Search PubMed⌕ Search

Biomedical subjects

J Henderson

Publications and source records attributed to J Henderson.

At least 55 records · Page 3Linked to original sources
PubMed2001

Hypertension treatment patterns in American Indians: the strong heart study.

Pharmacologic treatment patterns for hypertensive American Indians from 13 communities in Arizona, Oklahoma, South Dakota, and North Dakota were assessed. Participants (2254 women and 1384 men, aged 48 to 79 years) completed a clinical examination between July 1993 and December 1995. The mean of two blood pressure (BP) measurements and detailed medication histories were obtained. The observed prevalence of hypertension was 46.7% (n=1698). In participants taking antihypertensive medications (n=1114), four principal drug classes were evaluated: diuretics, calcium channel blocking agents, beta-blocking agents, and angiotensin-converting enzyme (ACE) inhibitors. Among treated hypertensive participants, 71.4%, 24.6%, and 4.0% received one, two, and three medications, respectively. Among single drug regimens, ACE inhibitors (n=340) were used most often (49.4%), with calcium channel blocking agents and diuretics accounting for 24.2% and 19.9%, respectively. Although multiple drug class therapies varied, the combination of a diuretic and ACE inhibitor (n=120) accounted for 47.4% of dual therapy use. Hypertension control (SBP < 140 mm Hg, DBP < 90 mm Hg) rates were highest for those on dual therapies (65.4%), followed by participants on single (53.8%) and triple (43.6%) therapies. Among monotherapies, diuretics exhibited the best overall hypertension control rate in both diabetics (63.0%) and nondiabetics (68.0%), versus 47% to 61% for other remaining agents. The frequent use of ACE inhibitors, used singly or in combination, reflects the high prevalence of diabetes among American Indians. ACE inhibitors, combined with diuretics, were particularly useful in achieving BP control in this population.

Age Factors↗
PubMed2001

Economic aspects of caesarean section and alternative modes of delivery.

Increases in caesarean section rates worldwide have raised questions about the economic implications of caesarean section and alternative modes of delivery. This chapter reviews economic aspects of caesarean section and alternative modes of delivery and identifies areas where further research is required. The chapter presents the results of a systematic review of the literature and analyses of three large observational data sets. It provides evidence for the cost of labour and delivery, the cost of the postnatal stay and the cost of the long-term health consequences of alternative modes of delivery. The chapter highlights the paucity of methodologically robust economic analyses in this area of health care and concludes that primary research is required to estimate the cost and utilization of services attributable to caesarean section and alternative modes of delivery. Future research studies should recognize the long-term health service costs and the costs that arise outside the health service, which are likely to vary according to mode of delivery.

Cesarean Section↗
PubMed2001

Learning, changing and managing in mental health.

This paper draws on research which considers the implications for practitioners and managers of implementing new ideas for practice gained from learning and education in mental health in the UK. Using a questionnaire survey followed by eight semi-structured interviews, the research set out to identify the issues facing workers trying to implement change in the workplace as a result of new learning gained from study of an Open University mental health course. The paper argues that much management literature on change within organisations is problematic in this specific context. This is largely because it takes insufficient account of the complexities surrounding work within social care (particularly mental health). Findings show that workers who have undertaken learning in mental health often feel disempowered and isolated when attempting to introduce new ideas for practice into the workplace. The first line manager operates at the intersection of practice and learning and has a key role in enabling and supporting staff through practice as well as service change and professional development. This paper locates the distance learning experience within a wider framework of student/practitioner support, and explores the role of the first line manager in supporting and enabling staff.

Education, Distance↗
PubMed2001

Risk factor associations with wheezing patterns in children followed longitudinally from birth to 3(1/2) years.

BACKGROUND: There is a paucity of detailed longitudinal data on wheeze in early childhood. Not all children who wheeze in early infancy will continue to wheeze into childhood and beyond. This study aims to investigate possible risk factors for different patterns of wheeze in the pre-school years. SUBJECTS AND METHODS: Study participants were part of the Avon Longitudinal Study of Parents and Children (ALSPAC). Maternal reports of child wheeze between birth and 6 months and again between 30 and 42 months were gathered prospectively. Children were categorized into early wheeze, persistent wheeze or late onset wheeze. A large number of risk factors were assessed for each wheezing phenotype using multivariable logistic regression models. RESULTS: Over 70% of children who wheezed in the first 6 months did not wheeze 3 years later. Wheezing between 0-6 months was independently associated with the presence of older siblings, male sex, delivery between April and December, bottle feeding, young maternal age, prenatal tobacco smoke exposure, atopy and parental history of asthma. From within this group of early wheezers, risk factors for wheeze that persisted beyond 6 months included pre-term delivery, young maternal age, living in rented local authority housing, atopy and a maternal (not paternal) history of asthma. Atopy and a family history of asthma emerged as the main predictors of wheeze that developed after 6 months of age. CONCLUSION: It is clear that a number of wheezing syndromes exist by 3(1/2) years, albeit with some degree of overlap. Detailed follow-up of this cohort is underway to determine whether risk factor associations determined in the first 3(1/2) years have long-term significance for the clinical entity termed 'asthma'.

