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Asthma intervention program prevents readmissions in high healthcare users |
Castro M, Zimmermann N A, Crocker S, Bradley J, Leven C, Schechtman K B |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The use of an asthma nurse specialist intervention aimed at preventing the readmission of asthma sufferers. The study intervention comprised:
suggestions by the nurse to the primary physician about the simplification or consolidation of the current regimen, in accordance with the National Asthma Education and Prevention Program;
the completion of a daily "Asthma Care" flow sheet while in the hospital;
the provision of asthma education to the patient;
the provision of psychosocial support, and screening patients for potential counselling;
the establishment of an individualised asthma self-management plan;
consultation with social service professionals to facilitate discharge planning; and
the provision of outpatient follow-up through telephone contact, home visits, and appointments with the primary physician.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients admitted to hospital with a primary admitting diagnosis of asthma. The inclusion criteria were a physician diagnosis of asthma of at least 12 months duration, age 18 to 65 years, FEV1 to FVC ratio of less than 80%, and a history of at least one hospitalisations in the last 12 months.
Setting The setting was primary care. The economic study was conducted at the Washington School of Medicine and Barnes-Jewish Hospital, St. Louis (MO), USA.
Dates to which data relate Patients were screened for participation from September 1996 to July 1999. The costs were estimated using cost logs that were collected by all patients during the enrolment period. The price year appears to have been 1999.
Source of effectiveness data The evidence for the final outcomes was derived from a single study.
Link between effectiveness and cost data The costing was undertaken prospectively on the same patient sample as that used in the effectiveness study.
Study sample No power calculations to determine the sample size were reported, and no specific sample size was determined in the planning phase of the study. From a total of 828 patients hospitalised at the Barnes-Jewish Hospital, 96 patients were eligible for randomisation. Of these, 46 were randomised to the control group and 50 to the intervention group. The intervention group contained 40 (80%) females and the control group contained 39 (85%) females. The mean age was 35 (+/- 11) years in the intervention group and 38 (+/- 12) years in the control group.
Study design The study was a randomised, controlled prospective trial that was conducted in a single centre. The study patients were randomly assigned to the intervention or control group by means of a blind selection procedure. The patients were followed up for 360 days. The authors did not report the loss to follow-up, although quality of life questionnaires at 6 months were obtained for 33 patients in each of the two groups.
Analysis of effectiveness The analysis was conducted on the basis of intention to treat. The primary end point was readmission due to asthma within 360 days. The secondary end points included total readmissions, emergency department visits, quality of life and cumulative number of days of hospitalisation. Quality of life was measured using a disease-specific measure, the Asthma Quality of Life Questionnaire, at entry into the study and at 6 months. At analysis, both groups were shown to be comparable in terms of age, gender and prognostic features. The authors also analysed whether the assignment to the intervention group was associated with being readmitted at least twice within a year, after adjusting for baseline demographic factors, lung function and quality of life.
Effectiveness results Compared with the control group, there was a 60% reduction in total readmissions in the intervention group over 12 months. There were 31 readmissions in the intervention group versus 71 in the control group, (p=0.04). The majority of these readmissions were due to asthma, 21 in the intervention group versus 42 in the control group, (p=0.04).
Multiple readmissions (i.e. two or more) were more frequent in the control group (15) than in the intervention group (7), (p=0.03). There was a 69% reduction in total hospital days in the intervention group compared with the control group over 12 months. The total hospital days were 82 in the intervention group versus 244 in the control group, (p=0.04). This overall reduction in hospitalisation was mostly driven by the reduced number of hospital days for asthma, 53 in the intervention group versus 129 in the control group, (p=0.04).
There were no significant differences in the number of health care provider visits or emergency visits between the two groups.
The authors found that, after adjusting for baseline demographic factors, lung function and quality of life, patients in the control group were 3.6 (95% confidence interval: 1.2 - 10.9) times more likely to be readmitted at least twice in 12 months than patients receiving the intervention.
The overall asthma-specific quality of life in the control group improved significantly, from 2.74 at baseline to 3.9 six months later (change of 1.18; p<0.001). It also improved significantly in the intervention group, from 2.7 at baseline to 4.02 (change of 1.35; p>0.001). However, there was no significant difference in the improvement of quality of life between the two groups.
Clinical conclusions The study demonstrated that a brief, nurse-directed intervention in asthmatic patients significantly reduced subsequent readmissions.
Measure of benefits used in the economic analysis No summary measure of benefit was derived. The study was, effectively, a cost-consequences analysis.
Direct costs The resource quantities and the costs were reported separately. The direct costs included in the study were those of the health care system and the patients' relatives. These included the costs of hospitalisation for asthma and all other reasons, emergency department visits, health care provider visits, tests, asthma medications, and the costs of both paid and non-paid care-giving (both professional and non-professional). The costs were estimated using cost logs that were collected contemporaneously by all patients during the 180-day enrolment period. Except for medication costs, which were calculated from the 1999 average wholesale costs, the authors did not report the source from which the unit costs were derived. Discounting was not relevant since all the costs were incurred during less than one year and, appropriately, was not performed. The study reported the mean costs per patient. The price year appears to have been 1999.
