Impact of mental disorders on unplanned readmissions for congestive heart failure patients: a population-level study

AIMS

Reducing preventable hospitalization for congestive heart failure (CHF) patients is a challenge for health systems worldwide. CHF patients who also have a recent or ongoing mental disorder may have worse health outcomes compared with CHF patients with no mental disorders. This study examined the impact of mental disorders on 28 day unplanned readmissions of CHF patients.

METHODS AND RESULTS

This retrospective cohort study used population-level linked public and private hospitalization and death data of adults aged ≥18 years who had a CHF admission in New South Wales, Australia, between 1 January 2014 and 31 December 2020. Individuals' mental disorder diagnosis and Charlson comorbidity and hospital frailty index scores were derived from admission records. Competing risk and cause-specific risk analyses were conducted to examine the impact of having a mental disorder diagnosis on all-cause hospital readmission. Of the 65 861 adults with index CHF admission discharged alive (mean age: 78.6 ± 12.1; 48% female), 19.2% (12 675) had at least one unplanned readmission within 28 days following discharge. Adults with CHF with a mental disorder diagnosis within 12 months had a higher risk of 28 day all-cause unplanned readmission [hazard ratio (HR): 1.21, 95% confidence interval (CI): 1.15-1.27, P-value < 0.001], particularly those with anxiety disorder (HR: 1.49, 95% CI: 1.35-1.65, P-value < 0.001). CHF patients aged ≥85 years (HR: 1.19, 95% CI: 1.11-1.28), having ≥3 other comorbidities (HR: 1.35, 95% CI: 1.25-1.46), and having an intermediate (HR: 1.34, 95% CI: 1.28-1.40) or high (HR: 1.37, 95% CI: 1.27-1.47) frailty score on admission had a higher risk of unplanned readmission. CHF patients with a mental disorder who have ≥3 other comorbidities and an intermediate frailty score had the highest probability of unplanned readmission (29.84%, 95% CI: 24.68-35.73%) after considering other patient-level factors and competing events.

CONCLUSIONS

CHF patients who had a mental disorder diagnosis in the past 12 months are more likely to be readmitted compared with those without a mental disorder diagnosis. CHF patients with frailty and a mental disorder have the highest probability of readmission. Addressing mental health care services in CHF patient's discharge plan could potentially assist reduce unplanned readmissions.

Implementation of large, multi-site hospital interventions: a realist evaluation of strategies for developing capability

BACKGROUND

This study presents guidelines for implementation distilled from the findings of a realist evaluation. The setting was local health districts in New South Wales, Australia that implemented three clinical improvement initiatives as part of a state-wide program. We focussed on implementation strategies designed to develop health professionals' capability to deliver value-based care initiatives for multisite programs. Capability, which increases implementers' ability to cope with unexpected scenarios is key to managing change.

METHODS

We used a mixed methods realist evaluation which tested and refined program theories elucidating the complex dynamic between context (C), mechanism (M) and outcome (O) to determine what works, for whom, under what circumstances. Data was drawn from program documents, a realist synthesis, informal discussions with implementation designers, and interviews with 10 key informants (out of 37 identified) from seven sites. Data analysis employed a retroductive approach to interrogate the causal factors identified as contributors to outcomes.

RESULTS

CMO statements were refined for four initial program theories: Making it Relevant- where participation in activities was increased when targeted to the needs of the staff; Investment in Quality Improvement- where engagement in capability development was enhanced when it was valued by all levels of the organisation; Turnover and Capability Loss- where the effects of staff turnover were mitigated; and Community-Wide Priority- where there was a strategy of spanning sites. From these data five guiding principles for implementers were distilled: (1) Involve all levels of the health system to effectively implement large-scale capability development, (2) Design capability development activities in a way that supports a learning culture, (3) Plan capability development activities with staff turnover in mind, (4) Increased capability should be distributed across teams to avoid bottlenecks in workflows and the risk of losing key staff, (5) Foster cross-site collaboration to focus effort, reduce variation in practice and promote greater cohesion in patient care.

CONCLUSIONS

A key implementation strategy for interventions to standardise high quality practice is development of clinical capability. We illustrate how leadership support, attention to staff turnover patterns, and making activities relevant to current issues, can lead to an emergent learning culture.

The role of frailty risk for fracture-related hospital readmission and mortality after a hip fracture

BACKGROUND

Frailty risk estimated using hospital administrative data may provide a useful clinical tool to identify older hip fracture patients at-risk of fracture-related readmissions and mortality. This study examined hip fracture hospitalisation temporal trends and explore the role of frailty risk in fracture-related readmission and mortality.

METHODS

This retrospective cohort study was conducted using linked hospital admission and mortality data in New South Wales, Australia. Patients aged ≥65 years were admitted after a hip fracture between 2014 and 2021 for temporal trends and those admitted and discharged after a hip fracture in 2014-2018 for fracture-related readmission. The Hospital Frailty Risk Score was estimated, and patients were followed for at least 36 months after discharge. A semi-competing risk analysis was used to examine the associations of frailty with fracture-related readmission and/or mortality.

RESULTS

Hip fracture hospitalisation rate was 472 per 100,000 and declined by 2.9 % (95 % confidence intervals (CI): -3.7 to -2.1) annually. Amongst 28,567 patients, 9.8 % were identified with low frailty risk, 39.4 %, intermediate frailty risk, and 50.6 % with high frailty risk. Patients with intermediate or high frailty risk had a higher chance of fracture-related readmission (Hazard ratios (HR): 1.33, 95 %CI: 1.21-1.47, HR: 1.65, 95 %CI: 1.49-1.83), death (HR: 1.50, 95 %CI: 1.38-1.63, HR: 1.80, 95 %CI: 1.65-1.96) and death post fracture-related readmission (HR: 1.32, 95 %CI: 1.12-1.56, HR: 1.56, 95 %CI: 1.32-1.84) than those with low frailty risk.

CONCLUSIONS

It appears that frailty risk estimated using hospital administrative data can contribute to identify patients who could benefit from targeted interventions to prevent further fractures.

Audit and feedback to reduce unwarranted clinical variation at scale: a realist study of implementation strategy mechanisms

BACKGROUND

Unwarranted clinical variation in hospital care includes the underuse, overuse, or misuse of services. Audit and feedback is a common strategy to reduce unwarranted variation, but its effectiveness varies widely across contexts. We aimed to identify implementation strategies, mechanisms, and contextual circumstances contributing to the impact of audit and feedback on unwarranted clinical variation.

METHODS

Realist study examining a state-wide value-based healthcare program implemented between 2017 and 2021 in New South Wales, Australia. Three initiatives within the program included audit and feedback to reduce unwarranted variation in inpatient care for different conditions. Multiple data sources were used to formulate the initial audit and feedback program theory: a systematic review, realist review, program document review, and informal discussions with key program stakeholders. Semi-structured interviews were then conducted with 56 participants to refute, refine, or confirm the initial program theories. Data were analysed retroductively using a context-mechanism-outcome framework for 11 transcripts which were coded into the audit and feedback program theory. The program theory was validated with three expert panels: senior health leaders (n = 19), Agency for Clinical Innovation (n = 11), and Ministry of Health (n = 21) staff.