Child, Preschool↗
PubMed2001

Systematic review of economic aspects of alternative modes of delivery.

OBJECTIVE: To carry out a systematic review of the literature relating to economic aspects of alternative modes of delivery. METHODS: A comprehensive literature search of the years 1990-1999 was conducted of electronic and non-electronic sources using a tested search strategy. Papers considered to contain useful cost or resource use data were read in full and classified according to their relevance to the review and their methodological quality. Relevant cost and resource use data were converted to pound sterling and inflated to 1998-1999 price levels. RESULTS: The literature search resulted in 975 papers, 49 of which met criteria for the review. Thirty-two papers were from the USA where the organisation, structure and costs of health care are significantly different from that of other industrialised countries. The aggregate costs of different modes of delivery reported in these American studies were between four and five times higher than costs reported in other studies. The majority of included studies were of poor quality. Data from the better quality studies demonstrated that caesarean section costs a health service substantially more than other modes of delivery. The range of costs of an uncomplicated vaginal delivery were 629 pound sterling - 1,298 pound sterling compared with1,238 pound sterling - 3,551 pound sterling for a caesarean section. However, papers have so far only considered short term health service costs. CONCLUSIONS: Research is required to estimate the cost and resource use attributable to alternative modes of delivery. Future research should investigate the long term health service costs and the costs that arise outside the health service which are likely to vary according to mode of delivery.

Cesarean Section↗
PubMed2001

Home treatment for mental health problems: a systematic review.

