Uptake of immunisation in district health authorities in England

The uptakes of immunisation in the district health authorities in England were studied for the years 1983-5. Multiple regression analysis showed that the factors significantly associated with a low uptake of immunisation were mainly related to social conditions, particularly overcrowding of households and population density. Of the service factors, high proportions of elderly and singlehanded general practitioners and high average list sizes were also associated with a low uptake of immunisation in some of the analyses.The results suggest that the measures outlined in the government''s white paper on improving primary health care services are likely to lead to improved uptakes of immunisation. If, however, the uptakes of immunisation are used as a measure of standards of the services provided they should first be adjusted to control for variations in social conditions, and the quality of vaccination data would have to be improved.     

Quantifying population structure using the F-model

We review a model-based approach to estimate local population F(ST) 's that is based on the multinomial-Dirichlet distribution, the so-called F-model. As opposed to the standard method of estimating a single F(ST) value, this approach takes into account the fact that in most if not all realistic situations, local populations differ in their effective sizes and migration rates. Therefore, the use of this approach can help better describe the genetic structure of populations. Despite this obvious advantage, this method has remained largely underutilized by molecular ecologists. Thus, the objective of this review is to foster its use for studying the genetic structure of metapopulations. We present the derivation of the Bayesian formulation for the estimation of population-specific F(ST) 's based on the multinomial-Dirichlet distribution. We describe several recent applications of the F-model and present the results of a small simulation study that explains how the F-model can help better describe the genetic structure of populations.     

Opinions of general practitioners in Nottinghamshire about provision of intrapartum care.

OBJECTIVE--To examine the beliefs of general practitioners concerning intrapartum care. DESIGN--Postal questionnaire survey. SUBJECTS--All general practitioners with patients in Nottinghamshire Family Health Services Authority in September 1993. MAIN OUTCOME MEASURES--General practitioners'' current involvement in maternity care, and beliefs on intrapartum care. RESULTS--Of 694 general practitioners sent questionnaires, 550 (79.2%) replied. 529 of these were on the obstetric list; 437 had not attended a delivery in the past 12 months; 36 had attended two or more; 358 general practitioners did not wish to provide more intrapartum care; 349 did not feel competent to do so. Reasons for not wanting to provide intrapartum care included current workload (453), disruption to personal life (407), and the fear of litigation (377). General practitioners who already booked women for home delivery were more likely to wish to do more deliveries (62/42 v 61/316, chi 2 = 85.3; P < 0.0001) and to have more positive attitudes towards increasing women''s choice in maternity care (90/22 v 195/151, chi 2 = 227; P < 0.0001). CONCLUSIONS--The involvement of general practitioners in intrapartum care in Nottinghamshire is low, and most general practitioners are unwilling to increase their role. However, general practitioners who already book for home delivery are keen to do more.     

An evaluation of home visiting of patients by physicians in geriatric medicine

The practice of preadmission home visiting of patients referred to geriatric medicine units has in recent years been criticised as being unnecessary on the grounds that if there is no waiting list there is no need for allocation of priority for admission; as being wasteful of doctors'' time; as being resented by general practitioners; and as failing to provide adequate clinical information. The geriatric medicine department at the City Hospital with no waiting list for patients referred by general practitioners has retained home visits for most referrals because of the advantages in terms of acceptability to general practitioners (98-100%); the quantity and quality of information obtained; the usefulness of this information in deciding appropriate management and in planning discharge from hospital; and the provision of a unique teaching opportunity, which is highly valued by students and teachers alike.     

General practitioners' continuing medical education within and outside their practice.

To study continuing medical education 96 out of 101 general practitioners chosen at random from the list held by a family practitioner committee were interviewed. The results provided little evidence of regular attendance at local postgraduate centre meetings, though practice based educational meetings were common. Thirty one of the general practitioners worked in practices that held one or more practice based educational meetings each month at which the doctors provided the main educational content. Performance review was undertaken in the practices of 51 of the general practitioners, and 80 of the doctors recognised its value. The general practitioners considered that the most valuable educational activities occurred within the practice, the most valued being contact with partners. They asked for increased contact with hospital doctors. The development of general practitioners'' continuing medical education should be based on the content of the individual general practitioner''s day to day work and entail contact with his or her professional colleagues.     