Statistical analysis of costs Resource use and costs were treated stochastically. T-tests were used to compare variables between the two groups. The level of statistical significance was set at 0.05.
Indirect Costs The indirect costs included in the analysis were those of the patients and relatives. These were for lost work or school days by patient and lost workdays by family members. The costs were estimated using cost logs that were collected contemporaneously by all patients during the 180-day enrolment period. The authors did not report the source from which the unit costs for lost working or school days were derived. Discounting was not relevant since all the costs were incurred during less than one year and, appropriately, was not performed. The study reported the mean costs per patient. The price year appears to have been 1999.
Sensitivity analysis No sensitivity analysis was performed.
Estimated benefits used in the economic analysis See the 'Effectiveness Results' section.
Cost results The mean cost per patient was $5,726 (+/- 5,679) in the intervention group compared with $12,188 (+/- 19,352) in the control group, (p=0.03).
Synthesis of costs and benefits The costs and benefits were not combined.
Authors' conclusions The study demonstrated that a brief nurse-directed intervention in hospitalised asthma patients with a frequent history of health care use resulted in a significant reduction in subsequent readmissions, lost work or school days, and direct and indirect health care costs.
CRD COMMENTARY - Selection of comparators A justification was given for the comparator used. It represented current practice in the authors' setting. You should decide if this is a widely used health technology in your own setting.
Validity of estimate of measure of effectiveness The basis of the analysis was a randomised controlled trial. This was appropriate for the study question, as well-conducted randomised controlled trials are the 'gold' standard study design when comparing different health technologies. The study groups were shown to be comparable at analysis in terms of age, gender and prognostic features. However, as the authors acknowledged, there may have been observation bias as the asthma nurse specialist conducting the intervention collected all the data for the study. The nurses were trained as far as possible to follow strict procedures. The outcomes were analysed on an intention to treat basis. In addition, appropriate statistical techniques were used to account for any confounding factors such as baseline demographic factors, lung function and quality of life. The authors did not, however, report the loss to follow-up.
Validity of estimate of measure of benefit The authors did not derive a summary measure of health benefit. The analysis was, in effect, a cost-consequences analysis.
Validity of estimate of costs All the categories of cost relevant to the societal perspective adopted were included in the analysis. In addition, for each category of cost all the relevant costs appear to have been included. The costs and the quantities were reported separately, which will enhance the generalisability of the authors' results. Resource use was derived from the study, and appropriate statistical tests were performed to test for any statistically significant differences between the two study groups. The authors did not report the source from which the unit costs were derived, which will limit the validity of their findings. However, all cost differences between the two groups were tested for statistical significance using appropriate statistical techniques. Discounting was unnecessary since all the costs were incurred during one year. The price year was not explicitly reported but, based on the price year used to cost the pharmaceuticals, it appears that 1999 prices have been used.
Other issues The authors made appropriate comparisons of their findings with those from other studies, some of which also demonstrated the benefits of the nurse-directed intervention on health care use and asthma knowledge. However, the other studies had relatively small sample sizes, selected cohorts, used historical controls, or ignored the impact of such a programme on the health care costs. The issue of generalisability to other settings was not addressed. The authors acknowledged that the lack of generalisability of the results was one of the main limitations of the study, as the study focused on high health care users in an urban academic medical centre, where the majority of the patients were young African American women of low socioeconomic status. The authors do not appear to have presented their results selectively, and their conclusions reflected the scope of the analysis. A further limitation reported by the authors was that they were unable to identify which specific component of the intervention was the most effective.
Implications of the study The authors recommended the widespread implementation of a brief, nurse-directed intervention in asthmatic individuals with a history of frequent health care use. This would result in substantially improved patient satisfaction and would reduce health care costs due to asthma.
Source of funding Supported by Barnes-Jewish Hospital Foundation.
Bibliographic details Castro M, Zimmermann N A, Crocker S, Bradley J, Leven C, Schechtman K B. Asthma intervention program prevents readmissions in high healthcare users. American Journal of Respiratory and Critical Care Medicine 2003; 168(9): 1095-1099 Other publications of related interest Doan T, Grammar L, Yarnold P, et al. An intervention program to reduce the hospitalisation cost of asthmatic patients requiring intubation. Annals of Allergy, Asthma and Immunology 1996;76:513-8.
McDowell K, Chatburn R, Myers T, et al. A cost-saving algorithm for children hospitalised for status asthmaticus. Archives of Pediatrics and Adolescent Medicine 1998;152:977-84.
Gallefoss F, Bakke P. Cost-effectiveness of self-management in asthmatics: a 1-yr follow-up randomised, controlled trial. European Respiratory Journal 2001;17:206-13.
Indexing Status Subject indexing assigned by NLM MeSH Adult; Asthma /drug therapy /economics /nursing; Caregivers /economics; Emergency Service, Hospital /utilization; Female; Health Care Costs; Humans; Male; Missouri; Patient Acceptance of Health Care /statistics & Patient Readmission /economics /statistics & Prospective Studies; Quality of Life; numerical data; numerical data AccessionNumber 22003001450 Date bibliographic record published 30/11/2004 Date abstract record published 30/11/2004 |
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