The outpatient treatment of deep vein thrombosis delivers cost savings to patients and their families, compared to inpatient therapy

Thrombosis Research 112 (2003) 13 – 18

Regular Article

The outpatient treatment of deep vein thrombosis delivers cost savings to patients and their families, compared to inpatient therapy Marc A. Rodger a,b,c,*, Christine Gagne´-Rodger c, Heather E. Howley b, Marc Carrier a,c, Doug Coyle a,b, Philip S. Wells a,b,c b

a University of Ottawa, Ottawa, ON, Canada Ottawa Health Research Institute, Ottawa, ON, Canada c The Ottawa Hospital, Ottawa, ON, Canada

Received 25 September 2003; accepted 29 September 2003

Abstract Background: The outpatient treatment of deep vein thrombosis (DVT) with low-molecular-weight heparin (LMWH) has been shown to be cost-effective from the perspective of a third party payer. The aim of this study is to determine if some or all of these cost savings to third party payers are shifted to patients and their families. Methods: A prospective cohort study with micro-costing of patient/family costs was conducted at the thrombosis units of The Ottawa Hospital. Costs were determined by administering a questionnaire at the end of the patients’ heparin therapy. Over a period of 4 months, consecutive patients presenting at the thrombosis units were approached at the initiation of their heparin therapy; 44 patients consented to participate and completed questionnaires were obtained for 41. Results: The mean patient/family costs associated with outpatient therapy were significantly less than those associated with inpatient therapy ($219.42 versus $402.93, p = 0.003); a savings of $190.91 per patient. Even when lost income to patients/families was ignored, mean patient/family costs remained significantly less for outpatient therapy ($72.00 versus $134.29, p = 0.004); a savings of $62.30 per patient. Furthermore, patients preferred outpatient to inpatient therapy by almost 3:1 (30 versus 11, respectively). Interpretation: The outpatient treatment of DVT does not result in any net shifting of costs to patients and their families, and further, brings about cost savings. Given the cost savings associated with and the preference of patients for outpatient care, this study further supports the shift of DVT therapy from the inpatient unit to the outpatient clinic. D 2003 Elsevier Ltd. All rights reserved. Keywords: Cost-shifting; Outpatient treatment; DVT therapy; Patient costs

1. Introduction Deep vein thrombosis (DVT) is a common and potentially fatal disorder that may affect hospital inpatients as well as otherwise healthy people. The incidence of DVT has been estimated to be 48 cases per 100,000 persons [1]. Patients presenting with acute proximal DVT require immediate anticoagulant treatment to prevent pulmonary embolism (PE) and recurrent thrombosis [2]. Low-molecular-weight heparin (LMWH) administration is becoming an increasingly desirable alternative to conventional unfractionated heparin (UFH) therapy. Several meta-analyses of randomised clinical trials have found LMWH to be at least * Corresponding author. CEU F650, The Ottawa Hospital, Civic Campus, 1053 Carling Avenue, Ottawa, ON, Canada ON K1Y 4E9. Tel.: +1-613-738-7100x12694; fax: +1-613-761-5351. E-mail address: [email protected] (M.A. Rodger). 0049-3848/$ - see front matter D 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.thromres.2003.09.027

as effective and safe as UFH [3 –6]. The once or twice daily subcutaneous unmonitored administration of LMWH has the advantage of permitting patients with acute DVT to be treated at home, rather than in the hospital. Indeed, several separate studies have found outpatient-based LMWH therapy to be as safe and effective as inpatient UFH treatment in controlled clinical trials [7 – 9]. Additional studies have shown outpatient LMWH therapy to be feasible, safe and effective in the clinical setting [10 – 12]. Furthermore, we have found that outpatient LMWH DVT therapy is more cost-effective for the third party payer than inpatient UFH therapy. For those who are eligible for outpatient treatment, LMWH therapy results in savings of $912 (Can) per patient compared to inpatient UFH therapy [13]. Other groups have published similar findings [14 –16]. The importance of examining possible cost shifting to patients has been stressed by our group [13] and by van den Belt et al. [17], but has otherwise been largely ignored in the

