Randomised controlled trial comparing cost effectiveness of general practitioners and nurse practitioners in primary care

OBJECTIVE

To compare the cost effectiveness of general practitioners and nurse practitioners as first point of contact in primary care.

DESIGN

Multicentre randomised controlled trial of patients requesting an appointment the same day.

SETTING

20 general practices in England and Wales.

PARTICIPANTS

1716 patients were eligible for randomisation, of whom 1316 agreed to randomisation and 1303 subsequently attended the clinic. Data were available for analysis on 1292 patients (651 general practitioner consultations and 641 nurse practitioner consultations).

MAIN OUTCOME MEASURES

Consultation process (length of consultation, examinations, prescriptions, referrals), patient satisfaction, health status, return clinic visits over two weeks, and costs.

RESULTS

Nurse practitioner consultations were significantly longer than those of the general practitioners (11.57 v 7.28 min; adjusted difference 4. 20, 95% confidence interval 2.98 to 5.41), and nurses carried out more tests (8.7% v 5.6% of patients; odds ratio 1.66, 95% confidence interval 1.04 to 2.66) and asked patients to return more often (37. 2% v 24.8%; 1.93, 1.36 to 2.73). There was no significant difference in patterns of prescribing or health status outcome for the two groups. Patients were more satisfied with nurse practitioner consultations (mean score 4.40 v 4.24 for general practitioners; adjusted difference 0.18, 0.092 to 0.257). This difference remained after consultation length was controlled for. There was no significant difference in health service costs (nurse practitioner 18.ll pound sterling v general practitioner 20.70 pound sterling adjusted difference 2.33 pound sterling - 1.62 pound sterling to 6.28 pound sterling).

CONCLUSIONS

The clinical care an health service costs of nurse practitioners and general practitioners were similar. If nurse practitioners were able to maintain the benefits while reducing their return consultation rate or shortening consultation times, they could be more cost effective than general practitioners.

Gender and cancer support group participation

PURPOSE

Although support groups are offered to many patients who have received a diagnosis of cancer, a majority of patients choose not to participate. This article reports the results of a study comparing the behavior of men diagnosed with prostate cancer and women diagnosed with breast cancer in their responses to invitations to participate in support groups.

DESCRIPTION OF STUDY

One hundred thirty women with breast cancer and 87 men with prostate cancer completed a structured telephone interview. The interview included questions about the patients' choices about support group participation.

RESULTS

Interview findings showed that men are less likely to join a support group, but those men who do join attend meetings for about 1 year, as do the women who join. Men and women cite essentially the same reasons for participation: to learn more about their diagnosis, to share their, concerns to compare their physical and emotional progress with other individuals.

CLINICAL IMPLICATIONS

These results indicate the need for further exploration of effective interventions for men and women who have been diagnosed with prostate and breast cancer, respectively, in an effort to offer support for the difficult psychological and emotional issues associated with their diagnoses. Although more women than men join support groups, the majority of both populations (67% for women, 87% for men) do not attend any support group meetings. Innovative approaches are needed to encourage participation in existing support groups or to design alternative interventions.

Hitting up in the top end: characteristics of needle exchange clients in Darwin

OBJECTIVE

Little is known about injecting drug use (IDU) and blood-borne viral (BBV) infection in rural Australia.

METHOD

These repeat cross-sectional studies were conducted during a two-week period in July and October-November 1998 at the Darwin needle exchange, with 129 and 121 respondents respectively.

RESULTS

The commonest drug of choice was heroin, but the commonest drug injected was morphine. Self-reported sharing of needles and syringes was uncommon. Self-reported serostatus for HIV was high (8% and 11.4% respectively), but seemingly mostly associated with sexual rather than IDU risk; for hepatitis C (HCV) status, these were 54% and 37%. Among IDUs of Aboriginal or Torres Strait Islander (ATSI) background, who made up 14% of the first round respondents, patterns of IDU and of BBV infection were the same as among non-ATSI respondents.

CONCLUSIONS

These surveys reveal patterns of IDU in Darwin that have both similarities and differences with those in the major urban centres in Australia. In the absence of a comprehensive methadone maintenance program, many participate in a more or less informal morphine substitution program. HIV is present among these IDUs, and the risks of further sexual transmission may be high.

