Variations in Neisseria meningitidis carriage by socioeconomic status: a cross-sectional study.

BACKGROUND: Deprivation is associated with an increased risk of invasive Neisseria meningitidis disease, but little is known about the relationship between deprivation and asymptomatic carriage of N. meningitidis. This analysis was conducted to examine the relationship between meningococcal carriage and deprivation. METHODS: As part of a rapid meningococcal carriage prevalence study conducted in West Cumbria to investigate an apparent cluster of invasive meningococcal disease, data were collected on lifestyle and social factors, including area-level indicators of socioeconomic status, to identify factors associated with meningococcal carriage. RESULTS: In a multivariable log binomial regression model adjusted for age, lower socioeconomic status was significantly associated with higher prevalence of meningococcal carriage. A 1-unit increase in Index of Multiple Deprivation (2010) score was associated with a 1.7% increase in meningococcal carriage prevalence (95% confidence interval 0.3-3.0%). Age was the only significant predictor of carriage of Neisseria lactamica. CONCLUSIONS: Living in a deprived area is associated with increased carriage of Group B meningococcus. Deprivation is an important factor to consider in the evaluation of the effectiveness and cost-effectiveness of the introduction of new meningococcal B vaccines and the development and implementation of immunization policies. Further work is required to understand whether deprivation has an effect on meningococcal carriage through other factors such as smoking.

Barrow-in-Furness: a large community legionellosis outbreak in the UK.

A community outbreak of legionellosis occurred in Barrow-in-Furness, Cumbria, during July and August 2002. A descriptive study and active case-finding were instigated and all known wet cooling systems and other potential sources were investigated. Genotypic and phenotypic analysis, and amplified fragment length polymorphism of clinical human and environmental isolates confirmed the air-conditioning unit of a council-owned arts and leisure centre to be the source of infection. Subsequent sequence-based typing confirmed this link. One hundred and seventy-nine cases, including seven deaths [case fatality rate (CFR) 3·9%] were attributed to the outbreak. Timely recognition and management of the incident very likely led to the low CFR compared to other outbreaks. The outbreak highlights the responsibility associated with managing an aerosol-producing system, with the potential to expose and infect a large proportion of the local population and the consequent legal ramifications and human cost.

Cost-effectiveness analysis of the use of a high-intensity statin compared to a low-intensity statin in the management of patients with familial hypercholesterolaemia.

OBJECTIVES: To estimate, using probabilistic decision-analytic modelling techniques, the cost effectiveness of treating familial hypercholesterolaemia (FH) patients with high-intensity statins compared to treatment with low-intensity statins. For the purpose of this economic analysis, and based on their known differences, statins were categorised as high intensity if they produce greater LDL-cholesterol reductions than simvastatin 40 mg (e.g., simvastatin 80 mg and appropriate doses of atorvastatin and rosuvastatin or combination of statins + ezetimibe). METHODS: A lifetime Markov model was developed to estimate the incremental cost per quality adjusted life year (QALY) of treating a hypothetical cohort of 1000 FH patients aged between 20 and 70 years. Baseline coronary heart disease risks reported in the NICE TA 94 on statins, and age-adjusted risk of cardiovascular disease reported in the FH population, were used to populate the model. A meta-analysis estimate of the reduction in cardiovascular events from using high-intensity compared with low-intensity statins was obtained from published trials. Results were interpreted using a cost-effectiveness threshold of pound20 000/QALY. RESULTS: Fewer cardiovascular events and deaths were predicted to occur in the group treated with higher-intensity statins, and the incremental cost-effectiveness ratio (ICER) was estimated at pound11 103/QALY. The ICER remained below the pound20 000 threshold for 20-39-year-olds and 40-59-year-olds, but rose above this threshold in individuals aged over 60 years. One-way sensitivity analysis showed that results were most sensitive to variation in treatment effect on mortality and the cost of high-intensity statins. CONCLUSIONS: Modelling demonstrates that high-intensity statins are cost-effective for the treatment of younger FH patients. If, as is likely, the relative price of high-intensity statins fall in the future as they come off patent, then their cost effectiveness will improve further.

A hotel-based outbreak of Salmonella enterica subsp. Enterica serovar Enteritidis (Salmonella Enteritidis) in the United Kingdom, 2006.

An outbreak of food-borne Salmonella Enteritidis PT4 occurred in Cumbria, in north-west England, in the summer of 2006. Fifteen people, all with positive stool samples, met the case definition; three of these were admitted to hospital, including one patient who died. Preliminary investigations suggested a link to a meal served at a local hotel. A case control study was implemented, together with microbiological and environmental investigations. Fifteen microbiologically confirmed cases and 27 unmatched controls were included in the study, controls being randomly selected from people who had eaten at the hotel on the same day. The epidemiological evidence indicated a very strong association between infection and consumption of tiramisu made with raw shell eggs, although none were available for microbiological investigation. These results are in line with other salmonellosis outbreaks that have been associated with the use of raw shell eggs in food manufacturing and production. This paper highlights the continuing need for a greater awareness by those who work in the food industry of the health risks associated with the consumption of raw shell eggs.