A quantitative review of heterozygosity–fitness correlations in animal populations

The ease of obtaining genotypic data from wild populations has renewed interest in the relationship between individual genetic diversity and fitness-related traits (heterozygosity–fitness correlations, or HFC). Here we present a comprehensive meta-analysis of HFC studies using powerful multivariate techniques which account for nonindependence of data. We compare these findings with those from univariate techniques, and test the influence of a range of factors hypothesized to influence the strength of HFCs. We found small but significantly positive effect sizes for life-history, morphological, and physiological traits; while theory predicts higher mean effect sizes for life-history traits, effect size did not differ consistently with trait type. Newly proposed measures of variation were no more powerful at detecting relationships than multilocus heterozygosity, and populations predicted to have elevated inbreeding variance did not exhibit higher mean effect sizes. Finally, we found evidence for publication bias, with studies reporting weak, nonsignificant effects being under-represented in the literature. In general, our review shows that HFC studies do not generally reveal patterns predicted by population genetic theory, and are of small effect (less than 1% of the variance in phenotypic characters explained). Future studies should use more genetic marker data and utilize sampling designs that shed more light on the biological mechanisms that may modulate the strength of association, for example by contrasting the strength of HFCs in mainland and island populations of the same species, investigating the role of environmental stress, or by considering how selection has shaped the traits under investigation.     

Patients' accounts of being removed from their general practitioner's list: qualitative study

Objective To explore patients'' accounts of being removed from a general practitioner''s list.Design Qualitative analysis of semistructured interviews.Setting Patients'' homes in Leicestershire.Participants 28 patients who had recently been removed from a general practitioner''s list.Results The removed patients gave an account of themselves as having genuine illnesses needing medical care. In putting their case that their removal was unjustified, patients were concerned to show that they were “good” patients who complied with the rules that they understood to govern the doctor-patient relationship: they tried to cope with their illness and follow medical advice, used general practice services “appropriately,” were uncomplaining, and were polite with doctors. Removed patients also used their accounts to characterise the removing general practitioner as one who broke the lay rules of the doctor-patient relationship. These “bad” general practitioners were rude, impersonal, uncaring, and clinically incompetent and lied to patients. Patients felt very threatened by being removed from their general practitioner''s list; they experienced removal as an attack on their right to be an NHS patient, as deeply distressing, and as stigmatising.Conclusions Removal is an overwhelmingly negative and distressing experience for patients. Many of the problems encountered by removed patients may be remediable through general practices having an explicit policy on removal and procedures in place to help with “difficult” patients.     

The views of singlehanded general practitioners: a qualitative study.

OBJECTIVES--To examine the concerns of singlehanded general practitioners working in an inner London area and to compare the views of general practitioners in partnerships. DESIGN--Qualitative analysis of semistructured interviews with a random sample of singlehanded general practitioners and a sample of general practitioners from partnerships matched for age and sex. SETTING--The area covered by Lambeth, Southwark, and Lewisham Family Health Services Authority. RESULTS--The singlehanded general practitioners were more likely to be older, male, and first qualified abroad than general practitioners in partnerships. Their major concerns were inadequate premises, maintaining their singlehanded status, and coping with recent changes to their contract. Most were very satisfied with their solo status and did not see the provision of 24 hour care as stressful. CONCLUSION--Singlehanded general practitioners saw themselves as providing a unique service for patients, and their status as an alternative for general practitioners who were unhappy in partnerships. Such practices are unlikely to wither away as a pattern of provision. Any comprehensive development of primary care must take their needs into account.     

Designing a deprivation payment for general practitioners: the UPA(8) wonderland.

OBJECTIVE--To analyse critically the deprived area payment introduced in the new general practitioner contract. The payment formula is based on the Jarman underprivileged area index (UPA(8)) and aims at compensating general practitioners for increases in workload. DESIGN--Evaluation of the deprived area payment against the stated policy objective with a set of criteria for developing resource allocation formulas. MAIN OUTCOME MEASURES--The degree to which the components of the Jarman index predict the workload of general practitioners; whether construction of the index is sensible and comprehensible; and how the formula incorporates the index and is likely to work in practice. RESULTS--The fact that the index relies on census data and the way the weighting was derived means that the formula will not accurately reflect the workload. The use of statistical transformations obscures the original policy intent. There has been no validation to support the application of the index as part of a national policy. The payments are not linked to the quality of service provided and may have the perverse effect of increasing list size. CONCLUSION--The formula used as the basis of the deprived area payments is poorly suited to the policy objective of compensating general practitioners for increases in workload. More research is urgently needed to enable the effect of the payment to be monitored and a more empirically sound set of incentives to be developed.     

