Effect of fundholding and indicative prescribing schemes on general practitioners' prescribing costs.

OBJECTIVE--To compare general practitioners'' prescribing costs in fundholding and non-fundholding practices before and after implementation of the NHS reforms in April 1991. DESIGN--Analysis of prescribing and cost information (PACT data; levels 2 and 3) over two six month periods in 1991 and 1992. SETTING--Oxford region. PARTICIPANTS--Three dispensing fundholding practices; five non-dispensing fundholding practices; and seven non-dispensing, non-fundholding practices. MAIN OUTCOME MEASURES--Percentage change in net cost of ingredients, number of items prescribed, average cost per item, and proportion of generic drugs prescribed after NHS reforms. RESULTS--Prescribing costs increased in all practices in the six months after the reforms. The net costs of ingredients increased among dispensing fundholders by 10.2%, among non-dispensing fundholders by 13.2%, and among non-fundholders by 18.7%. The number of items prescribed also increased in all three groups (by 5.2%, 7.5%, and 6.1% respectively). The increase in average cost per item was 4.8% for dispensing fundholders, 5.3% for non-dispensing fundholders, and 11.9% for non-fundholders. Dispensing fundholders increased the proportion of generic drugs prescribed from 26.9% to 34.5% and non-dispensing fundholders from 44.5% to 48.7%; non-fundholders showed no change (47%). Five of the eight fundholding practices made savings in their drugs budgets at the end of the first year of fundholding (range 2.9-10.7%; the three other practices overspent by up to 3.6%). All non-fundholding practices exceeded their indicative prescribing amounts (range 3.2-20.0%). CONCLUSIONS--Fundholding has helped to curb increases in prescribing costs, even among dispensing general practitioners, for whom the incentives are different. Indicative prescribing amounts for non-fundholding practices do not seem to have had the same effect.     

Influences of practice characteristics on prescribing in fundholding and non-fundholding general practices: an observational study.

OBJECTIVE: To investigate the variation in prescribing among general practices by examining the contribution to this variation of fundholding, training status, partnership status, and the level of deprivation in the practice population and to investigate the extent to which fundholding has been responsible for any changes in prescribing. DESIGN: Analysis of prescribing data (PACT) for the years 1990-1 (before fundholding) and 1993-4 (after fundholding), Use of multiple linear regressions to investigate the variation among practices in total prescribing costs (net ingredient cost per prescribing units), and mean cost per item in each of the two years and also the change in these variables between years. SETTING: Former Mersey region. SUBJECTS: 384 practices. RESULTS: The models developed explained the variation in cost per item (43% of variation explained for 1990-1, 38% for 1993-4) and prescribing volume (34% for 1990-1, 38% for 1993-4) better than the variation in total prescribing costs (3% for 1990-1, 7% for 1993-4). The models developed to explain the change in these variables between years did not explain more than 10% of the variation. Most of the explained variation in the change in total prescribing costs was accounted for by fundholding. Of the pounds 3.71 saved by first wave fundholders compared with non-fundholders pounds 3.57 was attributable to fundholding alone. CONCLUSION: In neither year did fundholding make a major contribution to the variation in prescribing behaviour among practices, which was better explained by deprivation, training status, and partnership status, but it did seem largely responsible for differences in the rise of total prescribing costs between fundholders and non fundholders.     

Age,sex, and temporary resident originated prescribing units (ASTRO-PUs): new weightings for analysing prescribing of general practices in England.

OBJECTIVE--To derive demographic weightings to replace the existing system of prescribing units used in analysing prescribing by general practitioners in England. DESIGN--The prescribing data for one year from a sample of 90 practices in 80 family health service authority areas were used to calculate the relative frequency with which items were prescribed, for each sex, in nine age bands and for temporary residents. Data on the variation in cost per item by age and sex then allowed estimates to be made of the relative costs for these groups. Integer values for both the item based and cost based weightings were obtained by conversion to optimal integer scales. MAIN OUTCOME MEASURES--Item based and cost based weightings for each of the 18 age-sex groups and for temporary residents. The cost based weightings were considered more appropriate to the context in which the new system was to be used. RESULTS--Prescribing costs increased noticeably, for both sexes, in the middle years (ages 35-64). Compared with the existing system, the cost based weightings (ASTRO-PUs) gave greater weight to patients aged 45 and over, especially those in the 55-64 age band, at the expense of younger patients. Children under 5 received twice as many items as those aged 5-14, but the inexpensiveness of their drugs made the cost based weightings of the two groups equal. Similarly, women were generally given more items than men, but at a lower average cost per item, which reduced differences between the sexes in the cost based weightings. Costs for patients aged 75 and over, compared with those aged 65-74, were higher only for women. CONCLUSIONS--The cost based weightings proposed are believed to reflect the present distribution of prescribing costs, in relation to age and sex, in English general practice. They are intended for use in analyses at practice level.     

