Cost-effectiveness of alternative strategies for the initial medical management of non-ST elevation acute coronary syndrome: systematic review and decision-analytical modelling.

OBJECTIVES: To identify and prioritise key areas of clinical uncertainty regarding the medical management of non-ST elevation acute coronary syndrome (ACS) in current UK practice. DATA SOURCES: Electronic databases. Consultations with clinical advisors. Postal survey of cardiologists. REVIEW METHODS: Potential areas of important uncertainty were identified and 'decision problems' prioritised. A systematic literature review was carried out using standard methods. The constructed decision model consisted of a short-term phase that applied the results of the systematic review and a long-term phase that included relevant information from a UK observational study to extrapolate estimated costs and effects. Sensitivity analyses were undertaken to examine the dependence of the results on baseline parameters, using alternative data sources. Expected value of information analysis was undertaken to estimate the expected value of perfect information associated with the decision problem. This provided an upper bound on the monetary value associated with additional research in the area. RESULTS: Seven current areas of clinical uncertainty (decision problems) in the drug treatment of unstable angina patients were identified. The agents concerned were clopidogrel, low molecular weight heparin, hirudin and intravenous glycoprotein antagonists (GPAs). Twelve published clinical guidelines for unstable angina or non-ST elevation ACS were identified, but few contained recommendations about the specified decision problems. The postal survey of clinicians showed that the greatest disagreement existed for the use of small molecule GPAs, and the greatest uncertainty existed for decisions relating to the use of abciximab (a large molecule GPA). Overall, decision problems concerning the GPA class of drugs were considered to be the highest priority for further study. Selected papers describing the clinical efficacy of treatment were divided into three groups, each representing an alternative strategy. The strategy involving the use of GPAs as part of the initial medical management of all non-ST elevation ACS was the optimal choice, with an incremental cost-effectiveness ratio (ICER) of 5738 pounds per quality-adjusted life-year (QALY) compared with no use of GPAs. Stochastic analysis showed that if the health service is willing to pay 10,000 pounds per additional QALY, the probability of this strategy being cost-effective was around 82%, increasing to 95% at a threshold of 50,000 pounds per QALY. A sensitivity analysis including an additional strategy of using GPAs as part of initial medical management only in patients at particular high risk (as defined by age, ST depression or diabetes) showed that this additional strategy was yet more cost-effective, with an ICER of 3996 pounds per QALY compared with no treatment with GPA. Value of information analysis suggested that there was considerable merit in additional research to reduce the level of uncertainty in the optimal decision. At a threshold of 10,000 pounds per QALY, the maximum potential value of such research in the base case was calculated as 12.7 million pounds per annum for the UK as a whole. Taking account of the greater uncertainty in the sensitivity analyses including clopidogrel, this figure was increased to approximately 50 million pounds. CONCLUSIONS: This study suggests the use of GPAs in all non-ST elevation ACS patients as part of their initial medical management. Sensitivity analysis showed that virtually all of the benefit could be realised by treating only high-risk patients. Further clarification of the optimum role of GPAs in the UK NHS depends on the availability of further high-quality observational and trial data. Value of information analysis derived from the model suggests that a relatively large investment in such research may be worthwhile. Further research should focus on the identification of the characteristics of patients who benefit most from GPAs as part of medical management, the comparison of GPAs with clopidogrel as an adjunct to standard care, follow-up cohort studies of the costs and outcomes of high-risk non-ST elevation ACS over several years, and exploring how clinicians' decisions combine a normative evidence-based decision model with their own personal behavioural perspective.

Psychometric properties of a new health needs analysis tool designed for cardiac patients.

BACKGROUND AND OBJECTIVES: Assessing health needs is pivotal in healthcare systems, ensuring that services are appropriate for a population's genuine needs. In the absence of an appropriate investigational tool, a comprehensive process of questionnaire development was undertaken to evaluate and validate a specific health needs assessment tool for cardiac patients (Nottingham Health Needs Assessment; NHNA). Its psychometric properties were investigated in a survey of patients admitted with acute coronary syndromes. METHOD: Two hundred and forty-two consecutive patients admitted to an acute cardiac unit with symptoms suggestive of acute myocardial infarction completed a postal questionnaire about health needs and quality-of-life, using generic (Short Form 12 and EuroQol-5D) and specific (Seattle Angina Questionnaire) health-related quality-of-life instruments. RESULTS: Forty-six items were assigned to five domains of health-related needs according to principal component analysis, with high internal consistency (0.83-0.89). Each domain in the NHNA questionnaire correlated highly with its quality-of-life counterpart, indicating relatively high concurrent validity. CONCLUSION: The NHNA questionnaire has acceptable psychometric features, with satisfactory construct validity as determined by quality-of-life analysis. This health needs assessment instrument appears to be a reliable means of identifying patients' needs, which is an important landmark for directing health services.

