Use of pharmacoeconomics in prescribing research. Part 1: costs--moving beyond the acquisition price for drugs

This paper addresses pharmacoeconomics in prescribing research and reflects the increasing use of techniques of economic evaluation to aid drug purchasing decisions in a variety of settings -- for national drug subsidization programmes, provincial purchasing plans, insurance programmes, and for hospital and area health authority formulary decisions. First, we focus on the cost component of an economic evaluation and discuss methodological issues that are relevant to all pharmacoeconomic analyses.

Sedation effects on responsiveness: evaluating the reduction of antipsychotic medication in people with intellectual disability using a conditional probability approach

BACKGROUND

The impact of the withdrawal of long-term antipsychotic medication prescribed to adults with intellectual disabilities on behavioural functioning has been investigated using a real-time direct observation methodology. Previous authors have reported a significant post-reduction difference in engagement in activity between the successful drug reduction and control groups.

METHOD

In the present study, sequential analysis of the relationship between staff:resident interaction and behavioural engagement was used to give a more precise measure of the extent to which user responsiveness is affected by drug withdrawal. Responsiveness was measured by calculating the likelihood of engagement occurring given the occurrence of staff interaction. This likelihood was represented by the statistic Yule's Q-value.

RESULTS

High Yule's Q-value results pre- and post-baseline were found, indicating that clients were highly responsive to staff interaction. However, Yule's Q-value did not significantly increase following drug withdrawal.

CONCLUSION

The present study provides no evidence of greater responsiveness following the withdrawal of psychotropic medication.

Body image and weight change in middle age: a qualitative study

AIMS

To explore men's and women's experiences of weight change in adulthood, body image preferences and beliefs about the health consequences of overweight and to inform the development of a primary care intervention to prevent obesity.

SAMPLE

Seventy-two men and women aged 35-55, with a range of BMIs from 22 to 29.9, were identified from two UK general practice registers and invited to participate in an interview about experiences of weight change in adulthood.

METHODS

Audio tape recorded, semi-structured interviews were conducted in respondents' homes by trained researchers. Open-ended questions were used to collect experiences of weight change since early adulthood and views about weight change in middle age. Illustrations of a range of men's and women's body shapes were used to prompt discussion of respondents' preferences for male and female body shapes and their perspectives of the health, social and practical problems associated with underweight and overweight. The data were analysed using both quantitative and qualitative methods.

RESULTS

Some 87% (33/38) of the women and 59% (20/34) of the men said that they had ever tried to lose weight. At least one instance of successful weight loss was reported by 58% of the women and 47% of the men, although many of these attempts were relatively short-lived and often motivated by specific goals such as a holiday or a wedding. Respondents were sceptical of the possibility of controlling weight without considerable personal sacrifice. Explanations for middle-age weight gain included a sedentary lifestyle, as well as several gender-specific reasons, including hormonal changes and comfort eating for women and beer drinking for men. Nearly all (97%) respondents associated heart disease with overweight, while diabetes was mentioned by only 22% and none mentioned cancer.

CONCLUSION

People who have gained weight in middle age may be deterred from trying to prevent further gain by pessimism about the effort required. The efficacy of interventions to encourage relatively small substitutions and changes to diet and physical activity need to be tested. Interventions to help prevent weight gain in middle age could include information about the less widely known health risks such as diabetes and cancer.

Costs of village community, residential campus and dispersed housing provision for people with intellectual disability

BACKGROUND

In recent years, a growing volume of research evidence has been generated about the relative cost-effectiveness of various types of community-based residential supports for people with intellectual disability (ID) in the UK. However, few reliable data are available to inform planners, commissioners or service providers about the quality and costs of providing support within residential or village communities.

METHODS

The evaluation described in the present paper aimed to fill some of the gaps in knowledge by examining the comparative costs of supporting people in village community settings, in National Health Service (NHS) residential campuses and in dispersed, community-based housing schemes. The complete service package received by each study participant was described and costed, and a series of statistical analyses was undertaken to identify factors associated with variations in the cost of support. The analyses reported in the present paper were based on comparisons of 86 people living in village communities, 133 in residential campuses and 281 in dispersed housing schemes.

RESULTS

Wide variations in cost were found, not only between models of accommodation, but between individual organizations, settings and service users. Multivariate analysis revealed that higher costs were associated with supports for people with higher levels of ID and more severe challenging behaviour. The cost of support was affected by the size of the residential setting, with smaller facilities likely to be more expensive. Associations were also found between increased costs, and services for younger users, male users and people who had not moved from a NHS hospital. Generally, more sophisticated service processes within the setting were associated with higher costs; although systematic arrangements for supervision and training of staff had a negative effect on cost.

CONCLUSIONS

The cost findings should be considered alongside evidence on outcomes. A comparison of village communities and dispersed housing schemes suggests that both models of provision appear be associated with particular benefits, although different types of setting are appropriate for different individuals and therefore, the continued development of a range of residential models is important.

Social class gradients in health during adolescence

STUDY OBJECTIVE

To review existing data on social class gradients in adolescent health and to examine whether such gradients exist in new data concerning US adolescents.

