By Job Gutteling and Iris Blonk | 8 September 2014
Despite the presence of a nursing warehouse with a pool system, Onze Lieve Vrouwe Gasthuis was convinced that medical equipment could be used even more efficiently. From a proof-of-concept measurement, in which 200 devices received an RFID tag, it can be concluded that a significant reduction in equipment is indeed possible.
Most medical equipment is rarely used continuously. Sometimes there are good reasons for this, such as being available for emergencies, but usually it is less clear how the use of equipment actually relates to its presence (and numbers).
Better use of equipment can contribute to the effectiveness of medical technology in several ways. Less equipment is required, which means a reduced investment burden, but because less equipment needs to be maintained, costs are also decreasing there, both in terms of material and personnel.
For the remainder of this story a distinction must be made, in a somewhat trivial manner, between types of medical equipment: relatively small equipment of which many are present (bulk) and expensive, complex equipment with low numbers (specials). With regard to the latter category, there are probably very specific circumstances with regard to utilization, such as a non-planned system or operating room that we will not discuss here. For the bulk device category, on the other hand, it is used in many places and their use can therefore be analyzed in general. Due to the large numbers, a possible efficiency gain is at least as interesting here as with the expensive equipment, certainly also if that means reduced handling at the Medical Technology department in the area of maintenance and management.
The planned and efficient purchase of medical equipment based on actual use is currently a utopia. An important condition, namely reliable usage data, is often completely missing. A track & trace solution through active RFID tags is a great tool for collecting data about use. The hypothesis in the Onze Lieve Vrouwe Gasthuis (OLVG) in Amsterdam is intended to show that the number of bulk devices can be reduced considerably. With the savings achieved in this way (in investment and maintenance), the track & trace system can be rolled out at least cost-neutral over a large part of the medical inventory. This paves the way for other groups of equipment to utilize all the benefits of track & trace: process improvements, findability, but also more efficient use.
We have gathered evidence for this hypothesis by means of a pilot measurement, in which we track all 183 pumps present in 9 nursing departments and the nursing warehouse with active RFID tags (CureTrack company). These pumps, volumetric (107), syringe (57) and feed pumps (19), were followed for 5 weeks during a representative period by a dozen sending / receiving stations (one per department). No other pumps were used in these departments during that time. The stations were able to trace the position of the pumps via triangulation. It is important that a tag cannot detect whether a device is on or off. A pump is therefore defined as “in use” when having a distance of more than a few meters to the storage space of each department (where the station also hung). These could be existing or specially designated storage areas for the pilot. It was agreed with the departments that equipment that is not in use should be returned to the storage room. In addition, employees of the nursing warehouse were actively looking for equipment that was not in use but was on the ward every day. In this way a small overestimation of the utilization rate is created, because some equipment can be erroneously earmarked for a time as being in use. However, this is not a bad thing for this pilot, since it was expected that sufficient profit could still be achieved.
Because the range of the sending / receiving stations was limited, a small part of each of the participating departments fell out of reach. As a result, the total number of (visible) devices in the results is lower than the actual total number of devices with a tag. This was corrected for by a sample in which the non-counted devices were detected manually and about 50% of them were found to be in use.
Table 1 shows that the capacity utilization of the three types of pumps is not yet optimal. The volumetric infusion pump is best used with an average of 65%, but that is considerably lower for the syringe and feed pump. The percentages are calculated by summing up all the hours that a pump is or is not in the storage room and determining its ratio. Example: a department that uses 1 infusion pump for 8 hours a day and then puts it in the storage room for 16 hours has an occupancy rate of 33% for this pump.
What is also striking about the results is that use during the week has a dip on Monday to rise during the week and then fall again during the weekend, see figure 1. A possible explanation for this is that more patients are admitted during the week and they can then go home again in the weekend, after which the influx starts again from Monday.
