V-t.com.cn

Domiciliary non-invasive ventilation for recurrent
acidotic exacerbations of COPD: an economic
analysis
Thoraxdoi:10.1136/thorax.58.10.867 Updated information and services can be found at: References
This article cites 16 articles, 14 of which can be accessed free at: 7 online articles that cite this article can be accessed at: Email alerting
Receive free email alerts when new articles cite this article - sign up in the box at the To order reprints of this article go to: Domiciliary non-invasive ventilation for recurrent acidotic exacerbations of COPD: an economic analysisJ M Tuggey, P K Plant, M W Elliott. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Background: Patients with chronic obstructive pulmonary disease (COPD) pose a significant burden tohealthcare providers with frequent exacerbations necessitating hospital admission. Randomised controlleddata exist supporting the use of acute non-invasive ventilation (NIV) in patients with exacerbations ofCOPD with mild to moderate acidosis. The use of NIV is also described in chronic stable COPD, withevidence suggesting a reduction in hospital admissions and general practitioner care. We presenteconomic data on the impact of domiciliary NIV on the need for admission to hospital and its attendantcosts.
Methods: A cost and consequences analysis of domiciliary NIV based on a before and after case note . . . . . . . . . . . . . . . . . . . . . . .
audit was performed in patients with recurrent acidotic exacerbations of COPD who tolerated andresponded well to NIV. The primary outcome measure was the total cost incurred per patient per year from the perspective of the acute hospital. Effectiveness outcomes were total days in hospital and in intensive Results: Thirteen patients were identified. Provision of a home NIV service resulted in a mean (95% CI) saving of £8254 (£4013 to £12 495) (J11 720; J5698 to J17 743) per patient per year. Total days in hospital fell from a mean (SD) of 78 (51) to 25 (25) (p = 0.004), number of admissions from 5 (3) to 2 (2) (p = 0.007), and ICU days fell from a total of 25 to 4 (p = 0.24). Outpatient visits fell from a mean of 5 (3)to 4 (2) (p = 0.14).
Conclusions: This study suggests that domiciliary NIV for a highly selected group of COPD patients with recurrent admissions requiring NIV is effective at reducing admissions and minimises costs from the perspective of the acute hospital. Such evidence is important in obtaining financial support for providing . . . . . . . . . . . . . . . . . . . . . . .
Patients with chronic obstructive pulmonary disease Theaimofthestudywastocomparetheeffectivenessand (COPD) represent a significant burden to healthcare costs of domiciliary NIV with conventional treatment in a providers. They may have frequent exacerbations, often group of patients with recurrent admissions because of an necessitating admission to hospital. Each admission has been acidotic exacerbation of COPD. The evaluation was limited to estimated to cost £3000,1 and it will be much more expensive the perspective of the acute hospital (a university teaching if the patient requires intensive care. There is now a cohort of hospital serving a population of 500 000). Only costs borne by randomised controlled trials2–8 and a systematic review9 the hospital were identified and valued. Costs to the patient, supporting the use of acute non-invasive ventilation (NIV) family, and to the primary care physician were not included.
in patients with an exacerbation of COPD with mild to The primary outcome measure was the total cost incurred per moderate acidosis. An average district general hospital with a patient per year. Measured consequences were total days in catchment population of 250 000 and a standardised hospital and in intensive care. In addition, an estimate of mortality rate for COPD of 100 will treat approximately six survival was performed based on patients using home NIV.
patients per month who present to hospital with a respiratoryacidosis with NIV (this figure does not include patients who deteriorate after admission); 20% will be readmitted at least A cost and consequences analysis based on a year before and once in the following year and the median survival is of the year after case note audit was performed.
order of 15 months.10 These patients therefore represent agroup at high risk of death who consume significant Patients admitted frequently to hospital requiring inpatient The use of NIV has been described in chronic stable COPD NIV for an acidotic (pH ,7.35) exacerbation of COPD, who and there is some evidence of a reduction in the need for tolerated and responded to it well, and who requested or hospital and general practitioner care,11–13 but there are few were offered the option of domiciliary NIV formed the study published long term randomised controlled trials.14 15 At this group. Patients who tolerated inpatient NIV poorly were centre a small subgroup of patients with severe COPD with either not offered or declined home treatment. This was recurrent admissions due to respiratory acidosis, during therefore a highly selected group. All patients who had which they have required NIV acutely (according to received domiciliary NIV at this centre for this indication recognised criteria5) and who have tolerated it well, have between the years 1995 and 2000 were identified from a requested or been offered domiciliary NIV with the aim of database. Medical case records were retrieved for these reducing the number of future hospital admissions. We patients from both this hospital and from the local (to the present data on the impact of domiciliary NIV on the need for patient) hospital where appropriate. Duration of all inpatient hospitalisation and its attendant costs.