RESULTS

The program's audit and feedback implementation strategy operated through eight mechanistic processes. The strategy worked well when clinicians (1) felt ownership and buy-in, (2) could make sense of the information provided, (3) were motivated by social influence, and (4) accepted responsibility and accountability for proposed changes. The success of the strategy was constrained when the audit process led to (5) rationalising current practice instead of creating a learning opportunity, (6) perceptions of unfairness and concerns about data integrity, 7) development of improvement plans that were not followed, and (8) perceived intrusions on professional autonomy.

CONCLUSIONS

Audit and feedback strategies may help reduce unwarranted clinical variation in care where there is engagement between auditors and local clinicians, meaningful audit indicators, clear improvement plans, and respect for clinical expertise. We contribute theoretical development for audit and feedback by proposing a Model for Audit and Feedback Implementation at Scale. Recommendations include limiting the number of audit indicators, involving clinical staff and local leaders in feedback, and providing opportunities for reflection.

Guiding principles for effective collaborative implementation strategies for multisite hospital improvement initiatives: a mixed-method realist evaluation of collaborative strategies used in four multisite initiatives at public hospitals in New South Wales, Australia

OBJECTIVE

Large-scale, multisite hospital improvement initiatives can advance high-quality care for patients. Implementation support is key to adoption of change in this context. Strategies that foster collaboration within local teams, across sites and between initiative developers and users are important. However not all implementation strategies are successful in all settings, sometimes realising poor or unintended outcomes. Our objective here is to develop guiding principles for effective collaborative implementation strategies for multi-site hospital initiatives.

DESIGN

Mixed-method realist evaluation. Realist studies aim to examine the underlying theories that explain differing outcomes, identifying mechanisms and contextual factors that may trigger them.

SETTING

We report on collaborative strategies used in four multi-site initiatives conducted in all public hospitals in New South Wales, Australia (n>100).

PARTICIPANTS

Using an iterative process, information was gathered on collaborative implementation strategies used, then initial programme theories hypothesised to underlie the strategies' outcomes were surfaced using a realist dialogic approach. A realist interview schedule was developed to elicit evidence for the posited initial programme theories. Fourteen participants from 20 key informants invited participated. Interviews were conducted via Zoom, transcribed and analysed. From these data, guiding principles of fostering collaboration were developed.

RESULTS

Six guiding principles were distilled: (1) structure opportunities for collaboration across sites; (2) facilitate meetings to foster learning and problem-solving across sites; (3) broker useful long-term relationships; (4) enable support agencies to assist implementers by giving legitimacy to their efforts in the eyes of senior management; (5) consider investment in collaboration as effective well beyond the current projects; (6) promote a shared vision and build momentum for change by ensuring inclusive networks where everyone has a voice.

CONCLUSION

Structuring and supporting collaboration in large-scale initiatives is a powerful implementation strategy if contexts described in the guiding principles are present.

Patient-reported experiences and outcomes following hospital care are associated with risk of readmission among adults with chronic health conditions

This study quantifies the association between patient reported measures (PRMs) and readmission to inform efforts to improve hospital care. A retrospective, cross-sectional study was conducted with adults who had chronic obstructive pulmonary disease (COPD) or congestive heart failure (CHF) and were admitted for acute care in a public hospital in New South Wales, Australia for any reason (n = 2394 COPD and 2476 CHF patients in 2018-2020). Patient- level survey data were linked with inpatient data for one year prior to risk-adjust outcomes and after discharge to detect all cause unplanned readmission to a public or private hospital. Ninety-day readmission rates for respondents with COPD or CHF were 17% and 19%. Crude rates for adults with COPD were highest among those who reported that hospital care and treatment helped "not at all" (28%), compared to those who responded, "to some extent" (20%) or "definitely" (15%). After accounting for patient characteristics, adults with COPD or CHF who said care and treatment didn't help at all were at twice the risk of readmission compared to those who responded that care and treatment helped "definitely" (Hazard ratio for COPD 1.97, CI: 1.17-3.32; CHF 2.07, CI 1.25-3.42). Patients who offered the most unfavourable ratings of overall care, understandable explanations, organised care, or preparedness for discharge were at a 1.5 to more than two times higher risk of readmission. Respect and dignity, effective and clear communications, and timely and coordinated care also matter. PRMs are strong predictors of readmission even after accounting for risk related to age and co-morbidities. More moderate ratings were associated with attenuation of risk, and the most positive ratings were associated with the lowest readmission rate. These results suggest that increasing each patient's positive experiences progressively reduces the risk of adults with chronic conditions returning to acute care.

Association between number of replacements and readmissions following total knee and total hip replacements in New South Wales' public hospitals

BACKGROUND

Total knee and total hip replacement are common and resource-intensive procedures. Complications are associated with worse outcomes and can add to the health care costs, particularly if associated with readmission. The aims of this study were to inform quality improvement by reporting on the extent of variation in readmissions across public hospitals and investigating the association between hospital volume and readmissions.

METHODS

This retrospective population-based cohort study used linked, admitted patient data for a census of all admissions to public and private hospitals. Adults who had an acute hospitalization for total knee or total hip replacement elective surgery and were discharged alive between 1 July 2015 and 30 June 2018 were included. Hospital volumes and risk standardized readmission ratios were calculated, and readmissions included acute hospitalizations following discharge and returns to acute care from non-acute settings within 60 days.

RESULTS

In 2015-2018, one in 10 patients were readmitted following total knee or total hip replacement (11.9 and 10.6 per 100 hospitalizations) an increase of 4.9% and 13.1% respectively, compared to 2012-2015. The majority of hospitals had risk standardized readmission ratios no different than expected. The median annual hospital volume was 170 total knee (interquartile range 116-247) and 93 total hip (interquartile range 61-141) procedures with no evidence of a meaningful association between hospital volume and readmissions.

CONCLUSION

Readmissions rates for total knee and total hip replacements are increasing. While hospital volume varies, it was not associated with readmission after adjusting for risk factors and any non-linear association.

Implementing large-system, value-based healthcare initiatives: a realist study protocol for seven natural experiments

INTRODUCTION

Value-based healthcare delivery models have emerged to address the unprecedented pressure on long-term health system performance and sustainability and to respond to the changing needs and expectations of patients. Implementing and scaling the benefits from these care delivery models to achieve large-system transformation are challenging and require consideration of complexity and context. Realist studies enable researchers to explore factors beyond 'what works' towards more nuanced understanding of 'what tends to work for whom under which circumstances'. This research proposes a realist study of the implementation approach for seven large-system, value-based healthcare initiatives in New South Wales, Australia, to elucidate how different implementation strategies and processes stimulate the uptake, adoption, fidelity and adherence of initiatives to achieve sustainable impacts across a variety of contexts.

METHODS AND ANALYSIS

This exploratory, sequential, mixed methods realist study followed RAMESES II (Realist And Meta-narrative Evidence Syntheses: Evolving Standards) reporting standards for realist studies. Stage 1 will formulate initial programme theories from review of existing literature, analysis of programme documents and qualitative interviews with programme designers, implementation support staff and evaluators. Stage 2 envisages testing and refining these hypothesised programme theories through qualitative interviews with local hospital network staff running initiatives, and analyses of quantitative data from the programme evaluation, hospital administrative systems and an implementation outcome survey. Stage 3 proposes to produce generalisable middle-range theories by synthesising data from context-mechanism-outcome configurations across initiatives. Qualitative data will be analysed retroductively and quantitative data will be analysed to identify relationships between the implementation strategies and processes, and implementation and programme outcomes. Mixed methods triangulation will be performed.

