Randomised controlled trial evaluating cardiovascular screening and intervention in general practice: principal results of British family heart study. Family Heart Study Group.

OBJECTIVE--To measure the change in cardiovascular risk factors achievable in families over one year by a cardiovascular screening and lifestyle intervention in general practice. DESIGN--Randomised controlled trial in 26 general practices in 13 towns in Britain. SUBJECTS--12,472 men aged 40-59 and their partners (7460 men and 5012 women) identified by household. INTERVENTION--Nurse led programme using a family centred approach with follow up according to degree of risk. MAIN OUTCOME MEASURES--After one year the pairs of practices were compared for differences in (a) total coronary (Dundee) risk score and (b) cigarette smoking, weight, blood pressure, and random blood cholesterol and glucose concentrations. RESULTS--In men the overall reduction in coronary risk score was 16% (95% confidence interval 11% to 21%) in the intervention practices at one year. This was partitioned between systolic pressure (7%), smoking (5%), and cholesterol concentration (4%). The reduction for women was similar. For both sexes reported cigarette smoking at one year was lower by about 4%, systolic pressure by 7 mm Hg, diastolic pressure by 3 mm Hg, weight by 1 kg, and cholesterol concentration by 0.1 mmol/l, but there was no shift in glucose concentration. Weight, blood pressure, and cholesterol concentration showed the greatest difference at the top of the distribution. If maintained long term the differences in risk factors achieved would mean only a 12% reduction in risk of coronary events. CONCLUSIONS--As most general practices are not using such an intensive programme the changes in coronary risk factors achieved by the voluntary health promotion package for primary care are likely to be even smaller. The government''s screening policy cannot be justified by these results.     

What can be concluded from the Oxcheck and British family heart studies: commentary on cost effectiveness analyses.

OBJECTIVES--To provide a commentary on the economic evaluations of the Oxcheck and British family heart studies: direct comparison of their relative effectiveness and cost effectiveness; comparisons with other interventions; and consideration of problems encountered. DESIGN--Modelling from cost and effectiveness data to estimate of cost per life year gained. SUBJECTS--Middle aged men and women. INTERVENTIONS--Screening for cardiovascular risk factors followed by appropriate lifestyle advice and drug intervention in general practice, and other primary coronary risk management strategies. MAIN OUTCOME MEASURES--Life years gained; cost per life year gained. RESULTS--Depending on the assumed duration of risk reduction, the programme cost per discounted life year gained ranged from 34,800 pounds for a 1 year duration to 1500 pounds for 20 years for the British family heart study and from 29,300 pounds to 900 pounds for Oxcheck. These figures exclude broader net clinical and cost effects and longer term clinical and cost effects other than coronary mortality. CONCLUSIONS--Despite differences in underlying methods, the estimates in the two economic analyses of the studies can be directly compared. Neither study was large enough to provide precise estimates of the overall net cost. Modelling to cost per life year gained provides more readily interpretable measures. These estimates emphasise the importance of the relatively weak evidence on duration effect. Only if the effect lasts at least five years is the Oxcheck programme likely to be cost effective. The effect must last for about 10 years to justify the extra cost associated with the British family heart study.     

Costs and cost effectiveness of health checks conducted by nurses in primary care: the Oxcheck study.

OBJECTIVE--To measure the costs and cost effectiveness of the Oxcheck cardiovascular risk factor screening and intervention programme. DESIGN--Cost effectiveness analysis of a randomised controlled trial using clinical and economic data taken from the trial. SETTING--Five general practices in Luton and Dunstable, England. SUBJECTS--2205 patients who attended a health check in 1989-90 and were scheduled for re-examination in 1992-3 (intervention group); 1916 patients who attended their initial health check in 1992-3 (control group). Participants were men and women aged 35-64 years. INTERVENTION--Health check conducted by nurse, with health education and follow up according to degree of risk. MAIN OUTCOME MEASURES--Cost of health check programme; cost per 1% reduction in coronary risk. RESULTS--Health check and follow up cost 29.27 pounds per patient. Estimated programme cost per 1% reduction in coronary risk per participant was between 1.46 pounds and 2.25 pounds; it was nearly twice as much for men as women. CONCLUSIONS--The cost to the practice of implementing Oxcheck-style health checks in an average sized practice of 7500 patients would be 47,000 pounds, a proportion of which could be paid for through staff pay reimbursements and Band Three health promotion target payments. This study highlights the considerable difficulties faced when calculating the costs and benefits of a health promotion programme. Economic evaluations should be integrated into the protocols of randomised controlled trials to enable judgments to be made on the relative cost effectiveness of different prevention strategies.     

