British Journal of Rheumatology 1998;37:837–847
DIRECT COST OF RHEUMATOID ARTHRITIS DURING THE FIRST SIX YEARS:
A COST-OF-ILLNESS STUDY
C. H. M. VAN JAARSVELD, J. W. G. JACOBS, A. J. P. SCHRIJVERS,‡ A. H. M. HEURKENS,*
H. C. M. HAANEN† and J. W. J. BIJLSMA
Department of Rheumatology and Clinical Immunology, University Hospital Utrecht, PO Box 85500, 3508 GA Utrecht,
*Department of Rheumatology, Eemland Hospital, Utrechtseweg 160, 3818 ES Amersfoort, †Department of Rheumatology,
St Antonius Hospital, Koekoekslaan 1, 3435 CM Nieuwegein and ‡Julius Centre for Patient Oriented Research, PO Box 80046,
3508 TA Utrecht, The Netherlands
SUMMARY
The objective was to estimate the annual direct disease-related cost of rheumatoid arthritis (RA) during the first 6 yr and to
determine which socio-demographic and clinical characteristics relate to these costs. The study population consisted of 424 RA
patients who had participated in a (population-based) trial on therapeutic strategies for early RA since 1990 and were not lost
to follow-up in April 1996. A questionnaire on costs due to RA was sent to these patients; 363 (86%) completed questionnaires
were analysed. The total annual direct cost per patient was estimated by adding up the costs of health care workers, days
admitted to care facilities, medication, monitoring for side-effects, alternative medicine, adaptations in the home, devices, and
other direct costs such as travelling expenses. The mean annual direct cost due to RA was estimated to be Dfl. 11 550 per
patient. An obvious increase in direct cost with increasing disease duration was not found. Patients with higher disease activity
exhibited significantly higher costs compared to patients with lower disease activity. A multiple logistic regression model
showed that greater disability and lower age increased the odds for high costs. The annual direct cost of RA averaged out at
Dfl. 11 550 per patient (i.e. £3680). A high total direct cost in the first 6 yr of disease is related to severe functional disability
and lower age.
K : Rheumatoid arthritis, Cost of illness, Direct cost, The Netherlands.
R arthritis (RA) is a systemic condition,
chronic symmetrical polyarthritis being its most
common manifestation. The prevalence of RA in the
Dutch population aged over 40 yr has been estimated
to be 1–1.5% [1]. The absolute number of RA patients
in the total Dutch population was estimated to be
136 400 in 1990 [2]. RA causes, even early after disease
onset, functional disability and irreversible joint
damage. In addition to an impact on the financial
situation of individual patients and their families, RA
also has an economic impact on society. To study the
cost of a disease, several perspectives can be used,
depending on the audience targeted. A societal perspective was assumed for this cost-of-illness study,
meaning that no distinction was made between payments by the patient, the National Health Service or
somebody else. In this manner, a picture of the economic influence of the disease on all segments of
society will be obtained.
The costs of illness consist of three components:
direct costs, indirect costs and intangible costs [3].
Direct costs are those requiring actual payment, such
as those owed mainly to the health care sector for
treatment of the disease. In addition to these direct
medical costs, there are also direct non-medical costs
for RA patients, which include adaptations in the
home, special means of transportation and devices
(medical aids) needed to perform activities of daily life.
Indirect costs are those which do not require direct
payment since they represent lost resources. These
costs include production losses attributable to those
who are unemployed or cannot work as a result of
illness. Illness also causes a reduction in the quality of
life; these intangible costs are virtually impossible to
estimate. However, it is essential to note their importance, especially for patients with a disease such as RA
in which pain plays a major role.
The economic impact of RA on society in England
was estimated to be £1256 million (i.e. Dfl. 3925
million) in 1992, 52% of which is production loss
caused by RA disability (indirect costs); direct costs
accounted for 48% [4]. In studies conducted a decade
ago in the USA, the annual direct cost averaged $6000
(1990 dollars) (i.e. Dfl. 11 800 or £3800) per RA patient
and indirect costs exceeded direct costs at least
3-fold [3]. The results of a study of Dutch patients
with diverse rheumatic disorders of varying duration
showed that the financial situation deteriorated due to
the disease in 67% of these cases [5]. An estimation of
the financial consequences of RA during the first years
of disease in The Netherlands was not available.