ETHICS AND DISSEMINATION

Ethical approval has been granted by Macquarie University (Project ID 23816) and Hunter New England (Project ID 2020/ETH02186) Human Research Ethics Committees. The findings will be published in peer-reviewed journals. Results will be fed back to partner organisations and roundtable discussions with other health jurisdictions will be held, to share learnings.

Sepsis within 30 days following elective surgeries in NSW public hospitals, January 2015-December 2017

IntroductionPostsurgical sepsis is a common complication, accounting for one-third of all sepsis cases and associated with higher risk of mortality. Objectives and ApproachThe Bureau of Health Information (BHI) in New South Wales (NSW), Australia produces independent reports and information about the performance of the healthcare system. Our report investigates the rate of sepsis within 30-days following surgery, and explores variation in risk standardised postoperative sepsis across NSW public hospitals. The study cohort and outcome definitions were drawn from existing international patient safety indicators, modified for appropriate use with Australian linked hospital and mortality data to identify patients transferred, or readmitted to any NSW public or private hospital with postoperative sepsis. Fine and Gray competing risks regression models were used to calculate risk-adjusted rates, and funnel plots were used to identify outliers. ResultsRate of 30-day postoperative sepsis was 0.9% among 66,143 adult elective surgeries that met the inclusion criteria during January 2015 to December 2017. Results showed around 33% of post-operative sepsis were identified as occurring during either a transfer or readmission to hospital. Hospital-level unadjusted rates of postsurgical sepsis ranged from 0% to 2% across more than 80 NSW public hospitals. The majority of hospitals (94%) had postoperative sepsis results lower or no different than expected. Conclusion/ImplicationsWe explored postoperative sepsis to help understanding of sepsis risk during the follow up period. Results showed a considerable number of postoperative sepsis cases would not have been identified without the use of linked data. Results on hospital risk standardised 30-day postoperative sepsis may prove useful as a screening tool for quality improvement in this area.

Hospital level risk-standardised all-cause readmission and returns to acute care following hospitalisations for eight clinical conditions

IntroductionMeasures that assess how healthcare affects health outcomes make an important contribution to efforts to inform local efforts to improve care for patients in NSW. Objectives and ApproachThe Bureau of Health Information (BHI) in New South Wales, Australia produces independent reports and information about the performance of the healthcare system. Our reports on readmission and returns to acute care following hospitalisation from eight clinical conditions investigated variation across more than 70 NSW public hospitals, with information available for 2000 to 2018. Readmissions included both returns to acute care from non-acute inpatient settings and readmissions to any public or private hospital within 30-days or 60-days following hospital discharge. Risk standardised readmission ratios (RSRR) were calculated following linkage of admitted patient and mortality data, to also account for competing risk of death. Hospital outliers were identified using funnel plots. A sensitivity analysis explored the effect of residence in an aged care facility. ResultsIn the most recent period, the unadjusted rate of readmission ranged from 10% for ischaemic stroke to 22% for congestive heart failure with rates remaining relatively stable over time for most of the condition. The proportion of readmissions that were returns to acute care from a non-acute hospitalisation ranged from 2% for chronic obstructive pulmonary disease (COPD) to 42% for hip fracture surgery. Across all eight conditions majority of hospitals had results lower or no different than expected. Number of hospitals with higher than expected readmissions ranged from none for total knee replacement to six for COPD. Taking into account residence in an aged care facility did not impact the results in a meaningful way. Conclusion/ImplicationsThe RSRR method compares a hospital’s readmissions given its case-mix with an average NSW hospital with the same case-mix. In NSW, this method is a screening tool, identifying areas of excellence and of potential improvement.

Avoiding unnecessary hospitalisation for patients with chronic conditions: a systematic review of implementation determinants for hospital avoidance programmes

Background

Studies of clinical effectiveness have demonstrated the many benefits of programmes that avoid unnecessary hospitalisations. Therefore, it is imperative to examine the factors influencing implementation of these programmes to ensure these benefits are realised across different healthcare contexts and settings. Numerous factors may act as determinants of implementation success or failure (facilitators and barriers), by either obstructing or enabling changes in healthcare delivery. Understanding the relationships between these determinants is needed to design and tailor strategies that integrate effective programmes into routine practice. Our aims were to describe the implementation determinants for hospital avoidance programmes for people with chronic conditions and the relationships between these determinants.

Methods

An electronic search of four databases was conducted from inception to October 2019, supplemented by snowballing for additional articles. Data were extracted using a structured data extraction tool and risk of bias assessed using the Hawker Tool. Thematic synthesis was undertaken to identify determinants of implementation success or failure for hospital avoidance programmes for people with chronic conditions, which were categorised according to the Consolidated Framework for Implementation Research (CFIR). The relationships between these determinants were also mapped.

Results

The initial search returned 3537 articles after duplicates were removed. After title and abstract screening, 123 articles underwent full-text review. Thirteen articles (14 studies) met the inclusion criteria. Thematic synthesis yielded 23 determinants of implementation across the five CFIR domains. ‘Availability of resources’, ‘compatibility and fit’, and ‘engagement of interprofessional team’ emerged as the most prominent determinants across the included studies. The most interconnected implementation determinants were the ‘compatibility and fit’ of interventions and ‘leadership influence’ factors.

Conclusions

Evidence is emerging for how chronic condition hospital avoidance programmes can be successfully implemented and scaled across different settings and contexts. This review provides a summary of key implementation determinants and their relationships. We propose a hypothesised causal loop diagram to represent the relationship between determinants within a complex adaptive system.

Trial registration

PROSPERO 162812 

Disparities in experiences of emergency department care for people with a mental health condition

BACKGROUND

The aim of this study was to explore differences in experiences of care in Emergency Departments (EDs) for people with and without mental health conditions.

METHODS

Secondary analyses of a survey of 15,995 patients from 82 EDs in New South Wales, Australia was conducted focusing on the most positive responses for 53 questions across nine dimensions of experiences. Logistic regression was used to compare experiences between people with and without a self-reported mental health condition, regardless of the reason for presentation.

RESULTS

Most patients reported positive experiences, with 60% rating care as 'very good'. However, fewer people with mental health conditions gave 'very good' ratings (52%). Their experiences were significantly less positive for 40 of 53 questions. For overall impressions of professionals, physical comfort, and continuity dimensions, experiences for those with mental health conditions were at least eight percentage points lower than those with no condition. Differences were minimal for other questions such as experiences with facilities (e.g. clean treatment areas).

CONCLUSIONS

Regardless of the reason for their visit, improvements in experiences for people with mental health conditions should focus on interactions with healthcare professionals, comfort, engagement and continuity. Improving experiences of this group can help improve their outcomes of care.

Experiences of maternity care in New South Wales among women with mental health conditions

Background

High quality maternity care is increasingly understood to represent a continuum of care. As well as ensuring a positive experience for mothers and families, integrated maternity care is responsive to mental health needs of mothers. The aim of this paper is to summarize differences in women’s experiences of maternity care between women with and without a self-reported mental health condition.