episodes including ‘‘NIV days’’, ‘‘conventional days’’, and ‘‘intensive care days’’ were recorded for each episode from with associated equipment such as a humidifier (HC100, entries in the clinical notes and from the hospital compu- Fisher & Paykel, UK), tubing, mask and medical, nursing and terised patient administration system. Admission arterial technical support. Home ventilators are the same as those blood gas tensions were recorded for each episode and a used for acute NIV and were therefore valued in the same record was made of all respiratory outpatient attendances way. Masks and tubing were discounted for an 8 month during the study period, including spirometric indices and lifespan (estimated lifespan within this unit).
stable arterial blood gas tensions where available. If patientson home NIV attended for elective ‘‘check’’ sleep studies, these were also included in the analysis in terms of days in Within the study centre outpatient support to patients with home NIV is provided by a respiratory nurse specialist (Hgrade, 4th increment point, i.e. senior clinical nurse). It was estimated that they spent approximately 1 hour per week Four main types of cost were identified and valued: hospital involved in direct care or administration relating to home admission (either acute inpatient NIV or acute inpatient NIV for COPD patients (3% of a 37.5 hour working week).
conventional treatment), intensive care treatment, and Outpatient attendances were valued per visit using the mean total cost derived from the hospital which included capitalcost of buildings, equipment, doctor, nursing, and clerical The days in hospital were identified retrospectively from casenotes and valued using costings from a previous cost effectiveness analysis of NIV for acute exacerbations of COPD performed alongside a randomised controlled trial.16 In Data were analysed using Access 2000 and SPSS Version 10.
this study the cost of a day in hospital was based on nursing Normally distributed data are reported as means with 95% and medical staff costs, pharmacy costs, investigation costs, confidence intervals (95% CI). Non-normally distributed data and hotel costs. Hotel costs included heating, lighting, food, are expressed as medians with 5th and 95th centiles. All tests repairs, the costs of building, and administration overhead and p values are two tailed. A paired t test was used for costs such as salaries and wages. Nursing time in the study by within patient comparison of before versus after home NIV.
Plant et al was measured by an end of bed log of all nursing Survival was estimated using a Kaplan-Meier plot based on activity.16 This was valued by assessing the ward duty roster events (i.e. death) in the years following commencement of and bed base, and calculating a ‘‘per shift’’ cost based on the ward nursing budget derived from the respective hospitalfinance departments. Hotel costs were obtained from hospital finance departments and valued in a ‘‘top down’’ approach.
The total cost per patient in the year before (conventional Pharmacy costs were obtained from those cited in the British treatment) and the year after commencing home NIV was National Formulary (BNF)17 for a standard prescription of salbutamol 5 mg and ipratropium bromide 500 mg four timesa day. Additional treatments such as aminophylline were valued from the BNF. Investigation costs related to an acute Economic evaluations are often based on estimates. By exacerbation of COPD (arterial blood gas analysis, chest subjecting the analysis to varying effects of uncertainty, the radiography, sputum culture and blood tests) were not sensitivity of the analysis to different estimates can be measured since they were felt to be negligible in comparison assessed. If large variations in the assumptions do not with the total costs incurred (this would bias against any cost produce significant changes in the results, then there can be benefit of domiciliary NIV). The mean cost for each day on an greater confidence in the accuracy of the original results. The intensive care unit was derived from hospital finance conclusion was tested for sensitivity against the number of admissions during the NIV year, the length of stay per Daily hospital costs for inpatient conventional treatment admission, and the length of ICU stay. In each case the 5th to and intensive care treatment based on the above measure- 95th centiles were used. In addition, the analysis was tested ments were valued according to the relevant hospital and as against changes in the cost of home NIV machines and appropriate for each patient episode identified from the medical records. Valuations were corrected for inflation tothe financial year 1999/2000 using the Health Services Cost Thirteen patients were identified with severe COPD andrecurrent acidotic exacerbations requiring acute NIV in hospital. No patients offered home NIV had been intolerant All patients received acute NIV during exacerbations of their of it. The demographic data of the patients are shown in disease. The capital cost of purchasing NIV machines (NIPPY table 1. These represent a group of patients with severe COPD 2, B & D Electromedical, UK) was discounted to allow for a (mean pH on admission 7.31 during the year before home 5 year lifespan at the UK Treasury recommended rate of 6%.19 NIV, mean FEV1 0.58 l/min recorded in outpatient clinic).