DESIGN

Review of relevant publications and unpublished data; regression analyses using adolescent self reported health status data to determine whether there are gradients by social class, using three classes categorised by adolescent reported parental work status and education.

PARTICIPANTS

Adolescents of ages 11-17.

MAIN RESULTS

Findings from the literature indicate the presence of social class gradients in some but not all aspects of adolescent health. Results from new data showed social class gradients in several domains of health and in profiles of health. The likelihood of being satisfied with one's health, of being more resilient (better family involvement, better problem solving, more physical activity, better home safety), having higher school achievement, and of being in the best health profiles were significantly and progressively greater as social class rose. Moreover, the probability of being in the poorest health profile type group was progressively higher as social class declined.

CONCLUSIONS

The review of existing data and the new findings support the existence of social class gradients in satisfaction with one's health, in resilience to health threats, in school achievement, and in being in the best health overall (as manifested by the health profiles composed of four major domains of health). The study had two especially notable findings: (1) the paucity of studies using the same or similar indicators, and (2) the consistent existence of social class gradients in characteristics related to subsequent health, particularly intake of nutritional foods and physical activity. The sparseness of existing data and the different aspects of health investigated in the relatively few studies underscore the need for (1) the development of conceptual models specifically focused on adolescent health and social class; (2) additional inquiry into the measurement of social class and adolescent perceptions of class; (3) inclusion of contextual variables in study design; and (4) longitudinal cohort studies to better understand the specific determinants of health during adolescence.

Non-lethal viral challenge of influenza haemagglutinin and nucleoprotein DNA vaccinated mice results in reduced viral replication

Influenza DNA vaccines have been widely studied in experimental animal models and protection documented after lethal viral challenge. In this study, we have investigated the humoral response after a non-lethal viral challenge of mice vaccinated with plasmids encoding the influenza haemagglutinin (HA) or nucleoprotein (NP) genes. BALB/c mice were immunized intramuscularly with three doses (100 microg) of HA, NP or backbone plasmid at 3-week intervals, or alternatively infected intranasally, before being challenged with homologous virus 13 weeks later. Mice were then sacrificed at weekly intervals and the antibody-secreting cell response was examined systemically (spleen and bone marrow) and in the respiratory tract (nasal associated lymphoid tissue (NALT) and lungs). Sera were collected after each dose of vaccine and at sacrifice and analyzed by ELISA, haemagglutination inhibition and virus neutralization assays. We found that previous viral infection apparently elicits sterilizing immunity. Vaccination with HA or NP DNA significantly reduced viral replication in the nasal cavity after viral challenge, however, increases in serum antibody titres were observed after challenge. Prior to challenge, specific antibody-secreting cells were observed in the systemic compartment after HA or NP DNA vaccination but were also found in the NALT after viral challenge. In conclusion, intramuscular DNA vaccination resulted in immunological memory in the systemic compartment, which was rapidly reactivated upon viral challenge.

The receptor tyrosine kinase EphB2 regulates NMDA-dependent synaptic function

Members of the Eph family of receptor tyrosine kinases control many aspects of cellular interactions during development, including axon guidance. Here, we demonstrate that EphB2 also regulates postnatal synaptic function in the mammalian CNS. Mice lacking the EphB2 intracellular kinase domain showed wild-type levels of LTP, whereas mice lacking the entire EphB2 receptor had reduced LTP at hippocampal CA1 and dentate gyrus synapses. Synaptic NMDA-mediated current was reduced in dentate granule neurons in EphB2 null mice, as was synaptically localized NR1 as revealed by immunogold localization. Finally, we show that EphB2 is upregulated in hippocampal pyramidal neurons in vitro and in vivo by stimuli known to induce changes in synaptic structure. Together, these data demonstrate that EphB2 plays an important role in regulating synaptic function.

Estrogen replacement and brachial artery flow-mediated vasodilation in older women

It remains unclear whether estrogen therapy (with or without progestin) improves endothelial function in older postmenopausal women with or at risk for coronary heart disease. To address this issue, we analyzed brachial artery flow-mediated vasodilation in the Cardiovascular Health Study, a longitudinal study of cardiovascular risk factors in subjects over 65 years of age. At the tenth annual Cardiovascular Health Study examination, 1662 women returned for follow-up. Eighteen percent (n=291) were current users of estrogen replacement, most of whom (75.9%, n=221) took unopposed estrogen. Brachial artery ultrasound examinations measuring vasodilation in response to a flow stimulus (hyperemia) were performed on 1636 women. There were no statistical differences in brachial flow-mediated vasodilator responses between users and nonusers, even after adjustment for potential confounders. Absence of an effect was most notable in women over 80 years old and in those with established cardiovascular disease. However, among women without clinical or subclinical cardiovascular disease or its risk factors, there was a significant association between hormone replacement therapy use and flow-mediated vasodilator responses (P=0.01). Among older postmenopausal women, favorable vascular effects of estrogen may be limited to those who have not yet developed atherosclerotic vascular disease. These data emphasize the importance of ongoing efforts to determine the role of hormone replacement therapy for primary prevention of cardiovascular disease.