Changing the diagnostic criteria for myocardial infarction in patients with a suspected heart attack affects the measurement of 30 day mortality but not long term survival.

OBJECTIVES: To explore the effects of alternative methods of defining myocardial infarction on the numbers and survival patterns of patients identified as having sustained a confirmed myocardial infarct. DESIGN: An inclusive historical cohort of patients admitted with a suspected heart attack. Patients were recoded from raw clinical data (collected at the index admission) to the epidemiological definitions of myocardial infarction used by the Nottingham heart attack register (NHAR), the World Health Organization (MONICA), and the UK heart attack study. SETTING: Single health district. PATIENTS: The NHAR identified all patients admitted in 1992 with suspected myocardial infarction. OUTCOME MEASURES: Survival at 30 days and four year postdischarge. RESULTS: 2739 patients were identified, of whom 90% survived to discharge. Recoding increased the numbers of patients defined as having confirmed myocardial infarction from 26% under the original NHAR classification to 69%, depending on the classification system used. In confirmed myocardial infarction, subsequent 30 day survival from admission varied from 77-86% depending on the classification system; four year survival after discharge was not affected. The distribution of important prognostic variables differed significantly between groups of patients with confirmed myocardial infarction defined by different systems. Patients with suspected but unconfirmed myocardial infarction under all classification systems had a worse postdischarge mortality. CONCLUSIONS: The classification system used had a substantial effect on the numbers of patients identified as having had a myocardial infarct, and on the 30 day survival. There were significant numbers of patients with more atypical presentations, not labelled as myocardial infarction, who did badly following discharge. More research is needed on these patients.

Mortality of patients admitted with a suspected acute myocardial infarction in whom the diagnosis is not confirmed.

AIMS: To examine the survival of patients admitted with a suspected acute myocardial infarction in whom the diagnosis was not confirmed ('possible myocardial infarction'). METHODS AND RESULTS: A cohort study based on the Nottingham Heart Attack Register of 1716 sequential patients discharged alive from two acute teaching hospitals following admission in 1992. The main outcome was mortality following hospital discharge after 5 years of follow-up. Survival of the cohort of patients in whom myocardial infarction was suspected but not confirmed was 58% (95% C.I. 56 to 60%) after 5 years of follow-up, compared with an expected survival of 76% in an age/sex matched general population. Patients with ECG abnormalities that were not diagnostic of myocardial infarction had a 5-year survival of 56%, compared with 77% in those without such changes (P<0.00001). In the 703 patients who died in the first 5 years of follow-up, the cause of death was cardiovascular in at least 53% of cases. Survival following hospital discharge was worse than that in patients discharged alive in the same year following a confirmed myocardial infarction (63% vs 69% after 4 years of follow-up P=0.0016). CONCLUSION: Patients in this study had a substantially increased risk of death in the 5 years after discharge from hospital, compared with an age- and sex-matched population, and worse than patients discharged following a confirmed myocardial infarction. Almost half of those with ECG changes at the time of their admission died over the next 5 years. As over half of all deaths in this cohort were due to cardiovascular causes, further work is needed to identify patients at high and low risk of subsequent mortality who may warrant investigation and treatment following hospital discharge.

Identifying the risk of death following hospital discharge in patients admitted with a suspected acute myocardial infarction in whom the diagnosis is not confirmed.

AIMS: To describe clinical factors, available at the time of discharge, that predicted survival of patients admitted with a suspected acute myocardial infarction in whom the diagnosis was not confirmed. METHODS AND RESULTS: A cohort study based on the Nottingham Heart Attack Register of 1716 sequential patients discharged alive from two acute teaching hospitals following admission in 1992. The main outcome was identification of high and low mortality risk groups over 5 years of follow-up. Overall 5-year survival was 58% (95% CI 56 to 60%). Having abnormal cardiac enzyme changes or an abnormal ECG that was insufficient to meet established diagnostic criteria of myocardial infarction, or both, identified three groups with a 5 year survival of 77%, 60% or 51%. Multivariate methods were used to develop a risk score from seven variables available at the time of discharge (age, sex, past history of myocardial infarction, ECG abnormalities, cardiac enzyme abnormalities, Killip score of 2 or 3 on admission and being discharged on a diuretic). Quartiles of this risk score then identified four groups with 5 year survival ranging from 89% to 25%. CONCLUSION: Among the study cohort, it was possible to identify subgroups with a markedly different risk of subsequent mortality from clinical indicators that were readily available at the time of hospital discharge. Risk stratification has the potential to improve targeting of subsequent secondary preventive efforts, but further work is required to ascertain whether cardiovascular risk can be modified through a more intensive approach to management.