Mammography screening: an incremental cost effectiveness analysis of double versus single reading of mammograms.

OBJECTIVE--To compare mammography reading by one radiologist with independent reading by two radiologists. DESIGN--An observational non-randomised trial at St Margaret''s Hospital, Epping. SUBJECTS-- 33 734 consecutive attenders for breast screening in the main trial and a sample of 132 attenders for assessment who provided data on private costs. INTERVENTIONS--Three reporting policies were compared: single reading, consensus double reading, and non-consensus double reading. MAIN OUTCOME MEASURES--Numbers of cancers detected, recall rates, screening and assessment costs, and cost effectiveness ratios. RESULTS--A policy of double reading followed by consensus detected an additional nine cancers per 10 000 women screened (95% confidence interval 5 to 13) compared with single reading. A non-consensus double reading policy detected an additional 10 cancers per 10 000 women screened (95% confidence interval 6 to 14). The difference in numbers of cancers detected between the consensus and non-consensus double reading policies was not significant (95% confidence interval -0.2 to 2.2). The proportion of women recalled for assessment after consensus double reading was significantly lower than after single reading (difference 2.7%; 95% confidence interval 2.4% to 3.0%). The recall rate with the non-consensus policy was significantly higher than with single reading (difference 3.0%; 2.5% to 3.5%). Consensus double reading cost less than single reading (saving 4853 pounds per 10 000 women screened). Non-consensus double reading cost more than single reading (difference 19 259 pounds per 10 000 women screened). CONCLUSIONS--In the screening unit studied a consensus double reading policy was more effective and less costly than a single reading policy.     

Coronary heart disease prevention: insights from modelling incremental cost effectiveness

Objective To determine which treatments for preventing coronary heart disease should be offered to which patients by assessing their incremental cost effectiveness.Design Modelling studyData sources Cost estimates (for NHS) and estimates of effectiveness obtained for aspirin, antihypertensive drugs, statins and clopidogrel.Data synthesis Treatment effects were assumed to be independent, and cost per coronary event prevented was calculated for treatments individually and in combination across patients at a range of coronary risks.Results The most cost effective preventive treatments are aspirin, initial antihypertensive treatment (bendrofluazide and atenolol), and intensive antihypertensive treatment (bendrofluazide, atenolol and enalapril), whereas simvastatin and clopidogrel are the least cost effective (cost per coronary event prevented in a patient at 10% coronary risk over five years is £3500 for aspirin, £12 500 for initial antihypertensives, £18 300 for intensive antihypertensives, £60 000 for clopidogrel, and £61 400 for simvastatin). Aspirin in a patient at 5% five year coronary risk costs less than a fifth as much per event prevented (£7900) as simvastatin in a patient at 30% five year risk (£40 800).Discussion A cost effective prevention strategy would offer aspirin and initial antihypertensive treatment to all patients at greater than 7.5% five year coronary risk before offering statins or clopidogrel to patients at greater than 15% five year coronary risk. Incremental cost effectiveness analysis of treatments produces robust, practical cost effectiveness rankings that can be used to inform treatment guidelines.     

Reuse of haemodialysis equipment: convenience and cost effectiveness.

The shortage of resources for providing renal replacement makes it essential to reduce revenue costs wherever possible. Assuming that haemodialysis is likely to remain a mainstay of renal replacement, a policy of reusing the expensive disposable dialysers and blood lines could offer substantial cost savings. Such reuse has been shown to be safe and to maintain efficiency, but it must also take account of convenience to the patient, especially those dialysing at home. A survey of patients treated with home dialysis shows that the rate of reuse of the complete extracorporeal circuit was highest for those patients who had automated reuse systems.     

Neonatal intensive care and cost effectiveness.

During the past decade the rate of death among newborns weighing less than 1500 g at birth has decreased by approximately half. This dramatic reduction has resulted from the application of research findings and technologic advances, but it has proved expensive. Perhaps as a consequence of articles demonstrating the costs as well as the recognition that the overall prevalence of disabilities in infants is relatively unchanged, neonatal intensive care has recently been viewed as a possible area for cost containment. We reviewed the literature on the cost of neonatal intensive care and the limited information on other expensive medical programs and found that the cost of neonatal intensive care compared favourably, especially for infants whose birth weight was 1000 to 1500 g. Better information on the outcome of infants of very low birth weight and comparable rigorous studies of the cost effectiveness of other expensive medical programs are required, and other less easily quantified factors must be considered before decisions are made to limit neonatal intensive care on the basis of gestational age or birth weight.     