IMPLICATIONS

These surveys confirm the presence among injecting drug users in Darwin of HIV, HBV and HCV, and of the risk for further spread of these viruses. Control of blood-borne virus transmission among IDUs requires an even greater commitment to abolishing sharing of needles and syringes, and therefore continued support and enhancement of needle and syringe availability.

Universal precautions: improving the knowledge of trained nurses

Universal precautions relate to the management of blood-borne viruses such as human immunodeficiency virus (HIV) and hepatitis B and C. Advice on the transmission of blood-borne viruses and the precautionary measures used to reduce or eliminate cross-infection have been addressed by national and professional bodies. There is a significant amount of research which assesses trained nurses' knowledge of universal precautions and includes understanding of the transmission routes of blood-borne viruses and the measures required to prevent cross-infection. However, the majority of the literature indicates an incomplete knowledge among trained nurses of the principles and application of universal precautions. The ability of the trained nurse to fulfil his/her role as health educator, teacher and therefore effective infection control practitioner is questioned by the literature. This article discusses the role of education in improving the knowledge of trained nurses and considers the implementation of in-service training and preregistration education.

Assessment of muscle oxygenation in the horse by near infrared spectroscopy

This study examined the ability of near infrared spectroscopy (NIRS) to noninvasively determine changes to muscle oxygenation in the resting horse. Five horses had (NIRS) performed over extremity muscle while under general anaesthesia, first with 8 min limb ischaemia, then systemic hypoxaemia for 5 min. A second group of 6 awake horses had NIRS performed over extremity muscle while being administered hypoxic gas (F(I)O2 0.10) for 5 min, and after return to steady state, limb ischaemia was induced for an additional 5 min. In the anaesthetised horses' ischaemia induced marked and significant muscle deoxygenation of haemoglobin/myoglobin (P<0.01), with corresponding arterial saturation decreasing from 98.9 to 81.9%. Hypoxaemia induced small yet significant muscle deoxygenation (P<0.01) that was 3.2% of the ischaemia deoxygenation signal, with a corresponding decrease in arterial saturation from 98.6 to 90.4%. In the awake horses muscle deoxygenation was not detectable during hypoxia despite reduction of arterial saturation from 97.8 to 86.8%, whereas ischaemia induced rapid and significant deoxygenation of muscle (P<0.05), with corresponding reduction of venous saturation from 78.4 to 75.4%. In neither group of horses was there evidence of cytochrome aa3 reduction, despite complete ischaemia for up to 8 min. NIRS changes in the resting horse muscle clearly differed between ischaemia and hypoxaemia, and can readily show muscle deoxygenation in clinically relevant hypoxaemia in the horse under anaesthesia. Further, as the deoxygenation signal induced by ischaemia was clearly detectable above a background movement artefact, NIRS application to study of muscle oxygenation in the working horse should be explored.

Development of a protocol for the automated analysis of amino acids in brain tissue samples and microdialysates

An automated precolumn derivatisation method has been developed for the measurement of fourteen amino acids in brain tissue and microdialysate samples. The method involves labelling amino acids with naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide (CN-). The resulting highly stable N-substituted 1-cyanobenz[f]isoindole (CBI) derivatives were separated using a binary gradient elution profile and detected fluorometrically. The order of elution of the derivatised amino acids was confirmed by using liquid chromatography with fluorescence and mass spectrometric detection in tandem. Linear calibration plots were obtained for all amino acids in the range studied (0.2-12.5 microM). The limit of detection for CBI derivatives of amino acids was in the range 5-20 fmol (S/N=2) using a 5 microl injection volume. The method has been used for the measurement of amino acids in microdialysates from rat brain and tissue homogenates from different regions of mouse brain.

Optical properties of human trabecular meshwork in the visible and near-infrared region

BACKGROUND AND OBJECTIVES

Despite disparate treatment parameters, similar success in laser trabeculoplasty (LT) is attained using the argon (514.5 nm) and diode (810 nm) laser. However, the mechanism of this success remains unresolved. To further understand LT, this study characterizes the optical properties of trabecular meshwork (TM).