Methods

Secondary analyses of a randomized, stratified sample patient experience survey of 4787 women who gave birth in a New South Wales public hospital in 2017. We focused on 64 measures of experiences of antenatal care, hospital care during and following birth and follow up at home. Experiences covered eight dimensions: overall impressions, emotional support, respect for preferences, information, involvement, physical comfort and continuity. Multivariable logistic regression was used to compare experiences of women with and without a self-reported longstanding mental health condition.

Results

Compared to women without a condition, women with a longstanding mental health condition (n = 353) reported significantly less positive experiences by eight percentage points on average, with significant differences on 41 out of 64 measures after adjusting for age, education, language, parity, type of birth and region. Disparities were pronounced for key measures of emotional support (discussion of worries and fears, trust in providers), physical comfort (assistance, pain management) and overall impressions of care. Most women with mental health conditions (75% or more) reported positive experiences for measures related to guidelines for maternity care for women with mental illness (discussion of emotional health, healthy behaviours, weight gain). Their experiences were not significantly different from those of women with no reported conditions.

Conclusions

Women with a mental health condition had significantly less positive experiences of maternity care across all stages of care compared to women with no condition. However, for some measures, including those related to guidelines for maternity care for women with mental illness, there were highly positive ratings and no significant differences between groups. This suggests disparities in experiences of care for women with mental health conditions are not inevitable. More can be done to improve experiences of maternity care for women with mental health conditions.

Variation in the recording of common health conditions in routine hospital data: study using linked survey and administrative data in New South Wales, Australia

OBJECTIVES

To investigate the nature and potential implications of under-reporting of morbidity information in administrative hospital data.

SETTING AND PARTICIPANTS

Retrospective analysis of linked self-report and administrative hospital data for 32,832 participants in the large-scale cohort study (45 and Up Study), who joined the study from 2006 to 2009 and who were admitted to 313 hospitals in New South Wales, Australia, for at least an overnight stay, up to a year prior to study entry.

OUTCOME MEASURES

Agreement between self-report and recording of six morbidities in administrative hospital data, and between-hospital variation and predictors of positive agreement between the two data sources.

RESULTS

Agreement between data sources was good for diabetes (κ=0.79); moderate for smoking (κ=0.59); fair for heart disease, stroke and hypertension (κ=0.40, κ=0.30 and κ =0.24, respectively); and poor for obesity (κ=0.09), indicating that a large number of individuals with self-reported morbidities did not have a corresponding diagnosis coded in their hospital records. Significant between-hospital variation was found (ranging from 8% of unexplained variation for diabetes to 22% for heart disease), with higher agreement in public and large hospitals, and hospitals with greater depth of coding.

CONCLUSIONS

The recording of six common health conditions in administrative hospital data is highly variable, and for some conditions, very poor. To support more valid performance comparisons, it is important to stratify or control for factors that predict the completeness of recording, including hospital depth of coding and hospital type (public/private), and to increase efforts to standardise recording across hospitals. Studies using these conditions for risk adjustment should also be cautious of their use in smaller hospitals.

Can a book of charts catalyze improvements in quality? Views of a healthcare alchemist

This commentary reviews international evidence about the impact of public reporting on better care and outcomes, outlines conditions under which publicly available performance information can become a potent catalyst to precipitate improvements in quality and the optimal conditions in healthcare systems to ensure that such a catalyst results in a desirable reaction.

Musings on collaborative health policy - 15 years on

Strategies to facilitate an understanding of successful collaborations between researchers and policy makers in the article "Twisting the Lion's Tail: Collaborative Health Policy Making in British Columbia" have relatively good face validity and fairly good construct validity. It's been my experience, however, that strategies that work for one project don't necessarily work for others and strategies that work for parts of one project don't always work for other parts of the same project. What seems important is that health policy collaborators establish clarity on roles, responsibilities and rules of engagement for specific projects, knowing prospectively that these will vary across time and depending on the nature of a project.

Highly selective hydrolysis of kinins by recombinant prolylcarboxypeptidase

We have previously cloned a cDNA encoding human prolylcarboxypeptidase (PRCP) and expressed the cDNA in the Schneider 2 (S2) drosophila cell line. Here, we further characterized this recombinant enzyme. Investigations were performed to determine whether recombinant PRCP (rPRCP) metabolizes kinins (BK 1-9 and BK 1-8). The metabolites of these kinins were identified by LC/MS. rPRCP metabolized BK 1-8 to BK 1-7, whereas rPRCP was ineffective in metabolizing BK 1-9. The hydrolysis of BK 1-8 by rPRCP was dose- and time-dependent. A homology model of PRCP was developed based upon the sequence of dipeptidyl-peptidase 7 (DPP7, PDB ID: 3JYH), and providentially, the structure of PRCP (PDB ID: 3N2Z) was characterized during the course of our investigation. Docking studies of bradykinin oligopeptides were performed both from the homology model, and from the crystal structure of PRCP. These docking studies may provide a better understanding of the contribution of specific residues involved in substrate selectivity of human PRCP.

Using what we gather--harnessing information for improved care

Currently available data can be used to focus clinical quality, patient centredness and safety of care in hospitals.

Growing Old Together: The Influence of Population and Workforce Aging on Supply and Use of Family Physicians

Canadians have expressed concern that access to a family physician (FP) has declined precipitously. Yet FP-to-population ratios remained relatively stable over the last decade, and there were perceptions of physician surpluses, at least in urban centres, 10 years ago. We evaluated whether demographic changes among patients and FPs, and in the volume of care received and provided over the period, contribute to this paradox. Given the relationship between age and FP use in fiscal year 1991/1992, an aging population should have been associated with a 2 per cent increase in visits by 2000/2001. Likewise, given the relationship between FP age and workloads in 1991/1992, an aging workforce should have been associated with a 12 per cent increase in service provision a decade later. Yet visit rates and average FP workloads remained unchanged. There was an increase in age-specific rates of FP use among older adults and a decline in rates among the young, and an increase in age-specific workloads such that older FPs provided many more services than their predecessors (30%) and younger FPs provided many fewer (20%). In terms of impact on future requirements for FPs, both changes in age-specific rates of use, and changes in age-specific patterns of FP productivity, trump population aging as key drivers.

Public perspectives on health human resources in primary healthcare: context, choices and change

The purpose of this study was to examine factors identified by patients as relevant to health human resources (HHR) planning for primary healthcare (PHC). Eleven focus groups were conducted in British Columbia and a thematic analysis was undertaken, informed by a needs-based HHR planning framework. Three themes emerged: (a) the importance of geographic context, (b) change management at the practice level and (c) the need for choices and changes in delivery of PHC. Findings suggest that more attention could be focused on overcoming geographic barriers to providing services, change management within office-based practices, and providing support structures that allow primary care providers to work closer to their full scope of practice. That these factors align with many strategic directions set out by government and planners signals the readiness for change in how PHC is delivered and HHR planned.