OBJECTIVE: This review investigates the effectiveness of 'home treatment' for mental health problems in terms of hospitalisation and cost-effectiveness. For the purposes of this review, 'home treatment' is defined as a service that enables the patient to be treated outside hospital as far as possible and remain in their usual place of residence. METHODS - SYSTEMATIC LITERATURE SEARCH: 'Home treatment' excluded studies focused on day, residential and foster care. The review was based on Cochrane methodology, but non-randomised studies were included if they compared two services; these were only analysed if they provided evidence of the groups' baseline clinical comparability. METHODS - REVIEW OF ECONOMIC EVALUATIONS: Economic evaluations among the studies found were reviewed against established criteria. METHODS - IDENTIFICATION OF SERVICE COMPONENTS: A three-round Delphi exercise ascertained the degree of consensus among expert psychiatrists concerning the important components of community-based services that enable them to treat patients outside hospital. The identified components were used to construct the follow-up questionnaire. METHODS - FOLLOW-UP OF AUTHORS: As a supplement to the information available in the papers, authors of all the studies were followed up for data on service components, sustainability of programmes and service utilisation. METHODS - DATA ANALYSIS: The outcome measure was mean days in hospital per patient per month over the follow-up period. (1) Comparative analysis - compared experimental to control services. It analysed all studies with available data, divided into 'inpatient-control' and 'community-control' studies, and tested for associations between service components and difference in hospital days. (2) Experimental services analysis - analysed only experimental service data and tested for associations between service components and hospital days. RESULTS - SYSTEMATIC LITERATURE SEARCH: A total of 91 studies were found, conducted over a 30-year period. The majority (87) focused on people with psychotic disorders. RESULTS - REVIEW OF ECONOMIC EVALUATIONS: Only 22 studies included economic evaluations. They provided little conclusive evidence about cost-effectiveness because of problems with the heterogeneity of services, sample size, outcome measures and quality of analysis. RESULTS - DELPHI EXERCISE: In all, 16 items were rated as 'essential', falling into six categories: home environment; skill-mix; psychiatrist involvement; service management; caseload size; and health/social care integration. There was consensus that caseloads under 25 and flexible working hours over 7 days were important, but little support for caseloads under 15 or for 24-hour services, and consensus that home visiting was essential, but not on teams being 'explicitly dedicated' to home treatment. RESULTS - RESPONSE TO FOLLOW-UP: A total of 60% of authors responded, supplying data on service components and hospital days in most cases. Other service utilisation data were far less readily available. RESULTS - SERVICE CHARACTERISATION AND CLASSIFICATION: The services were homogeneous in terms of 'home treatment function' but fairly heterogeneous in terms of other components. There was some evidence for a group of services that were multidisciplinary, had psychiatrists as integrated team members, had smaller caseloads, visited patients at home regularly and took responsibility for both health and social care. This was not a cohesive group, however. RESULTS - SUSTAINABILITY OF SERVICES: The sustainability of home treatment services was modest: less than half the services whose authors responded were still identifiable. Services were more likely to be operational if the study had found them to reduce hospitalisation significantly. RESULTS - META-ANALYSIS: Meta-analysis with heterogeneous studies is problematic. The evidence base for the effectiveness of services identifiable as 'home treatment' was not strong. Within the 'inpatient-control' study group, the mean reduction in hospitalisation was 5 days per patient per month (for 1-year studies only). No statistical significance could be measured for this result. For 'community-control' studies, the reduction in hospitalisation was negligible. Moreover, the heterogeneity of control services, the wide range of outcome measures and the limited availability of data might have confounded the analysis. Regularly visiting at home and dual responsibility for health and social care were associated with reduced hospitalisation. Evidence for other components was inconclusive. Few conclusions could be drawn from the analysis of service utilisation data. RESULTS - LOCATION: Studies were predominately from the USA and UK, more of them being from the USA. North American studies found a reduction in hospitalisation of 1 day per patient per month more than European studies. North American and European services differed on some service components, but this was unlikely to account for this finding, particularly as no difference was found in their experimental service results. CONCLUSIONS - STATE OF RESEARCH: There is a clear need for further studies, particularly in the UK. The benefit of home treatment over admission in terms of days in hospital was clear, but over other community-based alternatives was inconclusive. CONCLUSIONS - NON-RANDOMISED STUDIES: Difficulties in systematically searching for non-randomised studies may have contributed to the smaller number of such studies found (35, compared with 56 randomised controlled trials). This imbalance was compounded by a relatively poor response rate from non-randomised controlled trial authors. Including them in the analysis had little effect. CONCLUSIONS - LIMITATIONS OF THIS REVIEW: A broad area was reviewed in order to avoid the problem of analysing by service label. While reviews of narrower areas may risk implying a homogeneity of the services that is unwarranted, the current strategy has the drawback that the studies cover a range of heterogeneous services. The poor definition of control services, however, is ubiquitous in this field, however reviewed areas are defined. Inclusion of mean data for which no standard deviations were available was problematic in that it prevented measuring the significance of the main findings. The lack of availability of this data, however, is an important finding, demonstrating the difficulty in seeking certainty in this area. Only days in hospital and cost-effectiveness were analysed here. The range and lack of uniformity of measures used in this field made meta-analysis of other outcomes impossible. It should be noted, however, that the findings pertain to these aspects alone. The Delphi exercise reported here was limited in being conducted only with psychiatrists, rather than a multidisciplinary panel. Its findings were used as a framework for the follow-up and analysis. Their possible bias should be borne in mind when considering them as findings in themselves. CONCLUSIONS - IMPLICATIONS FOR CLINICIANS: The evidence base for home treatment compared with other community-based services is not strong, although it does show that home treatment reduces days spent in hospital compared with inpatient treatment. There is evidence that visiting patients at home regularly and taking responsibility for both health and social care each reduce days in hospital. CONCLUSIONS - IMPLICATIONS FOR CONSUMERS: Services that visit patients at home regularly and those that take responsibility for both health and social care are likely to reduce time spent in hospital. Psychiatrists surveyed in this review also considered support for carers to be essential. The evidence from this review, however, was that few services currently have protocols for meeting carers' needs. CONCLUSIONS - RECOMMENDATIONS FOR RESEARCH AND COMMISSIONERS: A centrally coordinated research strategy, with attention to study design, is recommended. Studies should include economic evaluations that report health and social service utilisation. Service components should be collected and reported for both experimental and control services. Studies should be designed with adequate power and longer durations of follow-up and use comparable outcome measures to facilitate meta-analysis. Research protocols should be adhered to throughout the studies. It may be advisable that independent researchers conduct studies in future. It is no longer recommended that home treatment be tested against inpatient care, or that small, localised studies replicate existing, more highly powered studies.

Adolescent↗
PubMed2001

Seroprevalence of Neospora caninum in beef cattle in northern Alberta.