STUDY DESIGN/MATERIALS AND METHODS

Reflectance was measured from 10 TM samples over wavelengths of 400-820 nm, using an integrating sphere/spectrophotometer. Corrections were made for reflections at boundaries of refractive index mismatch. Kubelka-Munk coefficients were calculated and converted to linear transport coefficients.

RESULTS

Scattering greatly dominated absorption. The scattering and absorption coefficients were, respectively, 141.20 +/- 15.80 cm(-1) and 4.89 +/- 1.95 cm(-1) at 514.5 nm, and 94.44 +/- 15.03 cm(-1) and 0.0874 +/- 0.111 cm(-1) at 810 nm (estimated anisotropy of 0.90). The corresponding penetration depths (1/e) were 69 microm (514.5 nm) and 106 microm (810 nm).

CONCLUSION

The absorption coefficient of 514 nm energy is two orders of magnitude greater than 810 nm energy, while scattering coefficients are much closer. The fluence used at 514.5 nm is higher at the surface than that at 810 nm, but falls below it deep within the TM due to the differential absorption. Therefore, similar initial therapeutic effects are obtained with 810 nm using less total absorbed energy. Thermal damage resultant from excess energy deposited at 514.5 nm may be related to the lack of success in repeat argon LT, pointing out the need for studies of repeat diode LT.

The implications of variation in outcome between health professionals for the design and analysis of randomized controlled trials

Methodological work on randomized trials has largely concerned pharmacological interventions in which the effects of the attending health professional may be regarded as minor. In other clinical settings, such as surgery, talk or physical therapies, staff specific variation may make generalization problematic, undermining the value of the trial. Such variation has been the basis of some objections to controlled trial methodology and non-acceptance of trial results. The implication of this source of variation will be considered for studies in which different types of health professional deliver the intervention in each arm of the trial. Such a trial may involve individual patient or group randomization. Whichever method is used, it is argued that variation in outcome between health professionals may lead to design effects. These issues will be illustrated using data from a large trial comparing primary care service delivered by two types of medical doctor. Random effect models are most suitable for analyzing this type of trial, as they allow adjustment for patient characteristics whilst controlling for design effects. This type of model illustrates that there can be substantial variation in the performance within each category of doctor.

Have we reached the therapeutic ceiling in acute myocardial infarction?

Despite the recent introduction of several new agents into the fibrinolytic market, none have proven more efficacious than earlier agents. However, new routes of administration may provide some benefit in terms of time to treatment and ease of administration. The best possibility for breaking the therapeutic ceiling is in finding new ways to use fibrinolytic agents, such as combination therapy with GP IIb/IIIa inhibitors and low-molecular-weight heparin. Use with PCI may decrease mortality rates in some patient groups. Prehospital administration of fibrinolytics is also an option for expediting care and improving outcomes.

Magma intrusion beneath long valley caldera confirmed by temporal changes in gravity

Precise relative gravity measurements conducted in Long Valley (California) in 1982 and 1998 reveal a decrease in gravity of as much as -107 +/- 6 microgals (1 microgal = 10(-8) meters per square second) centered on the uplifting resurgent dome. A positive residual gravity change of up to 64 +/- 15 microgals was found after correcting for the effects of uplift and water table fluctuations. Assuming a point source of intrusion, the density of the intruding material is 2.7 x 10(3) to 4.1 x 10(3) kilograms per cubic meter at 95 percent confidence. The gravity results require intrusion of silicate magma and exclude in situ thermal expansion or pressurization of the hydrothermal system as the cause of uplift and seismicity.