A textile fibre survey as an aid to the interpretation of fibre evidence in the Sydney region

Frequency figures of the fibre population on textile cinema seats were measured in Sydney, Australia, in winter. Sixteen seats were analysed from a very popular cinema complex, with 3025 fibres classified according to colour, generic class and fluorescence properties (100 grey-black cotton fibres only). The recovered fibres were mostly natural fibres (84%) with cotton the most common generic type (70%). On the contrary, man made fibres were relatively rare (15%) with rayon constituting the majority of these (51%). The most common colour/generic class combinations were grey-black cotton (33%) and blue cotton (30%) accounting for 63% of the total population. All other frequencies were below 5%, most below 1% using only the two properties of colour and generic class. Fluorescence properties were found to be very discriminating as far as grey-black cotton fibres were concerned. These features are considered and discussed and in particular, to emphasise the significance of fibres as evidence of contact.

Mutational analysis of early region 4 of bovine adenovirus type 3

The primary objective of characterizing bovine adenovirus type 3 (BAV3) in greater detail is to develop it as a vector for gene therapy and vaccination of humans and animals. A series of BAV3 early region 4 (E4) deletion-mutant viruses, containing deletions in individual E4 open reading frames (Orf) or combinations of Orfs, were generated by transfecting primary fetal bovine retinal cells with E4-modified genomic DNA. Each of these mutants was further analyzed for growth kinetics, viral DNA accumulation, and early-late protein synthesis. Mutant viruses carrying deletions in Orf1, Orf2, Orf3, or Orf4 showed growth characteristics similar to those of the E3-deleted BAV3 (BAV302). DNA accumulation and early/late protein synthesis were also indistinguishable from those of BAV302. However, mutant viruses carrying a deletion in Orf5, Orfs 1-3 (BAV429), or Orfs 3-5 (BAV430) were modestly compromised in their ability to grow in bovine cells and express early/late proteins. E4 mutants containing larger deletions, Orfs 1-3 (BAV429) and Orfs 3-5 (BAV430), were further tested in a cotton rat model. Both mutants replicated as efficiently as BAV3 or BAV302 in the lungs of cotton rats. BAV3-specific IgA and IgG responses were detected in serum and at the mucosal surfaces in cotton rats inoculated with mutant viruses. In vitro and in vivo characterization of these E4 mutants suggests that none of the individual E4 Orfs are essential for viral replication. Moreover, successful deletion of a 1.5-kb fragment in the BAV3 E4 region increased the available insertion capacity of replication-competent BAV3 vector (E3-E4 deleted) to approximately 4.5 kb and that of replication-defective BAV3 vector (E1a-E3-E4 deleted) to approximately 5.0 kb. This is extremely useful for the construction of BAV3 vectors that express multiple genes and/or regulatory elements for gene therapy and vaccination.

Environmental opportunities and supports for exercising self-determination in community-based residential settings

Information was collected on the environmental opportunities for exercising self-determination among 281 adults with mental retardation receiving community-based residential supports. The results indicated that: (1) the majority of participants had little or no opportunity to exercise self-determination over major life decisions (e.g., with whom and where to live, the recruitment and retention of care staff); (2) even in more mundane areas, such as where and when to eat, the majority of participants were not supported to exercise effective control; (3) variation in environmental opportunities to exercise self-determination was strongly related to a range of factors including participant ability, previous residential history, and structural and procedural aspects of the residential supports currently provided.

The impact of specialists on prescribing by general practitioners

OBJECTIVE

To investigate the direct impact of specialists on prescribing by general practitioners.

DESIGN

Cross-sectional, prescription-based study.

SUBJECTS AND SETTING

88 GPs in the Hunter Urban Division of General Practice, Hunter Valley, NSW.

MAIN OUTCOME MEASURE

Proportions of specialist-initiated prescriptions for eight commonly prescribed drug classes.

RESULTS

The proportion of specialist-initiated prescriptions was greatest for proton pump inhibitors (85%), and lowest for diuretics (8%), newer antidepressants (10%) and H2-receptor antagonists (13%). Specialists initiated 29% of prescriptions for beta-blockers, 26% for calcium-channel blockers, 20% for statins and 19% for angiotensin-converting enzyme inhibitors or angiotensin II antagonists. Specialists were more likely to have been involved in starting therapy with metoprolol than other beta-blockers (51% v 23%) and diltiazem than other calcium-channel blockers (48% v 19%), and this was related to indication for treatment. In contrast, prescriptions for the more recently introduced drugs (angiotensin II antagonists and atorvastatin) were not more likely to have been specialist-initiated than prescriptions for established angiotensin-converting enzyme inhibitors and statins.

CONCLUSIONS

The direct impact of specialists on prescribing in the Hunter Urban Division of General Practice is substantial and varies with the drug class. This highlights the need to engage both GPs and specialists in efforts to improve prescribing practices.