Consultations in general practice: a comparison of patients' and doctors' satisfaction.

OBJECTIVE--To provide an objective means of assessing patients'' and doctors'' satisfaction with a consultation. DESIGN--Questionnaire study of patients and general practitioners after consultations. SETTING--Urban general practice. SUBJECTS--250 Patients attending consecutive consultations conducted by five general practitioners. MAIN OUTCOME MEASURE--Identification of deficiencies within a consultation as perceived by both doctors and patients. RESULTS--The doctor''s and patient''s questionnaires for each consultation were matched and the results analysed on a group basis. The response rate for individual questions was high (81-89%). The doctors and patients significantly disagreed about the doctors'' ability to assess and put patients at ease, to offer explanations and advice on treatment, and to allow expression of emotional feelings and about the overall benefit that the patients gained from the consultation. In all cases of disagreement the doctor had a more negative view of the consultation than the patient. CONCLUSIONS--The results of giving structured questionnaires on consultations to both patients and doctors could be a useful teaching tool for established doctors or those in training to improve the quality and sensitivity of care they provide.     

Junior doctors' on call activities: differences in workload and work patterns among grades.

OBJECTIVE--To examine the workload and work patterns of junior doctors of all grades while on call. DESIGN--Pilot study of activity data self recorded by junior doctors, with the help of students during busy periods. SETTING--A general surgical firm and a general medical firm based at University Hospital, Nottingham. SUBJECTS--Four registrars, three senior house officers, and five preregistration house officers. RESULTS--Senior house officers and preregistration house officers spent nearly half of all their on call duty time working, but less than half of that time was spent in direct contact with patients. Registrars were on call more often than the house officers but spent less than one fifth of their on call duty time working, and almost two thirds of that time was spent in direct contact with patients. CONCLUSIONS--Workload while on duty is excessive for both senior and preregistration house officers. Changes in some administrative procedures and employment of more non-medical staff during on call periods might reduce the time spent on non-clinical activities, thereby reducing the overall workload and allowing more time for patient contact.     

Hospital admissions for asthma in east London: associations with characteristics of local general practices,prescribing, and population.

OBJECTIVE: To determine the relative importance of appropriate prescribing for asthma in explaining high rates of hospital admission for asthma among east London general practices. DESIGN: Poisson regression analysis describing relation of each general practice''s admission rates for asthma with prescribing for asthma and characteristics of general practitioners, practices, and practice populations. SETTING: East London, a deprived inner city area with high admission rates for asthma. SUBJECTS: All 163 general practices in East London and the City Health Authority (complete data available for 124 practices). MAIN OUTCOME MEASURES: Admission rates for asthma, excluding readmissions, for ages 5-64 years; ratio of asthma prophylaxis to bronchodilator prescribing; selected characteristics of general practitioners, practices, and practice populations. RESULTS: Median admission rate for asthma was 0.9 (range 0-3.6) per 1000 patients per year. Higher admission rates were most strongly associated with small size of practice partnership: admission rates of singlehanded and two partner practices were higher than those of practices with three or more principals by 1.7 times (95% confidence interval 1.4 to 2.0, P < 0.001) and 1.3 times (1.1 to 1.6, P = 0.001) respectively. Practices with higher rates of night visits also had significantly higher admission rates: an increase in night visiting rate by 10 visits per 1000 patients over two years was associated with an increase in admission rates for asthma by 4% (1% to 7%). These associations were independent of asthma prescribing ratios, measures of practice resources, and characteristics of practice populations. CONCLUSIONS: Higher asthma admission rates in east London practices were most strongly associated with smaller partnership size and higher rates of night visiting. Evaluating ways of helping smaller partnerships develop structured proactive care for asthma patients at high risk of admission is a priority.     

Effect of medicolegal liability on patterns of general and family practice in Canada.