Attachments in public health for physicians.

Hospital-based specialist registrars in Nottingham are offered six month secondments in public health medicine. These attachments give clinicians valuable skills in public health and an opportunity to influence the development of local health service provision. Other skills gained are an understanding of the balance between health promotion and disease treatment; the management of limited resources; an appreciation of the effects of social deprivation; the chairing and preparing of committee meetings; and contact tracing of communicable diseases. We strongly recommend the experience gained from working in a lively public health department.

Cardiac rehabilitation: socially deprived patients are less likely to attend but patients ineligible for thrombolysis are less likely to be invited.

OBJECTIVE: To identify factors associated with the uptake of cardiac rehabilitation following acute myocardial infarction. DESIGN: Retrospective analysis using multivariate logistic regression modelling. SETTING: Two large teaching hospitals in Nottingham. PATIENTS: Cohorts of patients admitted with acute myocardial infarction in 1992 and 1996. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Factors in multivariate analysis found to be associated with attendance at cardiac rehabilitation. Use of secondary prevention in those who were and were not invited and those who did and did not attend cardiac rehabilitation. RESULTS: 58% of all patients were offered cardiac rehabilitation. Attendance rates were 60% in 1992 and 74% in 1996. Invitations were more likely to be offered to younger patients, those who had received thrombolysis, and to patients admitted to one of the two Nottingham hospitals. Use of secondary prevention was only 48% in 1992 but this increased to 80% in 1996. Patients not receiving secondary prevention were less likely to be invited to cardiac rehabilitation. Social deprivation was the only factor significantly associated with poor uptake of cardiac rehabilitation in both years. There was no difference in the use of secondary prevention between those who did and did not attend cardiac rehabilitation. CONCLUSION: Those invited to attend a cardiac rehabilitation programme are likely to be in a good prognosis group, comprising those who are young and have received thrombolysis. Those at greatest risk, particularly patients from socially deprived areas, seem to be missing out on the potential benefits of cardiac rehabilitation. High risk patients should be specifically targeted to ensure that they are invited to, and encouraged to, attend a programme of cardiac rehabilitation.

Statin prescribing in Nottingham general practices: a cross-sectional study.

BACKGROUND: The aim of the study was to determine the effect of deprivation on variations in statin prescribing in Nottingham general practices. Deprivation is used as a measure of population cardiovascular morbidity and need for statin treatment. The setting was all 118 general practices in contract with Nottingham Health Authority. METHODS: A cross-sectional study was undertaken. Statin prescribing in general practice during 1996 was related to indices of practice deprivation based on enumeration district (ED) level data from the 1991 Census. The relationship between statin prescribing per 1000 patients aged 35-69 and practice deprivation (measured both as Townsend score and as Jarman UPA(8) score) with additional adjustment for practice characteristics (number of partners, training status, total list size, fundholding status) cardiovascular prescribing costs net of lipid prescribing and hospital activity (total and medical admissions and new general practitioner total and medical out-patient referrals) for each practice. RESULTS: The prescription of statins during 1996 varied between nil and 14.1 'statin-years' of prescribing per 1000 patients aged 35-69. There was a significant inverse relationship between the rate of statin prescribing and the level of deprivation of that practice (p < 0.0001). Deprivation, as measured by Townsend index, accounted for 13 per cent of the total variability in statin prescribing, which rose to 19 per cent after adjustment. The prescribing of other lipid lowering agents of the fibrate class was positively associated with statin prescribing (p=0.001) and this association persisted after adjusting for deprivation. None of the other practice characteristics were found to be significantly associated with rates of statin prescribing. CONCLUSIONS: General practices with high deprivation indices serve more deprived populations with a higher prevalence of cardiovascular disease, and may be assumed to have a greater need for statins. Despite this, practices with higher deprivation indices prescribed fewer statins to their patients than less deprived practices. It was not possible to identify whether the more deprived general practices had successfully identified at risk individuals but it is likely that special efforts are needed to increase the uptake of effective health care in their patients.

