FormalPara Key Points for Decision Makers

Implementing three improvements to optimize the organization of compression therapy in the Netherlands reduces healthcare costs for two out of three regions within 3 years.

Savings were primarily driven by increased self-reliance of patients, resulting in a decrease of home care utilization.

1 Introduction

Compression therapy is indicated for all patients with deep venous thrombosis (DVT) to reduce leg symptoms in the acute phase [1, 2] and to prevent post-thrombotic syndrome (PTS) in the long term [3, 4]. With a total annual incidence of one to two DVT cases per 1000 persons, compression therapy was found to present a potential burden to patients and the healthcare system in a publication from Norway [5, 6]. A similar annual incidence is observed in the Netherlands where approximately €21 million per year is spent on home care assistance associated with compression therapy [7, 8]. Furthermore, costs related to the development of PTS are also not neglectable [9,10,11].

Recent studies assessed the current care pathways for compression therapy in the Netherlands and revealed that these are suboptimal [12, 13]. A modified Delphi study reached consensus on three main improvement targets [14]. The first recommendation concerned selecting the optimal type of initial compression therapy (during the first weeks of treatment until edema has receded) for all patients with a preference for a temporary compression hosiery. The use of temporary compression hosieries instead of multi-layer compression bandages is expected to improve patients’ quality of life and autonomy and at the same time decrease costs [15]. The second recommendation focused on early and accessible consultation of occupational therapists to train patients on the use of assistive devices to preserve autonomy and increase adherence to compression therapy [16]. The third recommendation was to implement a tailored duration of elastic compression stocking (ECS) therapy based on clinical leg assessments and scoring symptomatology using the Villalta score [17]. This strategy was shown to be non-inferior to a standard treatment duration for the development of PTS [18].

To support the implementation of these improvement targets in current practice, it is essential to gain insight into the impact on healthcare resource use for different healthcare professionals and into the impact on the budget. In particular, home care providers are currently under pressure and already experience an increased workload because of the aging population [19]. In the Netherlands, the prognosis is that compared to 2020, 26,100 extra home care nurses are needed to provide care in 2030 [20]. Additionally, a survey in 2019 showed that 40% of home care employers already indicated an increasing workload among home care workers [21]. Reducing home care demands will likely contribute to the system’s future sustainability.

Studies that focused on the economic consequences of therapy for patients with DVT up till now mainly provided total costs (without information on resource use and costs for the different phases of compression therapy) or only focused on costs associated with pharmacological treatment [9, 22, 23]. We identified two studies that specifically calculated the economic impact of different treatment strategies for compression therapy. The first focused on the initial compression phase and showed that healthcare costs are significantly higher when prescribing multi-layer compression bandages than a temporary compression hosiery [15]. The second was a cost-effectiveness analysis of the IDEAL-DVT trial. The IDEAL-DVT trial showed that an individually shortened duration of ECS therapy based on clinical assessments using the Villalta score was non-inferior to standard ECS treatment duration. The subsequent cost-effectiveness analysis of this trial showed that this new approach was cost effective compared to standard ECS treatment duration [24].

Our budget impact study has three aims: (1) to provide insight into the per-patient and population resource use and costs in current care pathways for compression therapy in the Netherlands; (2) to evaluate the potential cost impact of the three earlier identified improvement targets as compared to current care; and (3) to assess the robustness of the results.

2 Methods

2.1 Current Care Pathways

We used the current care pathways for compression therapy as prescribed in two previously conducted studies: a realist evaluation and a functional resonance analysis method [12, 13]. A graphical representation of the pathways can be found in the Electronic Supplementary Material (ESM). We used the term compression therapy to refer to the entire compression pathway (including initial compression therapy and ECS therapy). The care pathways reflect the resource use associated with compression therapy in two regions in the Netherlands: Limburg and North Holland based on their geographical spread and differences in implementation status of interventions to improve patients’ self-reliance. In Limburg, patients would either be treated by the internist or the general practitioner. In North Holland, all patients were treated by internists and two variants in the management of compression therapy were observed: NH-A and NH-B. The main difference was that in NH-B no initial compression therapy was prescribed, while in NH-A temporary compression hosieries were prescribed if no contra-indications existed.