A results-based logic model for primary healthcare: a conceptual foundation for population-based information systems

A conceptual framework for population-based information systems is needed if these data are to be created and used to generate information to support healthcare policy, management and practice communities that seek to improve quality and account for progress in primary healthcare (PHC) renewal. This paper describes work conducted in British Columbia since 2003 to (1) create a Results-Based Logic Model for PHC using the approach of the Treasury Board of Canada in designing management and accountability frameworks, together with a literature review, policy analysis and broad consultation with approximately 650 people, (2) identify priorities for information within that logic model, (3) use the logic model and priorities within it to implement performance measurement and research and (4) identify how information systems need to be structured to assess the impact of variation or change in PHC inputs, activities and outputs on patient, population and healthcare system outcomes. The resulting logic model distinguishes among outcomes for which the PHC sector should be held more or less accountable.

Measuring the performance of primary healthcare: existing capacity and potential information to support population-based analyses

WHAT DID WE DO?: We reviewed the degree to which existing population-based data in Canada can be used to describe and report on primary healthcare (PHC) performance. We identified gaps in current data sources and made recommendations on how these gaps might be addressed to support quality improvement and public reporting for PHC. WHAT DID WE LEARN?: Population-based survey and administrative data are available to describe population characteristics and other contextual factors for PHC, as well as some aspects of the material, financial and human resources inputs, and selected activities and decisions at the policy, management and clinical levels. Existing data can also be used to describe some volumes and types of PHC outputs. However, we currently have limited population-based data to assess selected qualities of PHC services (e.g., coordination and interpersonal effectiveness) and most immediate outcomes of PHC. The ability to link data to assess outcomes and attribute changes in outcomes to PHC is limited. A full report describing more than 130 indicators from existing data sources and gaps in current data is available at www.chspr.ubc.ca. WHAT ARE THE IMPLICATIONS?: As we look to the future, there is a clear need to build on existing data sources to expand PHC data capacity in Canada. Data are needed to inform an understanding of PHC outputs, outcomes and the linkages among PHC dimensions. Commitment to a comprehensive PHC data collection strategy and information system is needed across Canadian provinces and territories to inform policy development and planning, to evaluate PHC redesign initiatives and to meet the accountability expectations of Canadians.

Methods to develop and maintain a valid physician registry in evolving information environments

WHAT DID WE DO?: As the amount of alternative funding for physician services grows in Canada, the usefulness of fee-for-services (FFS) payment data as a source of population-based information declines. This paper describes methods used to develop and validate an anonymous registry of the physician workforce to support policy-relevant analyses in environments where doctors are increasingly funded through diverse arrangements. WHAT DID WE LEARN?: Among the 8,558 physicians in clinical practice in British Columbia in 2004, 97% could be identified via FFS payment data. In 1996, 2000 and 2004, a similar number of physicians in clinical practice (N=340, 326, 290) did not submit FFS claims, and a stable proportion of these doctors (65%, 67%, 69%) could be identified using hospital discharge abstract data. Province-wide, local health areas varied in the proportion of total physicians' expenditures in 2004 attributable to FFS payments (0 to 100%). WHAT ARE THE IMPLICATIONS?: FFS and hospital files could be used in tandem to identify physicians in clinical practice in order to create complete registries intended to support population-based workforce analyses. FFS and alternative funding payment files could be used together to calculate each physician's income and clinical activity, and to identify physicians for whom there is high likelihood of measurement error because they reside in local health areas where a large proportion of clinical activity is not captured.

RECOMMENDATIONS

Systems designed to track alternative funding should be uniformly structured within and across jurisdictions to maintain or increase the availability of population-based clinical data useful for secondary analyses. Only then can these data be used to support Canadian policy, management and clinical decision-making.

Supply and distribution of primary healthcare registered nurses in british columbia

WHAT DID WE DO?: This study uses an existing data source to (a) describe the population and geographic distribution of registered nurses (RNs) working in primary healthcare (PHC) in British Columbia, (b) compare this workforce to PHC physicians and (c) assess the distribution of PHC-RNs relative to population health status. WHAT DID WE LEARN?: Of the 27,570 practising RNs in British Columbia in 2000, there were 3,179 (12%) in the PHC workforce. This translates into 147 people per practising RN and 1,277 people per PHC-RN. In 2000, there were 990 people per PHC physician. PHC-RNs represented 43% of the combined PHC workforce of physicians and RNs. A large proportion (47%) of PHC-RNs worked in community health centres, whereas less than 2% worked in physicians' offices. Geographic distribution of PHC-RNs is similar to the distribution of PHC physicians and is not associated with population health status. WHAT ARE THE IMPLICATIONS?: There seem to be sufficient PHC-RNs to implement policy objectives in support of interdisciplinary PHC teams, but physicians and nurses will increasingly need to practice in the same location or have access to electronic information systems to support coordination, continuity and comprehensiveness of PHC. The PHC workforce could be better deployed to align with population health status.

For discussion: a roadmap for population-based information systems to enhance primary healthcare in Canada

The purpose of this paper is to promote expansion of population-based information systems to enhance primary healthcare renewal (PHC) across Canada. The vision is to ensure that healthcare policy makers, managers and clinical leaders receive relevant, valid and timely information that is useful to them in exercising their responsibilities in accountability and performance improvement. The paper sketches a roadmap of options for new information systems and describes the opportunities and limitations associated with each. The intent is to offer an array of alternatives for consideration because jurisdictions vary in their vision and objectives for renewal and priorities for information.

More doctors or better care?

The Canadian Medical Association's More Doctors, More Care campaign seeks to align physician supply targets with policy decisions elsewhere in the Organisation for Economic Co-operation and Development (OECD). Using OECD data for 19 countries to assess the relationship between physician supply and healthcare outcomes, we have determined that there is no association between avoidable mortality and overall physician supply. Similarly, there is no relationship between avoidable mortality and general practitioners and family physicians per capita, specialists per capita, nurses per capita, doctors and nurses per capita or health expenditures per capita. These findings should move us to recognize that (a) more doctors will not necessarily translate into better healthcare outcomes for Canadians and (b) it is in Canadians' better interests that we instead focus on realizing opportunities to improve access to high-quality care and to ensure that changes in physician turnover do not threaten the current generalist-to-specialist mix.

More doctors or better care?

The Canadian Medical Association's More Doctors, More Care campaign seeks to align physician supply targets with policy decisions elsewhere in the Organisation for Economic Co-operation and Development (OECD). Using OECD data for 19 countries to assess the relationship between physician supply and healthcare outcomes, we have determined that there is no association between avoidable mortality and overall physician supply. Similarly, there is no relationship between avoidable mortality and general practitioners and family physicians per capita, specialists per capita, nurses per capita, doctors and nurses per capita or health expenditures per capita. These findings should move us to recognize that (a) more doctors will not necessarily translate into better healthcare outcomes for Canadians and (b) it is in Canadians' better interests that we instead focus on realizing opportunities to improve access to high-quality care and to ensure that changes in physician turnover do not threaten the current generalist-to-specialist mix.