Blood samples were collected from 1806 pregnancy-tested cows from 174 herds at a northern Alberta auction mart in the fall of 1998. One hundred sixty-two (9.0%) of these samples were positive for antibodies to N. caninum. Thirty-five of 260 samples (13.5%) collected from the same region in the 1980s were also serologically positive for N. caninum.

Alberta↗
PubMed2001

Reproductive performance of a cow-calf herd following a Neospora caninum-associated abortion epidemic.

This study examines the long-term impact of a Neospora caninum-associated abortion outbreak in a large cow-calf herd in northern Alberta. Blood samples were collected 4 times from all bred females and heifer calves born during the spring before the outbreak: (1) at the time of the outbreak, (2) the following spring, (3) the subsequent fall, and, finally, (4) the second spring after the outbreak. The samples were analyzed using a commercially available enzyme-linked immunosorbent assay for N. caninum. Calves born immediately following the outbreak were also monitored. Individual calving or abortion records were available from all cows for 2 calving seasons. All cows and heifers were pregnancy tested after the 2 subsequent breeding seasons. At the time of the abortion outbreak in 1997, 81% of all bred females and 87% of the heifer calves were serologically positive. In spring 1998, 49% of the cows and 47% of the heifer calves remained positive. In fall 1998, 48% of the remaining cows and heifers were serologically positive. After the first breeding season following the outbreak (1998), 13.5% of the heifers and 22.2% of the cows were open (not pregnant). Animals that were serologically positive in the spring were more likely to be open in the fall (odds ratio, 2.0; 95% confidence interval, 1.1 to 3.7). No subsequent associations with increased risk of abortion, stillbirth, or nonpregnancy were identified.

Abortion, Veterinary↗
PubMed2000

In vitro selection and characterisation of a drought tolerant clone of Tagetes minuta.

Aromatic Tagetes plants produce secondary products which have a biological activity against a wide range of micro-organisms, insects and nematodes. Tagetes oils are also used as pharmaceuticals and as flavour components in the food industry. This study aimed to use somaclonal variation to select drought tolerant plants of Tagetes. Cotyledons cultured on MS medium containing 3 mg l(-1) IAA and 10 mg l(-1) BA (callus growth medium; CGM) with 60 mM mannitol died. Shoot clumps developed on CGM for 6 months and then subcultured onto CGM containing 80 mM mannitol also died. Four shoots were regenerated from 72 shoot clumps on 12 MS medium containing 0.5 mg l(-1) IAA (shoot growth medium; SGM) after culturing on CGM without mannitol for 6 months and then on CGM with 60 mM mannitol for 3 months. Twelve shoots developed from 72 shoot clumps on SGM after culture for 9 months on CGM. Significant variations were observed in biomass amongst regenerated clones when cultured on medium containing mannitol. After growth in greenhouse conditions for 2 months, one clone developed from shoot clumps selected on medium with mannitol exhibited a significant tolerance in vitro in medium containing 90 mM mannitol; this medium completely inhibited growth of control plants. This clone had significantly higher proline content and soluble sugars than the non-stress-selected clone when cultured on medium containing 0 or 30 mM mannitol. When tested for drought tolerance (growth at 40% soil field capacity) in the greenhouse for 2 months, this clone showed a significant tolerance compared with other regenerated and control plants and revealed lower water potential, greater accumulated biomass and a higher relative growth rate.

Journal Article↗
PubMed2000

The oil palm in all our lives: how this came about

Over time, the oil palm has become the crop of central importance to both our daily lifestyle and to many of the great industries that man has developed. Remarkably, few recognize the oil palm and its fruit, and even fewer know its history. This article tells the story of the oil palm's rise to prominence from a wild plant of Equatorial Africa to becoming the most valuable plantation economy of the tropical world.

Journal Article↗
PubMed2000

Course of symptoms and quality of life measurement in Complex Regional Pain Syndrome: a pilot survey.

Few data have been published regarding the natural history, course of symptoms, and quality of life in Complex Regional Pain Syndrome (CRPS). To obtain preliminary data regarding these important issues in CRPS, a set of patient self-report questionnaires were mailed to patients with the diagnosis of CRPS who had been assessed and/or treated at a tertiary university-based pain center in the United States. Self-reports of demographic information, symptoms, the Neuropathic Pain Scale, and a modified Brief Pain Inventory (mBPI) were received from 31 CRPS patients. Approximately 75% of patients reported initial symptoms of pain, swelling, coldness, and color changes. An additional 71% had weakness and inability to move the extremity as initial symptoms. Weakness at some time during their course of CRPS was described by 97%. A majority reported no overall improvement or worsening of symptoms over time (mean 3.3 years). The pain descriptors with the highest mean values were "deep" (6.4/10), "unpleasant" (6.4), "sensitive" (5.7), "surface" (5.4), and "dull" (5.3) pains. Significant sleep disturbance was reported by 80%. CRPS had a severe impact on quality of life, with substantial interference reported in 9 of 10 mBPI activity items by a majority of these patients. These findings should be viewed with caution and should not be generalized to the entire CRPS population because the cohort was small and select. A large multicenter prospective study needs to be performed to validate these preliminary findings.