This report on the cross-sectional study focuses only
on the direct costs, i.e. medical and non-medical direct
costs. Data on the indirect costs will be reported
separately, since these costs are estimated in a different
way. The study design is a cost-of-illness analysis which
comprises an inventory of direct costs, rather than
exact estimates of costs for individual patients. The
three central questions of this study are as follows. (1)
What is the estimated annual direct cost per RA patient
during the first 6 yr? (2) Is there a trend in the direct
Submitted 9 June 1997; revised version accepted 20 October 1997.
Correspondence to: C. H. M. van Jaarsveld, Department of
Rheumatology and Clinical Immunology, University Hospital
Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands.
© 1998 British Society for Rheumatology
837
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BRITISH JOURNAL OF RHEUMATOLOGY VOL. 37 NO. 8
annual cost with increasing disease duration? (3)
Which socio-demographic or clinical characteristics are
related to these costs?
SUBJECTS AND METHODS
Subjects
Since 1990, RA patients attending a rheumatology
centre in the region of Utrecht, The Netherlands, were
managed according to a protocol for therapeutic strategies [6 ]. All RA patients, diagnosed according to the
1987 American College of Rheumatology criteria [7],
with a maximum disease duration of 1 yr were asked
to participate. Therefore, it is a population-based
study. In this open clinical study, patients were randomly assigned to one of the therapeutic strategy
groups. Data on the clinical course of the disease,
psychological well-being, medication and side-effects
were collected regularly. In April 1996, 424 patients
were enrolled in this trial. A self-reporting questionnaire on the cost of RA was sent to these patients by
mail. RA patients with a disease duration of 0–6 yr
were the subjects of this study, since the first patients
were enrolled in 1990.
Estimation of direct costs
Seven categories of direct cost were distinguished.
The costs of health care workers, days spent in care
facilities, medication, monitoring for side-effects of
medication and alternative medicine were grouped as
direct medical costs. The costs of devices, adaptations
in the home and other costs were considered direct
non-medical costs. Cost per category was estimated by
multiplying volumes by cost per unit.
Volume of direct costs
Information on the volumes of the diverse costs was
collected by means of a questionnaire consisting of 31
items, designed especially for this study. In a pilot
study of 10 RA patients, the questionnaire was found
to be clear and feasible. The following data were
collected: number of contacts with health care workers
in the past 3 months; number of days spent in a
hospital, rehabilitation centre and nursing home in the
past 12 months; adaptations in the home, and devices
needed to perform activities of daily life acquired in
the past 12 months. Lists of 13 kinds of health care
worker and frequently acquired devices were included
with the questionnaire. Patients reported the number
of contacts with each kind of health care worker and
checked the devices they had acquired. Contacts with
health care workers who were not on the list were also
specified by the patient; the same applied for other
devices. Data on medication used in the past 12 months
and data on monitoring the side-effects of antirheumatic medicines were collected from the clinical
trial database.
Direct medical costs
All costs are presented in Dutch florins (Dfl. 1.00 =
£0.32 or US $0.51 in September 1997). Main costs are
also provided in pounds sterling.
Contacts with health care workers. Cost per contact
was estimated by dividing the total national cost by
the total annual number of contacts for each kind of
health care worker (see Appendix 1) [8]. These calculations were based on national data and are not specific
for RA patients. For a visit to the occupational therapist, the cost of the physiotherapist was used (Dfl. 53)
because other data were not available. A visit to a
rheumatology nurse was estimated to cost Dfl. 75 [9].
For visits to a company medical officer, personnel
officer and other care workers specified by the patient,
the cost of a consultation with the medical specialist
(Dfl. 81) was used, since data for a more precise
calculation were not available.
Days in care facilities. For hospitals, rehabilitation
centres and nursing homes, we estimated the cost per
day. The total national cost for all Dutch hospitals
and all Dutch nursing homes was divided by the
average annual number of nursing days found for
all hospitals and nursing homes, respectively. Since
national data on rehabilitation centres were not available, we used data known for one rehabilitation centre
in Utrecht. The total cost for all hospitals in The
Netherlands, including the cost of out-patient clinics,
was estimated to be Dfl. 15 967 million in 1995 [8].
