Improving cardiovascular health at population level: 39 community cluster randomised trial of Cardiovascular Health Awareness Program (CHAP)

OBJECTIVE

To evaluate the effectiveness of the community based Cardiovascular Health Awareness Program (CHAP) on morbidity from cardiovascular disease.

DESIGN

Community cluster randomised trial.

SETTING

39 mid-sized communities in Ontario, Canada, stratified by location and population size.

PARTICIPANTS

Community dwelling residents aged 65 years or over, family physicians, pharmacists, volunteers, community nurses, and local lead organisations.

INTERVENTION

Communities were randomised to receive CHAP (n = 20) or no intervention (n = 19). In CHAP communities, residents aged 65 or over were invited to attend volunteer run cardiovascular risk assessment and education sessions held in community based pharmacies over a 10 week period; automated blood pressure readings and self reported risk factor data were collected and shared with participants and their family physicians and pharmacists.

MAIN OUTCOME MEASURE

Composite of hospital admissions for acute myocardial infarction, stroke, and congestive heart failure among all community residents aged 65 and over in the year before compared with the year after implementation of CHAP.

RESULTS

All 20 intervention communities successfully implemented CHAP. A total of 1265 three hour long sessions were held in 129/145 (89%) pharmacies during the 10 week programme. 15,889 unique participants had a total of 27,358 cardiovascular assessments with the assistance of 577 peer volunteers. After adjustment for hospital admission rates in the year before the intervention, CHAP was associated with a 9% relative reduction in the composite end point (rate ratio 0.91, 95% confidence interval 0.86 to 0.97; P = 0.002) or 3.02 fewer annual hospital admissions for cardiovascular disease per 1000 people aged 65 and over. Statistically significant reductions favouring the intervention communities were seen in hospital admissions for acute myocardial infarction (rate ratio 0.87, 0.79 to 0.97; P = 0.008) and congestive heart failure (0.90, 0.81 to 0.99; P = 0.029) but not for stroke (0.99, 0.88 to 1.12; P = 0.89).

CONCLUSIONS

A collaborative, multi-pronged, community based health promotion and prevention programme targeted at older adults can reduce cardiovascular morbidity at the population level. Trial registration Current controlled trials ISRCTN50550004.

Shifts in expectations: evaluating physicians' perceptions as pharmacists become integrated into family practice

The objective of this study was to measure how primary care family physicians perceived their own and pharmacists' contributions to medication processes as pharmacists become integrated into primary care group family practices. The 22- item Family Medicine Medication Use Processes Matrix was mailed to physicians in seven sites at the 3rd, 12th and 19th month of pharmacist integration. Paired sample t-tests for the third month results were conducted to compare perceptions between pharmacist and physician contributions. One way repeated measure ANOVA test was conducted to determine significant changes over time. Physicians initially perceived their own contributions to be significantly higher than pharmacists in three subscales: Diagnosis & Prescribing, Monitoring and Administration/Documentation and their own contributions to be significantly lower than the pharmacists in the Education subscale. Over time, physicians perceived increases in the pharmacists' contribution to the Diagnosis & Prescribing, Monitoring and Medication Review subscales and decreases in their own contribution to the Diagnosis & Prescribing and Education subscales. Changes in family physicians' perceptions of pharmacists' contribution demonstrate an initial underestimate of pharmacists' role in primary care family practice and a gradual recognition of expertise and competence. This may have led to increased comfort in sharing aspects of contribution to medication use processes.

Discontinuing Benzodiazepine Therapy: An Interdisciplinary Approach at a Geriatric Day Hospital

Background:

Despite the known adverse effects of benzodiazepines, elderly people commonly use these drugs over long periods to treat insomnia and anxiety. This qualitative study was conducted to examine the experiences of patients and care providers in a geriatric day hospital (GDH) as patients participated in a benzodiazepine tapering process, to identify the components and processes of the benzodiazepine tapering intervention, and to begin exploring how they influence patient outcomes.

Methods:

The study was conducted in a GDH in a Canadian city. Data were gathered from a discussion group and from individual semistructured interviews with 13 health care providers and 5 patients. Charts were reviewed to gather demographic data and confirm provider activities. A reflexive approach was conducted whereby each care provider reviewed and modified the role description created from information provided during his or her interview. Themes were determined through constant comparative analysis of transcripts, which included 5 meetings of the research team.

Results:

The tapering of benzodiazepines at the GDH was effected primarily by 3 people: the physician, the pharmacist and the nurse. Other members of the interdisciplinary team were not always aware of which patients were tapering their benzodiazepine therapy, but they supported patients in a variety of ways. The patients included in this analysis were willing to taper their benzodiazepines and did not consider the experience significant in any way.