Ultrasound for central venous cannulation: economic evaluation of cost-effectiveness.

We compared the economics of using two-dimensional ultrasound locating devices and more traditional landmark methods for central venous cannulation in the National Health Service (NHS). The evaluation consisted of a systematic review of randomised controlled trials and an economic evaluation using decision analytic cost-effectiveness modelling. Incremental costs per complication avoided associated with landmark and ultrasound central venous cannulation were modelled for patients scheduled for central venous cannulation. The marginal economic cost of using ultrasound for central venous cannulation was less than 10 pounds sterling per procedure, assuming that a machine is used for 15 procedures each week. The base case scenario implied that 2000 pounds sterling worth of resource savings result for every 1000 procedures undertaken and 90 avoided complications. Sensitivity analysis indicated that the results of modelling appear robust to the central assumptions used. Ultrasound guidance used in central venous cannulation procedures saves NHS resources even with conservative modelling assumptions.

Cost effectiveness of diagnostic strategies for patients with acute, undifferentiated chest pain.

OBJECTIVES: Patients presenting to hospital with acute, undifferentiated chest pain have a low, but important, risk of significant myocardial ischaemia. Potential diagnostic strategies for patients with acute, undifferentiated chest pain vary from low cost, poor effectiveness (discharging all home) to high cost, high effectiveness (admission and intensive investigation). This paper aimed to estimate the relative cost effectiveness of these strategies. METHODS: Decision analysis modelling was used to measure the incremental cost per quality adjusted year of life (QALY) gained for five potential strategies to diagnose acute undifferentiated chest pain, compared with the next most effective strategy, or a baseline strategy of discharging all patients home without further testing. RESULTS: Cardiac enzyme testing alone costs pound 17 432/QALY compared with discharge without testing. Adding two to six hours of observation and repeat enzyme testing costs an additional pound 18 567/QALY. Adding exercise testing to this strategy costs pound 28 553/QALY. A strategy of overnight admission, enzyme, and exercise testing has an incremental cost of pound 120 369/QALY, while a strategy consisting of overnight admission without exercise testing is subject to extended dominance. Sensitivity analysis revealed that the results are sensitive to variations in the direct costs of running each strategy and to variation in assumptions regarding the effect of diagnostic testing upon quality of life of those with non-cardiac disease. CONCLUSION: Observation based strategies incur similar costs per QALY to presently funded interventions for coronary heart disease, while strategies requiring hospital admission may be prohibitively poor value for money. Validation of the true costs and effects of observation based strategies is essential before widespread implementation.

Effectiveness and cost-effectiveness of prognostic markers in prostate cancer.

This paper demonstrates how economic modelling can be used to derive estimates of the cost-effectiveness of prognostic markers in the management of clinically localised and moderately graded prostate cancer. The model uses a Markov process and is populated using published evidence and local data. The robustness of the results has been tested using sensitivity analysis. Three treatment policies of 'monitoring' (observation), radical prostatectomy, or a selection-based management policy using DNA-ploidy as an experimental marker, have been evaluated. Modelling indicates that a policy of managing these tumours utilising experimental markers has an estimated cost per quality-adjusted life year (QALY) of pound 12 068. Sensitivity analysis shows the results to be relatively sensitive to quality-of-life variables. If novel and experimental markers can achieve specificity in excess of 80%, then a policy of radical surgery for those identified as being at high risk and conservative treatment for the remainder would be both better for patients and cost-effective. The analysis suggests that a radical prostatectomy treatment policy for the moderately graded tumours (Gleason grades -7) modelled in this paper may be inferior to a conservative approach in the absence of reliable prognostic markers, being both more costly and yielding fewer QALYs.

Laparoscopic cholecystectomy: a good buy? A cost comparison with small-incision (mini) cholecystectomy.

OBJECTIVES: To compare inpatient costs for laparoscopic and small-incision cholecystectomy. DESIGN: Retrospective analysis using results of a single blind prospective randomised trial. SETTING: Teaching hospital, UK. SUBJECTS: 200 patients having elective cholecystectomy. INTERVENTIONS: Standard laparoscopic cholecystectomy with conversion to open cholecystectomy if necessary. Small-incision cholecystectomy using high right transverse epigastric incision, enlarged if necessary for safe exposure. MAIN OUTCOME MEASURES: Providers inpatient costs. RESULTS: Small-incision cholecystectomy cost Pound Sterling 995 and was 29% less expensive than the laparoscopic procedure which cost Pound Sterling 1397. Costs of equipment and operations themselves accounted for most of the difference. Results also suggest that costs to patients and society from time lost away from work may be lower for mini-cholecystectomy. CONCLUSIONS: The national health service could be spending over Pound Sterling 10m a year by encouraging laparoscopic rather than small-incision operations for cholecystectomy. Commissioners of health care should question whether the benefits of laparoscopic surgery justify the additional costs.

