International cross-cultural validation study of the Canadian haemophilia outcomes: kids' life assessment tool.

Health-related quality of life (HRQoL) assessment is recognized as an important outcome in the evaluation of different therapeutic regimens for persons with haemophilia. The Canadian Haemophilia Outcomes-Kids' Life Assessment Tool (CHO-KLAT) is a disease-specific measure of HRQoL for 4 to 18-year-old boys with haemophilia. The purpose of this study was to extend this disease-specific, child-centric, outcome measure for use in international clinical trials. We adapted the North American English CHO-KLAT version for use in five countries: France, Germany, the Netherlands, Spain and the United Kingdom (UK). The process included four stages: (i) translation; (ii) cognitive debriefing; (iii) validity assessment relative to the PedsQL (generic) and the Haemo-QoL (disease-specific) and (iv) assessment of inter and intra-rater reliability. Cognitive debriefing was performed in 57 boys (mean age 11.4 years), validation was performed in 144 boys (mean age 11.0 years) and reliability was assessed for a subgroup of 64 boys (mean age 12.0 years). Parents also participated. The mean scores reported by the boys were high: CHO-KLAT 77.0 (SD = 11.2); PedsQL 83.8 (SD = 11.9) and Haemo-QoL 79.6 (SD = 11.5). Correlations between the CHO-KLAT and PedsQL ranged from 0.63 in Germany to 0.39 in the Netherlands and Spain. Test-retest reliability (concordance) for child self-report was 0.67. Child-parent concordance was slightly lower at 0.57. The CHO-KLAT has been fully culturally adapted and validated for use in five different languages and cultures (in England, the Netherlands, France, Germany and Spain) where treatment is readily available either on demand or as prophylaxis.

Process and experience of cross-cultural adaptation of a quality of life measure (CHO-KLAT) for boys with haemophilia in Brazil.

Health-related quality of life (HRQoL) is an important outcome from the perspective of boys with haemophilia and their parents. Few studies have captured the HRQoL of boys with haemophilia in developing countries. This article reports on the cross-cultural adaptation of the Canadian Haemophilia Outcomes - Kids Life Assessment Tool (CHO-KLAT) for use in São Paulo, Brazil. The CHO-KLAT(2.0) was translated into Portuguese, and then translated back into English. The original English and back-translation versions were compared by a group of three clinicians, whose first language was Portuguese. The resulting Portuguese version was assessed through a series of cognitive debriefing interviews with children and their parents. This process identified concepts that were not clear and revised items to ensure appropriate understanding through an iterative process. The initial back-translation was not discrepant from the original English version. We made changes to 66% of the CHO-KLAT(2.0) items based on clinical expert review and 26% of the items based on cognitive debriefings. In addition, two new items were added to the final Portuguese version to reflect the local cultural context. The final result had good face validity. This process was found to be extremely valuable in ensuring the items were accurately interpreted by the boys/parents in São Paulo Brazil. The results suggest that professional translators, clinical experts and cognitive debriefing are all required to achieve a culturally appropriate instrument. The Portuguese CHO-KLAT(2.0) is well understood by Sao Paulo boys/parents. The next step will be to test its validity and reliability locally.

Extracellular processing of peptide antigens that bind class I major histocompatibility molecules.

One problem associated with the use of synthetic peptides as antigens in vivo is their susceptibility to inactivation by proteolytic degradation. A situation is described in which a serum protease, angiotensin-converting enzyme (ACE), is actually responsible for the class I binding activity of a commonly used influenza antigen, nucleoprotein (NP)(147-158R-). This peptide has been reported to be a highly efficient class I antigen. Evidence is presented that demonstrates that the peptide is inactive until cleaved by ACE, which is a normal constituent of serum. The enzyme removes a COOH-terminal dipeptide resulting in the sequence NP(147-155), which is identical to the naturally processed peptide. Such extracellular processing of peptides and proteins may occur for a variety of antigens both in vitro and in vivo, and could have important implications for the design of proteolytically resistant vaccines.

Health care services utilization stratified by virological and immunological markers of HIV: evidence from a universal health care setting.