Apoptotic death of neurons exhibiting peripherin aggregates is mediated by the proinflammatory cytokine tumor necrosis factor-alpha

Peripherin, a neuronal intermediate filament protein associated with axonal spheroids in amyotrophic lateral sclerosis (ALS), induces the selective degeneration of motor neurons when overexpressed in transgenic mice. To further clarify the selectivity and mechanism of peripherin-induced neuronal death, we analyzed the effects of peripherin overexpression in primary neuronal cultures. Peripherin overexpression led to the formation of cytoplasmic protein aggregates and caused the death not only of motor neurons, but also of dorsal root ganglion (DRG) neurons that were cultured from dissociated spinal cords of peripherin transgenic embryos. Apoptosis of DRG neurons containing peripherin aggregates was dependent on the proinflammatory central nervous system environment of spinal cultures, rich in activated microglia, and required TNF-alpha. This synergistic proapoptotic effect may contribute to neuronal selectivity in ALS.

Elementary school-aged children's reports of their health: a cognitive interviewing study

There are no standard methods for assessing the quality of young children's perceptions of their health and well-being and their ability to comprehend the tasks involved in reporting their health. This research involved three cross-sectional studies using cognitive interviews of 5-11-year-old children (N = 114) to determine their ability to respond to various presentations of pictorially illustrated questions about their health. The samples had a predominance of children in the 5-7-year-old range and families of lower and middle socio-economic status. The research questions in Study 1 involved children's ability to convert their health experiences into scaled responses and relate them to illustrated items (n = 35); Study 2 focused on the type of response format most effectively used by children (n = 19); and Study 3 involved testing children's understanding of health-related terms and use of a specific recall period (n = 60). The results of Study 1 showed that children identified with the cartoon drawing of a child depicted in the illustrated items, typically responding that the child was at or near their own age and of the same gender, with no differences related to race. Study 2 results indicated that children responded effectively to circles of graduated sizes to indicate their response and preferred them to same-size circles or a visual analogue scale. Tests of three-, four-, and five-point response formats demonstrated that children could use them all without confusion. In Study 3, expected age-related differences in understanding were obtained. In fact, the 5-year-old children were unable to understand a sufficient number of items to adequately describe their health. Virtually all children 8 years of age and older were able to fully understand the key terms and presentation of items, used the full five-point range of response options, and accurately used a 4-week recall period. Six- and seven-year-olds were more likely than older children to use only the extreme and middle responses on a five-point scale. No pattern of gender differences in understanding or in use of response options was found. We conclude that children as young as eight are able to report on all aspects of their health experiences and can use a five-point response format. Children aged 6-7 had difficulty with some health-related terms and tended to use extreme responses, but they understood the basic task requirements and were able to report on their health experiences. These results provide the guidance needed to develop and test a pediatric health status questionnaire for children 6-11 years old.

Quality and costs of supported living residences and group homes in the United Kingdom

Information was collected on 63 adults in supported living residences, 55 adults in small group homes, and 152 adults in large group homes. Results indicated that (a) there were no statistically significant differences in service costs once these had been adjusted to take account of participant characteristics; (b) compared with participants living in small group homes, those in supported living residences had greater choice, participated in more community-based activities, experienced fewer scheduled activities, were more likely to have had their home vandalized, and were considered at greater risk of exploitation; (c) compared with participants living in large group homes, those in small group homes had larger social networks, more people in their social networks who were not staff, not family, and did not have mental retardation. These residents were considered at less risk of abuse.

Bacterial translocation and immunohistochemical measurement of gut immune function

AIMS

The local immune response in the small bowel mucosa might play a role in bacterial translocation (BT). The aim of this study was to quantify immune cells and secretory antibodies in the small bowel mucosa, and relate this to BT as assessed by culture of a mesenteric lymph node.

METHODS

Immunohistochemical techniques were used to measure the frequency of plasma cells and IgA and IgM positive cells in the lamina propria and semiquantitatively to assess mucosal surface IgA and IgM values in small bowel specimens obtained from 11 patients in whom positive evidence of BT had been identified in a mesenteric lymph node harvested at the time of laparotomy. These were compared with similar specimens obtained from 11 patients in whom a similar lymph node had yielded no growth.

RESULTS

BT was associated with a significantly increased median frequency of plasma cells (p < 0.01) and IgA positive cells (p < 0.05) in the lamina propria. The frequency of IgM positive cells was also higher in these patients, although this difference was not significant. In addition, semiquantitatively scored IgA and IgM concentrations at the mucosal surface were both significantly higher in the patients in whom BT had been identified (p = 0.006 and 0.016, respectively).

CONCLUSION

Higher numbers of plasma cells and higher IgA and IgM values are present in the small bowel mucosa of patients in whom BT has been shown to occur, suggesting an increased local immune response.