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literature. To date, only one published report has attempted to examine the costs to patients associated with outpatient DVT therapy. O’Brien et al. [18] conducted a study to measure the societal costs of DVT treatment with LMWH at home versus UFH treatment in the hospital. This study was limited in measuring patient costs by only considering the costs of patient travel and lost productivity. Furthermore, lost productivity costs were valued using an industrial average wage rate for Ontario published in 1972. Notwithstanding these limitations, outpatient-based LMWH treatment was associated with significantly less patient and societal costs. Although these findings are encouraging, the measurement of patient costs was incomplete. In Ontario, the Ontario Health Insurance Plan (OHIP) covers all essential diagnostic and treatment services provided by physicians. However, OHIP does not cover the cost of prescription drugs used outside of a hospital setting. The Ontario Drug Benefit (ODB) program covers most of the cost of prescription drug products listed in the ODB Formulary. The ODB program is available to Ontario residents who have OHIP coverage and who are: (a) 65 years of age and older; (b) residents of a long-term care facility or home for special care; or (c) recipients of social assistance or professional home care services. Additional insurance is available from private sources, either through employment or from private insurance companies. The outpatient treatment and management of DVT using LMWH has been proven (from the perspective of a third party payer) to be cost-effective. Although it has been suggested that these savings may be realised by shifting costs away from the third party payer and onto patients and their families, the possibility of cost shifting to patients has not been sufficiently investigated. Considering that we should first and foremost be accountable to our patients and their families, it is imperative that we ascertain the burden (both monetary and non-monetary) of shifting care to an outpatient setting. Further, it is important that patient preferences be elicited and quantified prior to widespread approval of policies that shift care to an outpatient setting. This study aimed to determine if some or all of the cost savings achieved from transferring the treatment of DVT from the inpatient unit to the outpatient clinic are shifted to patients and their families. We also sought to examine the preference of patients for outpatient versus inpatient therapy.

2. Methods 2.1. Study design A prospective cohort study with micro-costing of patient/ family costs was conducted to assess cost shifting. Costs were evaluated strictly from the patient/family perspective. Patients were approached to participate at the initiation of their DVT treatment. A diary was given to consenting patients so that they could prospectively record costs in-

curred and time lost as a result of their heparin therapy. A questionnaire was administered, in person, at the completion of their heparin therapy to document the costs/time. The questionnaire (available from the authors) was developed through the collaboration of three physicians and three nurses directly involved in outpatient thrombosis units, a health administration student and a health economist. The questionnaire was a mixture of closed and openended questions, as well as numerous filter questions. The questionnaire addressed three primary areas: outpatient treatment costs, inpatient treatment costs and therapy preference. The section on outpatient treatment costs documented, in terms of dollars, the actual costs that patients and their families incurred as a result of their outpatient treatment (medication, transportation/parking, lost income, self-care, household maintenance and childcare). The inpatient treatment costs section required patients to consider the costs that they or their families would have incurred had they been hospitalised for their heparin therapy (visitor parking, lost income, hospital divertissements, household maintenance and childcare). A hypothetical model is required because The Ottawa Hospital no longer had a comparative inpatient DVT population. The vast majority of patients presenting with acute DVT are treated as outpatients and those who are admitted usually have significant co-morbidities. The final section of the questionnaire addressed the patients’ therapy preference. The question ‘‘if you had had the choice to treat your deep vein thrombosis (clot) as an inpatient or as an outpatient, which would you choose?’’ was asked after the sections on outpatient costs and inpatient costs. The aim of the repetition was to determine whether the consideration of inpatient costs

Table 1 Patient demographics Age Mean Standard deviation Range Gender Male Female Employment status Employed Retired Unemployed Annual gross employment income ($ Can) No income (e.g. retired) Less than 20,000 20,000 – 30,000 30,000 – 40,000 50,000 or more Not answered Holds either private or ODB insurance Yes No Not answered ODB = Ontario Drug Benefit program.