Providing welfare rights advice in primary care.

OBJECTIVE: To evaluate the introduction of dedicated open access welfare rights advice sessions in a general practice setting. DESIGN: A retrospective study of 416 client visits over a 11 month period from August 1995. A prospective questionnaire survey of 34 attendees over a three month period from April 1996. Semi-structured interviews with 11 involved primary care staff. SETTING: An inner city health centre. OUTCOMES: Social characteristics of clients attending; problems presented; benefit uptake; views from the health centre staff and welfare rights advisers and comments on future development. RESULTS: A total of 270 new clients used the service during the study period with 146 repeat visits (35%). Of the new clients, 158 out of 270 (59%) reported that they were disabled and 50% of the 158 had specific disability based welfare rights enquiries. 15% of new clients (40 out of 270) were found to be owed money by the current benefit system. Of these, 24 clients obtained one-off payments totalling l15,863 and 16 clients obtained regular payments totalling l539 a week. 58% of interviewed clients had not previously accessed any welfare rights advisory services. The welfare rights service was considered by the primary health care team to be a very useful contribution in a highly deprived area. CONCLUSIONS: The advice service increased the uptake of social security benefits in 15% of all new attendees. An open access service may not have been the most efficient method of delivering such advice. However, the high proportion of new clients who reported having a disability suggested that a health centre setting may be particularly accessible for those reporting disability. Further work is required to explore these findings and the most effective and efficient method of delivering the service in a deprived inner city setting.

Can primary care groups learn how to manage demand from fundholders? A study of fundholders in Nottingham.

BACKGROUND: Primary care groups (PCGs) will commission care for their patients and may be increasingly required to manage clearly defined resources. Existing general practice fundholders already operate in this environment, but can PCGs learn from the experience of fundholders in managing demand? AIM: To explore how general practice fundholders manage demand for hospital and community health services, and for prescribing. METHOD: A general practitioner (GP), and a fundholding manager from each of 26 practices were invited to take part. Questionnaires were developed, with structured and semi-structured components, and piloted in three practices. Interviews were conducted between October 1996 and February 1997 by the same interviewer (MDT). RESULTS: All practices stated that they were monitoring their waiting lists and giving priority to patients whose problems had become worse, but eight of the 23 GPs felt that they were unable to manage demand. Eight of the 15 fundholders who had developed in-house services actively managed the waiting list for these clinics. All fundholders had identified areas of unmet demand. Widely differing methods for increasing supply to meet demand were identified, and are described. Formularies were used by 12 out of the 23 fundholders. Guidelines were only considered useful by eight of the 23 practices; fundholders from later waves were less likely to find guidelines useful than fundholders from earlier waves (odds ratio [OR] = 0.11; 95% confidence interval [CI] = 0 to 0.96). Private specialist surgery was less likely to be accessed by later wave fundholders using the fund than by early wave fundholders (OR = 0.10; 95% CI = 0.09 to 0.97). CONCLUSION: Fundholders in Nottingham had not developed consistent approaches to managing demand within limited resources. Given the apparent diversity of attitudes and practices, the larger PCGs will require strong support to develop the intended commissioning function.

Recovery of some common solvents from an adhesive commercial skin adsorption pad by thermal desorption-gas chromatography.

A thermal desorption-gas chromatography (GC) system was developed for use with commercial adhesive plasters used for monitoring exposure of hands to common solvents. The efficiency of solvent adsorption on the activated carbon pads located on the plasters was determined for acetone, trichloroethylene, D-limonene, methanol, ethyl methyl ketone, toluene, tetrachloroethylene and m-xylene. The degree of solvent recovery for the system was also investigated for each solvent, as was its sensitivity and reproducibility. All solvents exhibited > 90% adsorption on the pads at spiking levels of 100-200 ng for each solvent, except for m-xylene and d-limonene. Solvent recovery was dependent on the volatility of the solvent at spiking volumes of about 1 microliter per pad with solvents with boiling points above 110 degrees C showing recoveries of < 75%. Increasing primary desorption times and temperatures increased these values. The precision was good with RSD < 5% for all solvents over the range 0.5-5.0 microliters of applied solvent. It was possible to detect 15-60 ng of each solvent component within solvent mixtures on the pads with the exception of D-limonene. It is concluded that all solvents tested except D-limonene can be determined on the pads under the conditions for thermal desorption-GC analysis described. The pads were used under protective gloves with six workers using xylene isomers as solvent in the workplace, when apparent solvent breakthrough through their gloves was observed.