Conclusion:

The health care provider roles, processes and tools described here could be replicated in other environments to assist patients who are tapering benzodiazepine therapy. Further research is needed to understand the interrelationships of all components of GDH care to determine their relative importance in facilitating behaviour change related to benzodiazepine tapering.

Managing clinical trials

Managing clinical trials, of whatever size and complexity, requires efficient trial management. Trials fail because tried and tested systems handed down through apprenticeships have not been documented, evaluated or published to guide new trialists starting out in this important field. For the past three decades, trialists have invented and reinvented the trial management wheel. We suggest that to improve the successful, timely delivery of important clinical trials for patient benefit, it is time to produce standard trial management guidelines and develop robust methods of evaluation.

Integrating into family practice: the experiences of pharmacists in Ontario, Canada

Aims and objectives

This research examines the experiences of pharmacists as they integrated and adapted to meet the drug-related needs of family practice settings.

Setting

This research took place in physician-led group family medicine practices in Ontario, Canada. Each practice was in the process of integrating an on-site pharmacist.

Methods

Qualitative design using monthly pharmacist narrative reports (over the first 4months of pharmacist integration) and N-VIVO qualitative analysis software. Four independent researchers with varied professional backgrounds used descriptive thematic editing analysis to determine process and content themes. The analysis team created a draft of themes and received written feedback from each pharmacist.

Key findings

Four key themes emerged describing how pharmacists experienced the first several months working in family practice: (1) feelings: emotional challenges and victories; (2) establishing and building relationships: positive and negative experiences with physicians and staff; (3) learning new skills to contribute effectively and efficiently to patient care; and (4) strategies for integration: including practical demonstration of potential value to physicians to facilitate integration process. In addition, they identified a number of supports and constraints for integration.

Conclusion

The pharmacists' narratives demonstrate the challenges and rewards of the integration process. Adaptability and practical demonstration of potential utilization and benefit were crucial in physician acceptance of the pharmacist program. This description of the pharmacists' journey will be helpful for pharmacists, managers, policy-makers, researchers and educators as more pharmacists enter this type of primary care practice.

Pharmacist's identity development within multidisciplinary primary health care teams in Ontario; qualitative results from the IMPACT project

BACKGROUND

Multidisciplinary team development generates changes in roles, responsibilities, and identities of individual health care providers. The Integrating Family Medicine and Pharmacy to Advance Primary Care Therapeutics (IMPACT) project introduced pharmacists into family practice teams across Ontario, Canada, to provide medication assessments, drug information, and academic detailing and to develop office system enhancements to improve drug therapy.

OBJECTIVE

To analyze pharmacists' narrative accounts during early integration to study identity development within emerging team-based care.

METHOD

Qualitative design using 63 pharmacist narrative reports of pharmacists' experiences over a 9-month integration period. Four independent researchers with varied professional backgrounds used immersion and crystallization to identify codes and iterative grounded theory to determine and debate process and content themes relevant to identity development.

RESULTS

The pharmacists' narratives spoke of the daily experiences of integrating into a family practice setting: feeling valued and contributing concretely to patient care; feeling underutilized; feeling like a nuisance, or feeling as though working too slowly. Pharmacist mentors helped deal with uncertainty and complexity of care. Pharmacists perceived that complementary clinical contributions enhanced their status with physicians and motivated pharmacists to take on new responsibilities. Changes in perspective, clinic-relevant skill development, and a new sense of professionalism signaled an emerging pharmacist family practice identity.

CONCLUSION

Pharmacists found that the integration into team-based primary health care provided both challenges and fresh opportunities. Pharmacists' professional identities evolved in relation to valued role models, emerging practice-level opportunities, and their patient-related contributions.

Integrating pharmacists into family practice teams: physicians' perspectives on collaborative care

OBJECTIVE

To explore family physicians' perspectives on collaborative practice 12 months after pharmacists were integrated into their family practices.

DESIGN

Qualitative design using focus groups followed by semistructured interviews.

SETTING

Seven physician-led group family practices in urban, suburban, and semirural Ontario communities.

PARTICIPANTS

Twelve purposively selected family physicians participating in the IMPACT (Integrating family Medicine and Pharmacy to Advance primary Care Therapeutics) project.