Dfl. 15 967 million divided by 16 141 000 nursing days
yielded Dfl. 990 per nursing day for a hospital [10].
The total cost for nursing homes was Dfl. 5317 million
in 1995 in The Netherlands, and the annual number
of nursing days was estimated to be 18 859 000 days,
which equals Dfl. 280 per day [8, 10]. The cost of a
day spent in a rehabilitation centre was estimated in
the same way, using the known data for one rehabilitation home in Utrecht: Dfl. 31 243 959 divided by 62 965
nursing days resulted in Dfl. 500 per day for a rehabilitation centre.
Medication and monitoring for side-effects. All medications for RA used by our patients in the past 12
months were included: slow-acting anti-rheumatic
drugs (SAARDs), non-steroidal anti-inflammatory
drugs (NSAIDs), analgesics, antacids, vitamins, minerals and corticosteroids (oral, i.v. and intra-articular).
Prices were obtained from the National Pharmacotherapeutical Catalogue of 1996. The cost per month
is presented in Appendix 2, assuming standard daily
doses. If, for example, a double dose was taken by a
patient, the monthly cost was doubled.
Monitoring for side-effects of SAARDs and
NSAIDs is standard procedure for all RA patients on
these drugs. Several schedules for monitoring exist. In
this study, the standard schedule of the University
Hospital Utrecht was used [11]. Laboratory tests,
X-rays, eye checks and lung function tests were
included (see Appendix 3). The total cost of standard
monitoring for the side-effects of SAARDs and
NSAIDs used by a patient in the past 12 months was
calculated.
Alternative medicine. The total cost of alternative
medicine for RA in the past 3 months was estimated
by the patient and reported in the questionnaire.
VAN JAARSVELD ET AL.: ANNUAL DIRECT COST OF RA IN DUTCH PATIENTS
Direct non-medical costs
Adaptations in the home and devices. Costs of adaptations in the home and devices were estimated using the
price lists of three catalogues for aids for activities of
daily life and adaptations in the home [12–14]. Missing
prices were estimated by an occupational therapist.
Other direct costs. Several other categories of cost
due to RA were listed in the questionnaire. The patients
were asked to report the total amount spent in the
past 3 months. The categories were: travelling expenses
for visits to health care workers, bills for medication
which were not refunded by the National Health
Service, extra costs of energy (central heating), telephone and clothing, small payments to neighbours or
friends who help, payments for extra help in and
around the house, such as cleaning, and other costs
specified by the patient.
Analyses
Annual direct costs of the seven categories were
combined to estimate the total direct cost of RA. Cost
might depend on disease duration. To identify a trend
in cost with increasing disease duration, patients were
divided into six groups according to their disease
duration. The mean, median and the .. of the annual
direct cost per year are presented. In order to determine
which socio-demographic and clinical characteristics
separated patients with relatively high costs from those
with lower costs, the population was divided into two
groups according to total annual cost. The differences
between the two groups were compared using the x2
test for categorical data and the Mann–Whitney test
for ordinal data. A multiple logistic regression model
was made for low vs high costs (dependent variable),
using socio-demographic and clinical data (independent variables). The stepwise method was applied, meaning that the variable which correlated best with the
total annual cost was included first in the model.
Statistical analyses were carried out using the SPSS
statistical package for Windows Version 6.1 [15].
RESULTS
Of the 424 questionnaires, 377 were returned within
the time limit of 2 months. The response was 89%. In
14 cases, the data on direct costs were incomplete,
leaving 363 patients for the analyses. Baseline characteristics of responders who sent in complete or incomplete questionnaires and non-responders did not differ
significantly (data not shown). Patients were divided
into six groups according to their disease duration.
Patient characteristics of the six groups at the time of
filling out the questionnaire are presented in Table I.
Direct medical costs
Contact with health care workers. Most patients, i.e.
341 (94%), had contacted at least one health care
worker in the past 3 months. Mean disease duration
did not differ between the 22 patients who did not,
and the 341 patients who did, contact a health care
worker. The number of contacts in the past 3 months
was multiplied by four to obtain estimations for the
839
past 12 months. The number of contacts and annual
cost per health care worker are summarized in
Appendix 1. The mean annual cost for all health care
workers together was Dfl. 769 800 or Dfl. 2120 per
patient (i.e. £680). Visits to physiotherapists and
rheumatologists accounted for the largest amounts:
Dfl. 666 and Dfl. 580 per patient, respectively.