2.2 New Care Pathways

We formulated four scenarios to evaluate the separate impact of the three improvement topics identified in the modified Delphi study: (1) providing optimal initial compression therapy for all patients; (2) early consultation of the occupational therapist to train patients to use assistive devices at the onset of long-term ECS therapy; and (3) using a tailored duration of ECS therapy based on clinical leg assessments [14]. We assessed the potential impact of these improvement targets on the current pathways for the regions Limburg, NH-A, and NH-B. In a fourth scenario, we combined scenarios 1–3 to evaluate the combined impact. The scenarios for the newly defined care pathways are described in detail below.

Scenario 1: Providing optimal initial compression therapy for all patients with a preference for a temporary compression hosiery. A temporary compression hosiery supports the patient’s self-reliance and was suitable for 93.7% of patients in a sub-study of the IDEAL-DVT trial [15, 18]. In this scenario, multi-layer compression bandages were only prescribed upon indication. This reflects the situation observed in NH-A and for internists in Limburg. Therefore, we calculated the impact of implementing this improvement only for those not yet working according to this strategy (NH-B and general practitioners in Limburg).

Scenario 2: Stimulating the consultation of the occupational therapist at an early stage, to train patients on how to use assistive devices at the onset of long-term ECS therapy to remain self-reliant and support adherence. We calculated the budget impact for four sub-scenarios: 2.1: To support adherence to ECS therapy, all patients in the NH pathways and the Limburg pathway who did not receive an assistive device and training and did not receive home care assistance were referred to the occupational therapist. In this newly referred group, it was assumed that the rate of successful implementation (self-reliant with an assistive device after training) would be 100% as these patients were already self-reliant without assistive devices or training in the current care pathways. 2.2: All patients in the North Holland pathways and the Limburg pathway who were directly referred for long-term home care assistance without training (either by the occupational therapist or home care) and without an assistive device were referred to the occupational therapist. 2.3: All patients trained to use an assistive device by home care nurses in the current Limburg pathway were referred to the occupational therapist. For sub-scenarios 2.2 and 2.3, we assumed that the successful implementation rate for the newly referred patients would be the same as for patients trained by the occupational therapist in the current care pathways. 2.4: All patients trained by the occupational therapist in the current care pathways (all regions) were directly referred to long-term home care assistance without any training (either from home care nurses or the occupational therapist).

Scenario 3: Implementing a tailored ECS treatment duration based on clinical assessments as was found efficient and cost effective in earlier studies [18, 24]. For this scenario, we added one extra follow-up visit to the strategy identified prior in order to check for adherence. We calculated the impact of implementing this strategy for the North Holland pathway and for general practitioners in Limburg (as this tailored duration of ECS therapy was already implemented by internists in Limburg).

Scenario 4: The improvement targets described above (except for sub-scenario 2.4) were combined for NH-A, NH-B, and Limburg. As a result, this scenario actually reflects the new situation after implementing the improvement targets.

2.3 Main Assumptions

The analysis was performed from a healthcare system perspective and targeted all newly diagnosed patients with DVT in the Netherlands independent of the treatment setting. We have chosen this perspective as this article is primarily written to inform the healthcare providers and payers regarding the costs of the improvement targets.

It was assumed that: one limb was affected and treated per patient [5], 10% of the emergency department visitation time was associated with compression therapy based on reported estimates by emergency department nurses, patients received one pair of ECS per affected limb that was replaced every 12 months, which is compliant with insurance regulations, home care assistance was required twice daily until delivery of the assistive device for all patients successfully trained by the occupational therapist with additional practicing guided by home care, and that if patients had an indication for ECS therapy for 2 years, this automatically indicated continued treatment in the third year, which is compliant with current clinical practice.

2.4 Input Data

For the current study, we used additional data from the interviews (n = 30) earlier described in our functional resonance analysis method paper [12]. We supplemented these with data from the surveys administered to healthcare professionals (n = 114) across different disciplines for our realist evaluation (n = 114) [13]. We used both the interviews and surveys as primary data for the current study. Questions regarding the estimated duration of visits, frequencies of health services use, and material use were used to deepen our knowledge of the total resource use. The methodology used to retrieve the interview data (including COREQ criteria), clinical pathways, survey design, and questions were published in more detail previously [12, 13].