METHODS

We conducted 4 exploratory focus groups to gather information on collaborative practice issues in order to construct our interview guide. We later interviewed 12 physicians 1 year into the integration process. Focus groups and interviews were audiotaped and transcribed verbatim. Four researchers used immersion and crystallization techniques to identify codes for the data and thematic editing to distil participants' perspectives on physician-pharmacist collaborative practice. FINDINGS The focus groups revealed concerns relating to operational efficiencies, medicolegal implications, effects on patient-physician relationships, and work satisfaction. The follow-up semistructured interviews revealed ongoing operational challenges, but several issues had resolved and clinical and practice-level benefits surfaced. Clinical benefits included having colleagues to provide reliable drug information, gaining fresh perspectives, and having increased security in prescribing. Practice-level benefits included group education, liaison with community pharmacies, and an enhanced sense of team. Persistent operational challenges included finding time to learn about pharmacists' role and skills and insufficient space in practices to accommodate both professionals.

CONCLUSION

Physicians' perspectives on collaborative practice 12 months after pharmacists were integrated into their family practices were positive overall. Some ongoing operational challenges remained. Several of the early concerns about collaborative practice had been resolved as physicians discovered the benefits of working with pharmacists, such as increased security in prescribing.

Cardiovascular Health Awareness Program (CHAP): a community cluster-randomised trial among elderly Canadians

OBJECTIVE

High blood pressure is an important and modifiable cardiovascular disease risk factor that remains under-detected and under-treated. Community-level interventions that address high blood pressure and other modifiable risk factors are a promising strategy to improve cardiovascular health in populations. The present study is a community cluster-randomised trial testing the effectiveness of CHAP (Cardiovascular Health Awareness Program) on the cardiovascular health of older adults.

METHODS

Thirty-nine mid-sized communities in Ontario, Canada were stratified by geographic location and size of the population aged >or=65 years and randomly allocated to receive CHAP or no intervention. In CHAP communities, residents aged >or=65 years were invited to attend cardiovascular risk assessment sessions held in pharmacies over 10 weeks in Fall, 2006. Sessions included blood pressure measurement and feedback to family physicians. Trained volunteers delivered the program with support from pharmacists, community nurses and local organisations.

RESULTS

The primary outcome measure is the relative change in the mean annual rate of hospital admission for acute myocardial infarction, congestive heart failure and stroke (composite end-point) among residents aged >or=65 years in intervention and control communities, using routinely collected, population-based administrative health data.

CONCLUSION

This paper highlights considerations in design, implementation and evaluation of a large-scale, community-wide cardiovascular health promotion initiative.

Narrative reports to monitor and evaluate the integration of pharmacists into family practice settings

PURPOSE

Narratives can capture unfolding events and negotiation of roles and thus can help to evaluate interventions in interdisciplinary health care teams. We describe a practical qualitative method, the narrative report, and its role in evaluating implementation research.

METHODS

We used narrative reports as a means to evaluate an intervention to integrate pharmacists into group family practices. The pharmacists submitted 63 written narrative reports during a 1-year period. Our interdisciplinary research team analyzed these reports to monitor the progress of the implementation, to identify pharmacists' needs, and to capture elements of the integration process.

RESULTS

The monthly narrative reports allowed the research team to document early learning and calibrate the program in terms of clinical support, adapting roles, and realigning expectations. The reports helped the research team stay in tune with practice-related implementation challenges, and the preliminary summary of narrative findings provided a forum for sharing innovations among the integrating pharmacists.

CONCLUSION

The narrative report can be a successful qualitative tool to track and evaluate the early stages of an intervention in the context of evolving primary health care teams.

Evaluation of the Ages and Stages Questionnaires in identifying children with neurosensory disability in the Magpie Trial follow-up study

AIM

To evaluate performance of the Ages and Stages Questionnaires (full ASQ), and a shortened version (short ASQ), in detecting children with severe neurosensory disability in the Magpie Trial follow-up study.

METHODS

All children, born to women in the Magpie Trial and selected for follow-up, with a completed full 30 items and/or short 9-items ASQ were included in this analysis. Sensitivity and specificity, corrected for verification bias, were computed to assess detection ability.

RESULTS

Of the 2046 children who completed a full ASQ, 406 (19.8%) failed the assessment, 54 of whom had confirmed neurosensory disability. Adjusted sensitivity and specificity (95% confidence intervals) were 87.4% (62.9-96.6%), and 82.3% (80.5-83.9%), respectively. Two of the five domains in the full ASQ (Fine Motor and Problem Solving) contributed little to detection ability. Sensitivity and specificity for the short ASQ were 69.2% and 95.7%, respectively.

CONCLUSIONS

Sensitivity of the full ASQ for severe neurosensory disability is generally good, and does not appear to be much reduced by restricting questions to three out of the five domains. The short ASQ reported here reduced performance, although this might be improved by a different choice of questions or scoring system.