In addition, it was investigated whether a day / night pattern can be discovered, but this turned out to be a virtually constant pattern. This is perhaps unexpected, since there is a lot less activity during the night, but probably due to the fact that most therapy continues during the night. It should be noted that unused pumps were also not actively searched during the night, so perhaps this contributes to a small overestimation of the utilization rate.
What is also striking about the results is that use during the week has a dip on Monday to increase during the week and then decrease again in the weekend, see figure 1. A possible explanation for this is that more patients during the week be admitted and then allowed to go home in the weekend, after which the influx starts again from Monday. In addition, it was investigated whether a day / night pattern can be discovered, but this turned out to be a virtually constant pattern. This is perhaps unexpected, since there is a lot less activity during the night, but probably because most therapy continues during the night. It should be noted that unused pumps were also not actively searched during the night, so perhaps this contributes to a small overestimation of the utilization rate.
Knowing that the resources are not used effectively is one thing, but linking consequences to it is a completely different one challenge. The three types of pumps are not used equally in the various departments, see figure 2. For example, on average one and a half feed pumps are used per department, but the number can vary from department to department on average less than one pump to four pumps per day. For spray pumps, the spread is between 1.0 and 7.2 per department and at volumetric pumps even between 1.4 and 19.2. This means that, even though there are “too many” pumps in total, a department with only one pump cannot hand them in easily.
Another problem with interpreting the data in this way is that the lowest and highest values per department are measured independently of time. Sometime in the measurement period, for example, sections 1 and 2 had the busiest period, with 6.1 and 11.6 volumetric pumps, respectively, in use. But this probably wasn’t on the same day. Figure 3 shows that the various departments are partly complementary to each other in terms of utilization of the equipment.
Figure 3 shows that the actually required (total) quantity of pumps varies much less than would be assumed on the basis of the departmental lowest and highest values (from Figure 2). There are daily between 46 and 86 pumps in use and between 45 and 78 pumps in a storage room. Based on these numbers, it should be possible to extract such a quantity of pumps from rotation so that the number in storage spaces is minimal. However, this requires a system that allows departments to quickly obtain a pump, if necessary, to prevent unnecessary search times.
Check with log files
Despite the careful methodology, it was uncertain whether the utilization of the equipment could be fully traced from the RFID data. After all, a pump present in the patient room is not by definition actively in use and the proactive removal only took place during office hours. The log files of the volumetric infusion pumps were used to get a picture of the reliability of the figures. The log files were read during a two-week sample of 47 pumps (who participated in the RFID test). The log files cover an average of more than 24 days, depending on the usage (each log has a fixed number of lines). These log files are used to calculate how long each pump has actually been used for infusion purposes. On average this use appears to be 37% over the measured time and varies greatly between 6% and 74% per pump. This means that the RFID estimate of 65% utilization for these pumps is on the high side. On the other hand, the necessary logistical operations must be taken into account, corrected for this, the utilization will be higher. All things considered, it can be concluded that RFID has overestimated the use of the volumetric infusion pump (65% on average) and that compared to the actual activity over the period of the sample (37% on average) the utilization of the pumps somewhere in the middle lies. A final value can be better approximated by additional samples.
The current results are also good evidence that having a nursing warehouse helps enormously in saving on the number of pumps required. In a model where each department would have a fixed number of its own, it is logical to expect that the highest values from Figure 2 would at least be needed. After all, these are real pumps required, as evidenced by a measurement period of 5 weeks (longer measurements might have resulted in a higher number). Summing all the high values across the departments yields the enormous number of 209 pumps, while Figure 3 shows that the actual maximum is 147; a difference of 62 pumps or 30%.
This does not alter the fact that even with a nursing warehouse, profit can still be gained by monitoring and optimizing the use of pumps. Probably, and certainly at the OLVG, this requires a new method whereby pumps are ordered and returned instead of maintaining small storage spaces on location. A system based on active RFID tags with which users can see where a pump can be obtained will have great added value for this.
Redactie MT-Integraal, "How efficiently is medical equipment used?“, 8 September 2018. [pdf in dutch]