55 17.1 20 – 81 24 (58.5%) 17 (41.5%) 19 (46%) 14 (34%) 8 (20%) 24 3 3 5 5 1

(58.5%) (7.3%) (7.3%) (12.2%) (12.2%) (2.4%)

30 (73%) 10 (24%) 1 (2%)

M.A. Rodger et al. / Thrombosis Research 112 (2003) 13–18

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Table 2 Costs incurred by patients and their families for DVT therapy Outpatient costs

All costs Lost income to patients Lost income to family/friends Prescription drug costs Parking costs Transportation costs Divertissement costs (telephone, television, books, food) Additional costsb

p valuea

Inpatient costs

Mean

Range

S.D.

Mean

Range

S.D.

219.42 145.43 2.00 43.96 18.78 6.93

0 – 1554.95 0 – 1385.50 0 – 82.00 0 – 469.20 0 – 123.75 0 – 180.00

371.82 333.14 12.81 84.21 23.70 29.23

410.34 245.27 30.78

40.00 – 1578.50 0 – 1344.00 0 – 764.00

498.39 424.81 130.27

2.32

0 – 60.00

All costs, not including costs due to lost income (to both patients and family/friends) 72.00 0 – 524.70

9.98

58.08 1.27 50.13 24.80

0 – 161.25 0 – 42.50 0 – 124.00 0 – 200

37.38 6.77 30.40 44.18

100.58

134.29

40.00 – 354.50

71.32

0.002

0.004

DVT = deep vein thrombosis; S.D. = standard deviation. a Mean inpatient costs were compared to mean outpatient costs by a two-tailed, paired samples t-test. b Costs not addressed in the questionnaire, but specified by the patient.

changed their preference. Patients were also asked to give reasons for their preference. Patient demographics are presented using descriptive statistics. Mean outpatient costs are compared with mean inpatient costs via a two-tailed, paired samples t-test. Patient preferences were tallied. Subgroup analyses examine the possible effect of patient demographics on cost savings or cost-shifting. A two-tailed unpaired t-test is used for binomial demographics such as gender, age (less than 55 years versus 55 years or more) and insurance status. ANOVA analysis is used to examine the effect, if any, of employment status and income range.

costs (66%), followed by the cost of prescription drugs (20%) and clinic/lab parking costs (9%). If all income losses due to outpatient therapy (to patient and family/ friends) are excluded, then the mean patient/family cost is $72.00. It should be noted that 32 out of 41 outpatients (78%) did not lose any income as a result of their therapy. Of these 32 patients, 23 were retired or unemployed and the remaining 9 were employed but did not take any time off work. For the nine outpatients who did lose income as a result of their therapy, income losses ranged from $76.00 to $1152.00 (mean of $593.00). 3.3. Inpatient treatment costs

3. Results 3.1. Patient demographics Over a period of 4 months, 44 patients agreed to participate, from whom 41 completed questionnaires (93%) were obtained. Patient demographics are listed in Table 1. The age of our population ranged from 20 to 81 years (median of 55 years) and the gender distribution was 24 (59%) men to 17 (41%) women. A total of 19 (46%) patients were employed, 14 (34%) retired and 8 (20%) unemployed. Patients were asked whether they had insurance to cover prescription drugs; either private health insurance or the Ontario Drug Plan (OPD). This information is available for 40 patients; 30 (73%) indicated they had coverage, 10 (24%) stated they did not have coverage. 3.2. Outpatient treatment costs The mean patient/family cost of outpatient DVT therapy was $219.42 (Table 2). It is clear from Table 2 that lost income was the greatest contributor to outpatient

The mean hypothetical patient/family cost associated with inpatient DVT therapy was $410.34 (Table 2). From Table 2, it is evident that lost income to patients was the greatest contributor to inpatient costs (60%), followed by visitor parking costs (14%), divertissement costs (12%)

Table 3 Patient preferences for DVT therapy Reason for preference

Number of patients

Prefer outpatient therapy (30 patients) Enjoy comforts of home Dislike of hospitals Too much time lost for inpatient therapy High cost of inpatient therapy to health care system

18 8 3 4

(60%) (27%) (10%) (13%)

Prefer inpatient therapy (11 patients) Does not wish to be responsible for own care Too much traveling required for outpatient therapy Too much time required for outpatient therapy Outpatient therapy is too expensive

5 3 2 1

(45%) (27%) (18%) (9%)

DVT = deep vein thrombosis.

