Financial and environmental costs of reusable and single-use anaesthetic equipment.

BACKGROUND.: An innovative approach to choosing hospital equipment is to consider the environmental costs in addition to other costs and benefits. METHODS.: We used life cycle assessment to model the environmental and financial costs of different scenarios of replacing reusable anaesthetic equipment with single-use variants. The primary environmental costs were CO 2 emissions (in CO 2 equivalents) and water use (in litres). We compared energy source mixes between Australia, the UK/Europe, and the USA. RESULTS.: For an Australian hospital with six operating rooms, the annual financial cost of converting from single-use equipment to reusable anaesthetic equipment would be an AUD$32 033 (£19 220), 46% decrease. In Australia, converting from single-use to reusable equipment would result in an increase of CO 2 emissions from 5095 (95% CI: 4614-5658) to 5575 kg CO 2 eq (95% CI: 5542-5608), a 480 kg CO 2 eq (9%) increase. Using the UK/European power mix, converting from single-use (5575 kg CO 2 eq) to reusable anaesthetic equipment (802 kg CO 2 eq) would result in an 84% reduction (4873 kg CO 2 eq) in CO 2 emissions, whilst in the USA converting to reusables would have led to a 2427 kg CO 2 eq (48%) reduction. In Australia, converting from single-use to reusable equipment would more than double water use from 34.4 to 90.6 kilolitres. CONCLUSIONS.: For an Australian hospital with six operating rooms, converting from single-use to reusable anaesthetic equipment saved more than AUD$30 000 (£18 000) per annum, but increased the CO 2 emissions by almost 10%. The CO 2 offset is highly dependent on the power source mix, while water consumption is greater for reusable equipment.

Work-exacerbated asthma in a workers' compensation population.

BACKGROUND: Asthma is becoming more prevalent with large numbers of individuals suffering from work-exacerbated asthma. AIMS: To examine the characteristics of workplace exposures and working days lost in relation to work-exacerbated asthma (WEA) in a workers' compensation population. METHODS: An analysis of accepted workers' compensation asthma claims in Ontario over a 5-year period. Claims among the top three industry groups were categorized based on working time lost of 1 day or less, 2-5 days and 6 days or more. Attributable agents were subdivided into dusts, smoke, chemicals and sensitizers. RESULTS: Among the asthma claims, 72% (645) fulfilled criteria for WEA from their history. The commonest industry groups were services, education and health care, with 270 claims that met our analysis requirements. Within these industry groups, education had a lower proportion of workers with short exacerbations (missing 1 day or less: 27%) while the health care industry had a higher than expected proportion of short exacerbations (55%). The agents to which WEA was attributed differed across the groups, with dusts having the highest proportion in the education group (65%), smoke in the service industry (34%) and sensitizers in health care (41%). Those agents more commonly attributed to exacerbations tended to have lower rates of prolonged exacerbation compared with less commonly involved agents. CONCLUSIONS: The morbidity of WEA and the type of agents to which it was attributed varied between industry groups.

The microbiological and sustainability effects of washing anaesthesia breathing circuits less frequently.

In the presence of single-use airway filters, we quantified anaesthetic circuit aerobic microbial contamination rates when changed every 24 h, 48 h and 7 days. Microbiological samples were taken from the interior of 305 anaesthetic breathing circuits over a 15-month period (3197 operations). There was no significant difference in the proportion of contaminated circuits when changed every 24 h (57/105 (54%, 95% CI 45-64%)) compared with 48 h (43/100 (43%, 95% CI 33-53%, p = 0.12)) and up to 7 days (46/100 (46%, 95% CI 36-56%, p = 0.26)). Median bacterial counts were not increased at 48 h or 7 days provided circuits were routinely emptied of condensate. Annual savings for one hospital (six operating theatres) were $AU 5219 (£3079, €3654, $US 4846) and a 57% decrease in anaesthesia circuit steriliser loads associated with a yearly saving of 2760 kWh of electricity and 48 000 l of water. Our findings suggest that extended circuit use from 24 h up to 7 days does not significantly increase bacterial contamination, and is associated with labour, energy, water and financial savings.

Assessment of tumor blood flow distribution by dynamic contrast-enhanced CT.