Ward consumables (consisting of a range of different sizedmasks, headgear and tubing) were discounted for a 2 year lifespan. The additional nursing time of setting up NIV and There was a statistically significant reduction in the rate of recurring costs of machine servicing and equipment sterilis- admission, total days in hospital, and length of admission per ing was obtained from the work of Plant et al.16 An estimate of patient. Three patients spent time in the ICU (range 2– the cost of training nursing staff in the use of NIV is included, 17 days) before starting home NIV; this fell to just one patient spending 4 days in the ICU with home NIV(p = 0.45). The mean number of outpatient appointments fell with the introduction of home NIV (5 v 4, p = 0.14). There Provision of home NIV requires the supply of a ventilator was no significant difference in arterial blood gas tensions at (NIPPY 2) for each patient to use regularly at home, together presentation with an acute exacerbation when patients did or Domiciliary NIV for recurrent acidotic exacerbations of COPD available at any one time). It is estimated that the unit Table 1 Characteristics and outcomes of study patients requires approximately four ventilators to meet demand for acute inpatient NIV. However, not all ventilators will be used 365 days per year. The cost of providing inpatient NIV is therefore based on 90% occupancy of the ventilators, and thetotal cost of inpatient NIV was therefore valued as the annual discounted cost for four ventilators divided by 328 days (rather than 365) and multiplied by the total number of days Patients on home NIV have their own masks and tubing, with an equivalent annual cost of £224 allowing for an 8 month lifespan. Patients were also provided with a warm passover humidifier discounted for a 1 year lifespan (£179).
Based on the economic analysis by Plant et al,16 ongoing *p = 0.007; **p = 0.004; ***p = 0.03; NS not significant.
training of ward nursing staff consisted of just less than1 hour per month. This was provided equally between a did not have home ventilation. Mean (SD) arterial gas specialist registrar on the middle increment of the pay scale tensions when stable on home NIV were pH 7.38 (0.02), Po2 (£31 870) and an F grade nurse specialist (£20 770).
Cost savingThe mean cost per patient in the year before starting home NIV was £13 163 (95% CI £8695 to £17 631) compared with £4909 (95% CI £2888 to £6930) in the year with home NIV, a Cost data derived from the previously mentioned study16 are saving of £8254 (95% CI £4013 to £12 495 (p = 0.002). There described in table 2. The first day of admission incurred was a net saving of £107 298 to the acute hospital by greater costs because of a modest increase in nursing time providing a home NIV service for this highly selected group of involved in setting up the patient on NIV and recurring equipment costs (sterilising non-disposable equipment).
A sensitivity analysis was performed on the cost analysis The purchase cost of an NIV machine was discounted to (table 4). The sensitivity analysis focused on admission rates, allow for a 5 year lifespan (discount rate 6%), resulting in an length of stay, ICU time, and ventilator costs. Despite testing equivalent annual cost of £570. Similarly, ward consumables the analysis with 5–95th centile ranges, there was no effect (which would consist of a range of different size masks, on the significance of the cost saving.
headgear, and tubing) were discounted for a 1 year lifespanto an equivalent annual cost of £551. The initial equipment and consumables are fixed costs, independent of the number This study has identified a significant cost benefit to the of inpatient episodes (assuming sufficient ventilators are acute hospital by the provision of a home NIV service for aselected group of patients with recurrent admissions withacidotic exacerbations of COPD. This cost saving is achieved by a reduction in hospital admission rates and length of stay.
The home NIV service also resulted in a measurable (although not statistically significant) reduction in ICU occupancy and outpatient visits. These results are in keeping This study has some limitations, however. It was a retrospective audit of just 13 patients. The patients were highly selected and, as a result, a group was studied that was most likely to derive benefit in terms of a reduction in admissions. While this may be a criticism, the study did not aim to evaluate the use of NIV in ‘‘allcomers’’ with COPD, but Discounted at 6% *over 5 years or **over 1 year.
1 GBP (£) = 1.42 Euro (J).
*5–95th centiles.