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and lost income to family/friends (7.5%). If all income losses due to inpatient DVT therapy (to patients and family/friends) were excluded, then the mean patient/ family cost was $134.29. When income loss as a result of inpatient heparin therapy is examined, 29 patients would not have lost any income. Of these 29 patients, 23 were retired or unemployed and the remaining 6 were employed but were already off work for other reasons. For the 12 patients that would have lost income as a result of inpatient heparin therapy, losses ranged from $304.00 to $1344.00 (mean of $838.00). 3.4. Outpatient versus inpatient costs Outpatient and inpatient costs are compared in Table 2. The mean total outpatient costs were significantly less than the mean total inpatient costs ( p < 0.05, two-tailed paired samples t-test). Thus, outpatient DVT therapy achieves savings of $190.91 per patient. Even when excluding patients’ income loss, outpatient therapy costs were significantly less than inpatient treatment ( p < 0.05, two-tailed paired samples t-test) and the savings were $62.29 per patient.

Table 4 Effect of demographic characteristics on the difference between the cost of outpatient and inpatient DVT therapy Demographic Ageb Less than 55 years of age (20) 55 years of age or greater (21) Gender Male Female Employment status Employed Retired Unemployed Annual gross employment income ($ Can) No income (e.g. retired) Less than 20,000 20,000 – 30,000 30,000 – 40,000 50,000 or more Holds private or ODB prescription drug insurance Yes No

Mean differencea

S.D.

p value

90.19 281.49

235.73 460.28

0.108c

251.02 88.20

413.30 287.11

0.145c

331.53 31.06 69.73

493.15 196.02 79.20

0.054d

68.28 81.65 728.67 286.81 474.47

87.19 471.92 549.26 404.93 658.03

0.004d

184.90 189.28

335.80 497.88

0.980c

3.5. Therapy preference Patients preferred outpatient DVT therapy by almost 3:1; 30 preferred outpatient treatment, while 11 preferred inpatient treatment. Reasons for outpatient and inpatient therapy preference are displayed in Table 3. For the 30 patients preferring outpatient therapy, the comfort of home was the primary reason (60%), followed by a dislike of hospitals (27%). Other reasons (13%) included the time lost and cost to the health care system associated with inpatient therapy. For the 11 patients preferring inpatient treatment, concern for managing their own care was the primary reason (45%), followed by avoiding travelling (27%), and the time or cost involved with outpatient therapy (27%). Therapy preference did not change between completion of the outpatient and inpatient sections of the questionnaire (data not shown). 3.6. Subgroup analyses Demographic data were evaluated for possible effects on cost shifting or cost savings (Table 4). There was a trend ( p = 0.054) for employed persons to achieve greater cost savings as a result of outpatient therapy compared to retired or unemployed persons. Income loss was the greatest contributor to patient/family costs; retired/unemployed persons had no income to lose as a result of inpatient therapy and therefore would not have saved as much by being treated as an outpatient. Annual employment income has a significant ( p < 0.05) effect on cost savings. Once again, this reflects the impact of income losses on the cost savings achieved by outpatient therapy. Other demographic factors such as gender, age, insurance status had no significant effect ( p > 0.05) on cost savings.

4. Discussion

S.D. = Standard deviation; ODB = Ontario Drug Benefit program. a The mean difference was determined by subtracting mean inpatient costs from mean outpatient costs. A negative value indicates that outpatient therapy is less costly than inpatient therapy. b The mean age was 55 years, so this was used as the cut-off for examining age. c Mean differences between groups were compared via a two-tailed unpaired t-test.