Salmonella typhimurium DT104 infection in people and animals in Scotland: a collaborative epidemiological study 1993-96.

This paper describes a comparative analysis of human and farm animal salmonellosis in Scotland between 1993 and 1996, with particular reference to Salmonella typhimurium definitive type 104 (DT104). Cattle were the main reservoir, accounting for 73.1 per cent of incidents involving all salmonellae and 69.5 per cent of those involving S typhimurium DT104. The annual rates of incidence in people and cattle were recorded in each Health Board area. Dumfries and Galloway had the highest rate of incidence in cattle for all salmonellae (19.0 per 100,000) but people were affected uniformly across mainland Scotland. However, the rate of incidence of S typhimurium DT104 was highest in Dumfries and Galloway for both people (10.1 per 100,000) and cattle (13.0 per 100,000). In Dumfries and Galloway, Wigtownshire had the highest rates for all salmonellae and for S typhimurium DT104 in both people and cattle. In Dumfries and Galloway, 37.8 per cent of the adult cases of S typhimurium DT104 in people were among those known to have had regular contact with animals, and children under six years of age accounted for 36.3 per cent of the human infections in this region.

Measles immunity and response to revaccination among secondary school children in Cumbria.

The prevalence of antibody to measles virus in 759 children aged 11-18 years attending a secondary school in Cumbria was measured using a salivary IgG antibody capture assay. Serum IgG antibody levels were measured using a plaque reduction neutralization assay in subjects whose saliva was antibody negative. Vaccination histories were obtained from the child health computer and general practice record. A total of 662 pupils (87% of those tested) had detectable measles-specific IgG in saliva. Of the remaining 97, 82 provided blood samples and 29 had serum neutralizing antibody levels above 200 mIU/ml. Afer adjusting for non-participation rates, the proportion considered non-immune (no IgG in saliva and < or = 200 mIU/ml in serum) was 9% overall, ranging from 6% in vaccinated children to 20% in unvaccinated children. Measles-mumps-rubella vaccine was given to 50 children of whom 38 provided post-vaccination serum and 32 saliva samples. Thirty (79%) had a fourfold or greater rise in serum neutralizing antibody and 28 (88%) developed IgG antibody in saliva. Half of the children considered non-immune by antibody testing would have been overlooked in a selective vaccination programme targeted at those without a history of prior vaccination. A programme targeted at all school children should substantially reduce the proportion non-immune since a primary or booster response was achieved in three quarters of previously vaccinated children with low antibody levels and in all unvaccinated children. While it is feasible to screen a school-sized population for immunity to measles relatively quickly using a salivary IgG assay, a simple inexpensive field assay would need to be developed before salivary screening and selective vaccination could substitute for universal vaccination of populations at risk of measles outbreaks. The salivary IgG assay provided a sensitive measure of a booster response to vaccination.

Measles in secondary school children: implications for vaccination policy.

The reported incidence of measles in children of secondary school age rose in 1992, after a progressive decline between 1988 and 1991. This rise was maintained in 1993. Several school and community based outbreaks of measles have occurred in the United Kingdom. This paper reports the investigation of an outbreak of measles based in a secondary school, which took place in 1992. Thirty clinical cases were detected among the school's 840 pupils and 10 sporadic cases occurred outside the school. Twenty-one of the school cases provided samples of serum, in 19 of which measles IgM was detected. The overall attack rate was 3.6%, with no significant differences attributable to age and sex. Vaccine efficacy was about 90%. This outbreak is one of the first to be described in the United Kingdom, although other countries (notably the United States) have reported measles in teenagers. The small degree of spread in the community may reflect the current high uptake of measles, mumps, and rubella vaccine and the catch up campaign that took place in 1988. The feasibility and cost effectiveness of various policy options to prevent future outbreaks in secondary schools are now being evaluated.

Health promotion priorities for general practice: constructing and using "indicative prevalences".

OBJECTIVE: To construct indicative prevalences for a range of diseases and risk markers and use them in planning health promotion interventions in primary health care. DESIGN: Indicative prevalences comprised point prevalence, incidence, and mortality measures. Use of data from Office of Population Censuses and Surveys, Northern Regional Health Authority, and Newcastle health and lifestyle survey 1991, and research papers to determine prevalence adjusted for age and sex in a hypothetical practice with a list of 10,000 patients. SETTING: Newcastle upon Tyne, England. RESULTS: Indicative prevalences were highest for common risk markers such as failure to achieve exercise targets (6871), moderate to extreme obesity (2785), and smoking (2689); moderate for overt disease such as angina (175) and stroke (20/year); and low for events such as suicide (1/year) and deaths from malignant melanoma (2/10 years). CONCLUSIONS: Given limited time and resources, brief interventions to reduce smoking and the systematic case finding and management of patients with hypertension, angina, and previous myocardial infarction are likely to be the highest priorities for health promotion in primary care.