OBJECTIVE: The aim of the study was to determine rates of utilization of in-patient, out-patient and laboratory services stratified by virological and immunological markers of HIV disease among patients on antiretroviral treatment in British Columbia, Canada. METHODS: We estimated resource utilization for in-patient visits, out-patient visits, and laboratory tests among patients initiating antiretroviral treatment between 1 April 1994 and 31 December 2000, with follow-up to 31 March 2001. Resource use was stratified by CD4 cell count and plasma HIV viral load (pVL) at the time of utilization and rates per 100 patient-years were calculated for each health care resource. RESULTS: A total of 2718 patients were included in our analyses. The overall rates of in-patient visits, out-patient visits, and laboratory tests were 902, 3001 and 840 per 100 patient-years, respectively. Utilization was higher for patients with low CD4 cell counts and high pVLs when compared with patients with high CD4 cell counts and low pVLs. CONCLUSIONS: Patients with low CD4 cell counts and high pVLs had the highest use of health care services. Regular follow-up with health care providers in an out-patient setting, allowing for proper monitoring and maintenance of HIV care, is important in minimizing unnecessary and potentially costly in-patient care.

Localization of an Arg-Gly-Asp recognition site within an integrin adhesion receptor.

Many adhesive interactions are mediated by Arg-Gly-Asp (RGD) sequences within adhesive proteins. Such RGD sequences are frequently recognized by structurally related heterodimers that are members of the integrin family of adhesion receptors. A region was found in the platelet RGD receptor, gpIIb/IIIa, to which an RGD peptide becomes chemically cross-linked. This region corresponds to residues 109 to 171 of gpIIIa. This segment is conserved among the beta subunits of the integrins (76 percent identity of sequence), indicating that it may play a role in the adhesive functions of this family of receptors.

Cost-effectiveness of losartan-based therapy in patients with hypertension and left ventricular hypertrophy: a UK-based economic evaluation of the Losartan Intervention for Endpoint reduction in hypertension (LIFE) study.

The Losartan Intervention for Endpoint reduction in hypertension (LIFE) study demonstrated the clinical benefit of losartan-based therapy in hypertensive patients with left ventricular hypertrophy (LVH), mainly due to a highly significant 25% reduction in the relative risk of stroke compared with an atenolol-based regimen, for a similar reduction in blood pressure. The aim of this economic evaluation was to estimate the cost-effectiveness of losartan compared with atenolol from a UK national health system perspective. Quality-adjusted survival and direct medical costs were modelled beyond the trial using the within-trial incidence of stroke. Survival with stroke, study medication use and quality of life by stroke status were taken directly from the LIFE trial. The LIFE data were supplemented with UK data on lifetime direct medical costs of stroke and life expectancy in individuals without stroke. No additional stroke events or use of study treatment were assumed beyond the trial. Costs and benefits were discounted using current UK Treasury rates. In the base-case analysis, the reduction in stroke-related costs (by 968 sterling pound) offset 86% of the increase in study medication costs (1128 sterling pound) among losartan-treated patients. The incremental cost-effectiveness ratio (ICER) for losartan versus atenolol in hypertensive patients with LVH was 2130 sterling pound per quality-adjusted life year (QALY) gained (3195 Euro/QALY), and this increased to 11,352 sterling pound per QALY gained (16,450 Euro/QALY) when the costs of stroke beyond the first 5 years were excluded. Thus, the clinical benefit of losartan was achieved at a cost well within reported thresholds for cost-effectiveness.

A test of worker policing theory in an advanced eusocial wasp, Vespula rufa.

Mutual policing is an important mechanism for maintaining social harmony in group-living organisms. In some ants, bees, and wasps, workers police male eggs laid by other workers in order to maintain the reproductive primacy of the queen. Kin selection theory predicts that multiple mating by the queen is one factor that can selectively favor worker policing. This is because when the queen is mated to multiple males, workers are more closely related to queen's sons than to the sons of other workers. Here we provide an additional test of worker policing theory in Vespinae wasps. We show that the yellowjacket Vespula rufa is characterized by low mating frequency, and that a significant percentage of the males are workers' sons. This supports theoretical predictions for paternities below 2, and contrasts with other Vespula species, in which paternities are higher and few or no adult males are worker produced, probably due to worker policing, which has been shown in one species, Vespula vulgaris. Behavioral observations support the hypothesis that V. rufa has much reduced worker policing compared to other Vespula. In addition, a significant proportion of worker-laid eggs were policed by the queen.

Weight of the evidence on the human carcinogenicity of 2,4-D.

The phenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is widely used to control the growth of weeds and broadleaf plants. We convened a panel of 13 scientists to weigh the evidence on the human carcinogenicity of 2,4-D. The panel based its findings on a review of the toxicological and epidemiological literature on 2,4-D and related phenoxy herbicides. The toxicological data do not provide a strong basis for predicting that 2,4-D is a human carcinogen. Although a cause-effect relationship is far from being established, the epidemiological evidence for an association between exposure to 2,4-D and non-Hodgkin's lymphoma is suggestive and requires further investigation. There is little evidence of an association between use of 2,4-D and soft-tissue sarcoma or Hodgkin's disease, and no evidence of an association between 2,4-D use and any other form of cancer. Scientists on the panel were asked to categorize 2,4-D as a "known," "probable," "possible," or "unlikely" carcinogen or as a noncarcinogen in humans. The predominant opinion among the panel members was that the weight of the evidence indicates that it is possible that exposure to 2,4-D can cause cancer in humans, although not all of the panelists believed the possibility was equally likely: one thought the possibility was strong, leaning toward probable, and five thought the possibility was remote, leaning toward unlikely. Two panelists believed it unlikely that 2,4-D can cause cancer in humans.

Dyspepsia tolerability from the patients' perspective: a comparison of celecoxib with diclofenac.

AIM: To compare celecoxib (800 mg/day, n=1997) with diclofenac (150 mg/day, n=1996) on dyspepsia-related tolerability. METHODS: In one of the two protocols comprising the Celecoxib Long-Term Arthritis Safety Study, a randomized double-blind trial, patients completed the Severity of Dyspepsia Assessment Questionnaire at baseline and at weeks 4, 13, 26 and 52 for the following three scales: Pain Intensity, Non-Pain Symptoms and Satisfaction with Dyspepsia-Related Health. RESULTS: For the Pain Intensity scale, patients given diclofenac had significantly higher (worsening dyspepsia) mean changes, defined as follow-up minus baseline, than patients given celecoxib (P < 0.001, at all assessments). The mean changes in the Pain Intensity scale (scale, 2-47; higher score is higher pain intensity) were 0.99 (95% confidence interval (CI): 0.50, 1.48) for celecoxib and 2.76 (95% CI: 2.28, 3.25) for diclofenac at 4 weeks. Satisfaction was superior with celecoxib at all assessments (P < 0.001). At 4 weeks, the mean changes in the Satisfaction scale (scale, 7-35; higher score is higher satisfaction) were 0.02 (95% CI: - 0.26, 0.29) for celecoxib and - 0.72 (95% CI: - 1.00, - 0.45) for diclofenac. Diclofenac patients had significantly higher Non-Pain Symptoms at 4 weeks (P=0.005). CONCLUSIONS: Celecoxib, at two to four times the recommended dose, demonstrated a superior dyspepsia-related tolerability and satisfaction compared with standard dosages of diclofenac.

Adherence to proton pump inhibitors or H2-receptor antagonists during the use of non-steroidal anti-inflammatory drugs.

BACKGROUND: The efficacy of proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) prescribed as prophylaxis for NSAID-related upper gastrointestinal (UGI) toxicity is dependent upon patient adherence. AIM: To describe patient adherence to prophylactically prescribed PPIs and H2RAs in the clinical setting. METHODS: We conducted a retrospective observational cohort study using the Integrated Primary Care Information Project database. The study population consisted of incident non-specific NSAID users prescribed a PPI or H2RA specifically as prophylaxis for NSAID-related UGI toxicity. Patients were classified as non-adherent if < 75% of days of NSAID use were covered by one of these agents, and as continuing users after discontinuation of NSAID use if they had a renewed prescription for these agents after their last NSAID prescription. RESULTS: The study cohort comprised 784 patients: 374 with H2RAs, 405 with PPIs, and 5 with both PPI and H2RA. Eighty-five percent of H2RA users and 7% of PPI users were prescribed these drugs at doses below the minimum recommended/effective dose for NSAID-associated gastroduodenal ulcer prophylaxis. Thirty-seven percent of patients were non-adherent. The lowest rate of non-adherence was associated with the first NSAID prescription (9%), increasing to 61% for patients with >/= 3 prescriptions. In a cohort of subjects who stopped their NSAID and were followed for up to 2 years (n = 711), there was significant persistent use of acid suppressive agents; 40% of patients had at least one additional prescription for the acid suppressive agent after stopping NSAIDs, and> 30% received enough drug to cover a period longer than 2 months after stopping their NSAID. CONCLUSIONS: The pattern of PPI and H2RA prescriptions, when prescribed as prophylactic strategy, does not correspond with the pattern of NSAID use. Physicians should consider the medical impact of non-adherence with dual therapies and the impact of prolonged use of GPAs on treatment cost.