Population patterns of chronic health conditions, co-morbidity and healthcare use in Canada: implications for policy and practice

Managing chronic health conditions is a daily reality for approximately nine million Canadians, and the numbers of people affected are expected to increase as our population ages, particularly if risk factors that contribute to poor health continue to rise. These conditions impact health and well-being and represent a significant, and growing, healthcare and economic burden. The Health Council of Canada has focused its attention on the prevention and management of chronic conditions to encourage discussion of the changes to public policy, healthcare management and health services delivery required to improve health outcomes for Canadians. In December 2007, the Health Council released a report that described the health and healthcare use among Canadians who have chronic conditions as well as their self- reported experiences with chronic illness care. It highlighted initiatives under way in all jurisdictions to improve the situation. In order to inform that report, we analyzed population-based survey data from the Canadian Community Health Survey to report on patterns of health and healthcare use by community-dwelling youth and adults who have one or more of seven high-prevalence, high-impact chronic conditions. We demonstrated that the vast majority of people with chronic conditions have a regular medical doctor and visit community-based doctors and nurses frequently. Not surprisingly, people with chronic conditions use healthcare services more often and more intensively than do those without, and the intensity of service use increases as the numbers of conditions go up. The 33% of Canadians with one or more of seven chronic conditions account for approximately 51% of family physician/general practitioner consultations, 55% of specialist consultations, 66% of nursing consultations and 72% of nights spent in a hospital. This information highlights the imperative of immediate, comprehensive and sustained attention to undertake proven strategies to delay or prevent the onset of chronic conditions and to improve the quality of primary healthcare to prevent complications, reduce the need for more expensive health services and secure a better quality of life for Canadians.

Improving prescribing, improving health

Prescription drugs play an essential and growing role in Canada's healthcare system and the health of Canadians. But some drugs are not used correctly (misuse), used too frequently (overuse) or not used nearly enough (underuse), resulting in missed health benefits, harm to individual Canadians and unnecessary costs. In this article, we highlight lessons learned from the Health Council of Canada's synthesis of evidence and a recent symposium regarding what works to improve the appropriateness of prescribing.

What Do People Think Is Important about Primary Healthcare?

The purpose of this study was to inform quality improvement and performance measurement initiatives in primary healthcare based on the perceptions of British Columbia residents. Key features of care were identified during focus group discussions on important areas in primary healthcare, particularly those that could be improved.Eleven focus groups (n=75) were held. Ninety-six per cent of participants reported that they had a regular primary healthcare provider and had been with that provider for an average of 8.5 years. We conducted a thematic content analysis using a coding scheme based on a logic model for this sector.Analysis revealed the importance of six domains: accessibility (geographic location and timeliness of appointments), continuity, responsiveness, interpersonal communication, technical quality and whole-person care. Although participants discussed accessibility most frequently, domains more often associated with satisfaction were interpersonal communication and continuity.

Why healthcare renewal matters: lessons from diabetes

In this commentary, we offer evidence about the burden of chronic conditions and use diabetes as a case study to reveal the gap between recommended and actual care in Canada. What we found through our research is cause for concern - namely, that the care that Canadians with diabetes receive is simply not good enough (an inconvenient truth) and that the country has tremendous untapped potential to prevent chronic illness and improve the quality of care (a convenient truth). Our work and the work of others help Canadians understand the benefits that will accrue to them from investments to close the gap between what we know and what we do. Given the extent of recent initiatives highlighted in this commentary - initiatives that align with evidence regarding optimal prevention and chronic illness care - we should expect governments to simultaneously invest in assessing the degree to which progress is being attained. Without better data, more transparency and comprehensive reporting, Canadians will not be kept fully informed about the results of critical healthcare investments and governments will find it increasingly difficult to demonstrate that they are meeting their commitments.

Intergenerational differences in workloads among primary care physicians: a ten-year, population-based study

Analyses of population-based services and surveys in Canada from the early 1990s and early 2000s indicate that younger and middle-aged family physicians carried smaller workloads in 2003 than their same-age peers did ten years earlier and that older family physicians carried larger workloads in 2003 than their same-age peers did ten years earlier. Yet family physicians in all age groups worked similar numbers of hours in 2003. Intergenerational effects are similar for male and female physicians, although feminization of the workforce will affect supply, as a result of the falling service volumes delivered by women.

Wait time benchmarks, research evidence and the knowledge translation process

The first set of evidence-based benchmarks for medically acceptable wait times, announced in December 2005, were developed, in part, through a novel partnership between the Provincial and Territorial Ministries of Health, the Canadian Institutes of Health Research (CIHR) and Canada's health services research community. Responding to a direct request for assistance and demanding timelines from the Provincial and Territorial Ministries of Health, CIHR mounted a rapid-response funding process and supported eight Canadian teams to synthesize evidence to inform the development of the first set of benchmarks. This experience demonstrated that both the research funding process and research syntheses themselves can rapidly inform policy making in even the most heated of environments.

Use of physician services by older adults: 1991/1992 to 2000/2001

Canadians have expressed concern that access to family physicians (FP) has declined. Anonymized physician services data for 1991/1992 to 2000/2001 were used to evaluate changes in supply and age-specific rates of use of FPs and specialists in Winnipeg, Manitoba. Physician-to-population ratios declined 7.5 per cent, FP-to-population ratios declined 4.8 per cent, and specialist-to-population ratios declined 10.0 per cent. Among the general population, FP visit rates declined 3 per cent. Among older adults, physician visit rates increased 2.3 per cent, FP visit rates increased 10.9 per cent, and specialist visit rates declined 15.7 per cent. By comparison, we document declines in FP use by those younger than 5 years (25.5%) and those 6 to 19 years of age (18.6%). Increases in FP and declines in specialist use occurred primarily among those aged 65 to 84 years. By 2000/2001 older adults accounted for 25 per cent of all FP encounters. Gains in FP use among older adults was less attributable to the presence of more seniors and more related to the fact that a higher proportion of them are visiting a FP each year and, potentially, substituting primary for secondary care.

Population-based use of mental health services and patterns of delivery among family physicians, 1992 to 2001

OBJECTIVE

To examine 9-year rates of family physician (FP) and psychiatrist use, as well as patterns of mental health services delivery by FPs.

METHOD

We used population-based data from Winnipeg, Manitoba, to construct mutually exclusive cohorts of adults treated for major or minor mental health disorders in fiscal years 1992-1993 to 2000-2001. For each year, we measured patterns of use in this population and patterns of mental health practice among FPs.

RESULTS

The treatment prevalence rate was 224 per 1000 in 2000-2001 and 174 per 1000 in 1992-1993, and the rates for major and minor mental health disorders increased over the 9-year period by 15% and 31%, respectively. In 2000-2001, 92% of adults treated for mental illness saw at least one FP, and 45% saw an FP but no psychiatrist. Adults with major or minor mental health disorders visited an FP on average 9.1 and 6.9 times yearly, respectively, and FP visit rates remained relatively stable. There was a gradient in use by socioeconomic status: adults from communities with lower socioeconomic status had the highest rates of use. By 2000-2001, 24% of FPs billed for services related to psychosocial conditions as often as they did for the most frequent conditions seen in primary care.

CONCLUSION

Between 1992-1993 and 2000-2001, the study population's patterns of FP and psychiatrist use remained relatively stable. In more recent years, FPs provided more mental health services than in previous years; this related to increased treatment prevalence rather than to increases in use per adult. FPs played a major role in the provision of mental health care.

Effectiveness of occupational therapy following organ transplantation

BACKGROUND

Individuals who receive a solid organ transplant have pre-operative and post-operative impairments in physical function.