A community-based program for cardiovascular health awareness

OBJECTIVE

The objective of the Cardiovascular Health Awareness Program (CHAP) is to improve the processes of care related to the cardiovascular health of older adults.

PARTICIPANTS

Two Ontario communities including family physicians (FP), pharmacists, public health units and nurses, volunteer peer health educators, older adult patients and community organizations.

SETTING

Community pharmacies and family physician offices.

INTERVENTION

CHAP is designed to close a process of care loop around cardiovascular health awareness that originates from, and returns to, the FP. Older patients are invited by their FP to attend pharmacy CHAP sessions. At these sessions, trained volunteer peer health educators (PHEs) assist patients both in recording their blood pressure using a calibrated automated device and in completing a cardiovascular risk profile. This information is relayed to their respective FP via an automated computerized database. Pharmacists and patients receive copies of the results. Based on these cumulative risk profiles, patients are advised to follow-up with their FP.

OUTCOMES

Of the FPs and pharmacists asked, 47% and 79%, respectively, agreed to participate in the project. 39% of older adult patients invited by their FPs attended the CHAP community pharmacy sessions. Of these, 100% agreed to having their risk profile, including their blood pressure readings, forwarded to their FP. Positive feedback about CHAP was expressed by the volunteer PHEs, the FPs and the pharmacists.

CONCLUSION

The community-based pharmacy CHAP sessions are a feasible way of improving patient, physician, and pharmacist access to reliable blood pressure measurements and to cardiovascular health information. A randomized trial is in progress that will assess the impact of CHAP on monitoring of blood pressure.

A community-based program for cardiovascular health awareness

OBJECTIVE

The objective of the Cardiovascular Health Awareness Program (CHAP) is to improve the processes of care related to the cardiovascular health of older adults.

PARTICIPANTS

Two Ontario communities including family physicians (FP), pharmacists, public health units and nurses, volunteer peer health educators, older adult patients and community organizations.

SETTING

Community pharmacies and family physician offices.

INTERVENTION

CHAP is designed to close a process of care loop around cardiovascular health awareness that originates from, and returns to, the FP. Older patients are invited by their FP to attend pharmacy CHAP sessions. At these sessions, trained volunteer peer health educators (PHEs) assist patients both in recording their blood pressure using a calibrated automated device and in completing a cardiovascular risk profile. This information is relayed to their respective FP via an automated computerized database. Pharmacists and patients receive copies of the results. Based on these cumulative risk profiles, patients are advised to follow-up with their FP.

OUTCOMES

Of the FPs and pharmacists asked, 47% and 79%, respectively, agreed to participate in the project. 39% of older adult patients invited by their FPs attended the CHAP community pharmacy sessions. Of these, 100% agreed to having their risk profile, including their blood pressure readings, forwarded to their FP. Positive feedback about CHAP was expressed by the volunteer PHEs, the FPs and the pharmacists.

CONCLUSION

The community-based pharmacy CHAP sessions are a feasible way of improving patient, physician, and pharmacist access to reliable blood pressure measurements and to cardiovascular health information. A randomized trial is in progress that will assess the impact of CHAP on monitoring of blood pressure.

Final results of MRC CRASH, a randomised placebo-controlled trial of intravenous corticosteroid in adults with head injury-outcomes at 6 months

MRC CRASH is a randomised controlled trial (ISRCTN74459797) of the effect of corticosteroids on death and disability after head injury. We randomly allocated 10,008 adults with head injury and a Glasgow Coma Scale score of 14 or less, within 8 h of injury, to a 48-h infusion of corticosteroid (methylprednisolone) or placebo. Data at 6 months were obtained for 9673 (96.7%) patients. The risk of death was higher in the corticosteroid group than in the placebo group (1248 [25.7%] vs 1075 [22.3%] deaths; relative risk 1.15, 95% CI 1.07-1.24; p=0.0001), as was the risk of death or severe disability (1828 [38.1%] vs 1728 [36.3%] dead or severely disabled; 1.05, 0.99-1.10; p=0.079). There was no evidence that the effect of corticosteroids differed by injury severity or time since injury. These results lend support to our earlier conclusion that corticosteroids should not be used routinely in the treatment of head injury.

Effect of intravenous corticosteroids on death within 14 days in 10008 adults with clinically significant head injury (MRC CRASH trial): randomised placebo-controlled trial

BACKGROUND

Corticosteroids have been used to treat head injuries for more than 30 years. In 1997, findings of a systematic review suggested that these drugs reduce risk of death by 1-2%. The CRASH trial--a multicentre international collaboration--aimed to confirm or refute such an effect by recruiting 20000 patients. In May, 2004, the data monitoring committee disclosed the unmasked results to the steering committee, which stopped recruitment.