A distinct feature of the tumor vasculature is its tortuosity and irregular branching of vessels, which can translate to a wider dispersion and higher variability of blood flow in the tumor. To enable tumor blood flow variability to be assessed in vivo by imaging, a tracer kinetic model that accounts for flow dispersion is developed for use with dynamic contrast-enhanced (DCE) CT. The proposed model adopts a multiple-pathway approach and allows for the quantification of relative dispersion in the blood flow distribution, which reflects flow variability in the tumor vasculature. Monte Carlo simulation experiments were performed to study the possibility of reducing the number of model parameters based on the Akaike information criterion approach and to explore possible noise and tissue conditions in which the model might be applicable. The model was used for region-of-interest analysis and to generate perfusion parameter maps for three patient DCE CT cases with cerebral tumors, to illustrate clinical applicability.

[Conceptual model for assessment and management of human risk from transport pollution].

The existing methodology for human health risk assessment allows one to appreciably study cause-and-effect relationships between environmental factors and human health. Risk management is a logic continuation of the assessment of human health risk and it is aimed at substantiating the choice of decisions that are best in a specific situation to eliminate or minimize it, to make follow-up monitoring of exposures and a risk, to evaluate the efficiency of health-improving measures and to correct the latter. Risk management involves technical, technological, organizational, social, legal, economic, normative, political, and other decisions made on the conclusions and estimates obtained when characterizing the risk.

Prescribing and administration of nebulized bronchodilators: a prospective audit in a university hospital.

OBJECTIVE: Inaccurate and incomplete prescribing of nebulized bronchodilators can result in uncertainty and suboptimal treatment. A prospective study was carried out to assess the completeness of prescription and the quality of bronchodilator drug administration via nebulizers. METHODOLOGY: A total of 121 consecutive inpatient nebulized bronchodilator prescriptions and treatments administered to 93 adult medical inpatients in a university hospital were studied prospectively. Five different aspects of the prescriptions were examined to assess their accuracy and completeness. The administration of each nebulizer treatment was studied using audit of medication charts and interview with ward nurses. RESULTS: No prescription was correct and complete in all five aspects assessed. The most common mistake was failure to state the type and flow rate of driving gas (100%). This was followed by failure to prescribe recommended doses of bronchodilators (46%) and failure to give unambiguous instruction on frequency of treatment (39%). It was found that in only 21.5% of instances was the administration of nebulized bronchodilator drugs optimal. CONCLUSION: This prospective audit has demonstrated major deficiencies in the prescribing and administration of nebulized bronchodilators and it has highlighted the need for a local protocol and continuing staff education. The alternative method of administering bronchodilator via metered dose inhaler with large volume spacer should be evaluated in the treatment of acute airflow obstruction in hospitalized patients.

What is the optimal approach for using a direct amplification test in the routine diagnosis of pulmonary tuberculosis? A preliminary assessment.

OBJECTIVE: The aim of this study was to determine the most appropriate strategy for the rapid diagnosis of pulmonary tuberculosis (PTB) using a nucleic acid amplification (NAA) test. METHODOLOGY: This was a prospective study of 128 adult patients in whom respiratory secretions were tested for Mycobacterium tuberculosis by the AMPLICOR assay. The basis for starting PTB treatment was noted for each patient. The optimal approach was determined by using Bayes' theorem to compare different combinations of pretest probability, smear results with the AMPLICOR test. RESULTS: The incidence of PTB was 15.6%. In only one patient was treatment for PTB commenced because of a positive AMPLICOR result. The rest were managed according to the conventional approach which relied upon clinical judgment and direct smear. The optimal approach was to treat patients with high or intermediate pretest risk for PTB who returned positive AMPLICOR tests. The overall accuracies of the conventional approach, AMPLICOR test and optimal approach were 89.8, 95.3 and 96.1%, respectively. CONCLUSION: This small study suggests that NAA testing be limited to patients with high or intermediate pretest risk of PTB. In this group, positive results demand treatment while the management of those with negative results still relies on clinical judgment.

Empirical treatment of chronic cough--a cost-effectiveness analysis.

Chronic cough of unknown etiology is often difficult to diagnose, thus, there exists controversy regarding the management of such patients. Although the ACCP (American College of Chest Physicians) statement in 1998 recommended that treatment should follow testing, recent evidence suggests that empirical treatment of GERD is more cost-effective than testing followed by treatment, in both chronic cough and non-cardiac chest pain. In this paper, we evaluated the cost-effectiveness in managing patients with chronic unexplained cough by building a decision model, and compared the cost-effectiveness of six most common management strategies. The outcome of our analysis demonstrates that empirical treatment is the cheapest option, while testing followed by treatment is the most expensive option with the shortest time course.