Factors associated with expressed satisfaction among people with intellectual disability receiving residential supports

The aim of the present study was to identify factors associated with variations in the levels of expressed satisfaction among adults with intellectual disability (ID) receiving residential supports. Semi-structured interviews were conducted with 96 people with ID. Forty-five subjects lived in village communities and 51 received community-based residential supports. Ratings were made of the participants' expressed levels of satisfaction in seven domains: (1) their home; (2) daytime activities; (3) social and recreational activities; (4) support from services; (5) friendships and relationships; (6) choices available to them; and (7) risks. The data indicated that: (1) interviewees living in village communities expressed greater satisfaction with friendships and relationships than interviewees living in community-based residential supports; (2) in the other six domains of life satisfaction which were investigated, there were no statistically significant differences between groups; (3) interviewees expressed greater satisfaction with their accommodation and day activities than with friendships, risks and support received; and (4) a wide range of variables relating to the personal characteristics of the interviewees and support received were associated with variations in levels of expressed satisfaction. Variation in the levels of expressed satisfaction was reliably associated with variables relating to the personal characteristics of the interviewees and the nature of the support received.

Personal formularies. An index of prescribing quality?

OBJECTIVES

(1) To determine the extent to which Australian general practitioners (GPs) restrict the numbers of agents they prescribe within a drug class ('personal formularies'); (2) To assess concordance of these drug choices with standards based on established guidelines or recognised good prescribing practices; (3) To assess the potential of these measures as indicators of the quality of prescribing.

METHODS

Australian Health Insurance Commission (HIC) prescription data (1994 1997) for around 15,400 GPs providing 1500 or more Medicare services per year were analysed. Measures of an individual GP's use of a personal formulary (determined by number of agents) and concordance with prescribing criteria based on specified drugs for five classes of commonly prescribed drugs were derived.

RESULTS

Non-steroidal anti-inflammatory drugs (NSAIDs): GP concordance was higher with a non-specified personal formulary (any five NSAIDs) than with a list of specified drugs (five NSAIDs of 'low' or 'medium' risk of gastrointestinal toxicity), and concordance with both increased over time. In 1997, around 70% of GPs used five or fewer NSAIDs for 90% of their prescribing; 47% of GPs had 90% of prescribing from five selected agents. Angiotensin converting enzyme inhibitors/angiotensin-II receptor antagonists: The introduction of new agents appeared to increase the size of the GPs' personal formularies, and concordance with defined standards decreased over time. Antibacterial agents: Concordance with a specified drug standard (nine drugs listed in the Australian Antibiotic Guidelines) increased substantially over time but was largely due to increased prescribing of two heavily promoted drugs. Beta-blocking agents: Over time, GPs restricted most prescribing to two agents, atenolol and metoprolol. Calcium channel blockers: GPs did not appear to restrict prescribing of these drugs; most GPs prescribed all five agents available.

CONCLUSIONS

Australian GPs use 'personal formularies'. Formulary size varies with the drug class, can change over time as new agents become available, and its contents can be influenced by promotional activities. Prescribing standards based on numbers of drugs used may not always reflect rational prescribing choices. Criteria based on specified drugs provide more rigorous prescribing standards, but may give a misleading picture of prescribing quality in the absence of information on patients and the indications for treatment. Personal formulary measures are potentially useful prescribing indicators but need to be carefully defined and interpreted. GPs should be encouraged to identify their personal formularies and review the drugs included in them.

The adaptive behavior scale-residential and community (part I): towards the development of a short form

A potential 24-item short form (SABS) of the 73-item Adaptive Behavior Scale-Residential and Community (Part I) (ABS-RC2; Nihira et al., 1993a, b) was developed, based on data from two diverse UK samples of adults with intellectual disabilities living in residential services (n = 560 and 254). SABS factor and total scores showed good internal reliability in both samples (alpha 0.89-0.98), and were highly correlated with their full ABS-RC2 Part I equivalents (r = 0.97-0.99). Regression equations were calculated for SABS factor and total scores against their full ABS-RC2 Part I equivalents. Levels of agreement between predicted quartile scores (derived from the regression equations) and actual full ABS-RC2 Part I quartile scores were high (kappa 0.75-0.89; percentage agreement 82%-92%). It is concluded that the SABS is a potentially useful research tool, although further work is clearly needed to establish the reliability and cross-cultural validity of the instrument.

Toxicosis associated with dual oral exposure of rats to lead and trichloroethylene

To determine if additive or synergistic toxic effects would occur, adult male rats were exposed orally to lead carbonate (2,000 mg/kg) for 9 days before trichloroethylene (TCE), 2,000 mg/kg, was given concurrently for an additional 7 days. Comparisons were made with groups of vehicle-treated rats and rats given only lead or only TCE. Potential neurotoxicity was evaluated by using the Functional Observational Battery (FOB) recommended for neurotoxicity screening. Rats were sacrificed on day 16, and brain, testes, spleen, kidney/adrenals, heart, and liver weighed and observed for pathological changes. Results of the FOB indicated that lead carbonate was more responsible than TCE for changes observed. Additive or synergistic neurotoxicities were not noted. Histological examination of the kidney from lead-treated rats revealed inclusions, an increased incidence of coagulated proteins, and tubular dilation that was generally more severe in the medullary segments. Gastric and testicular necrosis were found in rats given lead carbonate both with and without TCE (15/20 and 6/20 treated, respectively). The results suggest that, even when given concurrently, the toxicities of lead carbonate and TCE are expressed only as though one toxicant was given.