METHODS

10008 adults with head injury and a Glasgow coma score (GCS) of 14 or less within 8 h of injury were randomly allocated 48 h infusion of corticosteroids (methylprednisolone) or placebo. Primary outcomes were death within 2 weeks of injury and death or disability at 6 months. Prespecified subgroup analyses were based on injury severity (GCS) at randomisation and on time from injury to randomisation. Analysis was by intention to treat. Effects on outcomes within 2 weeks of randomisation are presented in this report. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN74459797.

FINDINGS

Compared with placebo, the risk of death from all causes within 2 weeks was higher in the group allocated corticosteroids (1052 [21.1%] vs 893 [17.9%] deaths; relative risk 1.18 [95% CI 1.09-1.27]; p=0.0001). The relative increase in deaths due to corticosteroids did not differ by injury severity (p=0.22) or time since injury (p=0.05).

INTERPRETATION

Our results show there is no reduction in mortality with methylprednisolone in the 2 weeks after head injury. The cause of the rise in risk of death within 2 weeks is unclear.

The MRC CRASH Trial: study design, baseline data, and outcome in 1000 randomised patients in the pilot phase

OBJECTIVES

To test the design and feasibility of a large scale multicentre randomised controlled trial evaluating the efficacy and safety of a high dose corticosteroid infusion after head injury. To assess whether large numbers of patients could be enrolled and treated within eight hours from injury and then followed up at six months.

METHODS

Randomised placebo controlled multicentre trial of a 48 hour corticosteroid infusion after significant head injury. All head injured adults who were observed while in hospital to have GCS of 14 or less (out of a maximum score of 15), and who were within eight hours of the injury, were eligible for trial entry. Analysis of baseline and outcome data (for both treatment groups combined) for 1000 patients enrolled in the pilot phase of the MRC CRASH Trial.

RESULTS

Fifty two hospitals in 14 countries participated in the pilot phase, recruiting an average of one patient per hospital per month. Of the 1000 randomised patients, 330 (33%) had mild head injury, 289 (29%) had moderate head injury, and 381 (38%) had severe head injury. Seven hundred and nine (71%) patients were randomised within three hours of injury. Outcome at two weeks from injury was known for 991 (99%) patients, of whom 170 (17%) patients died. At the time of writing, six month follow up for the first 500 patients was nearly complete. Vital status was known for 465 (93%) of the 500 patients, of whom 97 (21%) had died. Functional status based on the Glasgow Outcome Scale was known for 438 (88%) of the 500 patients: 21% were dead, 17% were severely disabled, 22% were moderately disabled, and 34% had made a good recovery.

CONCLUSIONS

The trial procedures proved practicable and a wide variety of patients were recruited in the emergency department within eight hours of injury. Using simple outcome measures, large numbers of patients can be successfully followed up.

Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomised placebo-controlled trial

BACKGROUND

Anticonvulsants are used for pre-eclampsia in the belief they prevent eclamptic convulsions, and so improve outcome. Evidence supported magnesium sulphate as the drug to evaluate.

METHODS

Eligible women (n=10141) had not given birth or were 24 h or less postpartum; blood pressure of 140/90 mm Hg or more, and proteinuria of 1+ (30 mg/dL) or more; and there was clinical uncertainty about magnesium sulphate. Women were randomised in 33 countries to either magnesium sulphate (n=5071) or placebo (n=5070). Primary outcomes were eclampsia and, for women randomised before delivery, death of the baby. Follow up was until discharge from hospital after delivery. Analyses were by intention to treat.

FINDINGS

Follow-up data were available for 10,110 (99.7%) women, 9992 (99%) of whom received the allocated treatment. 1201 of 4999 (24%) women given magnesium sulphate reported side-effects versus 228 of 4993 (5%) given placebo. Women allocated magnesium sulphate had a 58% lower risk of eclampsia (95% CI 40-71) than those allocated placebo (40, 0.8%, vs 96, 1.9%; 11 fewer women with eclampsia per 1000 women). Maternal mortality was also lower among women allocated magnesium sulphate (relative risk 0.55, 0.26-1.14). For women randomised before delivery, there was no clear difference in the risk of the baby dying (576, 12.7%, vs 558, 12.4%; relative risk 1.02, 99% CI 0.92-1.14). The only notable difference in maternal or neonatal morbidity was for placental abruption (relative risk 0.67, 99% CI 0.45-0.89).

INTERPRETATION

Magnesium sulphate halves the risk of eclampsia, and probably reduces the risk of maternal death. There do not appear to be substantive harmful effects to mother or baby in the short term.

