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Reduced use of resources by early tracheostomy in ventilator-dependent patients with blunt trauma |
Armstrong P A, McCarthy M C, Peoples J 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 early tracheostomy in ventilator-dependent patients with blunt trauma.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised ventilator-dependent patients with blunt trauma. Patients were included if they met one of the following criteria:
they had blunt trauma involving two or more organ systems;
they were alive 24 hours after hospital admission;
an endotracheal airway with mechanical ventilation was established within 6 hours of hospital admission; or
the tracheostomy was performed during hospitalisation.
Patients were excluded if they required pre-admission cricothyroidotomy or were undergoing emergency tracheostomy as primary airway access for craniofacial injuries.
Setting The setting was a hospital. The economic study was carried out in the USA.
Dates to which data relate The effectiveness, resource use, and cost data were collected between January 1990 and July 1995. The price year was 1997.
Source of effectiveness data The effectiveness data were derived from a single study.
Link between effectiveness and cost data The costing was carried out retrospectively on the same patient sample as that used in the effectiveness analysis.
Study sample One hundred and fifty-seven patients were enrolled in the study. There were 118 men and 39 women, and their mean age was 40 years. The ET group comprised 62 patients and the LT group comprised 95 patients. No power calculations were performed to determine the sample size. The other baseline characteristics reported were the injury severity score and the predicted survival.
Study design This was a retrospective descriptive study carried out at a single centre. The patients were followed-up until hospital discharge. No patients were lost to follow-up. The need for tracheostomy was decided on the basis of standard ventilator weaning criteria. The factors that had an impact on the timing of the tracheostomy included severe thoracic injury, adult respiratory distress syndrome, and severe closed head injury with a Glasgow Coma Score of 6 or less. Increased experience enabled the tracheostomies to be performed progressively earlier. The follow-up did not seem to extend beyond the period of hospitalisation.
Analysis of effectiveness The effectiveness was analysed on an intention to treat basis. The primary health outcomes were complications, the mortality rate, and the rate of acquiring nosocomial pneumonias in the intensive care unit (ICU). There were no significant differences (p>0.05) between the two groups in terms of the gender distribution, injury severity scores, and probability of survival scores. The mean age of ET patients (34 years) was significantly lower than that of LT patients (43 years), (p<0.001).
Effectiveness results The mortality was 11.3% for ET patients versus 11.6% for LT patients, (not significant).
Two procedure-related complications, severe peritracheostomy cellulitis and tracheoesophageal fistula, were observed in the ET group.
There were no cases of tracheal stenosis.
Intensive care unit-acquired nosocomial pneumonias occurred in 47 ET patients and 88 LT patients, although the difference was not statistically significant.
Clinical conclusions There was no statistically significant difference in the mortality or ICU-acquired nosocomial pneumonia rate.
Measure of benefits used in the economic analysis The authors did not report a summary measure of benefit and left the clinical outcomes disaggregated. The study should, therefore, be regarded as a cost-consequences analysis.
Direct costs The direct costs were not discounted due to the short timeframe of the study (less than one year). The quantities and unit costs were reported separately for days spent in the hospital or in the ICU. The direct costs were for the ICU, the ventilator, and a standard room. The quantity/cost boundary adopted was that of the hospital. The costs were collected from the authors' institution, and were based on the daily hospital charges. The price year was 1997.
The length of stay in the ICU was 15 days for ET patients and 29 days for LT patients, (p<0.001). The length of stay in the hospital was 33 days for ET patients and 68 days for LT patients, (p<0.001).
Statistical analysis of costs The authors reported the costs per patient, but did not report any statistical tests or indicate a stochastic treatment of costs.
Indirect Costs The indirect costs were not included.
Sensitivity analysis No sensitivity analyses were conducted.
Estimated benefits used in the economic analysis See the 'Effectiveness Results' section.
Cost results The total charges per patient for hospital days and ventilator use were $73,714 for LT patients and $36,609 for ET patients. Using a hospital reimbursement rate of 67%, early tracheostomy would have resulted in a cost-saving over late tracheostomy of $24,860 per patient.
Synthesis of costs and benefits Authors' conclusions "By using early tracheostomy in patients with ventilator-dependent blunt trauma, the length of stay in both the ICU and the hospital can be reduced with no adverse effect on mortality or morbidity rates."
CRD COMMENTARY - Selection of comparators The comparator was justified on the grounds that it was a currently employed treatment strategy. You should decide if these health technologies are relevant to your own setting. However, the technologies defined did not necessarily match those actually employed: there was a lack of data on the precise timing of tracheostomy and the likelihood of other differences, for example in staffing, other procedures over time, and experience.
Validity of estimate of measure of effectiveness The analysis was based on a retrospective descriptive study, which is weak in terms of avoiding selection bias and confounding. The baseline characteristics generally showed there was no difference between the groups. However, age was statistically, and probably clinically, significantly lower in the ET group. Also, considering the changes in technology stated above, it was possible that there was confounding due to the lack of blinding. Since such confounding would affect morbidity, it is also likely that it would affect length of stay and, therefore, bias the cost results.
Validity of estimate of measure of benefit No summary measure of benefit was identified in the economic study, and as a result, the study was a cost-consequences analysis.
Validity of estimate of costs The positive feature of the cost analysis was that it was clear how the total cost was calculated, given that the quantities and costs were reported separately. However, no statistical or sensitivity analyses were reported on the quantities or unit costs. In addition, their source, in terms of the precise resources used and the concomitant unit cost, was not given. The authors acknowledged that they did not include the costs of physician visits, laboratory and pharmacy use, or the additional supplies used daily. In addition, they used their own charges.
Other issues The authors made appropriate comparisons of their findings with those from other studies. The authors do not appear to have presented their results selectively. The study considered ventilator-dependent patients with blunt trauma and this was reflected in the authors' conclusions. The authors noted that the study reflected practice patterns and pricing at their institution as of July 1997, which could affect the generalisability to other settings.
Implications of the study The authors argued that, by using ET in patients with ventilator-dependent blunt trauma, the length of stay in both the ICU and the hospital could be reduced with no adverse effect on the mortality or morbidity rates. However, the study design was weak with the distinct possibility of selection bias and confounding, which could have biased the estimation of effectiveness and length of stay.
Bibliographic details Armstrong P A, McCarthy M C, Peoples J B. Reduced use of resources by early tracheostomy in ventilator-dependent patients with blunt trauma. Surgery 1998; 124(4): 763-766 Other publications of related interest A discussion of this paper follows the original article. Surgery 1998;124:766-7.
Indexing Status Subject indexing assigned by NLM MeSH Adult; Female; Health Resources /economics /utilization; Hospital Charges; Humans; Intensive Care Units /economics /utilization; Length of Stay; Male; Middle Aged; Respiration, Artificial /adverse effects /economics; Retrospective Studies; Time Factors; Tracheostomy /adverse effects /economics; Wounds, Nonpenetrating /therapy AccessionNumber 21999006115 Date bibliographic record published 31/05/2002 Date abstract record published 31/05/2002 |
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