The present work explores the impact on the direct costs of internalizing the home CPAP service in patients with SAHS. The data presented show that the internalization of the service represents a lower cost than that of the current externalized service and a higher level of satisfaction perceived by the patient.
Given the high prevalence of SAHS and the proven clinical efficacy of treatment with CPAP , the cost of this treatment marks SAHS as one of the chronic diseases with a high impact on the cost of the health system . Consequently, all initiatives that provide added value in cost containment while maintaining the effectiveness and user satisfaction of the treatment should be explored. Initially, home therapy companies were responsible for oxygen therapy. This was administered through oxygen in cylinders that were left at the patient's home and had to be recharged periodically. Therefore, the supplying company required a protected physical space for an oxygen storage system in specific tanks. In addition, the company had to have a fleet of trucks suitable for the transport of dangerous goods and qualified personnel to drive these vehicles. Therefore, a very specialized service was required that was located apart from the main activity of a hospital. In this context, the National Health System of Spain and the countries around it chose to outsource this service. However, one of the risks of outsourcing healthcare services, such as home respiratory therapies, is the possibility that the healthcare organization will be excluded due to certain technological changes captured by the contracted providers [11, 12]. In this sense, the advancement of technology has simplified home oxygen therapy with convenient fixed or portable concentrators that no longer require the technical support of yesteryear. Moreover, in SAHS, the main treatment modality that occurs in respiratory therapies is CPAP, which does not require any type of storage or specific transport. In addition, the cost of CPAP treatments is progressively lower, and numerous models have appeared that do not need complex technical support beyond a small technical revision of the periodic device and an occasional change of mask, tubing and filters. Therefore, it seems that the need for a supplier company is becoming steadily less justifiable since the conditions that initially led to the outsourcing of home respiratory therapies have changed considerably.
In our work, the gross difference in direct costs between the two systems represents a considerable avoided cost three years after implementation, with a notable difference calculated on the basis of total cost and cost per device per day. Given the form of calculation, it is expected that the cost per device and day of the internalized system will tend to decrease over time since the cost of acquiring the CPAP is spread over the number of days that it is used. On the other hand, in the case of outsourcing, the cost per device and day approaches the figures for rates 2 and 3, which are significantly lower than those for rate 1 described in the method. In any case, the cost per device and day will always be lower in the internalized case.
One of the key reasons for choosing this type of partial economic evaluation analysis is that a change in the acquisition system does not mean an alteration in the effectiveness of the treatment, since the patient receives the same device in both forms of management and is not affected by how it is acquired. Therefore, our analysis is based on a detailed description of the activity carried out to identify and assess each assigned resource that is called the activity-based cost system . This analysis is especially appropriate for estimating costs in the health field, given that the activities generators of the uses, consumption or wear of productive factors are applied to each patient depending on the specific requirements of each diagnostic-therapeutic process and each clinical condition .
Some authors have indicated that the calculation of costs should be carried out by annualizing the initial capital outlay for the useful life of the asset, thus obtaining the equivalent annual cost, since this automatically considers both the depreciation aspect and the opportunity cost aspect of the asset. Regarding cost of capital, in our case, the calculation has not followed this method. In the present analysis, the cost of the CPAP and the cost of other necessary equipment (mask and humidifier) have been assigned directly without annualization. This consideration overestimates the annual cost per patient of the acquisition proposal versus the rental, especially the year of acquisition of the device, in which it would be very difficult for the proposal to obtain savings compared to the outsourced daily rental system. However, this mode of accounting faithfully reflects the actual expense incurred at each time for each patient.
Our study has various methodological considerations. The cost of the internalized system may vary depending on the price agreed with different commercial vendors for the device. In our case, we believe that the price we use to carry out the calculations is more unfavorable than that obtained by private providers of respiratory therapies. Furthermore, it would be normal for prices to go down once an offer to purchase the equipment has been made through a public tender. However, these prices may vary according to the different local agreements that are reached, or even owing to pressure from the supplier companies on the CPAP commercial vendors. In this sense, the analysis provided by increasing the price of the devices by 25% and 50% provides us with information on more adverse scenarios and a comparison with the traditional outsourced system. Another consideration is that the costs of the two systems being compared and the differences between them are dynamic and change every day. When carrying out the comparative cost analysis, we must take a still photo, with positive results for the alternative system. We cannot know exactly what will happen in the future, but as we have stated, the main investment, the purchase of CPAP devices, has already been made. If we take into account an estimated useful life of 5 years, it is reasonable to posit that savings will increase in the coming years, and the larger the reference area is, the greater the impact will be. Another consideration is that our calculations do not include indirect costs derived from the storage of the material since the number of patients is small. If the calculation is scaled to a higher service, this cost will likely need to be added. However, with the results of our analysis, it is expected that the internalized option will continue to be cheaper.
Although a change in the acquisition system does not imply an alteration in the effectiveness of the treatment, the evaluation of the quality of the system through satisfaction questionnaires proposed for the control of the patients by the clinicians involved does show information in this regard, as the patients perceived an improvement with the new internalized system. Therefore, in addition to significantly reducing costs, this change produces an improvement in the patients’ perceptions of the quality of service. When monitoring is performed by the hospital itself, with a nursing team linked to the pulmonology service, technical and clinical monitoring of the therapy can be carried out, and duplication can be avoided. In a study carried out by Antic et al., it was found that follow-up by a specialized nursing team with the occasional help of a pulmonologist is as effective as exclusive follow-up by a pulmonologist in these patients, which can translate into savings in consultations and unnecessary medical expenses, although, being conservative, we have not considered this aspect in our cost analysis.
In short, the comparative analysis of costs carried out indicates that the internalization of the service, that is, the acquisition of CPAP equipment owned by the hospital and the monitoring and maintenance of the therapy from the hospital center, represents significant savings from the perspective of the hospital and an improvement in the patients’ perceptions of the quality of service.