1 GBP (£) = 1.42 Euro (J).
was specifically targeted at a group at a high risk of death maintained with domiciliary NIV.13 This could be evaluated who consume significant hospital resources. Furthermore, further by an economic analysis of the outcome in pounds per they had been shown to be able to tolerate and benefit from quality adjusted life year (QALY). This is beyond the scope of NIV. The correct selection of patients most likely to benefit this study, but the data may be useful to inform the power from any intervention is part of the skill of clinical medicine and also ensures a cost effective use of resources. As with any This study has identified costs and placed values on these uncontrolled study, the possibility that the changes seen were costs from the acute hospital perspective. The acute hospital due to chance alone needs to be considered. These results has the most to be gained financially from reducing hospital may reflect regression to the mean; patients were started on admissions, but this may result in an increased demand on NIV when they were perceived to be at their worst. Any primary care services. The costs of this were not addressed in improvement in the subsequent period may reflect natural this study. However, for the provision of home NIV to become variation in the disease and not a direct effect of home NIV.
cost neutral, the increased burden on primary care would However, the magnitude of the changes seen makes this have to be of the order of £8254—that is, in excess of 450 unlikely. A prospective randomised controlled trial would consultations per patient or 200 home visits.1 The study by have been more rigorous, and the data from this study may Jones et al12 actually found a reduction in general practitioner inform the power calculation for such a study in the future.
consultations when NIV was instituted.
However, there are important ethical issues which may make In conclusion, NIV is a relatively new health technology for performing a prospective randomised controlled trial diffi- which there are an ever increasing number of indications. Its cult. Patients who have experienced, tolerated and benefited use, however, should be evidence based, ideally on the basis from inpatient NIV and who themselves consider that NIV of prospective randomised controlled trials, but these are not would obviate the need for future admission and improve always feasible or ethical. Cost effectiveness is an important their quality of life may be very reluctant to enter a study in requirement before any new intervention is accepted. This which allocation to this treatment would be based on chance study suggests that domiciliary NIV for a highly selected group of patients with recurrent admissions to hospital with The possibility that the change in admission rates could be acidotic exacerbations of their COPD saves the acute hospital attributed to other confounding factors needs to be a significant amount of money. Further longer term studies addressed. All patients were receiving regular nebulised are needed to address the quality of life of patients and costs bronchodilators before starting NIV. No patient had a change to society. This study provides useful data for the design of in treatment with oral theophyllines or long term oxygen therapy during the period studied. While most of the patients(n = 9) were already attending this centre in the year before ACKNOWLEDGEMENTSThe authors would like to thank Professor Christine Godfrey for her commencing NIV, four were referred from other centres for assistance in the economic aspects of this manuscript.
assessment and commencement of NIV. It is possible thatthere will have been a ‘‘centre’’ effect but, other than . . . . . . . . . . . . . . . . . . . . .
commencing NIV, there were no other changes in medical J M Tuggey, P K Plant, M W Elliott, Department of Respiratory Medicine, The time period examined was the year before and the year St James’s University Hospital, Beckett Street, Leeds LS9 7TF, UK after starting NIV. This was chosen to minimise the effect of The department has received equipment on loan from ventilator deterioration in the underlying condition in the absence of a companies. MWE has received honoraria from Respironics and Teijin control group. In this small group of patients, where some patients are still alive at 40 months, a Kaplan-Meier analysissuggests a median survival with the provision of home NIV of JT was funded by the Northern and Yorkshire NHS Executive.
29 (14) months. This compares very favourably with theimprovement in survival achieved by providing acute NIV for exacerbations of COPD (16.8 months) and with conventional 1 Netton A, Curtis L. Unit costs of health and social care. Canterbury: Personal treatment alone (13.4 months),20 and is similar to that Social Services Research Unit, 2000.
2 Bott J, Carroll MP, Conway JH, et al. Randomised controlled trial of nasal described by Jones.12 If NIV does indeed prolong life in these ventilation in acute ventilatory failure due to chronic obstructive airways patients, then it is possible that domiciliary NIV just postpones these costs to the acute hospital to a later date 3 Brochard L, Mancebo J, Wysocki M, et al. Noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease. N Engl J Med and that, if the study were extended, the savings from NIV would eventually be lost. Patients would have to have a 4 Kramer N, Meyer TJ, Meharg J, et al. Randomized, prospective trial of median survival of over 40 months for the increased costs noninvasive positive pressure ventilation in acute respiratory failure.
Am J Respir Crit Care Med 1995;151:1799–806.
associated with longer survival to outweigh the cost savings 5 Plant PK, Owen JL, Elliott MW. Early use of non-invasive ventilation for acute of domiciliary NIV compared with the provision of acute NIV exacerbations of chronic obstructive pulmonary disease on general respiratory only. It is also possible that prolonged survival comes with wards: a multicentre randomised controlled trial. Lancet 2000;355:1931–5.