Application of breath-hold T2-weighted, first-pass perfusion and gadolinium-enhanced T1-weighted MR imaging for assessment of myocardial viability in a pig model.

The purpose of this study was to correlate the abnormal signal area on various magnetic resonance (MR) images to the infarct area on pathologic examination and to assess the myocardial viability on the basis of MR images. T2-weighted, first-pass perfusion, and delayed gadolinium-enhanced T1-weighted images were used as "one-stop examinations" in a pig model of reperfused myocardial infarction. The results of each MR image were compared with those of 2,3, 5-triphenyltetrazolium chloride (TTC) staining. The abnormal signal areas on T2-weighted and Gd-enhanced T1-weighted images were larger than the infarct areas on TTC staining (34.7% and 32.3% vs. 28.3%; P< 0.05), whereas the nonperfused areas on perfusion images were correlated (25.6% vs, 28.3%; P = 0.139). Electron microscopic examination showed severely distorted ultrastructures in the infarct areas and mildly damaged ultrastructures in the peri-infarct areas. Perfusion images probably reflected the infarct areas, whereas T2-weighted and Gd-enhanced T1-weighted images seemed to include peri-infarct as well as infarct areas.

The rapid diagnosis of smear-negative pulmonary tuberculosis: a cost-effectiveness analysis.

OBJECTIVE: The prompt diagnosis of smear-negative pulmonary tuberculosis (PTB) is a clinical challenge. It may be achieved by a number of tests which have varying accuracies, costs and degrees of invasiveness. The objective of this study was to compare the cost-effectiveness of clinical judgement (empirical), the Roche Cobas amplicor assay for Mycobacterium tuberculosis (amplicor), acid-fast staining of bronchoalveolar lavage specimens (BAL), nucleic acid amplification tests of bronchoalveloar lavage specimens for M. tuberculosis (BAL + NAA), computed tomography (CT) and amplicor assay followed by BAL. METHODOLOGY: The range of predictive values of the various strategies were derived from published data and a new study of 441 consecutive adult patients with suspected smear-negative PTB prospectively stratified into three pretest risk groups: low, intermediate and high. The cost-effectiveness was evaluated with a decision tree model (DATA software). RESULTS: The incidence of PTB was 5.7% (4% culture positive) for the whole group, 95% in the high-risk group, 0.9% in the low-risk group and 3.4% in the intermediate-risk group. The sensitivity of the empirical approach was 49% and of the amplicor assay was 44%. Patient outcomes were expressed as life expectancy for the base case of a 58-year-old man with a pretest probability of 5.7%. At this low pretest risk the differences in life expectancies between tests was < 0.1 years and the empirical approach incurred the lowest cost. Sensitivity analysis at increasing pretest risks showed better life expectancies (approximately 1 years) for CT scan and test combinations than empirical and amplicor for additional costs of US$243-US$309. Bronchoalveolar lavage had the worst overall cost-effectiveness. CONCLUSIONS: We conclude that the pretest risk of active PTB was a key determinant of test utility; that the AMPLICOR assay was comparable to clinical judgement; that BAL was the least useful test; and that with increasing risks, CT scan and test combinations performed better. Further studies are needed to better define patients with intermediate risk for PTB and to directly compare the cost-effectiveness of more sensitive nucleic acid amplification tests such as the enhanced Gen Probe, CT scan and test combinations/sequences in these patients.

Hospitalised low-risk community-acquired pneumonia: outcome and potential for cost-savings.

Fine et al. from USA have identified a sub-group of patients with community-acquired pneumonia (CAP) with a low risk of mortality and suggested that it may be cost-effective to manage them as outpatients. The aims of this study were: to evaluate the outcome of low risk CAP patients that were hospitalised in our local setting, and to gauge the number of such patients in order to estimate the potential cost-savings by treating them as outpatients, as well as the safety of such an approach. All patients with CAP admitted to our hospital from 1 April 1997 to 1 March 1998 were enrolled into this prospective cohort study. Low-risk patients were identified, and their hospital outcome compared with other patients. Hospitalisation charges were obtained from the Finance Department. There were 226 patients with CAP. The average age was 64 years with a range of 12 to 96 years. The median hospital stay was 6 days. Mortality was 13.7%. 16.8% required admission to the ICU; none of these were low-risk patients. There were 47 (21%) low-risk patients, and there was no mortality in this group. They had significantly shorter hospital stay (6.4 days versus 10 days) and lower hospitalisation charges ($2,160 versus $5,770) compared to other CAP patients. Only one low-risk patient had a positive blood culture. In conclusion, nearly one-fifth of our CAP admissions consisted of low-risk patients that experienced no mortality, and required a significantly shorter hospitalisation. The management of such patients who are young (< or = 50 years), with no serious co-morbidities in an outpatient setting may be a cost-effective strategy, and this group of patients consumed 9% of the total hospitalisation charges for CAP.