Bird fanciers' lung: a case report

The clinical course of a case of bird fanciers' lung is described along with the considerations that are important in the management of this form of hypersensitivity pneumonitis. Diagnostic parameters, therapeutic considerations, and environmental issues are discussed in the context of the current literature.

Barbados Low Dose Aspirin Study in Pregnancy (BLASP): a randomised trial for the prevention of pre-eclampsia and its complications

OBJECTIVE

To determine whether prophylactic, low dose controlled-release aspirin improves outcome for pregnant women and their babies in Barbados.

DESIGN

Randomised placebo-controlled trial.

SETTING

The Queen Elizabeth Hospital, Barbados.

POPULATION

All women attending antenatal clinics between 12 and 32 weeks of gestation were eligible, if without specific contraindications to aspirin and unlikely to deliver immediately.

METHODS

Randomisation was computer-generated in the antenatal clinic; 1822 women were allocated to receive 75 mg controlled-release aspirin and 1825 matching placebo.

MAIN OUTCOME MEASURES

Proteinuric pre-eclampsia, other pregnancy-induced hypertension, pregnancy duration, birthweight, stillbirths and neonatal deaths, major neonatal events.

RESULTS

All but three women from each group were followed up successfully. Forty-four percent were primigravid, and 8% had previous obstetric complications. There were no significant differences between the allocated treatment groups in the incidence of proteinuric pre-eclampsia (40 [2.2%] of those allocated aspirin, compared with 46 [2.5%] allocated placebo), of preterm delivery (255 [14.0%] vs 270 [14.8%]), of birthweight < 1500 g (32 [1.7%] vs 33 [1.8%]) or of stillbirth and neonatal death (44 [2.4%] vs 38 [2.1%]). Aspirin was not associated with excess risk of maternal or fetal bleeding.

CONCLUSIONS

The results of this study in Barbados do not support the routine use of low dose aspirin for prevention of pre-eclampsia or its complications, confirming results of previous large trials in other settings.

Qualitative comparison of the reliability of health status assessments with the EuroQol and SF-36 questionnaires after stroke. United Kingdom Collaborators in the International Stroke Trial

BACKGROUND AND PURPOSE

The reliability of the EuroQol and SF-36 questionnaires after stroke is not known. We therefore aimed to assess and compare the test-retest reliability of both instruments in a group of stroke patients.

METHODS

A total of 2253 patients with stroke entered by United Kingdom hospitals in the International Stroke Trial were randomized to follow up with either the EuroQol or the SF-36 instruments. For both instruments, we randomly selected one third of respondents and asked them to complete another, identical questionnaire. We assessed test-retest reliability using agreement statistics: unweighted kappa statistics for the categorical domains of the EuroQol and intraclass correlation coefficients for the EuroQol visual analog scale, utility scores, and SF-36.

RESULTS

For the five categorical domains of the EuroQol, reproducibility was generally good (kappa ranged from 0.63 to 0.80). The reproducibility of the domains of the SF-36 was qualitatively similar for all the domains except mental health (intraclass correlation coefficient=.28). However, the 95% confidence intervals for the difference in scores between test and retest were substantial. For both instruments, reproducibility was better when the patient completed the questionnaires than when a proxy did.

CONCLUSIONS

Both the EuroQol and SF-36 have acceptable and qualitatively similar test-retest reliability. Therefore, either instrument might function effectively as a discriminatory measure for assessing health-related quality-of-life outcomes in groups of patients after stroke. However, our data do not support the use of either instrument for serial assessments in individual patients unless very large differences over time are expected.

Repair of craniofacial defects with hydroxyapatite cement

PURPOSE

The objective of this study was to evaluate the course of healing of craniofacial bone defects when filled with hydroxyapatite cement and to determine whether adding various percentages by weight of demineralized bone powder to the cement will result in enhanced bone formation.

MATERIALS AND METHODS

The model for the study was the canine calvarium. The implants were placed into cranial defects and harvested at 3 or 6 months for qualitative evaluation by light microscopy, microradiography, and quantitative histomorphometry.

RESULTS

The implantation of hydroxyapatite cement resulted in characteristic replacement of the material with new bone ingrowth. The addition of demineralized bone powder to the hydroxyapatite cement appeared to improve the handling characteristics of the cement; however, improvement in the replacement of the material by bone was not observed. The implantation of only allogeneic demineralized bone showed limited new bone formation within the defect site.

CONCLUSIONS

Hydroxyapatite cement formed an effective osseoconductive scaffold for bone replacement. The addition of demineralized bone powder to the cement to serve as a carrier of osseoinductive factors did not result in additional bone being formed.