Rheumatologists were costly because 90% of patients
had two consultations per year on average (range
0–12). Although only 24% visited a physiotherapist
(n = 87), the cost was high because each patient had
13 sessions on average, resulting in an average of three
contacts for the whole group (range 0–36). This was
not surprising, since in The Netherlands physiotherapy
is often prescribed for 10 sessions.
The total cost of contacts with health care workers
is presented for the six groups with increasing disease
duration in Table II. The mean (and median) cost was
Dfl. 3355 (2340) for patients with <1 yr RA; in
subsequent years, costs were slightly lower.
Days in care facilities. Forty-nine patients (13%)
spent at least 1 day in a hospital, rehabilitation centre
or nursing home during the last year. There were 41
patients who spent an average of 20 days in a hospital,
nine patients who spent an average of 7 days in a
rehabilitation home and one patient who was in a
nursing home for 1 day. Ten patients (16%) of the
group of patients with <1 yr RA had at least one
nursing day, and 12, 6, 11, 14 and 26% of the groups
in order of increasing disease duration. The mean cost
due to days spent in care facilities was Dfl. 18 695 per
hospitalized patient (.. 17 034). The mean cost for
the total group of patients was much lower than that
for this subgroup of patients with at least one nursing
day, since only 13% were responsible for these costs.
Owing to the skewed distribution, median costs were
zero. The mean cost of days spent in care facilities
during the past 12 months for all 363 patients together
was Dfl. 916 070, or Dfl. 2524 per patient (i.e. £810).
The cost per group according to increasing disease
duration is presented in Table II. The mean cost was
Dfl. 4620 for patients with <1 yr RA; in subsequent
years, mean costs were lower.
Medication and monitoring for side-effects. All
patients took medication for RA. The total mean cost
was Dfl. 1135 per patient over the past 12 months (i.e.
£360). In comparison with anti-rheumatic drugs, medication for preventing or treating stomach problems
(antacids) caused high costs (see Appendix 2). The
cost of medication did not differ over the first 6 yr of
disease. Results are shown in Table II.
Alternative medicine. In the past 3 months, 44
patients (12%) stated that they made use of at least
one type of alternative medicine. The mean cost for
these 44 patients was Dfl. 923 per patient (.. 1120).
Another 44 patients (12%) had used an alternative
medicine more than 3 months ago, and 275 patients
(76%) said they had never used alternative medicine.
For the total group of 363 patients, the mean cost was
Dfl. 112 (i.e. £40) per patient (see Table II ).
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BRITISH JOURNAL OF RHEUMATOLOGY VOL. 37 NO. 8
TABLE I
Patient characteristics at the time of filling out the questionnaire
Group
1
Number of patients
Disease duration in years
Age in years
Median
Range
% Female
% Positive rheumatoid factor test
% Radiological damage (Sharp 1)*
2
3
4
5
6
63
0–1
78
1–2
67
2–3
53
3–4
56
4–5
46
5–6
57
19–84
64
66
68
58
21–80
72
69
84
60
30–82
75
79
83
65
22–85
68
68
98
67
29–88
71
70
100
60
27–81
63
78
96
Total
363
∏6
60
19–88
69
72
90
*A modified method of Sharp was used to score radiological damage [24, 25]. According to this method, erosions and joint space narrowing
in hands, wrists and feet are scored (range 0–448). A Sharp score 1 means that at least one erosion or some joint space narrowing is visible.