PURPOSE

This pilot study evaluated the changes in physical function of 23 individuals with an organ transplant who received 2 or more hours of occupational therapy while inpatients in an acute care facility. These individuals also received physiotherapy treatment that was retrospectively quantified. Post-operative function was evaluated at assessment and discharge from occupational therapy with the Functional Independence Measure (FIM).

RESULTS

Significant improvements in FIM scores (mean change +22) were noted at discharge from occupational therapy and there was a positive correlation between attendances or minutes of occupational therapy and study participants' changes in function. Occupational therapy attendances or minutes were also negatively correlated with study participants' initial functional status, which suggests that individuals with lower function received more occupational therapy.

PRACTICE IMPLICATIONS

Notwithstanding the benefit of physiotherapy, and the methodological limits of an uncontrolled pre-test/post-test design, this study provides novel, preliminary evidence for the benefit of occupational therapy during the acute care stay of individuals with a solid organ transplant.

Family physician workloads and access to care in Winnipeg: 1991 to 2001

BACKGROUND

Current perceptions of family physician (FP) shortages in Canada have prompted policies to expand medical schools. Our objective was to assess how FP supply, workloads and access to care have changed over the past decade.

METHODS

We used an anonymized physician and population registry and administrative health service data from Winnipeg for the period 1991/92 to 2000/01. We calculated the following measures of supply and workload: ratios of FPs to population, of population to FPs and of FP full-time equivalents (FTEs) to population, as well as FP activity ratios (sum of FTEs/number of FPs), annual number of visits per FP and visits per FP per full-time day of work. Trends in FP remuneration were analyzed by age and sex. We also measured standardized visit rates and stratified the analysis by populations deemed at risk of needing FP services.

RESULTS

In 2000/01 FPs between 30 and 49 years of age (64% of the workforce) provided 20% fewer visits per year than their same-age peers did 10 years previously. Conversely, FPs 60 to 69 years of age (11% of the workforce) provided 33% more visits per year than the corresponding group a decade earlier. On a per capita basis, the number of FPs declined by 5%, from 97 per 100 000 population in 1991/92 to 92 per 100 000 population in 2000/01, which paralleled changes in national estimates of FP supply. Per capita visit rates among Winnipeg citizens (3.5 per year in 2000/01) and average workloads among FPs (4193 visits per year in 2000/01) were stable over the decade.

INTERPRETATION

Despite relative homeostasis in aggregate FP supply and use, there have been substantial temporal shifts in the volume of services provided by FPs of different age groups. Younger FPs are providing many fewer visits and older FPs are providing many more visits than their same-age predecessors did 10 years ago, a finding that was independent of physician sex. Given these data, the perpetual focus of policy-makers and care providers on increasing numbers of FPs will not help in diagnosing or treating issues of supply, workloads and access to care.

LacI mutation spectra following benzo[a]pyrene treatment of Big Blue mice

The mutation spectrum of the lacI gene from the liver of C57Bl6 Big Blue transgenic mice treated with benzo[a]pyrene (B[a]P) has been compared with the spectrum of spontaneous mutations observed in the liver of untreated Big Blue mice. Mice were treated with B[a]P for 3 days followed by a partial hepatectomy one day after the last injection. Liver tissue was removed for analysis at hepatectomy and, again, 3 days later at the time of sacrifice. Earlier, we reported that the lacI mutant frequency in these B[a]P-treated mice was elevated in the liver both at the time of hepatectomy and at sacrifice; however, a statistically significant increase in the mutant frequency was observed only at sacrifice. In this study, the DNA sequence spectra of lacI mutations observed in the liver of B[a]P-treated Big Blue mice at hepatectomy and at time of sacrifice were compared with each other and with the spectrum of spontaneous liver mutations. No differences were observed between the two B[a]P-treatment spectra. However, mutation frequencies of both GC-->TA and GC-->CG at the time of hepatectomy and at sacrifice were significantly elevated compared with the spontaneous frequency of these same transversions. Also, the frequency of AT-->TA transversions was significantly higher than the spontaneous frequency at the time of hepatectomy but not at sacrifice. The frequency of all other classes of mutations scored was not significantly different from the frequency of these same events in the spontaneous spectra. These data support the view that B[a]P treatment results in the induction of GC-->TA and GC-->CG transversions within 1 day of the last injection and they provide insights regarding the relative roles of benzo[a]pyrene-7,8-diol-9, 10-epoxide and radical cations of B[a]P in B[a]P-induced mutagenesis in vivo. Finally, these data provide evidence for B[a]P-induced mutagenesis under conditions where no statistical increase in mutant frequency could be shown.

Regulation of the sol locus genes for butanol and acetone formation in Clostridium acetobutylicum ATCC 824 by a putative transcriptional repressor

A gene (orf1, now designated solR) previously identified upstream of the aldehyde/alcohol dehydrogenase gene aad (R. V. Nair, G. N. Bennett, and E. T. Papoutsakis, J. Bacteriol. 176:871-885, 1994) was found to encode a repressor of the sol locus (aad, ctfA, ctfB and adc) genes for butanol and acetone formation in Clostridium acetobutylicum ATCC 824. Primer extension analysis identified a transcriptional start site 35 bp upstream of the solR start codon. Amino acid comparisons of SolR identified a potential helix-turn-helix DNA-binding motif in the C-terminal half towards the center of the protein, suggesting a regulatory role. Overexpression of SolR in strain ATCC 824(pCO1) resulted in a solvent-negative phenotype owing to its deleterious effect on the transcription of the sol locus genes. Inactivation of solR in C. acetobutylicum via homologous recombination yielded mutants B and H (ATCC 824 solR::pO1X) which exhibited deregulated solvent production characterized by increased flux towards butanol and acetone formation, earlier induction of aad, lower overall acid production, markedly improved yields of solvents on glucose, a prolonged solvent production phase, and increased biomass accumulation compared to those of the wild-type strain.

Characterization of new transgenic Big Blue(R) mouse and rat primary fibroblast cell strains for use in molecular toxicology studies

We have established and characterized primary mouse and rat cell strains for studies designed to complement in vivo gene mutation assays using the Big Blue(R) mouse or rat. Primary fibroblast cell strains, designated BBM1 and BBR1, were derived from a transgenic male Big Blue(R) B6C3F1 mouse and from a male Big Blue(R) Fischer-344 rat, respectively. Both BBM1 and BBR1 are genetically stable and mostly diploid. Both cell strains have low spontaneous frequencies of mutation at the lacI and cII loci as well as low frequencies of sister chromatid exchange and micronuclei formation. In addition, N-ethyl-N-nitrosourea (ENU) induces mutations at the cII locus in both BBM1 and BBR1 cells. These new primary Big Blue(R) mouse (BBM1) and rat (BBR1) fibroblast cell strains represent useful new models for molecular toxicology studies. Environ. Mol. Mutagen. 34:90-96, 1999 Published 1999 Wiley-Liss, Inc.