Personnel costs included in the analysis were based on standard unit prices from the Dutch costing manual [25]. Medical stocking suppliers’ costs per hour are not included in the manual, nor could be found elsewhere, and were assumed to be equal to home care nurses providing care and support. Other unit prices not stated in the Dutch costing manual were based on literature, interview and survey data, or market prices. All costs were adjusted for inflation and are expressed in 2021 euros [26].

2.5 Data Analysis

We used Microsoft Excel to calculate the proportion of patients who received initial compression therapy, who were self-reliant with ECS therapy, and who received a tailored ECS treatment duration, as well as the associated resource use and costs for the current pathways and the scenarios. Four consecutive phases were distinguished: initial compression therapy (in which the patient uses a temporary compression hosiery or multi-layer compression bandages until edema has receded), the onset of long-term ECS therapy (in which the medical stocking supplier fits and delivers the ECS), the implementation of assistive devices (in which patients can be trained to use assistive devices upon indication), and long-term ECS therapy (in which patients use the ECS with or without home care assistance until treatment can be stopped) [12]. The minimum and maximum ranges indicated are calculated by using the minimum and maximum provided for each input parameter.

We calculated the per-patient costs for the current pathways for a standard 2-year episode of compression therapy following DVT. This time horizon was chosen because a 2-year episode was considered to be the standard treatment duration in most clinical studies as most PTS cases will develop within these 2 years [27, 28]. However, for some patients with high Villalta scores, duration of therapy is not limited to 2 years but becomes long term [18]. In addition, we calculated the annual population costs in the current pathways, assuming nationwide implementation, for the first, second, and third year after implementation based on an annual incidence of 1.5 DVT cases per 1000 persons [5]. For the Netherlands, this amounts to a total of 26,500 cases per year [29]. The population-level costs were calculated for 3 years, this time horizon was chosen as the third year is the first year that patients with an indication for long-term use of compression therapy are included. As a result, this best reflects the total costs for the subsequent years.

Next, we assessed the impact of the three improvement targets on the per-patient costs of the 2-year episode and the annual population costs. We created line charts to visualize the results.

2.5.1 Sensitivity Analyses

Univariate sensitivity analyses were performed by computing the per-patient costs using the minimum and the maximum range indicated for input parameters for the current care pathways (as presented in the ESM). These results are shown in tornado diagrams. Furthermore, for initial compression therapy in scenario 1, we varied the percentages of patients treated by general practitioners from 0 to 50% for Limburg (based on information provided by our general practitioner stakeholders). For the implementation of assistive devices in scenarios 2.1–2.3, we varied the successful implementation rate achieved during training by the occupational therapist (from 36 to 95% for the North Holland pathways and from 10 to 90% for the Limburg pathway based on the ranges indicated in the regional occupational therapists’ surveys). For long-term ECS therapy in scenario 3, we varied the proportion of patients treated for certain treatment durations by internists in Limburg and all new pathways from 50 to 59% for patients treated for 6 months, from 9 to 12% for patients treated for 12 months, and from 29 to 41% for patients treated for 2 years. These ranges were based on the calculated 95% confidence interval of the ranges observed in the IDEAL-DVT trial [18]. The results are presented in bar graphs.

3 Results

3.1 Current Care Pathways

The detailed resource use and costs associated with the current care pathways can be found in the ESM. All patients in NH-A (100%), none of the patients in NH-B (0%), and 96% of patients in Limburg received initial compression therapy. In NH-A, 90% of these patients received a temporary compression hosiery compared with 74% in Limburg. Only 5% of patients using a temporary compression hosiery required (home care) assistance compared with 100% of patients using multi-layer compression bandages (either at the outpatient clinic or assistance by home care).