As part of the Federal/Provincial/Territorial Review on Liability and Compensation Issues in Health Care, in 1988 we surveyed Canadian general practitioners and family physicians to determine the effect of liability concerns on their practices in the previous 5 years. Questionnaires were sent to a random, stratified national sample of 1295 physicians, with a response rate of 64.6%. However, a high proportion of the returned questionnaires were ineligible because the physicians were not in general or family practice, were not involved in direct patient care, or had died or moved; thus, the corrected response rate was 50.8%. The newsletter of the Canadian Medical Protective Association was the source of information on liability most frequently cited (by 88.1% of the physicians) and most influential (to 62.4%). Only 15.5% of the physicians cited personal involvement with medicolegal issues as a source of information; the rate was higher for Ontario physicians and those in urban areas generally. A total of 74.6% of the respondents had altered their style of practice in the previous 5 years, and 56.3% reported changes in the scope of their practice. Concern about litigation was the most important reason for changing style of practice and reducing or eliminating administration of anesthesia, whereas lifestyle and other issues along with liability concerns most influenced decisions to reduce obstetric care and emergency department work. Our findings suggest that physicians'' perceptions of liability issues have had a profound influence on primary care practice in Canada in the past several years.     

Theory of the effects of population structure and sampling on patterns of linkage disequilibrium applied to genomic data from humans

We develop predictions for the correlation of heterozygosity and for linkage disequilibrium between two loci using a simple model of population structure that includes migration among local populations, or demes. We compare the results for a sample of size two from the same deme (a single-deme sample) to those for a sample of size two from two different demes (a scattered sample). The correlation in heterozygosity for a scattered sample is surprisingly insensitive to both the migration rate and the number of demes. In contrast, the correlation in heterozygosity for a single-deme sample is sensitive to both, and the effect of an increase in the number of demes is qualitatively similar to that of a decrease in the migration rate: both increase the correlation in heterozygosity. These same conclusions hold for a commonly used measure of linkage disequilibrium (r(2)). We compare the predictions of the theory to genomic data from humans and show that subdivision might account for a substantial portion of the genetic associations observed within the human genome, even though migration rates among local populations of humans are relatively large. Because correlations due to subdivision rather than to physical linkage can be large even in a single-deme sample, then if long-term migration has been important in shaping patterns of human polymorphism, the common practice of disease mapping using linkage disequilibrium in "isolated" local populations may be subject to error.     

Patients' and general practitioners' satisfaction with information given on discharge from hospital: audit of a new information card.

OBJECTIVE--To determine the attitudes of patients discharged from hospital and their general practitioners to a new information card giving details about admission, diagnosis, and treatment and to assess the completeness of the information on the card. DESIGN--Consecutive patients discharged from the care of three consultant physicians over 16 weeks. SETTING--One general medical ward in a large teaching hospital. PATIENTS--A total of 275 consecutive discharges of 258 patients were studied. The mean age of patients was 60 years and mean duration of admission five days. INTERVENTION--At discharge from the ward all study patients received an information card and a copy of the card in the form of an interim discharge letter to be delivered to their general practitioner. Patients and general practitioners were asked to complete a questionnaire giving their views on the legibility, helpfulness, quality, and quantity of the information they received. Copies of all the information cards were scrutinised for completeness. MAIN RESULTS--The results were based on 208 (76%) forms returned by patients and 214 (78%) forms returned by general practitioners. Information was considered very helpful or quite helpful according to 170 (83%) forms from patients and 197 (92%) forms from general practitioners; sufficient information was provided according to 160 and 182 forms. Most patients and nearly all general practitioners thought it was a good idea to provide this information for patients at discharge. According to 125 forms from patients and 188 from general practitioners the information card was very easy or quite easy to read; 155 patients had read it at least twice and 149 were likely to refer to it again. OTHER RESULTS--The written information about the patient, the diagnosis, and what the patient had been told was generally well completed, although the date of discharge was omitted from 42 (15%) cards. Details of drugs prescribed at discharge were generally thorough. CONCLUSIONS--Giving an information card to all patients at discharge was feasible and favoured by most patients and their general practitioners. Having made minor changes in design, we think that we have produced an information card that is a convenient size and will improve communication between patients, their general practitioners, and hospital doctors. We now issue this card routinely to all patients discharged from our ward and hope that it might be widely adopted.     