Social networks of people with mental retardation in residential settings

Information was collected on the social networks of 500 adults with mental retardation receiving different types of residential supports. Results indicated that (a) the reported median size of participants' social networks (excluding staff) was 2 people; (b) 83% of participants were reported to have a staff member; 72%, a member of their family; 54%, another person with mental retardation; and 30%, a person who did not fit into any of these categories in their social network; (c) variation in the size and composition of participants' social networks was associated with a range of variables, including the personal characteristics of residents (age, autism, ability, and challenging behavior), the type of previous and current accommodation, staffing ratios, institutional climate, and the implementation of "active support."

Statistical issues in analyzing 24-hour dietary recall and 24-hour urine collection data for sodium and potassium intakes

Dietary recalls and urine assays provide different metrics for assessing sodium and potassium intakes. Means, variances, and correlations of data obtained from these two modes of measurement differ. Pooling of these data is not straightforward, and results from studies employing the different modes may not be comparable. To explore differences between these metrics, the authors used data from the Trial of Nonpharmacologic Intervention in the Elderly (TONE), which included repeated standardized 24-hour dietary recalls and 24-hour urine collections administered over 3 years of follow-up, to estimate sodium and potassium intakes. The authors examined data from 341 control participants assigned to usual care that were collected between August 1992 and December 1995. Dietary recalls yielded estimates of sodium intake that averaged 22% less than those from urine assays and estimates of potassium intake that averaged 16% greater than those from urine assays. Sodium intake estimates were less repeatable (r = 0.22 for diet; r = 0.30 for urine) than potassium intake estimates (r = 0.49 for diet; r = 0.50 for urine), making relations with outcomes more difficult to characterize. Overall, the performance of the two measurement modes was fairly similar across demographic subgroups. Errors in separate estimations of long term sodium and potassium intakes using short term data were strongly correlated, more strongly than the underlying long term intakes of these electrolytes. Because of the correlated measurement error, estimated regression coefficients for linear models including both electrolytes as predictors may be confounded such that the separate relations between these nutrients and outcomes such as blood pressure cannot be reliably estimated by common analytical strategies.

The effect of implanting gentamicin-impregnated polymethylmethacrylate beads in the tarsocrural joint of the horse

OBJECTIVE

To determine the effect of intra-articular gentamicin-impregnated polymethylmethacrylate (PMMA) beads inserted in the equine tarsocrural joint on the synovial fluid, synovial lining, and cartilage, and to determine the peak and sustainable gentamicin concentrations in synovial fluid and plasma.

STUDY DESIGN

Pharmacokinetic, cytologic, and histologic study of the effect of gentamicin-impregnated PMMA on normal equine tarsocrural joints.

ANIMALS

Five healthy adult horses.

METHODS

Gentamicin-impregnated PMMA bead strands (3 strands each of 40 beads, with each strand containing 100 mg gentamicin) were surgically inserted into one radiographically normal tarsocrural joint in 5 horses. Each horse had both joints flushed with 1 L of lactated Ringer's solution before bead administration. Synovial fluid total protein concentration, white blood cell (WBC) count, gentamicin concentration, synovial histology, cartilage integrity, and cartilage glycosaminoglycan (GAG) concentrations were determined.

RESULTS

Gentamicin concentration (mean +/- SEM peak concentration, 27.9 +/- 2.27 microg/mL) occurred in the first 24 hours and remained above 2 microg/mL for 9 days. Gentamicin concentrations in control joints and the plasma remained below detectable levels. The synovial fluid WBC count for treated joints was increased compared with control joints for 72 hours, but was similar at day 6. The synovial protein concentration in gentamicin-treated joints remained increased for 21 days. Synovium in treated joints had diffuse synovitis, whereas control joints had less fibrovascular proliferation. Superficial cartilage erosion was present in all treated joints. There was no difference in the GAG content of treated and control joint cartilage.

CONCLUSIONS

Short-term implantation of gentamicin (300 mg)-impregnated PMMA beads can provide therapeutic levels of gentamicin (>2 microg/mL) in the normal tarsocrural joint for 9 days; however, gentamicin-impregnated PMMA beads induce synovitis and superficial cartilage erosion.

CLINICAL RELEVANCE

Temporary intra-articular administration of antibiotic-impregnated PMMA may be an effective way to treat septic joints that require constant high concentrations of antibiotics.

BRCA1 screening in a woman with breast cancer: a patient's perspective with commentary

Genetic screening for breast cancer and other diseases poses major personal and psychological challenges for persons facing the prospect of testing. The personal report of those dilemmas by a woman considering BRCA1 screening who had had a lumpectomy for breast cancer and whose mother had died from that disease is presented here. Commentaries by a bioethicist and a genetics counselor show further complexities in the testing experience which persons considering testing and those providing them will need to confront.

A comparison of methods for measuring socio-economic status by occupation or postal area

Seven methods of estimating socio-economic status (SES) were compared, including four based on data specific to individuals (Blishen, Pineo-Porter, British Registrar General, Hollingshead) and three based on the average characteristics of the postal code area in which people live (income alone, education alone, income and education combined). Data from the files of 151 patients undergoing in vitro fertilization were used. The four individual scales were highly correlated among themselves (Spearman's correlation coefficient between 0.6 and 0.9) but only moderately correlated with the measures based on postal code (Spearman's correlation coefficient between 0.2 and 0.3).