TABLE II
Direct cost in Dfl. per patient during the past year, for six groups with increasing disease duration; figures are the mean (..) and median*
Disease duration (yr)
0–1
Patients (n)
Health care worker
Days in care
facilities
Medication
Monitoring for
side-effects
Alternative
medicine
Subtotal
medical cost†
Adaptations and
devices
Other cost
Subtotal
non-medical
cost†
Total
direct cost
63
3355
2340
4620
0
1340
1170
484
416
83
0
9882
4444
2814
150
1759
600
4573
2268
1–2
3–4
67
1682
648
(6982) 1374
0
(647)
1041
850
(315)
253
224
(810)
193
0
(8167) 4543
2006
(16 307) 2921
0
(2759) 1993
532
(17 504) 4914
800
53
1381
648
(5885) 1047
0
(912)
1168
984
(203)
243
240
(602)
30
0
(7059) 3869
244
(8277)
888
0
(7653) 1476
200
(14 688) 2364
240
14 455 (20 411) 13 800 (20 250) 9457
7370
5656
4727
(17 711) 6233
2862
(3112)
(15 521)
(682)
(311)
(299)
(1898)
(6797)
(3101)
(8934)
78
1952
1284
1891
0
1268
1251
401
240
177
0
5689
3442
6359
126
1752
696
8111
2252
2–3
(1782)
(1731)
(1686)
(4000)
(929)
(191)
(112)
(5378)
(3566)
(3040)
(4600)
(8181)
4–5
56
2309
648
2814
0
808
497
177
206
54
0
6126
2064
5443
88
1400
354
6843
2040
(3574)
(9839)
(790)
(150)
(172)
(11 830)
(15 616)
(2085)
(15 892)
5–6
46
1975
636
3747
0
1123
880
218
216
86
0
7149
2493
3909
0
919
174
4009
788
(2888)
(8007)
(939)
(198)
(269)
(9658)
(9716)
(1459)
(10 067)
Total
group
363
2120
960
2524
0
1135
980
307
240
112
0
6198
2808
3755
55
1597
520
5352
1360
(2581)
(8911)
(823)
(266)
(490)
(10 364)
(11 447)
(4037)
(13 261)
13 005 (24 289) 11 158 (17 772) 11 550 (19 030)
5642
6027
5085
*Mean and median cost are both presented and differ due to the skewed distribution of cost.
†Subtotal of medical direct cost includes costs due to contacts with health care workers, days spent in care facilities, medication, monitoring
for side-effects and alternative medicine; subtotal of non-medical direct cost includes costs of adaptations in the home, devices and other costs
(specified in Table III ).
Direct non-medical costs
Adaptations in the home and devices. In the past year,
186 patients (51%) needed at least one adaptation in
the home or device. The mean cost for these 186
patients was Dfl. 7328 (median Dfl. 2136; range
32–100 420). For the total group, the mean cost was
Dfl. 3755 (i.e. £1200) (median: Dfl. 55). The most
expensive adaptation was full adaptation of the kitchen
(Dfl. 45 000). Toilet adaptation (Dfl. 150) was required
by the largest percentage of patients, namely 13% (n =
49). Of the 63 patients with <1 yr RA, 43 (68%) had
acquired at least one adaptation or device in the past
year (three on average). In the other five groups, based
on increasing disease duration, the percentage of
patients requiring at least one adaptation or device
was 63, 40, 34, 52 and 43. The prices of all reported
adaptations and devices were added up. The average
cost per patient group in the past year is presented in
Table II. The mean cost of devices and adaptations in
the first year was Dfl. 2814 (median Dfl. 150), in the
second year it was Dfl. 6359 (median Dfl. 126); in
subsequent years, the costs were lower.
Other costs. Several other categories of cost due to
RA, specified in Table III, added up to a total of Dfl.
1597 (i.e. £510) per patient per year (see also Table II ).
The category with the highest cost was ‘maintenance
in and around the house’ which the patient could not
carry out due to RA. These expenses averaged Dfl.
101 per patient in 3 months.
Total direct costs. The subtotals of the direct medical
VAN JAARSVELD ET AL.: ANNUAL DIRECT COST OF RA IN DUTCH PATIENTS
841
TABLE III
Specification of other costs due to RA in the past 3 months, irrespective of disease duration
Patients with
costs in
the past
3 months
Category
Maintenance in and around the house
Medicines, not paid by medical insurance
Transport, parking permit
Clothing
Energy cost
Payments to friends for help
Telephone
Remaining cost
Total in 3 months
Total in 12 months
Cost per patient who
reported cost (Dfl.)
Cost per patient for
whole group (Dfl.)
n
(%)
Mean
(..)
Median
Mean
(..)