Scarce health care resources dictate an increasing pressure to shift inpatient care to an outpatient setting. The costeffectiveness of this shift has been examined for a variety of conditions [19 – 23] and therapies [7,8,11,24 – 27]. All of the above reports demonstrate that outpatient-based treatment is both safe and cost-effective compared to inpatient therapy. It is unclear whether the reduction in costs to third party payers if offset by an increase in costs to patients and their families. To our knowledge, only two published reports have attempted to examine the possible shifting of costs onto patients and their families. In one study on outpatientbased bone marrow transplantation, Rizzo [26] surveyed the out-of-pocket expenses to patients. Surviving inpatients and outpatients were surveyed 1 year following transplantation to determine the direct and indirect costs which they incurred as a result of their treatment. No significant differences were found in the out-of-pocket expenses incurred between inpatients and outpatients. O’Brien et al. [18]

M.A. Rodger et al. / Thrombosis Research 112 (2003) 13–18

conducted an economic analysis alongside a clinical trial and measured the societal costs of DVT treatment with LMWH at home versus UFH treatment in the hospital. This study was limited in measuring patient costs by only considering the costs of patient travel and lost work hours (of both patient and informal caregiver). Nevertheless, outpatient-based LMWH treatment was associated with significantly less patient and societal costs. Our results demonstrate that outpatient DVT therapy does not result in any net shifting of costs onto patients and their families. Moreover, outpatient therapy delivers cost-savings to patients and their families, and these savings remain significant whether or not lost income due to therapy is considered. Given that patients preferred outpatient therapy by almost 3:1; our results further support the shift of DVT therapy from the inpatient unit to the outpatient clinic. The comfort of home or a dislike of hospitals was the main reason for the majority of patients preferred outpatient care (87%). In Canada, publicly funded benefits for prescription drugs are not uniformly available. As a result, when prescription drugs are used outside a hospital setting, the cost often becomes the patient’s responsibility. The shift away from inpatient therapies will only compound this burden. Almost 25% of our patients do not have private or ODB health insurance, and the 1996/1997 National Population Health Survey revealed that 39% of Canadians (34% of Ontarians) reported not having prescription drug insurance [28]. Prescription costs contribute to 20% of total outpatient costs, so it is not surprising that patients without private health insurance incur almost four times as much for outpatient therapy compared to patients with insurance ($579.92 versus $105.05, p < 0.05, data not shown). In our study, outpatients pay for their LMWH and warfarin therapy, spending an average of $43.96. In 1998, Canadian households spent an average of $355 on health insurance premiums (including provincial and private plans) and $198 on prescription medications and pharmaceutical products [29]. If the Ontario government was to implement a universal drug benefit plan, the savings to patients would be even greater without decreasing the savings to third party payers (such as the Ministry of Health and Long Term Care). In a previous study on the cost-effectiveness of outpatient LMWH therapy, we found that a savings of $912 (Can) per patient was achieved [13]. In determining the cost of outpatient treatment with LMWH, we used the actual cost of treating outpatients in our medical day care unit and assumed that all outpatient-eligible patients had been treated with LMWH on an outpatient basis. In such a scenario, patients would have presented to our medical day care unit for daily injections of LMWH, nursing assessment and monitoring of warfarin therapy; all antithrombotic drugs would have been paid for by the hospital. Thus, the calculated savings of $912 per patient included the cost of antithrombotic medications.

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Inpatient therapy resulted in significantly greater patient costs even when income losses were ignored. This is surprising; on the surface, it would seem that the cost of prescription drugs and travelling to clinics and laboratories would create a significant financial burden on outpatients. However, 23% of total inpatient costs ($95.82 Can) are the result of hospital charges (visitor parking and television and phone rental). Although these costs are not by definition user fees, they do represent a significant burden to patients. This work has shown that the transition from inpatient to outpatient DVT care is a win – win situation for patients and third party payers. Outpatient DVT care is cost-effective for third party payers, is preferred by patients, and also delivers cost savings to them and their families.

Acknowledgements The authors are indebted to Dr. Doug Angus for his mentorship and supervision of this project. We gratefully acknowledge our thrombosis unit nurse Linda Hamelin for her assistance with data collection. We would like to thank Miche`le Willson for her help with manuscript preparation.

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