6 Angus RM, Ahmed AA, Fenwick LJ, et al. Comparison of the acute effects on the cost of life of marginal quality. However, other studies gas exchange of nasal ventilation and doxapram in exacerbations of chronic have shown that health status and quality of life are obstructive pulmonary disease. Thorax 1996;51:1048–50.
Domiciliary NIV for recurrent acidotic exacerbations of COPD 7 Celikel T, Sungur M, Ceyhan B, et al. Comparison of noninvasive positive 13 Perrin C, El Far Y, Vandenbos F, et al. Domiciliary nasal intermittent positive pressure ventilation with standard medical therapy in hypercapnic acute pressure ventilation in severe COPD: effects on lung function and quality of respiratory failure. Chest 1998;114:1636–42.
life. Eur Respir J 1997;10:2835–9.
8 Thys F, Roeseler J, Reynaert M, et al. Noninvasive ventilation for acute 14 Clini E, Sturani C, Rossi A, et al. The Italian multicentre study on noninvasive respiratory failure: a prospective randomised placebo-controlled trial. Eur ventilation in chronic obstructive pulmonary disease patients. Eur Respir J 9 Lightowler JV, Wedzicha JA, Elliott MW, et al. Non-invasive positive pressure 15 Casanova C, Celli BR, Tost L, et al. Long-term controlled trial of nocturnal nasal ventilation to treat respiratory failure resulting from exacerbations of chronic positive pressure ventilation in patients with severe COPD. Chest obstructive pulmonary disease: Cochrane systematic review and meta- 16 Plant PK, Owen JL, Elliott MW. Cost effectiveness of ward based non-invasive 10 Plant PK, Owen J, Elliott MW. One year period prevalance study of ventilation for acute exacerbations of chronic obstructive pulmonary disease: respiratory acidosis in acute exacerbation of COPD; implications for the economic analysis of randomised controlled trial. BMJ 2003;326:956.
provision of non-invasive ventilation and oxygen administration. Thorax 17 British National Formulary. BMA and Royal Pharmaceutical Society of Great 11 Leger P, Bedicam JM, Cornette A, et al. Nasal intermittent positive pressure 18 Brown F. Health services cost index, London: HMSO, 2001.
ventilation. Long-term follow-up in patients with severe chronic respiratory 19 HM Treasury. Economic appraisal in central government: a technical guide for insufficiency. Chest 1994;105:100–5.
government departments. London: HMSO, 1997.
12 Jones SE, Packham S, Hebden M, et al. Domiciliary nocturnal intermittent 20 Plant PK, Owen JL, Elliott MW. Non-invasive ventilation in acute positive pressure ventilation in patients with respiratory failure due to severe exacerbations of chronic obstructive pulmonary disease: long term survival COPD: long term follow up and effect on survival. Thorax 1998;53:495–8.
and predictors of in-hospital outcome. Thorax 2001;56:708–12.
No effect of nebulised adrenaline on clinically important outcomes in viralbronchiolitism Wainwright C, Altamirano L, Cheney M, et al. A multicenter, randomized, double-blind, controlled trial of nebulized epinephrine in infants with acute bronchiolitis. N Engl J Med 2003;349:27235 Theevidencethatoxygenistheonlyeffectivetreatmentinviralbronchiolitiscontinuesto mount. The largest double blind, randomised, placebo controlled trial to date ofnebulised adrenaline (epinephrine) showed no improvement in duration of hospital stay/time until ready for discharge with adrenaline compared with placebo. Indeed, in thosewith more severe bronchiolitis, adrenaline was associated with an increase in the duration ofhospital stay. There was no improvement in oxygenation or clinical score in the groupreceiving adrenaline. The best predictor of severity of bronchiolitis and duration of stay inhospital was oxygen saturation in room air at admission. Interestingly, oxygen saturation atadmission was also a good predictor of severity in acute asthma.
Previous studies of the role of adrenaline in bronchiolitis have shown improved respiratory mechanics and clinical severity scores but the methodology has been flawedwith too few patients, inclusion of older infants with previous wheezing episodes, and lackof clinically important outcomes (for example, duration of hospitalisation or need forintensive care/mechanical ventilation). Bronchodilators have not been shown to be effectivein bronchiolitis although a trial of their use is common, especially in older infants with apersonal or family history of atopy. Wainright’s paper suggests that adrenaline is noteffective in this subgroup, although the study was not sufficiently powered to answer thisquestion.
It would appear that, for the moment at least, supplemental oxygen and supportive care remain the only effective treatment for viral bronchiolitis.
Royal Children’s Hospital, Parkville, Australia;

Source: http://www.v-t.com.cn/upload/accessory/200912/2009128155819343891.pdf