Modelling urban populations of the Australian White Ibis (Threskiornis molucca) to inform management

Since the 1970s, populations of the Australian White Ibis (Threskiornis molucca) have dramatically increased in many Australian urban centres. Managers of ibis are currently focusing on limiting this bird's reproductive success in order to reduce population sizes or at least halt further increases in urban areas. Here we use data on nesting success and survival for three populations of ibis around greater Sydney to develop an age-structured population model. The estimated growth rate for all populations combined was about 1.5 % per year and for individual sites were more variable at −1, −7, and 9 %. For all populations, growth rates were most sensitive (based on elasticity analyses) to the survival of adults and least sensitive to fecundity, especially of 3 year olds. Further exploration of the importance of fecundity rates, which are relatively poorly known for these populations, suggests that rates of <0.4 fledglings per nest per year is very likely to lead to a population decline (λ less than lower bound of 95 % CI). Conversely, positive population growth is nearly assured (λ greater than upper bound of 95 % CI) for fecundities of >0.7 fledgling per nest per year. The results suggest that ibis from other locations (probably their traditional breeding areas in inland Australia) have immigrated into urban environments as estimated growth rates cannot account for current population sizes. Management strategies must take these findings into account and also consider that ibis are declining in their traditional habitats to avoid exacerbating their decline at a regional scale.     

The use of Markovian metapopulation models: a comparison of three methods reducing the dimensionality of transition matrices

The use of Markovian models is an established way for deriving the complete distribution of the size of a population and the probability of extinction. However, computationally impractical transition matrices frequently result if this mathematical approach is applied to natural populations. Binning, or aggregating population sizes, has been used to permit a reduction in the dimensionality of matrices. Here, we present three deterministic binning methods and study the errors due to binning for a metapopulation model. Our results indicate that estimation errors of the investigated methods are not consistent and one cannot make generalizations about the quality of a method. For some compared output variables of populations studied, binning methods that caused a strong reduction in dimensionality of matrices resulted in better estimations than methods that produced a weaker reduction. The main problem with deterministic binning methods is that they do not properly take into account the stochastic population process itself. Straightforward usage of binning methods may lead to substantial errors in population-dynamical predictions.     

Fundholding in general practice and financial risk.

OBJECTIVE--To estimate the financial effect of random yearly variations in need for services on fundholding practices with various list sizes. DESIGN--A simulation model was derived using historical data on general practitioner referrals for the 113 surgical procedures covered by the general practitioner fund, combined with data on the hospital prices for those procedures. PATIENTS--Resident population of Central Birmingham Health Authority. MAIN OUTCOME MEASURES--Expected expenditure on the relevant surgical procedures for the whole district and for practices with list sizes of 9000, 12,000, 15,000, 18,000, 21,000, or 24,000 for each of 100 simulated years. RESULTS--By using average hospital prices for the West Midlands region the mean (SD) annual expenditure for the 179,400 residents was 4,832,471 pounds (87,149 pounds); the random variation between the 5th and 95th most expensive years was 5.7% of the mean cost. For a practice with a list size of 9000 the values were 244,891 pounds (18,349 pounds), with a variation of 27.5%. With a list size of 24,000 the values were 652,762 pounds (32,512 pounds), with a variation of 15.3%. CONCLUSIONS--Random variations in need for inpatient services will have a significant financial impact on the practice fund. The problem will be particularly great for smaller practices. Additional measures are required to ensure that the scheme is not undermined and that the potential benefits are secured.     

Multilist population estimation with incomplete and partial stratification

Multilist capture-recapture methods are commonly used to estimate the size of elusive populations. In many situations, lists are stratified by distinguishing features, such as age or sex. Stratification has often been used to reduce biases caused by heterogeneity in the probability of list membership among members of the population; however, it is increasingly common to find lists that are structurally not active in all strata. We develop a general method to deal with cases when not all lists are active in all strata using an expectation maximization (EM) algorithm. We use a flexible log-linear modeling framework that allows for list dependencies and differential probabilities of ascertainment in each list. Finally, we apply our method of estimating population size to two examples.     

Effect of unsampled populations on the estimation of population sizes and migration rates between sampled populations

Current estimators of gene flow come in two methods; those that estimate parameters assuming that the populations investigated are a small random sample of a large number of populations and those that assume that all populations were sampled. Maximum likelihood or Bayesian approaches that estimate the migration rates and population sizes directly using coalescent theory can easily accommodate datasets that contain a population that has no data, a so-called 'ghost' population. This manipulation allows us to explore the effects of missing populations on the estimation of population sizes and migration rates between two specific populations. The biases of the inferred population parameters depend on the magnitude of the migration rate from the unknown populations. The effects on the population sizes are larger than the effects on the migration rates. The more immigrants from the unknown populations that are arriving in the sample populations the larger the estimated population sizes. Taking into account a ghost population improves or at least does not harm the estimation of population sizes. Estimates of the scaled migration rate M (migration rate per generation divided by the mutation rate per generation) are fairly robust as long as migration rates from the unknown populations are not huge. The inclusion of a ghost population does not improve the estimation of the migration rate M; when the migration rates are estimated as the number of immigrants Nm then a ghost population improves the estimates because of its effect on population size estimation. It seems that for 'real world' analyses one should carefully choose which populations to sample, but there is no need to sample every population in the neighbourhood of a population of interest.