Enhancement of 5-HT1B and 5-HT1D receptor antagonist effects on extracellular 5-HT levels in the guinea-pig brain following concurrent 5-HT1A or 5-HT re-uptake site blockade

The effects of selective serotonin re-uptake inhibitor (SSRI), paroxetine, and 5-HT1A, 5-HT1B and 5-HT1B/1D receptor antagonists on in vivo extracellular 5-HT levels in the guinea-pig frontal cortex and dorsal hippocampus were investigated using the technique of microdialysis. The aim of the study was to further investigate the autoreceptor roles of the 5-HT1A, 5-HT1B and 5-HT1D receptors in the median vs dorsal raphe nuclei. In the frontal cortex, 5-HT1A (WAY 100635, 1 mg/kg i.p.) or 5-HT1B (SB-224289, 4 mg/kg i.p.) receptor antagonists had no effect on extracellular levels of 5-HT, whilst the mixed 5-HT1B/1D receptor antagonist (GR 127935, 0.3 mg/kg i.p) produced a significant decrease in extracellular 5-HT levels. Paroxetine (10 microM) significantly increased extracellular 5-HT levels when perfused locally into the cortex. Administration of SB-224289, followed 120 min later by WAY 100635, had no effect on extracellular 5-HT levels. In contrast, sequential administration of either WAY 100635 and GR 127935, or SB-224289 and paroxetine significantly increased extracellular 5-HT levels. In the dorsal hippocampus, whilst 5-HT1A receptor antagonism elicited by administration of WAY 100635 had no effect, both 5-HT1B and mixed 5-HT1B/1D receptor blockade significantly increased extracellular 5-HT levels. Administration of SB-224289 followed 120 min later with WAY 100635, or WAY 100635 followed 30 min later with GR 127935, potentiated the effect of the three compounds alone, significantly increasing extracellular 5-HT levels. These data demonstrate that to simultaneously increase extracellular 5-HT in both frontal cortex and dorsal hippocampus of the guinea-pig brain concurrent 5-HTA1A, 5-HT1B and 5-HT1D receptor blockade is required. Whereas in the dorsal hippocampus, 5-HT1B receptor blockade is sufficient to elicit an increase in extracellular 5-HT levels.

Maternal uniparental isodisomy for chromosome 14 detected prenatally

Maternal uniparental disomy (UPD) for chromosome 14 (upd(14)mat) has been associated with a distinct phenotype. We describe the first case of maternal uniparental isodisomy for chromosome 14 detected prenatally, in a pregnancy with mosaicism for trisomy 14 observed in both a chorionic villus sample (CVS) and in amniocytes. Detailed analysis of polymorphic microsatellites showed that the fetus was essentially isodisomic for one of the mother's chromosomes 14 and that recombination had introduced a mid-long arm region of heterodisomy. The fetus, which died in utero at 18 weeks, showed no apparent pathological features. The case demonstrates for the first time a maternal meiosis II non-disjunction of chromosome 14 leading to a trisomic conception which has been incompletely corrected by 'rescue' in the early embryo.

Near infrared spectroscopy in large animals: optical pathlength and influence of hair covering and epidermal pigmentation

The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues at four wavelengths in the NIR range were subsequently determined. Black hair covering and black or dark-coloured hooves prevented NIR light from penetration sufficient for conduction of pathlength or NIR spectroscopy measurements. Non-pigmented hair covering of the head did not appear to be a barrier to successful NIR light transmission. Tissues sufficiently transparent to NIR light had the differential pathlength factor (DPF, i.e. the ratio of the observed light pathlength and the geometric light source-detector separation) of NIR light determined by intensity modulated spectroscopy at the wavelengths 744, 806, 834 and 860 nm. Horse gluteal muscles had DPFs of 6.2, 6.2, 6.0, and 5.6, whereas forelimb muscles had DPF of 4.7, 4.4, 4.5 and 3.9 at the respective wavelengths. Sheep heads had DPF of 7.2 +/- 0.3, 5.8 +/- 0.5, 5.5 +/- 0.4 and 4.4 +/- 0.6 (+/- SEM) for the above respective wavelengths, of which the pathlengths all differed significantly from the other, except for between 806 and 834 nm, and 834 and 860 nm. The DPF of horse hooves were 4.8 +/- 0.1, 4.8 +/- 0.1, 4.7 +/- 0.1 and 4.4 +/- 0.1 (SEM) for the above noted wavelengths, of which the pathlength at 744 and 806 nm differed from the pathlength at 860 nm (P>0.05). These results show that NIRS is possible through lighter pigmented hair and epidermal tissues, and provide DPFs of horse feet and muscle and the sheep head that enables quantitative NIRS in these species