Ninety-three percent of the patients in the North Holland pathways and 90% in Limburg were able to self-reliantly apply and remove the long-term ECS (Table 1). In the NH pathways, 50% of patients were treated for 1 year, and the remaining 50% were treated for 2 years based on an experience-based clinical estimation of the treating internist. In Limburg, 83% of patients received a tailored ECS treatment duration (all of the patients treated by internists); of these patients 55% were treated for 6 months, 11% for 12 months, and 34% for 2 years. The remaining 17% of patients in Limburg were treated by general practitioners and did not receive a tailored ECS duration; 50% of these patients were treated for 1 year, and the remaining 50% were treated for 2 years.

Table 1 Resource use and costs per patient for the current care pathways
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As presented in Table 1, the per-patient costs in NH-A were €1046 (range €293–€4004), €947 (€120–€3786) in NH-B, and €1256 (€441–€3679) in Limburg. For all pathways, costs were highest for the long-term ECS therapy phase, and amounted to €738 (€119–€3229) in NH-A/B and €887 (€250–€2708) in Limburg. The difference in costs between regions could mainly be explained by the larger amount of patients who required home care in Limburg and the time planned for home care assistance. The costs for initial compression therapy in NH-A (€107 [€78–€218]) were comparable to the costs in Limburg (€119 [€78–€237]) and were €0 in NH-B as initial compression therapy was omitted in NH-B. Costs for the implementation of assistive devices were twice as high in the Limburg pathway (€89 [€9–€530] compared with the NH pathways (€44 [€1–€324]). This was primarily explained by the observation that more patients trained by occupational therapists in Limburg required additional practicing guided by home care personnel, and a longer practicing duration was required. Costs for the onset of long-term ECS therapy were comparable in all three pathways (€157 [€95–€233] in NH-A, €166 [€95–€233] in NH-B, respectively, and €160 [€104–€204] in Limburg).

The annual nationwide population costs ranged between €18.9 million (NH-B) and €27.0 million (Limburg) for the first year, between €25.1 million (NH-B) and €33.3 million (Limburg) for the second year, and between €31.3 million (NH-B) and €39.6 million (Limburg) for the third year. Details regarding the total and incremental population costs are presented in Table 2. As represented in Table 3, 1935 patients received long-term home care in the first year for the NH pathways, accumulating to 2915 in the second year and 3896 in the third year. For Limburg, these were 2544, 3472, and 4399 patients, respectively.

Table 2 Total and incremental population costs
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Table 3 Total number of patients receiving home care assistance during long-term elastic compression stocking therapy
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3.2 Impact of the Improvement Targets

For scenario 1, regarding the preferred use of temporary compression hosieries, the per-patient costs for initial compression therapy in NH-B equated to the costs for this phase in NH-A. As a result, total per-patient costs increased from €947 to €1053. In Limburg, costs decreased from €1256 to €1237 per patient. All costs reflecting the new scenarios can be found in Table 4.

Table 4 Total costs after implementation of the scenarios
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For scenario 2.1 (in which patients not receiving an assistive device and training and not receiving home care assistance were referred to the occupational therapist), we found that the total per-patient costs increased from €1046 to €1196 for NH-A, from €947 to €1097 for NH-B, and from €1256 to €1347 for Limburg. In this scenario, the occupational therapist trained five times (North Holland) and two times (Limburg) more patients than in current care. For scenario 2.2 (in which patients who were directly referred for long-term home care assistance were referred to the occupational therapist), the total per-patient costs decreased from €1046 to €907 for NH-A, from €947 to €808 for NH-B, and from €1256 to €1143 for Limburg. Occupational therapists trained approximately 30% (North Holland) and 20% (Limburg) more patients than in current care. For scenario 2.3 (in which patients trained to use an assistive device by home care nurses in the current Limburg pathway were referred to the occupational therapist), total per-patient costs decreased from €1256 to €1197 and the occupational therapist trained approximately 20% more patients. For scenario 2.4 (in which patients who were currently trained by the occupational therapist were directly referred to long-term home care assistance), costs increased from €1046 to €1527 for NH-A, from €947 to €1429 for NH-B, and from €1256 to €1854 for Limburg.