Cost effectiveness evaluation of the Ministry of Health Malaysia dialysis programme.

We determine the cost effectiveness of centre and home haemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and intermittent peritoneal dialysis (IPD) treatment in the Ministry of Health (MOH) programme. The viewpoint taken for this evaluation is that of MOH. Cost categories identified were capital cost, dialysis operational cost, medical cost and general hospital cost. Cost estimates were mostly based on actual resource utilisation. Life years saved were estimated based on Dialysis Registry data on 2480 HD and 732 CAPD patients. Overall, the cost-effectiveness ratio (CER) of centre HD was RM21620/life year saved. Those of home HD, CAPD and IPD were RM23375, RM30469 and RM36016 respectively. Sensitivity analyses did not change the ranking of the CER. We conclude the MOH dialysis programme was cost-effective, and among the various dialysis modalities centre HD was the most cost-effective.

Outcome assessment of the Ministry of Health Malaysia dialysis programme.

We describe the outcomes on haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) provided by the Ministry of Health (MOH). The assessment was based on data from the Malaysian Dialysis Registry on 2480 HD and 732 CAPD patients who commenced dialysis between 1980 and 1996. Young patients (age < 40) have remarkable long term survival (life expectancies of 16 years on HD, 18 years on CAPD). Adjusting for background mortality, relative survival of older patients was as good as younger ones. Diabetics did poorly. 52% of HD and 26% of CAPD patients were employed in 1996. 71% of HD patients scored 10(normal) on QL index (a measure of quality of life) while 60% of CAPD patients have similar score. Differences in rehabilitation and QL index scores by age, gender and diabetes were also observed. Outcomes of dialysis in the MOH programme are reassuring.

Asthma management: evidence based studies and their implications for cost-efficacy.

This review attempts to infer a cost-effective strategy for the management of bronchial asthma based on evidence from randomized controlled trials. Acute severe asthma should be treated with short-acting inhaled beta-agonists followed by a short course of oral steroids. Decisions on hospital admission should be made within 1 to 2 hours and prolonged treatment in emergency departments avoided. A comprehensive educational and drug optimizing program will prevent chronic illness and relapse. Educational programs should be brief but intensive, supervised by asthma specialists and incorporate self monitoring of symptoms plus written action plans. Peak expiratory flow monitoring should not be mandated for all patients. Inhaled corticosteroids (ICS) are the most cost-effective drugs for the long term prevention of asthma. ICS should be started at low doses. If the symptoms of asthma are not well controlled by moderate doses of ICS, high dose ICS treatment should be avoided and add on medication prescribed instead. Oral bronchodilators are less expensive add on medication than long-acting inhaled beta-agonists.

Cross cultural adaptation and validation of the Chinese Health Assessment Questionnaire for use in rheumatoid arthritis.

OBJECTIVE: The Health Assessment Questionnaire - Disability Index (HAQ), used as a disability and outcome measurement in rheumatoid arthritis (RA), has been validated in several languages, but not in Chinese. Our aim was to validate the Chinese version of HAQ (Chinese-HAQ) to suit the needs of Chinese speaking patients with RA in an Asian setting. METHODS: The original HAQ was modified in the context of Chinese culture and translated into Chinese by 2 translators aware of the objective of the questionnaire. The Chinese HAQ was self-administered by 42 patients with RA during their routine followup visit and one week later. RESULTS: The test-retest reliability assessed using Spearman's correlation coefficient was 0.84. Between dimensions measured in the HAQ, the highest test-retest reliability was observed for walking (Spearman correlation coefficient rs=0.80) and the lowest was for eating (rs=0.54). The internal consistency of the scale using Cronbach's alpha was high at 0.86. In terms of criterion validity, the Chinese-HAQ score was found to correlate well with American College of Rheumatology functional status (rs=0.501, p=0.01). The Chinese-HAQ scores also correlated well with markers of disease activity such as patient's perception of pain measured on a visual analog scale (rs=0.55, p < 0.001), grip strength in mm Hg (rs=-0.55. p < 0.001 ), and physician's assessment of disease activity (rs=0.59, p < 0.001). CONCLUSION: The Chinese HAQ is a reliable and valid instrument for studies measuring disability of patients with RA in Singapore.