Kinetics of release of serotonin from isolated secretory granules. I. Amperometric detection of serotonin from electroporated granules

We developed a method for measuring the efflux of 5-hydroxytryptamine (5-HT, serotonin) from isolated intact granules of the mast cell of the beige mouse. This method combines electroporation of the vesicle membrane with amperometric detection of 5-HT. A single secretory granule is placed between two platinum electrodes (distance approximately 100 microm) and positioned adjacent (<1 microm) to a carbon fiber microelectrode. A short (approximately 30 micros) high-intensity voltage pulse (electric field of approximately 5 kV/cm) is delivered to the electrodes to trigger the mechanical breakdown of the granule membrane, which activates the release of 5-HT. We observed concurrent swelling of the granule matrix with the oxidation of 5-HT at the carbon fiber electrode (overpotential + 650 mV). Similar to the release of secretory products during exocytosis, the oxidation current exhibits a spike-like time course with a noninstantaneous rising phase (time between onset of current and maximum flux, t(max)) with approximately 25% of the molecules released during this period. When the current reaches its maximum, the granule matrix attains its maximum swollen state. We found that the rising phase depends on the initial cross-sectional area of the granule (t(max) approximately 21r2) and reflects the time required for membrane rupture. The average t(1/2)spike of the amperometric spikes was found to be approximately 150 ms, which is 3-7 times faster than the t(1/2) measured during cellular exocytosis.

Kinetics of release of serotonin from isolated secretory granules. II. Ion exchange determines the diffusivity of serotonin

We measured the efflux of 5-hydroxytryptamine (5-HT, serotonin) from an intact secretory granule extracted from the mast cell of the beige mouse. The efflux was measured with amperometry after rupture of the granule membrane was triggered by electroporation. We determined the diffusivity of 5-HT within the secretory granule to be 2.0 x 10(-8) cm2 s(-1) when the granule is in contact with a physiological saline and found that this diffusivity depends on the valence of the cation in the external electrolyte. There is a fivefold increase in the diffusion coefficient of 5-HT determined in CsCl (150 mM, pH 7.2) at 3.7 x 10(-8) cm2 s(-1) compared to that determined in histamine dihydrochloride (Hi, 100 mM at pH 4.5) at 0.7 x 10(-8) cm2 s(-1). We found that the rate of expansion of the granule matrix observed in physiological medium correlates with the efflux of 5-HT, and that the rate of swelling of the matrix and the efflux depend on the microviscosity within the granule matrix and not the bulk viscosity of the external solution. The low diffusivity of 5-HT (approximately 500-fold less than in the bulk), the observation that the valence of the counterion affects this diffusivity, and the relationship between the volume changes of the matrix and the efflux suggest that 5-HT is released from the granule by ion exchange. We discuss the implications of this result for exocytotic release in mast cells and propose that an ion exchange mechanism could control the rate of release in other secretory systems.

The effect of hydralazine on the development of tolerance to continuous nitroglycerin

It has been reported that nitroglycerin (GTN) tolerance can be prevented by the concurrent administration of hydralazine. Although the mechanism of this effect remains unknown, it is possible that hydralazine modifies counter-regulatory responses to nitrate administration. To address this question, we examined the impact of hydralazine therapy on the development of tolerance during sustained therapy with GTN. Twenty normal volunteers and 18 patients with chronic heart failure (mean ejection fraction 30 +/- 2%) were treated for 1 week with hydralazine or placebo in a randomized double-blind fashion. Hydralazine therapy (or placebo) was continued, and subjects then received continuous transdermal GTN for 5 to 7 days. On the first and last day of transdermal GTN therapy, standing HR, systolic blood pressure and hematocrit responses were assessed. HR and blood pressure responses to sublingual GTN (0.6 mg) were also evaluated before and during sustained transdermal GTN therapy. Significant loss of the hemodynamic effects of transdermal GTN occurred during sustained therapy in both the normal volunteer and heart failure groups. Hydralazine had no effect on the development of tolerance to the hemodynamic effect of GTN in either group. In both, transdermal GTN therapy was associated with a significant fall in hematocrit that persisted for the entire treatment period. Hydralazine had no effect on this response. These data suggest that hydralazine therapy does not prevent loss of systemic arterial effects or prevent plasma volume expansion during sustained transdermal GTN therapy.

Effects of diuretic therapy on the development of tolerance to nitroglycerin and exercise capacity in patients with chronic stable angina

BACKGROUND

Therapy with diuretics has been reported to prevent the development of nitrate tolerance. Importantly, diuretics may have independent antianginal effects through their effects on intravascular volume. The present investigation was designed to determine whether diuretic therapy could prevent the development of tolerance to continuous transdermal nitroglycerin. The study was also designed to examine whether diuretic therapy has an independent antianginal effect.