Comparison of 'model-free' and 'model-based' linkage statistics in the presence of locus heterogeneity: single data set and multiple data set applications

Earlier work [Knapp et al.: Hum Hered 1994;44:44-51] focusing on affected sib pair (ASP) data established the equivalence between the mean test and a test based on a simple recessive lod score, as well as equivalences between certain forms of the maximum likelihood score (MLS) statistic [Risch: Am J Hum Genet 1990;46:242-253] and particular forms of the lod score. Here we extend the results of Knapp et al. [1994] by reconsidering these equivalences for ASP data, but in the presence of locus heterogeneity. We show that Risch's MLS statistic under the possible triangle constraints [Holmans: Am J Hum Genet 1993;52:362-374] is locally equivalent to the ordinary heterogeneity lod score assuming a simple recessive model (HLOD/R); while the one-parameter MLS assuming no dominance variance is locally equivalent to the (homogeneity) recessive lod. The companion paper (this issue, pp 199-208) showed that when considering multiple data sets in the presence of locus heterogeneity, the HLOD can suffer appreciable losses in power. We show here that in ASP data, these equivalences ensure that this same loss in power is incurred by both forms of the MLS statistic as well. The companion paper also introduced an adaptation of the lod, the compound lod score (HLOD/C). We confirm that the HLOD/C maintains higher power than these 'model-free' methods when applied to multiple heterogeneous data sets, even when it is calculated assuming the wrong genetic model.     

Effect of ethnicity and sex on the growth of the axial and appendicular skeleton of children living in a developing country

Bones in the axial and appendicular skeletons exhibit heterogeneous growth patterns between different ethnic and sex groups. However, the influence of this differential growth on the expression of bone mineral content is not yet established. The aims of the present study were to investigate: 1) whether there are ethnic and sex differences in axial and appendicular dimensions of South African children; and 2) whether regional segment length is a better predictor of bone mass than stature. Anthropometric measurements of stature, weight, sitting height, and limb lengths were taken on 368 black and white, male and female 9-year-old children. DXA (dual-energy x-ray absorptiometry) scans of the distal ulna, distal radius, and hip and lumbar spine were also obtained. Analyses of covariance were performed to assess differences in limb lengths, adjusted for differences in stature. Multiple regression analyses were used to assess significant predictors of site-specific bone mass. Stature-adjusted means of limb lengths show that black boys have longer legs and humeri but shorter trunks than white boys. In addition, black children have longer forearms than white children, and girls have longer thighs than boys. The regression analysis demonstrated that site-specific bone mass was more strongly associated with regional segment length than stature, but this had little effect on the overall pattern of ethnic and sex differences. In conclusion, there is a differential effect of ethnicity and sex on the growth of the axial and appendicular skeletons, and regional segment length is a better predictor of site-specific bone mass than stature.     

Positive and negative factors in defensive medicine: a questionnaire study of general practitioners.

OBJECTIVES--(a) To investigate defensive medical practices among general practitioners; (b) to compare any such practices with general practitioners'' understanding of certain aspects of the terms of service and medical negligence and practitioners'' concerns about the risk of being sued or having a complaint lodged. DESIGN--Postal questionnaire survey. Each questionnaire was followed by a reminder. SUBJECTS--500 systematically selected general practitioners on the membership list of the Medical Defence Union. MAIN OUTCOME MEASURES--Answers to questions on defensive medical practices, understanding of certain aspects of the terms of service and medical negligence, and concerns about the risk of being sued or having a complaint lodged. RESULTS--300 general practitioners returned the questionnaire (response rate 60%). 294 (98%) claimed to have made some practice changes as a result of the possibility of a patient complaining. Of the defensive medical practices adopted, the most common (over half of doctors stating likely or very likely) seemed to be increased diagnostic testing, increased referrals, increased follow up, and more detailed patient explanations and note taking. Respondents practised defensive medicine as a possible consequence of concerns about the risks of being sued or having a complaint lodged. This association was particularly strong for negative defensive practices. Defensive medical practice did not correlate with any misunderstanding about the law of negligence or the general practitioners'' terms of service. CONCLUSIONS--General practitioners are practising defensive medicine. Some defensive practices such as increased patient explanations or more detailed note taking are clearly beneficial. However, implementing the findings of the Wilson report may increase negative defensive medical practices.     