The Wisdom Project: virtual education in primary care

This article examines the development of the Wisdom Project, a pilot for the teaching of informatics to primary health care professionals, using an original educational model based on e-mail and Web pages. The article begins by placing the development of the Wisdom Project in the context of changes in medical education and training. The aims and objectives of Wisdom are outlined, and the methodologies for setting up and evaluating the project are described. The article then presents the results of the evaluation, including the identification of significant improvements in knowledge of CD ROMs (P = 0.01), e-mail (P = 0.03), Medline (P = 0.02), operating systems (P = 0.02), Web browsers (P = 0.003) and word processing (P = 0.03). Improvements in evidence-based practice (EBP) did not reach significance. Finally, a number of conclusions are presented, considering the lessons learnt for the future development of such projects.

Modelling method comparison data

We explore a range of linear regression models that might be useful for either: (a) the relative calibration of two or more methods or (b) to evaluate their precisions relative to each other. Ideally, one should be able to use a single data set to carry out the jobs (a) and (b) together. Throughout this review we consider the constraints (assumptions) needed to attain identifiability of the models and the possible pitfalls to the unwary in having to introduce them. We also pay particular attention to the possible problems arising from the presence of random matrix effects (reproducible random measurement 'errors' that are characteristic of a given method when being used on a given specimen or sample, i.e. specimen specific biases or subject by method interactions). Finally, we stress the importance of a fully-informative design (using replicate measurements on each subject using at least three independent methods) and large sample sizes.

The WISDOM project: training primary care professionals in informatics in a collaborative 'virtual classroom'

OBJECTIVES

The WISDOM project applies Internet technologies to create a virtual classroom in health informatics for primary care professionals. Participants use a facilitated E-mail discussion list supported by a web site which provides on-line resources and an archive of teaching materials.

DESIGN

The project took an adult-learning model in which participants identify their learning needs, emphasized using informatics skills in practice, and focused on skills likely to enhance evidence-based practice. The paper describes the project and an evaluation of the first programme which ran in 1997 with 28 participants. Pre- and post-intervention questionnaires were used to assess perceived skills in informatics and evidence-based practice.

SETTING

University of Sheffield.

SUBJECTS

Primary care professionals.

RESULTS

Participants reported statistically significant increases in eight informatics skills. There were no significant changes in evidence-based practice skills. The web-site, seminar programme and discussion list were highly rated as useful in delivering informatics training.

CONCLUSIONS

The WISDOM approach is effective for the delivery of informatics training to primary care professionals, and may be used more widely for other subjects and professional groups. There is a need for further research into facilitating virtual classrooms.

Retention of young general practitioners entering the NHS from 1991-1992

BACKGROUND

The supply of general practitioners (GPs) in the National Health Service (NHS) is dynamic and there are fears that there will be an inadequate number of doctors to meet the needs of the NHS. There are particular concerns about changes in the career trajectory of young GPs and what they mean for overall supply.

AIM

To identify predictors of retention among young, new entrant GPs entering the NHS between 1 October 1991 and 1 October 1992.

METHOD

Two-year retention rates of young (35 years of age or less) new entrant GPs have been modelled using a multilevel logit model. Retention is defined as young, new entrant GPs remaining in their initial health authority for two years or more.

RESULTS

Two hundred and fifty-two (13.0%) members of the study group left general practice within two years of entry (i.e. were not retained). Sex (females had lower retention [95% CI = 0.43-0.75]), practice size (young GPs in larger practices had higher retention [95% CI = 1.10-1.29]), and belonging to a practice in one of 16 Greater London Health Authorities (which had lower retention [95% CI = 0.39-0.82]) were identified as major predictors of retention. Deprivation, measured at the individual GP patient list level, had a very slight association with retention (P = 0.097; 95% CI = 1.00-1.02). Deprivation measured at the health authority level (95% CI = 0.99-1.01) was not found to be a statistically significant predictor of retention (P = 0.83).

CONCLUSION

None of the statistically significant predictors of retention suggest any policy panacea to end this phenomenon. The challenge for policy is to learn to deal with the dynamic nature of the GP workforce with a non-crisis mentality.