METHODS AND RESULTS

Twelve patients with chronic stable angina were studied in a randomized, double-blind, crossover trial. Patients received diuretic (hydrochlorothiazide plus amiloride) or placebo for 14 to 20 days. During each double-blind treatment period, patients underwent treadmill exercise testing on three separate occasions. The first exercise testing was performed after 7 to 10 days of single-blind, placebo transdermal nitroglycerin therapy. Subsequently, exercise testing was repeated on the first day of active transdermal nitroglycerin therapy and following 7 to 10 days of continuous transdermal nitroglycerin application. Therapy with a diuretic was associated with an increase in exercise capacity but had no effect on nitroglycerin tolerance. During therapy with placebo transdermal nitroglycerin, diuretic therapy caused an increase in treadmill walking time to the development of moderate angina compared with placebo (371 +/- 26 versus 288 +/- 16 seconds, diuretic versus placebo, P < .01). Similar results were obtained during both acute and sustained nitroglycerin therapy.

CONCLUSIONS

The results of this study demonstrate that therapy with a diuretic has no effect on the development of tolerance to continuous transdermal nitroglycerin. Interestingly, diuretic therapy itself has important antianginal effects and improves exercise capacity in patients with stable angina.

Experimental phase changes at the mica-silver interface illustrate the experimental accuracy of the central film thickness in a symmetrical three-layer interferometer

Experimentally measured phase changes of light on reflection at the mica-silver interface are reexamined and found to be in agreement with those calculated using modern optical constants. Phase changes on reflection at a dielectric-silver interface can therefore be calculated using the well-known analytical (cf. empirical) expressions and the optical constants, provided the refractive index of the dielectric is known or measured and the silver films are prepared in a similar manner. This discussion is relevant to measurements obtained from the surface forces apparatus. When the surface separation is calculated by Airy's method, we show that the phase changes on reflection at the dielectric-silver interface at the reference wavelengths are either explicitly or implicitly accounted for in all the expressions. We also show that the surface forces technique (spectrometer resolution, ~32 Å mm(-1)) is inaccurate for measuring the thickness of very thin aqueous films (<10 Å) and that for all practical purposes the central film thickness has to be >50 Å to achieve a resolution of 1 Å.

Intermittent transdermal nitroglycerin therapy. Decreased anginal threshold during the nitrate-free interval

BACKGROUND

Intermittent transdermal nitroglycerin therapy is effective in the treatment of stable angina and prevents the development of tolerance. Previous investigations have suggested that removal of nitroglycerin patches may be associated with a decrease in anginal threshold. This study examines the effect of nitroglycerin patch removal on anginal threshold in a group of patients with stable angina.

METHODS AND RESULTS

Twelve patients with stable angina were enrolled in a randomized, double-blind, placebo-controlled, crossover study. These patients had reproducible treadmill walking times and were taking no other long-acting antianginal medications or vasodilators. They received 0.8 mg/h transdermal nitroglycerin or wore a matching placebo patch for 5 to 7 days and then crossed over to the other treatment arm of the study. Transdermal nitroglycerin was applied at 8:00 PM and removed at 8:00 AM each day. On the last day of each treatment period, patients underwent treadmill exercise testing at 8:00 AM (before patch removal) and at 2, 4, and 6 hours after patch removal. The primary end point was the treadmill walking time until moderate angina (P2). Other end points included the treadmill walking time until onset of angina (P1), the amount of ST segment depression at P1 and P2, and treadmill walking time until the development of 1 mm ST depression. Heart rate, systolic blood pressure, and the rate-pressure product were determined at rest before exercise and at P1 and P2. At 8:00 AM P1 and P2 were not significantly affected by active nitroglycerin compared with placebo, indicating the development of tolerance. Removal of the active transdermal nitroglycerin patch was associated with a significant decrease in the time to P1 at 2, 4, and 6 hours after patch removal compared with placebo. There was also a decrease in the time to P2 after active patch removal that was statistically significant compared with placebo at 2 and 4 hours and was of borderline significance at 6 hours. There were no differences in heart rate, blood pressure, or amount of ST segment depression at either P1 or P2 after active compared with placebo patch removal.

CONCLUSIONS

In patients with stable angina pectoris, intermittent transdermal nitroglycerin therapy is associated with a decrease in anginal threshold for 4 to 6 hours after patch removal. Although the cause of this phenomenon remains uncertain, it may be due to counterregulatory responses that develop during nitroglycerin patch application.