Population impact of losartan use on stroke in the European Union (EU): projections from the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study.

The Losartan Intervention for Endpoint reduction in hypertension (LIFE) study was designed to compare losartan- vs atenolol-based antihypertensive treatment on cardiovascular morbidity and mortality in a population of 9193 hypertensive patients with left ventricular hypertrophy (LVH). In LIFE, the losartan-based treatment further reduced the primary composite end point (cardiovascular death, myocardial infarction, or stroke) by 13% (risk reduction (RR) 0.87, 95% confidence interval (CI) 0.77-0.98, P=0.021). The further reduction in stroke with losartan (RR 0.75, 95% CI 0.63-0.89, P=0.001) was the major contributing factor to the reduction in the primary end point. Our objective was to project the reduction in stroke observed with a losartan- vs an atenolol-based antihypertensive treatment regimen in the LIFE study to the European Union (EU) population. The number of stroke events averted was estimated by identifying the number of persons in the EU expected to meet the LIFE inclusion criteria, and multiplying this figure by the cumulative incidence risk difference in stroke from LIFE at 5.5 years. The age- and gender-specific prevalence of hypertension, electrocardiographically (ECG)-diagnosed LVH among those with hypertension (inclusion criteria), and heart failure among those with LVH and hypertension (exclusion criteria) were applied to the EU census estimates. We conservatively projected that an estimated 7.8 million individuals aged 55-80 years in the EU are affected by hypertension and ECG-diagnosed LVH. Use of a losartan-based antihypertensive treatment in this population is projected to prevent approximately 125 000 first strokes over a 5.5-year period. A population-wide prevention strategy of using losartan in patients with LVH and hypertension has the potential to have a major public health impact by reducing the morbidity and mortality of stroke in the EU.

A framework for evaluating the clinical consequences of initial therapy with NSAIDs, NSAIDs plus gastroprotective agents, or celecoxib in the treatment of arthritis.

OBJECTIVE: The purpose of this study is to provide a framework for estimating the economic efficiency of nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), concomitant gastroprotective agents (GPAs) to reduce the risk of NSAID toxicity, and celecoxib, a specific cyclo-oxygenase-2 inhibitor. Concomitant GPA therapies considered include one of the following: proton pump inhibitors (PPIs) plus NSAIDs, histamine H2 receptor antagonists (H2RAs) plus NSAIDs, misoprostol plus NSAIDs, and a single tablet formulation of diclofenac/misoprostol. DESIGN: The study employs a decision-tree framework to establish probabilities of upper gastrointestinal (GI) adverse events occurring over a 6-month time frame. Celecoxib clinical trial data are used to establish probabilities of upper GI events for celecoxib and NSAIDs, and published literature is used to predict upper GI events for the other concomitant therapies. Upper GI adverse events included in the decision-tree are as follows: GI discomfort, symptomatic ulcer, serious GI complications (with and without death), and anaemia with occult bleeding. MAIN OUTCOME MEASURES AND RESULTS: Clinical probabilities indicate celecoxib has significant tolerability and safety advantages compared with nonselective NSAIDs. Celecoxib also reduces the risk of GI adverse events to a similar or superior degree when compared with reductions observed with NSAIDs with concomitant GPAs. CONCLUSION: Use of celecoxib is expected to significantly reduce the economic costs of GI toxicity and its associated morbidity.

An economic model for determining the costs and consequences of using various treatment alternatives for the management of arthritis in Canada.

OBJECTIVE: To construct a decision analytical model to compare the costs and clinical consequences of treating patients with celecoxib or various nonsteroidal anti-inflammatory drug (NSAID)/gastrointestinal (GI) co-therapy regimens for the management of osteoarthritis and rheumatoid arthritis. The model quantified the number of patients expected to experience any GI complication commonly associated with NSAID therapy. DESIGN: Resource use for the treatment of each GI complication in the model was estimated after consulting Canadian experts. Standard unit costs from Ontario were applied to resources to calculate the cost of each complication. MAIN OUTCOME MEASURES AND RESULTS: The model revealed that the NSAID-alone regimen was associated with the lowest cost [$262 Canadian dollars ($Can) per patient per 6 months] followed by the celecoxib regimen ($Can273), diclofenac/misoprostol ($Can365), NSAID + histamine H2 receptor antagonist ($Can413), NSAID + misoprostol ($Can421), and NSAID + proton pump inhibitor ($Can731). A break-even analysis showed that up to 80% of the study cohort could be treated with celecoxib instead of the NSAID-alone regimen without increasing the health system's overall budget. Celecoxib was associated with the fewest GI-related deaths, hospitalised events; symptomatic ulcers, and cases of anaemia. The celecoxib regimen was also associated with the fewest cases of upper GI distress. Sensitivity analyses revealed that the model was most sensitive to the distribution of GI risk in the population and to the ingredient costs of the treatment alternatives. CONCLUSIONS: This model indicates that the use of celecoxib could lead to the avoidance of a significant number of NSAID-attributable GI adverse events, and the incremental cost of using celecoxib for arthritis patients > or = 65 years of age in place of current treatment alternatives would not impose an excessive incremental impact on a Canadian provincial healthcare budget.