For scenario 3 regarding the implementation of a tailored ECS treatment duration, we found that the total per-patient costs decreased from €1046 to €1016 for NH-A, from €947 to €917 for NH-B, and from €1256 to €1225 for Limburg. A shift in costs (as presented in Fig. 1) and resource use occurred for the long-term ECS therapy. The number of visitations by internists in North Holland and general practitioners in Limburg increased from two to three or four (depending on the determined treatment duration). Furthermore, for patients requiring home care assistance during long-term ECS therapy, the time needed for assistance decreased from 130 to 92 hours for North Holland, and from 115 to 108 hours for the Limburg as presented in Table 6 of the ESM.

Fig. 1
figure 1

Distribution of costs during long-term elastic compression stocking therapy

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For scenario 4 (combining all improvement targets), 100% of patients received initial compression therapy in all regions; 90% of patients received a temporary compression hosiery and 10% multi-layer compression bandages. In North Holland, 95% of patients were expected to be self-reliant using the ECS compared with 93% in Limburg. All patients were expected to receive a tailored ECS treatment duration in the new pathways. As a result of the combined improvements, per-patient costs increased from €1046 to €1070 for NH-A and from €947 to €1078 for NH-B. In Limburg, these costs decreased from €1256 to €1150. As presented in Fig. 2, costs for the implementation of assistive devices phase increased for all pathways, while costs for long-term ECS therapy decreased.

Fig. 2
figure 2

Effects of combined improvements on compression therapy costs

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On a population level, we found that the number of patients who required home care assistance during long-term ECS therapy decreased from 1935 to 1325 in the first year in the new North Holland pathways and from 2544 to 1802 for Limburg as compared with the current care. This number further decreased in years 2 and 3 as presented in Table 3. The incremental population costs for the entire compression therapy pathways are shown in Table 2. Incremental costs refer to the cost differences between the new care pathways compared to the current care pathways. We found an increase in costs for the first year for the North Holland pathways. The introduction of initial compression therapy for all patients in NH-B, the increased number of patients referred for training by the occupational therapist and the increased number of visits with the internist for tailored ECS therapy mainly contributed to this increase.

Region Limburg directly benefits by cost savings mainly owing to the prescription of a temporary compression hosiery by general practitioners, which is less expensive than multi-layer compression bandages. Furthermore, the increase in the number of patients referred to the occupational therapist was smaller for Limburg compared with North Holland. For NH-A and Limburg, cost savings were realised in year 3 driven by implementation of a shortened duration of ECS therapy and the associated shorter duration of home care assistance in 66% of patients, combined with an increased number of self-reliant patients also not requiring long-term home care anymore.

3.3 Sensitivity Analyses

The ESM shows how the per-patient costs per treatment episode for current care vary with the upper and lower bounds of the inputs. We found that the successful implementation rates during training with the occupational therapist (which influences the number of patients requiring home care assistance for long-term ECS therapy) and the treatment duration of long-term ECS therapy were the main drivers of the per-patient costs for all regions. Additionally, the sensitivity analyses of the scenarios also showed that the implementation rate during training of assistive devices with the occupational therapist was the main driver (ESM). The number of patients referred to the occupational therapist was another main driver for total costs.

4 Discussion

Our study provides a detailed insight into the per-patient and population resource use and costs associated with compression therapy for patients with DVT in the Netherlands and the anticipated impact of three previously identified improvement targets. We found that the per-patient costs depended on the organization of current care in the three different regions studied, with a range between €947 (NH-B) and €1256 (Limburg).

The nationwide population costs of the three improvement targets combined ranged from €1.0 million saved (Limburg pathway) to €6.4 million saved (NH-B pathway) spend for the first year after implementation. After 3 years, this was between €4.7 million saved (Limburg pathway) and €0.6 million spent (NH-B pathway). For regions in which population costs initially increased (NH-A and NH-B), the incremental costs decreased in the second and third year. This resulted in a considerable cost reduction for the NH-A and Limburg pathways. The improvements targets increased workload for internists (North Holland pathway), general practitioners (Limburg pathway), and occupational therapists and decreased workload for home care nurses. However, it should be investigated if these shifts in workload are feasible during implementation.