IVF births and pregnancies: an exploration of two methods of assessment using life-table analysis

PURPOSE

Our purpose was to explore two methods of expressing the performance of IVF programs.

METHODS

Using life-table methods, hazard and cure rates and a "monthly fecundability rate" were calculated for an Ontario IVF clinic. The rates were evaluated for their meaningfulness as indicators of the clinic's performance.

RESULTS AND CONCLUSIONS

While the hazard rate describes monthly fertility among those who will eventually become pregnant, the fecundability rate describes fertility for all patients who enter the program, making it the more appropriate index for program comparisons. However, from a prospective patient's perspective, both methods are valid indices for summarizing a program's performance.

Site-directed mutagenesis of K396R of the 65 kDa glutamic acid decarboxylase active site obliterates enzyme activity but not antibody binding

The role of K396 in the enzymatic catalysis and the antigenicity of the 65 kDa isoform of glutamate decarboxylase (GAD65) was analyzed using the K396R GAD65 mutant. GAD65 is a major autoantigen in Type 1 diabetes and autoantibodies directed to GAD65 are widely used markers for this disease. We found that (1) recombinant human GAD65 is fully enzymatically active; (2) the K396R mutation abolished GAD65 activity; and (3) the K396R mutant retained full antigenicity to GAD65 autoantibodies in serum from Type 1 diabetes patients, but not to polyclonal antibodies raised to the catalytic domain.

Recombinant bovine adenovirus type 3 expressing bovine viral diarrhea virus glycoprotein E2 induces an immune response in cotton rats

Recombinant bovine adenovirus is being developed as a live vector for animal vaccination and for human gene therapy. In this study, two replication-competent bovine adenovirus 3 (BAV-3) recombinants (BAV331 and BAV338) expressing bovine viral diarrhea virus (BVDV) glycoprotein E2 in the early region 3 (E3) of BAV-3 were constructed. Recombinant BAV331 contains chemically synthesized E2 gene (nucleotides modified to remove internal cryptic splice sites) under the control of BAV-3 E3/major late promoter (MLP), while recombinant BAV338 contains original E2 gene under the control of human cytomegalovirus immediate early promoter. Since E2, a class I membrane glycoprotein, does not contain its own signal peptide sequence at the 5' end, the bovine herpesvirus 1 (BHV-1) glycoprotein D signal sequence was fused in frame to the E2 open reading frame (ORF) for proper processing of the E2 glycoprotein in both the recombinant viruses. Recombinant E2 protein expressed by BAV331 and BAV338 recombinant viruses was recognized by E2-specific monoclonal antibodies as a 53-kDa protein, which also formed dimer with an apparent molecular weight of 94 kDa. Insertion of an E2-expression cassette in the E3 region did not effect the replication of recombinant BAV-3s. Intranasal immunization of cotton rats with these recombinant viruses generated E2-specific IgA and IgG responses at the mucosal surfaces and in the serum. In summary, these results show that the pestivirus glycoprotein can be expressed efficiently by BAV-3. In addition, mucosal immunization with replication-competent recombinant bovine adenovirus 3 can induce a specific immune response against the expressed antigen.

Inhibition of aberrant and constitutive phosphorylation of the high-molecular-mass neurofilament subunit by CEP-1347 (KT7515), an inhibitor of the stress-activated protein kinase signaling pathway

Previous studies have implicated stress-activated protein kinases (SAPKs) in aberrant phosphorylation of the high-molecular-mass neurofilament subunit (NFH). We now present direct evidence for this involvement using CEP-1347, a specific inhibitor of SAPK activation. Inhibition by this drug of stress-induced phosphorylation of NFH and the middle-molecular-mass neurofilament subunit in the perikaryon of dorsal root ganglion (DRG) neurons paralleled the decrease in levels of activated SAPKs and was essentially complete at 1 microM: CEP-1347. In addition, a role for SAPKs in the constitutive phosphorylation of NFH was demonstrated. Longterm treatment of unstressed DRG neurons with CEP-1347 lowered the steady-state phosphorylation level of NFH in neurites. No such effect was seen in neurons treated with PD 098059, which blocks activation of extracellular signal-regulated kinase 1/2. DRG neurites were shown to contain high basal levels of activated SAPKs. These included a 55-kDa SAPK whose activation was completely abolished at 0.05 microM: CEP-1347 and a 45-kDa SAPK that was not affected by the drug. These results indicate that SAPKs are involved in both stress-induced and constitutive phosphorylation of NFH. The differing responses of SAPKs in neurites and cell bodies to CEP-1347 inhibition further suggest the presence of different signaling pathways in the two neuronal compartments.