Adult↗
PubMed2000

The decision making process regarding the withdrawal or withholding of potential life-saving treatments in a children's hospital.

OBJECTIVES: To investigate the factors considered by staff, and the practicalities involved in the decision making process regarding the withdrawal or withholding of potential life-sustaining treatment in a children's hospital. To compare our current practice with that recommended by the Royal College of Paediatrics and Child Health (RCPCH) guidelines, published in 1997. DESIGN: A prospective, observational study using self-reported questionnaires. SETTING: Tertiary paediatric hospital. PATIENTS AND PARTICIPANTS: Consecutive patients identified during a six-month period, about whom a formal discussion took place between medical staff, nursing staff and family regarding the withholding or withdrawal of potentially life-sustaining treatments. The primary physician and primary nurse involved in the discussion were identified. METHOD: Two questionnaires completed independently by the primary physician and nurse. RESULTS: Twenty-two patients were identified (median age 1 year; range 1 day-34 years). In 20 cases treatment was withdrawn or withheld, in two cases treatment was continued. Nursing staff considered family wishes and family perceptions of patient suffering as significantly more important factors in decision making than medical staff, who considered prognostic factors as most important. In only two cases were the patient's expressed wishes apparently available. In most cases staff considered the patient's best interests were served and the process would not be enhanced by the involvement of an independent ethics committee. The exceptions were those cases in which treatment was continued following disagreement between parties. CONCLUSIONS: Our current practice is consistent with that recommended by the RCPCH. The contribution of the patient, provision of staff counselling and general practitioner (GP) involvement were identified as areas for improvement.

Child↗
PubMed2000

Recent economic evaluations of antenatal screening: a systematic review and critique.

A systematic review of recent economic evaluations of antenatal screening was conducted. Relevant studies were identified from a number of sources including computerised databases, bibliographies of economic evaluations, and searches of unpublished manuscripts. Each study identified by the literature searches was categorised on the basis of its title and abstract. Studies considered relevant to the systematic review were obtained from libraries. The methodology, results, and policy implications of studies categorised as economic evaluations upon full review were documented. A total of 566 studies were identified by the literature searches, 41 of which were categorised as economic evaluations upon full review. The economic evaluations covered a range of antenatal screening practices, aimed mainly at the prevention of infectious diseases and fetal anomalies. The review highlighted the poor methodological quality of the bulk of economic evaluations of antenatal screening. The study design, data collection methods, and analysis and interpretation of results frequently violated methodological guidelines adopted by health economists. The review also highlighted the narrow definition of benefits adopted by this body of literature, with most studies reporting outcomes in terms of cases detected, cases of particular disorders prevented or, most often, costs averted. The conclusions arrived at differed by area of antenatal screening. There appeared to be clear economic arguments in favour of some forms of antenatal screening, for example, triple test screening for Down's syndrome. Other economic evaluations pertained to specific locations, which suggests that the results may not necessarily be generalizable to different settings. For all areas of antenatal screening, an updating of published economic evaluations may be required to account for evolving economic, epidemiological, and clinical effectiveness evidence.

Costs and Cost Analysis↗
PubMed2000

Impact of HIV infection on tuberculosis.

Tuberculosis is increasing in prevalence in many countries and is now the leading infectious cause of death world wide, being responsible for three million deaths annually. Infection with HIV, likewise increasing in prevalence, has emerged as the most important predisposing factor for developing overt tuberculosis in people co-infected with Mycobacterium tuberculosis. Owing to the widespread geographical overlap of these two infections, it is estimated that in 1999, HIV related tuberculosis will reach one million cases and will cause 30% of the expected 2.5 million AIDS related deaths. Tuberculosis in HIV infected individuals may have unusual clinical features and can cause diagnostic difficulties. Despite the effectiveness of modern short course treatment, the mortality of HIV related tuberculosis during and after treatment remains high, and this may be due to other HIV related infections. The "cursed duet" of infection with both HIV and M tuberculosis is generating a threat to human health of unparalleled proportions which, if not taken seriously by health workers and decision makers, could become totally unmanageable.

AIDS-Related Opportunistic Infections↗