Use of gasoline exposure data and assessment. A summary report of work group III.

The overall consensus of the Work Group was that the workshop provided an excellent opportunity for discussion of the scientific issues pertaining to non-occupational exposures to gasoline as it related to public health officials, legal and regulatory agencies, and industrial (workplace) concerns. It was enlightening to discuss the implications of new and existing data and methods for determining the public's exposure to gasoline. The workshop resulted in a list of data needs and a vision of the future research that will be required to aid future users of exposure data.

Integrating science and policy in a National Human Exposure Assessment Survey.

Despite tremendous progress in environmental protection over the past two decades, critical gaps remain in our understanding of actual human exposures to environmental chemicals. While the research community and the policy makers share the common goal of reducing environmental risks, it must be recognized that their information needs are often divergent. The design of effective exposure research must consider the needs and practical limitations of regulators and policy-makers and balance the often conflicting needs of policy and science. This paper examines some of the inherent conflicts between exposure research (science) and regulatory (policy) realities, and describes how the needs of policy makers were integrated into the design of a National Human Exposure Assessment Survey (NHEXAS). NHEXAS represents perhaps the most ambitious exposure surveillance effort ever undertaken. Exposure surveillance is presented as a model for bridging the gap between policy and science in the development of risk management approaches. The success of risk-based priority setting will depend upon the quality of information to support the risk assessment process. Environmental exposure surveillance will be essential to the characterization of risks and, ultimately, to the evaluation of the effectiveness of regulatory strategies.

Costs of epilepsy in an intermediate care facility for persons with mental retardation.

Epilepsy is a significant comorbid condition in institutionalized persons with developmental disabilities and may contribute significant additional costs. This study was conducted to provide an estimate of the costs of epilepsy from the institutional perspective. Costs were measured retrospectively for 50 persons with epilepsy and 50 persons without epilepsy matched by severity of developmental disability. A time and motion study was employed to assign opportunity costs to documented nursing and physician activities. Two separate methods of attribution were used and incremental costs attributable to epilepsy were found to be approximately $825 and $918 per person over a 6-month period. The following categories accounted for costs: personnel (47.0%), drug (39.6%), hospitalization (9.4%), and laboratories/procedures (4.0%). Results are useful for describing the economic burden of epilepsy.

A large-scale comparison of perspectives on parenting between teenage runaways and nonrunaways.

Teenage runaways were compared to teenage nonrunaways concerning their views on parenting behaviors. In ratings of reasons for running away, the runaways emphasized typical teenage issues such as differences in values from parents and rebellion. On the other hand, nonrunaways gave highest ratings to more dramatic issues such as parental abuse and drug use. Runaways were less likely to want to have children than nonrunaways and, if they did have children, runaways anticipated being very different with their children than their parents had been with them (e.g., more involved and open). Nonrunaways generally expected to be about the same as their parents had been. Suggestions for treatment, based on the findings, are offered.

Understanding environmental risk: the role of the laboratory in epidemiology, evaluation, and policy setting.

This paper examines the role of the laboratory in identifying environmental hazards, understanding human exposures and health effects, measuring environmental progress, and shaping the environmental health policy agenda for the future. The advances in laboratory techniques in the 1970s and 1980s provided the scientific foundation for a revolution in environmental policy. Despite the progress of the past two decades, many questions about the health effects of environmental exposures remain. The challenge to the laboratories is to provide a scientific framework for answering these questions. Three case studies of hazardous waste sites are presented to illustrate the needs for improved measurement of total human exposure to environmental pollutants. Recommendations are presented for expanding the role of the laboratory in measuring public health risks, evaluating the effectiveness of risk management strategies, and shaping the development of future environmental health policies.