Detection of hTERT protein by flow cytometry

Telomerase is a telomere-specific DNA polymerase consisting of protein and RNA components, which is activated in germline cells and the majority of cancers and serves to counter the consequences of telomere shortening. The protein component, hTERT, is believed to be the catalytic subunit of human telomerase and its expression at the mRNA level correlates well with telomerase activity in vitro. Current techniques for assaying telomerase activity detect only the mean activity in a sample and are unable to isolate specific cell sub-populations. This report describes the development and validation of a cellular, immunofluorescence-based flow cytometry assay that allows detection of intranuclear hTERT while maintaining identifiable cell population characteristics. The assay was shown to be both sensitive to changes in telomerase expression and was semi-quantitative. In both cell line differentiation experiments and in primary cells, a good correlation existed between hTERT expression measured by flow cytometry and telomerase activity detected by the telomeric repeat amplification protocol (TRAP). The method developed offers a quick, simple and reproducible cellular-based assay for hTERT expression. This assay will provide a useful, new tool for future investigations, facilitating the analysis of hTERT expression in mixed cell populations.

Receipt of psychotropic medication by people with intellectual disability in residential settings

Previous studies have reported that the rate of prescription of antipsychotic medication for people with intellectual disability is far in excess of the expected prevalence of psychoses for this population. Recent research identifying factors which predict the use of psychotropic medication suggests that challenging behaviour may play a key role in determining the receipt of antipsychotic medication. The present study reports the prevalence of psychoactive medication receipt for 500 people with intellectual disability living in different forms of residential provision in the UK. Variables which predict the receipt of psychotropic medication are also identified. The results show differences between forms of residential provision in rates of medication receipt. Analyses of predictors of psychotropic medication receipt suggest that, whilst the receipt of antidepressants is predicted by symptoms of mental ill health, the receipt of both antipsychotics and hypnotics/anxiolytics is predicted by variables related to challenging behaviour.

Lifestyle related risk factors for poor health in residential settings for people with intellectual disabilities

Little information is available on the prevalence and determinants of lifestyle related risk factors for poor health (obesity, poor diet, physical inactivity, smoking and alcohol abuse) among people with intellectual disabilities. This study reports the prevalence of these risk factors for 500 people with intellectual disabilities living in different forms of residential provision in the UK. Variables which predict the presence of these risk factors are also identified. While levels of smoking and alcohol abuse were low, the prevalence of poor diet, obesity in women and physical inactivity was high. Analyses of predictors of risk factors present a mixed pattern with regard to participant and service characteristics, with greater ability and less restrictive residential settings being associated with poor diet, smoking and obesity, but physical inactivity being associated with lower ability and more restrictive settings. It is argued that increasing levels of moderate or vigorous physical activity among people with intellectual disabilities would be the single most effective way of improving the health of people with intellectual disabilities.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) deficiency results in exencephaly and is required for apoptosis within the developing CNS

Tumor necrosis factor receptor-associated factors (TRAFs) are adaptor proteins important in mediating intracellular signaling. We report here that targeted deletion of traf6 greatly increases the frequency of failure of neural tube closure and exencephaly in traf6 (-/-) mice. The penetrance of this defect is influenced by genetic background. Neural tube fusion requires the coordination of several biological processes, including cell migration invoked by contact-dependent signaling, cell proliferation, and programmed cell death (PCD). To gain greater insight into the role of TRAF6 in these processes, neural development and migration within the CNS of traf6 (-/-) mice and controls were assessed through temporal examination of a number of immunohistochemical markers. In addition, relative levels of cellular proliferation and PCD were examined throughout embryonic development using bromodeoxyuridine (BrdU) and in situ terminal deoxynucleotidyl transferase-mediated dUTP biotinylated nick end labeling (TUNEL), respectively. The data suggest that loss of TRAF6 does not significantly alter the level of cellular proliferation or the pattern of neural differentiation per se, but rather regulates the level of PCD within specific regions of the developing CNS. Substantial reductions in TUNEL were observed within the ventral diencephalon and mesencephalon in exencephalic traf6 (-/-) embryos. Our results demonstrate a novel and prominent role for TRAF6 in the regional control of PCD within the developing CNS.

Randomised study of anastrozole versus tamoxifen as first-line therapy for advanced breast cancer in postmenopausal women

A total of 668 patients (340 anastrozole and 328 tamoxifen) were randomised in a double-blind, double-dummy multicentre study. Anastrozole was given in a dose of 1 mg once daily and compared with tamoxifen 20 mg daily in postmenopausal patients with tumours that were hormone-receptor positive or of unknown receptor status. The efficacy and tolerability of anastrozole was compared with that of tamoxifen as first-line therapy for advanced breast cancer. The median time to progression was similar for both treatments (8.2 months in anastrozole patients and 8.3 months in tamoxifen patients). Anastrozole was also as effective as tamoxifen in terms of objective response-rate with 33% in the anastrozole group and 32.6% in the tamoxifen group achieving a complete or partial response. Both treatments were well tolerated. However, incidences of thromboembolic events and vaginal bleeding were reported in fewer patients treated with anastrozole than with tamoxifen. In conclusion, these findings indicate that anastrozole can be considered as first-line therapy for postmenopausal women with advanced breast cancer.