Costs and benefits of cervical screening. I. The costs of the cervical screening programme

In 1991, the average total Health Service cost of a cervical smear, including follow up at the colposcopy clinic, was almost £22.70 in the Perth and Kinross district of Scotland. The average cost per colposcopy clinic visit was £30. The main cost elements were in general practice (55% of total) and the laboratory (33%), and most of the cost was for staff time.     

Different strategies for screening and prevention of type 2 diabetes in adults: cost effectiveness analysis

Objective To compare four potential screening strategies, and subsequent interventions, for the prevention and treatment of type 2 diabetes: (a) screening for type 2 diabetes to enable early detection and treatment, (b) screening for type 2 diabetes and impaired glucose tolerance, intervening with lifestyle interventions in those with a diagnosis of impaired glucose tolerance to delay or prevent diabetes, (c) as for (b) but with pharmacological interventions, and (d) no screening.Design Cost effectiveness analysis based on development and evaluation of probabilistic, comprehensive economic decision analytic model, from screening to death.Setting A hypothetical population, aged 45 at time of screening, with above average risk of diabetes.Data sources Published clinical trials and epidemiological studies retrieved from electronic bibliographic databases; supplementary data obtained from the Department of Health statistics for England and Wales, the screening those at risk (STAR) study, and the Leicester division of the ADDITION study.Methods A hybrid decision tree/Markov model was developed to simulate the long term effects of each screening strategy, in terms of both clinical and cost effectiveness outcomes. The base case model assumed a 50 year time horizon with discounting of both costs and benefits at 3.5%. Sensitivity analyses were carried out to investigate assumptions of the model and to identify which model inputs had most impact on the results.Results Estimated costs for each quality adjusted life year (QALY) gained (discounted at 3.5% a year for both costs and benefits) were £14 150 (€17 560; $27 860) for screening for type 2 diabetes, £6242 for screening for diabetes and impaired glucose tolerance followed by lifestyle interventions, and £7023 for screening for diabetes and impaired glucose tolerance followed by pharmacological interventions, all compared with no screening. At a willingness-to-pay threshold of £20 000 the probability of the intervention being cost effective was 49%, 93%, and 85% for each of the active screening strategies respectively.Conclusions Screening for type 2 diabetes and impaired glucose tolerance, with appropriate intervention for those with impaired glucose tolerance, in an above average risk population aged 45, seems to be cost effective. The cost effectiveness of a policy of screening for diabetes alone, which offered no intervention to those with impaired glucose tolerance, is still uncertain.     

Inheritance of heart rate variability: the kibbutzim family study

Heart rate variability (HRV) measures are associated with coronary heart disease incidence and mortality. Therefore insight into the genetic and environmental determinants of these measures may have clinical relevance. We assessed the role of genetic and environmental factors of time domain and frequency domain HRV indices. Participants were 451 kibbutz members, aged 15 and up, belonging to 80 families. HRV indices were calculated from Holter recordings measured over 5 min. Our data indicate that for the two time- and four frequency domain indices, a mixture of two normal distributions fit the data significantly better than a single normal distribution (P<0.05). We used complex segregation analysis to infer the modes of inheritance of these HRV measures. We found evidence for possible involvement of a recessive major gene in the inheritance of the root mean square of successive differences in RR intervals (RMSSD), which is predominantly vagally mediated. A putative major gene explains 28%-34% of the adjusted inter-individual variability. The SD, determined by a mixture of mechanisms, is influenced by environmental and polygenic effects, but not by a major gene. The findings regarding the heritability of the frequency domain indices were not conclusive. However, the involvement of genetic factors was not rejected. Additional studies in extended families are needed to confirm the involvement of major genes in the determination of the autonomic activity.     

Costs and benefits of cervical screening IV: valuation by women of the cervical screening programme

OBJECTIVES: To assess the value of the cervical smear test to women, taking account of the positive and negative aspects of the cervical screening service. DESIGN: A postal survey. SETTING: Tayside Health Board region of Scotland. PARTICIPANTS: A sample of 2000 women aged 20-59. MAIN OUTCOME MEASURES: Maximum willingness to pay (WTP) for a cervical smear test. RESULTS: Women were prepared to pay 50.20 British pounds per smear on a 3-yearly basis. Willingness to pay was positively related to income, but unrelated to age and whether or not the respondent had previously had a smear. CONCLUSIONS: Previous studies have estimated the cost per screen or cost per life year saved by cervical screening. This study used the economic instrument of WTP to take account of other potential (dis)benefits to women. The value women place on having a smear was more than the cost to the National Health Service (NHS) of providing the service. The output of a WTP study is potentially useful at the policy level. Future work should explore both the value of alternative approaches to cervical screening, and the value of competing health care interventions.     