Dosimetry for occupational exposure to cosmic radiation.

In the course of their work, aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, aircraft structure, etc. This has been recognised for some time and estimates of the exposure of aircraft crew have been made previously and included in, for example, UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) publications. The recent increased interest has been brought about by several factors--the consideration that the relative biological effectiveness of the neutron component as being underestimated; the trend towards higher cruising altitudes for subsonic commercial aircraft and business jet aircraft; and, most importantly, the recommendations of the International Commission on Radiological Protection (ICRP) in Publication 60, and the revision of the Euratom Basic Safety Standards Directive (BSS). In 1992, the European Dosimetry Group (EURADOS) established a Working Group to consider the exposure to cosmic radiation of aircraft crew, and the scientific and technical problems associated with radiation protection dosimetry for this occupational group. The Working Group was composed of fifteen scientists (plus a corresponding member) involved in this field of study and with knowledge of radiation measurement at aviation altitudes. This paper is based on the findings of this Working Group. Where arrangements are made to take account of the exposure of aircraft crew to cosmic radiation, dose estimation procedures will not be necessary for persons for whom total annual doses are not liable to exceed 1 mSv, and therefore, in general, for crew on aircraft not routinely flying above 8 km. Where estimates of effective dose and, in the case of female staff who are pregnant, equivalent dose to the embryo or fetus, are required (for regulatory or other purposes), it was concluded that the preferred procedure was to determine route doses and fold these with data on staff rostering.

Fertility determinants in Indonesia: a sequential analysis of the proximate determinants.

PIP: Data drom the Indonesian Contraceptive Prevalence Survey in 1987 was used to examine the extent to which socioeconomic factors affect the direct association between proximate determinants and fertility. The Bongaarts framework was applied to individual level data on married women who had at least on birth between 1982 and 1987. The fertility measure was the probability of having a birth in the last 12 months before the survey. Proximate determinants were breast feeding, fertile period (non-amenorrhea), sexual exposure, and contraceptive use. Socioeconomic variables were husband's education, wife's education, husband's occupation, religion, urban/rural status, and region of residence. The logit regression analysis is controlled by the age of the respondent and number of children ever born at the time of the survey. There is a possibility that socioeconomic variables may have a direct impact on fertility and the logit framework does not model perfectly the true stochastic model. Thus, a regression is specified in which the probability of experiencing a birth is regressed on both proximate determinants and socioeconomic determinants and on socioeconomic determinants alone. Results show that fertility is lower when the duration of breast feeding and level of contraceptive use is higher. Fertility is higher when the length of the fertile period and sexual exposure is higher. Education showed no significant impact on duration of breast feeding, but when both parents' education is considered, women's lack of education is related to having longer fertile periods (an average of 64 months). When the wife's education is considered alone, women with no schooling and less education have 56-44 more months of sexual exposure. The husband's education considered alone followed the same pattern. As level of parents' education rose, the probability of contraception increased. Women have shorter fertile periods when husbands are farmers. Religion explains duration of breast feeding and contraception. Urban/rural status explains variations in breast feeding duration and fertile period length. Women on Bali and Java were shown to have shorter fertile periods, less sexual exposure, and higher probability of contraceptive use. All 4 proximate determinants had an effect on fertility; most socioeconomic factors had no net effect on current fertility. Contraceptive use had the strongest effect on limiting fertility.^ieng

Cost-effectiveness analysis of medical and surgical treatment for duodenal ulcer in Singapore.

A mathematical model involving transitions between possible states of duodenal ulcer was used to calculate the costs of various treatments, medical and surgical, which are available for the long-term management of duodenal ulcer. Costs of medical and surgical treatment were based on costs incurred at the National University Hospital, Singapore as at 1990. Elective surgery incurs a high cost, both financial and in terms of mortality, at the outset with minimal additional costs subsequently. The various medical options cost less initially but their costs are cumulative and eventually overtake the costs of surgical treatment. These calculations are based on the use of a proprietary preparation of a histamine-2-blocker. If a generic preparation is used, medical treatment becomes considerably cheaper over a 15 year period.