To our knowledge, this is the first study focussing on the costs and resource use associated with compression therapy for patients with DVT. Our results showed that the improvements in compression therapy require initial cost investments during the first years after implementation depending on how current care is organized. It should be noted that because the ultimate goal of the improvements is to lower the patients’ risk of developing PTS, it is expected that downstream costs of PTS will decrease. Immediate compression in the acute phase of DVT has been associated with an 8% absolute reduction of the PTS at 24 months [4]. Furthermore, the IDEAL-DVT trial showed that a tailored (shortened) duration of ECS therapy was non-inferior for preventing the PTS and was cost effective compared to a standard treatment duration of 2 years [18]. In the current study, we did not include the costs associated with PTS. However, up to 50% of patients develop PTS following DVT and costs related to the treatment of the syndrome are not negligible [30, 31]. A Swedish study reported costs as high as 6000 dollars per DVT complication with an additional 4300 dollars for complications associated with PTS [10]. In the USA, a literature-based Markov model including patients with DVT after a total hip replacement surgery revealed that the additional costs for treating PTS were 3000 dollars [11]. Another study in the USA, based on claims data for patients with pulmonary embolism or DVT, estimated that the mean adjusted annual incremental cost of developing PTS was approximately 7000 dollars per patient [9]. By not including these costs, the total savings of the improvement topics has most likely been underestimated as costs associated with the PTS are substantial.

Our results showed that after implementation of scenario 2, with stimulation of early consultation of the occupational therapists to train patients on how to use assistive devices, more patients are referred to an occupational therapist. Hence, this would lead to an increase in workload for occupational therapists and per-patient costs. However, a proportion of patients might not benefit from additional training as they already adhere to therapy and do not experience difficulties in applying and removing the ECS. In addition, severe cognitive or physical disabilities might make training impossible for others. Referring these categories of patients would introduce unnecessary costs and time investment. Therefore, we emphasize the importance of patient selection for training by occupational therapists at the onset of long-term ECS therapy to prevent unnecessary costs but meanwhile supporting patients’ self-reliance.

For this paper, we have chosen to use a healthcare payer’s perspective. However, we expect that the results will even be more beneficial from a societal perspective, in particular, when we take the risk of developing the post-thrombotic syndrome into account. As described before, the post-thrombotic syndrome is associated with a large loss in productivity and high costs. We expect that the incidence of PTS decreases as a result of implementation of the improvement targets, as we expect they increase patients’ self-reliance and compliance. Furthermore, with optimization of ECS therapy, we also expect that the severity of PTS would decrease. This will result in a decrease in total costs related to PTS, but also in a decrease in costs per patient with PTS. The decrease in the incidence and severity of PTS is a result of all of the improvement targets separately; however, the largest change can be made if all improvements are implemented. The total impact of all of the separate improvements on PTS costs will differ per scenario.

The main limitation of our study is that for most input parameters, no literature or data was available. Therefore, we used healthcare professionals’ estimations, which might have introduced response bias. As prescribed in the ISPOR principles of good practice for budget impact analysis, input parameters should be as evidence based as possible, and expert opinions should only be used where alternative data sources are not readily available [32]. We conducted a cross-check for all input parameters with all stakeholders to reduce this bias. For future research, we suggest validating estimated input parameters using patient-level data. Electronic patient records and developments in linking different routine-care datasets are promising developments that could facilitate this type of research tremendously. In addition, the outcomes presented specifically apply to the Dutch healthcare system and will differ for other countries with different healthcare systems. However, the key improvement targets, the use of initial compression hosiery instead of multi-layer bandaging, individualized duration of ECS therapy, and the promotion of patients’ self-reliance, will likely also be applicable in other healthcare settings. Furthermore, we used stylized pathways for typical patients to calculate compression therapies’ resource use and costs. Not all patients will fit this profile, for example, patients who have contraindications for ECS therapy or patients living in care facilities. The major strength of our study is that the budget impact models described adequately represent current ECS pathways as they are designed after an extensive investigation of daily practice [12, 13].

5 Conclusions

This budget impact analysis identified resource use and costs associated with compression therapy in current care for three different care pathways in the Netherlands. It showed that optimizing initial compression therapy for all patients, promoting early consultation of the occupational therapist at the onset of long-term ECS therapy, and a tailored shortened duration of ECS therapy resulted in cost saving for two out of three pathways within 3 years. Savings were primarily driven by increased self-reliance of patients, resulting in a decrease of home care utilization.