Adiposity and incident heart failure in older adults: the cardiovascular health study

While several studies have reported a positive association between overall adiposity and heart failure (HF) risk, limited and inconsistent data are available on the relation between central adiposity and incident HF in older adults. We sought to examine the association between waist circumference (WC) and incident HF and assess whether sex modifies the relation between WC and HF. Prospective study using data on 4,861 participants of the Cardiovascular Health Study (1989-2007). HF was adjudicated by a committee using information from medical records and medications. We used Cox proportional hazard models to compute hazard ratio (HR). The mean age was 73.0 years for men and 72.3 years for women; 42.5% were men and 15.3% were African Americans. WC was positively associated with an increased risk of HF: each standard deviation of WC was associated with a 14% increased risk of HF (95% CI: 3%-26%) in a multivariable model. There was not a statistically significant sex-by-WC interaction (P = 0.081). BMI was positively associated with incident HF (HR: 1.22 (95% CI: 1.15-1.29) per standard deviation increase of BMI); however, this association was attenuated and became nonstatistically significant upon additional adjustment for WC (HR: 1.09 (95% CI: 0.99-1.21)). In conclusion, a higher WC is associated with an increased risk of HF independent of BMI in community-living older men and women.     

Groundwater remediation and the cost effectiveness of phytoremediation

In 1999, phytoremediation was applied at the site of a Belgian car factory to contain two BTEX plumes. This case study evaluates the cost effectiveness of phytoremediation compared to other remediation options, applying a tailored approach for economic evaluation. Generally, when phytoremediation is addressed as being cost effective, the cost effectiveness is only determined on an average basis. This study however, demonstrates that an incremental analysis may provide a more nuanced conclusion. When the cost effectiveness is calculated on an average basis, in this particular case, the no containment strategy (natural attenuation) has the lowest cost per unit mass removed and hence, should be preferred. However, when the cost effectiveness is determined incrementally, no containment should only be preferred if the value of removing an extra gram of contaminant mass is lower than 320 euros. Otherwise, a permeable reactive barrier should be adopted. A similar analysis is provided for the effect determined on the basis of remediation time. Phytoremediation is preferred compared to 'no containment' if reaching the objective one year earlier is worth 7 000 euros.     

Different screening strategies (single or dual) for the diagnosis of suspected latent tuberculosis: a cost effectiveness analysis

Background

Obesity and asthma have reached epidemic proportions in the US. Their concurrent rise over the last 30 years suggests that they may be connected. Numerous observational studies support a temporally-correct, dose-response relationship between body mass index (BMI) and incident asthma. Weight loss, either induced by surgery or caloric restriction, has been reported to improve asthma symptoms and lung function. Due to methodological shortcomings of previous studies, however, well-controlled trials are needed to investigate the efficacy of weight loss strategies to improve asthma control in obese individuals.

Methods/Design

BE WELL is a 2-arm parallel randomized clinical trial (RCT) of the efficacy of an evidence-based, comprehensive, behavioral weight loss intervention, focusing on diet, physical activity, and behavioral therapy, as adjunct therapy to usual care in the management of asthma in obese adults. Trial participants (n = 324) are patients aged 18 to 70 years who have suboptimally controlled, persistent asthma, BMI between 30.0 and 44.9 kg/m², and who do not have serious comorbidities (e.g., diabetes, heart disease, stroke). The 12-month weight loss intervention to be studied is based on the principles of the highly successful Diabetes Prevention Program lifestyle intervention. Intervention participants will attend 13 weekly group sessions over a four-month period, followed by two monthly individual sessions, and will then receive individualized counseling primarily by phone, at least bi-monthly, for the remainder of the intervention. Follow-up assessment will occur at six and 12 months. The primary outcome variable is the overall score on the Juniper Asthma Control Questionnaire measured at 12 months. Secondary outcomes include lung function, asthma-specific and general quality of life, asthma medication use, asthma-related and total health care utilization. Potential mediators (e.g., weight loss and change in physical activity level and nutrient intake) and moderators (e.g., socio-demographic characteristics and comorbidities) of the intervention effects also will be examined.

Discussion

This RCT holds considerable potential for illuminating the nature of the obesity-asthma relationship and advancing current guidelines for treating obese adults with asthma, which may lead to reduced morbidity and mortality related to the comorbidity of the two disorders.

Trial registration

NCT00901095