Spontaneous and ENU-induced mutation spectra at the cII locus in Big Blue Rat2 embryonic fibroblasts

Big Blue Rat2 embryonic fibroblasts carry the lambda-Liz shuttle vector which is also present in the Big Blue mouse and rat. Mutations in the Big Blue systems have most often been measured at the lacI locus. However, a method for positive selection of mutations at the lambda cII locus was recently described. This assay appears to have many advantages over the use of lacI as a mutational target, but it has yet to be well characterized in mammalian mutagenesis studies. The objective of these studies was to determine the spontaneous and ethylnitrosourea (ENU)-induced mutant frequencies (MFs) and mutational spectra at cII using Big Blue Rat2 embryonic fibroblasts. The average spontaneous MF was 13 +/- 1.4 x 10(-5). The average induced MF was 60 +/- 10 x 10(-5) 10 days following a 30 min treatment with 0.1 mg/ml ENU. Eighty four independent spontaneous mutants were sequenced: 23 (27.4%) were frameshift mutations and 61 (72.6%) were base substitutions. Two spontaneous frameshift hotspots were detected, both in mononucleotide runs. G:C-->A:T transitions were the most common type of base substitution in cII; of these 71% occurred at CpG sites. The ENU-induced mutational spectrum at cII (44 mutants) consisted of 42 base substitutions (95.5%) and two -1 frameshift mutations (4.5%). Compared with the spontaneous spectrum, the ENU-induced spectrum had significantly fewer frameshift mutations (4.5 versus 27%) and base substitutions occurred predominantly at A:T base pairs (71 versus 34%). Overall, the spontaneous cII mutational spectrum reported here differs slightly from spontaneous spectra reported at the Big Blue lacI locus, but the mutational spectra and base substitution MFs following treatment with ENU were comparable at both loci. These data support the continued use of cII as a selectable marker in mutagenesis studies involving cells or tissues that carry a lambda transgene.

Induction of hepatic CYP1A in channel catfish increases binding of 2-aminoanthracene to DNA in vitro and in vivo

Data are presented from in vitro and in vivo studies that indicate cytochrome P4501A (CYP1A) in channel catfish (Ictalurus punctatus) hepatic tissue activates 2-amino-anthracene (AA) to a reactive metabolite that binds to DNA. Channel catfish were injected i.p. with vehicle or 10 mg/kg beta-naphthoflavone (betaNF) on two consecutive days. Two days after the final injection of vehicle or betaNF, vehicle or [3H]AA was injected i.p. at 10 mg/kg, creating four different treatments: vehicle only, betaNF only, [3H]AA only, and betaNF/[3H]AA. Hepatic tissue was examined for CYP1A-associated ethoxyresorufin-O-de-ethylase (EROD) activity, and for DNA adducts at 1, 2, 4 and 7 days following administration of vehicle or [3H]AA. Hepatic EROD activity in betaNF-treated fish was 17-fold higher at day 0 and remained significantly greater than untreated animals for the 7-day experiment. Hepatic DNA adducts, as measured by tritium-associated DNA, ranged from 4.8 to 8.6 pmol/mg DNA in vehicle-pretreated fish injected with [3H]AA, but ranged from 12.6 to 22.7 pmol/mg DNA in betaNF-pretreated fish injected with [3H]AA. Thus, pretreatment with betaNF significantly increased binding of [3H]AA to hepatic DNA in vivo at all four times. Analysis by 32P-post-labeling and thin layer chromatography of hepatic DNA from channel catfish treated with AA revealed two major and several minor spots, which are indicative of DNA adduct formation. Hepatic microsomes from betaNF-pretreated fish were more effective at catalysing the binding of [3H]AA to DNA in vitro than were microsomes from non-treated fish. In addition, binding was decreased by the CYP1A inhibitor 3,3',4,4'-tetrachlorobiphenyl. Collectively, these data demonstrate that CYP1A is involved in the activation of AA in channel catfish.

Cloning, sequence, and expression of the phosphofructokinase gene of Clostridium acetobutylicum ATCC 824 in Escherichia coli

The pfk gene encoding phosphofructokinase (Pfk) from the anaerobic bacterium Clostridium acetobutylicum ATCC 824 was cloned and sequenced. The gene was identified in a plasmid library by complementation of an E. coli pfk mutant and by the ability to amplify a fragment by PCR using primers based on homologous regions of Pfk from other microorganisms. Nucleotide sequence analysis revealed a coding region for a 319-aa protein homologous to Pfks from other organisms. Enzyme assay and ability to complement the growth defects of E. coli pfk mutants confirmed the expression of the clostridial pfk gene. The pyruvate kinase (pyk) gene was identified adjacent to pfk. Such an arrangement for the genes encoding key regulators of glycolytic flux had not yet been described in a strict anaerobe. This gene arrangement has been found in other Gram-positive organisms, but not in Gram-negative organisms.

Cloning and assembly of PCR products using modified primers and DNA repair enzymes

We present a method for the creation of ligatable 3' overhangs by the incorporation of a modified base, uracil, at a specific position in the PCR primer and subsequent treatment with the DNA-modifying enzyme uracil DNA glycosylase and then either T4 endonuclease V or human apurinic/apyrimidinic endonuclease 1. In this study, we describe the cloning of a fragment specifying the chloramphenicol-resistance gene into a SacI vector site. To further test this method, three segments of the lacZ gene were amplified by PCR, and after treatment with the DNA-modifying enzymes, the properly oriented segments were ligated into a SacI-cleaved plasmid. Using the methods described, we were able to assemble PCR products into appropriate structures.

Aminoanthracene is a mechanism-based inactivator of CYP1A in channel catfish hepatic tissue

In beta NF-induced channel catfish, hepatic ethoxyresorufin-O-deethylase (EROD) activity decreased 66.5% 24 hr after injection of 2-aminoanthracene (AA, 10 mg/kg) compared with non-AA-injected animals (p < 0.05). This difference in hepatic EROD activity was also significant 48 hr after treatment (p < 0.05), but no significant difference was observed after 4 or 7 days. Immunoblot analysis of hepatic microsomal protein from fish 24 hr after treatment with AA revealed two bands cross-reacting with CYP1A-specific monoclonal antibody 1-12-3: an apparently native CYP1A protein (52 kDa) and a 30-kDa protein. Furthermore, these two proteins were preferentially bound by [3H]AA compared with other microsomal proteins. Interestingly, the 30-kDa protein was observed only in fish exposed to AA and was immunoprecipitable with 1-12-3. In a separate in vivo experiment, hepatic EROD activity decreased and the 30-kDa protein increased with increased dose of AA. The 30-kDa protein is thought to be a CYP1A degradation product. In vitro experiments helped elucidate the mechanisms of interaction between AA and CYP1A. Incubation of microsomes with AA, prior to analysis of these microsomes for EROD activity, resulted in a NADPH- and time-dependent inhibition of EROD activity. Additionally, the P450 inhibitors 1-phenylimidazole and 3,3',4,4'-tetrachlorobiphenyl were used to decrease the binding of AA to CYP1A, suggesting that the binding of AA to CYP1A requires the enzymatic activity of CYP1A. It is proposed that mechanism-based inactivation of CYP1A by AA accounts for the observed AA-dependent decrease in hepatic EROD activity in vitro and in vivo in channel catfish.

Mandibular refracture as treatment method for jaw alignment. Case report

A case of malocclusion of the lower jaw following trauma and healing which was subsequently corrected by mandibular refracture is described.