Effect of protons on the amidase activity of human alpha-thrombin. Analysis in terms of a general linkage scheme

The amidase activity of human alpha-thrombin has been studied in the pH range 5.5 to 10, and at four different chloride concentrations from 5 mM to 1 M. The Michaelis-Menten constant, Km, shows a bell-shaped dependence over the pH range studied, with a minimum around pH 8. The pH dependence of the catalytic constant, kcat, shows multiple inflection points especially at low (less than 0.1 M) chloride concentrations, thereby implicating the existence of multiple catalytic forms of the enzyme. A general linkage scheme is proposed for the analysis of the effect of protons on thrombin amidase activity, and experimental data have globally been analysed over the entire pH range in terms of such a scheme. Four proton-linked ionizable groups seem to be involved in the control of thrombin amidase activity. Two of these groups change their pK value upon substrate binding to the enzyme and account for the pH dependence of Km. All four groups control the catalytic activity of the enzyme which decreases with increasing protonation. Chloride has little effect on Km, while kcat changes significantly at pH less than 8. This effect is due to an increased enzymatic activity of the highly protonated intermediates at high chloride concentrations, as well as to the pK shift of two proton-linked ionizable groups.     

Genetic counseling in rare syndromes: a resampling method for determining an approximate confidence interval for gene location with linkage data from a single pedigree.

Multipoint linkage analysis is a powerful method for mapping a rare disease gene on the human gene map despite limited genotype and pedigree data. However, there is no standard procedure for determining a confidence interval for gene location by using multipoint linkage analysis. A genetic counselor needs to know the confidence interval for gene location in order to determine the uncertainty of risk estimates provided to a consultant on the basis of DNA studies. We describe a resampling, or "bootstrap," method for deriving an approximate confidence interval for gene location on the basis of data from a single pedigree. This method was used to define an approximate confidence interval for the location of a gene causing nonsyndromal X-linked mental retardation in a single pedigree. The approach seemed robust in that similar confidence intervals were derived by using different resampling protocols. Quantitative bounds for the confidence interval were dependent on the genetic map chosen. Once an approximate confidence interval for gene location was determined for this pedigree, it was possible to use multipoint risk analysis to estimate risk intervals for women of unknown carrier status. Despite the limited genotype data, the combination of the resampling method and multipoint risk analysis had a dramatic impact on the genetic advice available to consultants.     

Estimating herbaceous aboveground biomass in Sahelian rangelands using Structure from Motion data collected on the ground and by UAV

Herbaceous aboveground biomass (HAB) is a key indicator of grassland vegetation and indirect estimation tools, such as remote sensing imagery, increase the potential for covering larger areas in a timely and cost‐efficient way. Structure from Motion (SfM) is an image analysis process that can create a variety of 3D spatial models as well as 2D orthomosaics from a set of images. Computed from Unmanned Aerial Vehicle (UAV) and ground camera measurements, the SfM potential to estimate the herbaceous aboveground biomass in Sahelian rangelands was tested in this study. Both UAV and ground camera recordings were used at three different scales: temporal, landscape, and national (across Senegal). All images were processed using PIX4D software (photogrammetry software) and were used to extract vegetation indices and heights. A random forest algorithm was used to estimate the HAB and the average estimation errors were around 150 g m⁻² for fresh mass (20% relative error) and 60 g m⁻² for dry mass (around 25% error). A comparison between different datasets revealed that the estimates based on camera data were slightly more accurate than those from UAV data. It was also found that combining datasets across scales for the same type of tool (UAV or camera) could be a useful option for monitoring HAB in Sahelian rangelands or in other grassy ecosystems.     

Close linkage between bovine prolactin and BoLA-DRB3 genes: genetic mapping in cattle by single sperm typing.

The major histocompatibility complex and prolactin (PRL) genes are syntenic in humans and cattle but the genetic distance between these loci has not been determined for either species. In this study, the sperm typing technique was used to measure the recombination frequency between the bovine lymphocyte antigen (BoLA)-DRB3 and PRL loci. A total of 300 sperm were typed from one doubly heterozygous bull for segregation of DRB3 and PRL alleles. Sperm typing was performed using the polymerase chain reaction (PCR) and restriction enzyme cleavage of the PCR products, followed by resolution of the restriction fragments in polyacrylamide gels. Digestion with the restriction endonuclease RsaI allowed the unambiguous discrimination of alleles for both loci. The maximum likelihood estimation of the recombination fraction theta = 0.04, with a 95% confidence interval of 0.01 to 0.07. Close linkage between PRL and DRB3 has important implications for marker-assisted selection in animal breeding since PRL has been shown to be closely linked to a locus that affects milk yield, and BoLA loci influence susceptibility to a number of infectious diseases. Our results demonstrate the general applicability of the sperm typing procedure for gene mapping in species other than humans and provide an example of how parallel efforts to map the genomes of agriculturally important species of animals can have a positive impact on the development of a primary human linkage map.