Median
63
56
104
38
79
47
29
37
220
220
(17)
(16)
(29)
(11)
(22)
(13)
(8)
(10)
(61)*
(61)
575
602
153
333
157
188
88
610
659
2656
(688)
(1263)
(155)
(287)
(136)
(179)
(56)
(489)
(1230)
(4919)
500
266
143
300
157
150
88
534
361
1444
101
94
45
36
35
25
7
65
399
1597
(360)
(539)
(108)
(138)
(91)
(90)
(29)
(245)
(1009)
(4037)
0
0
0
0
0
0
0
0
130
520
*Total number of patients (n = 220) is not the sum of the number of patients in each category since one patient could report costs in several
categories.
and non-medical costs are also presented in Table II.
Total mean (and median) direct cost was Dfl. 14 455
(7370) in the first year of the disease. Costs decreased
slightly in the following years, but after 4 yr the direct
medical cost increased again to Dfl. 11 158 (6027) per
patient in the sixth year. Figure 1 shows box plots of
the total direct cost for the six groups according to
increasing disease duration. Clearly, the total direct
cost did not differ significantly among these groups.
Patients with high costs
Comparison of mean with median direct costs
revealed a large discrepancy, especially for days in care
facilities and adaptations/devices, meaning that there
was a skewed distribution of these costs. Obviously,
some patients represented high costs, while the majority
cost less. We compared hospitalized patients (13%)
with the other 87% who were not in a care facility.
The 49 hospitalized patients had significantly higher
medical and non-medical costs (see Table IV ). The
cost of the care facility was excluded from the medical
costs in this calculation. Detailed analyses of patients
with extremely high costs (up to Dfl. 145 000) showed
that in most cases the cost of each category was high.
Figure 2 presents the total direct cost for all patients
regardless of their disease duration. In view of the
distribution of the total direct cost per patient, we
chose the 75th percentile (Dfl. 10 000 or £3200) as the
cut-off point for low vs high cost. Several sociodemographic and clinical characteristics of the 96
patients with high costs and the 267 patients with
lower costs were compared. The results are presented
in Table V. The mean disease activity during the year
for which costs were estimated was higher for patients
with high costs compared to patients with relatively
lower costs. Differences were statistically significant
F. 1. —Direct cost vs increasing disease duration. Box plots represent: median (thick line), 25–75% (box), 10–90% (thin lines), extremes (o/*).
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BRITISH JOURNAL OF RHEUMATOLOGY VOL. 37 NO. 8
TABLE IV
Direct medical and non-medical costs in Dfl. for hospitalized and non-hospitalized patients in the past year; figures are means (..)
Cost
Medical cost (nursing days excluded )
Non-medical cost
Total direct cost
Hospitalized
(n = 49)
Non-hospitalized
(n = 314)
P*
6611 (3637)
11 807 (18 290)
18 418 (20 051)
3215 (2761)
4345 (12 022)
7561 (12 990)
<0.001
<0.001
<0.001
*Mann–Whitney U-test.
F. 2.—Total direct cost per patient for all patients (regardless of disease duration): ‘low’ cost, ∏ Dfl. 10 000, n = 267; ‘high’ cost,
>Dfl. 10 000 (i.e. £3200), n = 96.
TABLE V
Mean disease activity in the past year and socio-demographic characteristics for patients with total annual direct cose ∏ Dfl. 10 000 and
patients with cost >Dfl. 10000
Cost ∏ Dfl. 10 000 (n = 267)
Variable
(actual range)
Disability (0–3)†
Joint score (0–428)†
Pain (0–95 mm)†
ESR (0–112 mm/1st h)†
Sharp score (0–169)†
Disease duration (0–6 yr)
% RF positive
Depressive mood (0–19)†
Anxiety (10–40)†
Age (19–88 yr)
% Female
% Low educational level‡
% Married/living together
Cost >Dfl. 10 000 (n = 96)
Mean
(..)
Median
Mean
(..)
Median
P*
0.9
56
21
22
17
2.8
71
3
18
59
68
51
75
(0.7)
(75)
(21)
(16)
(23)
(1.6)
0.9
33
14
18
9
2.6
(0.7)
(76)
(25)
(23)
(38)
(1.8)
1.5
66
27
27
10
2.3
(4)
(6)
(14)
2
17
61
1.6
81
32
30
28
2.7
73
5
21
57
72
53
71
(4)
(6)
(16)
4
19
59
< 0.0001
0.0004
0.0001
0.006
0.28
0.34
0.78
0.0005
0.002
0.23
0.50
0.74
0.41
*Mann–Whitney U-test for continuous data and x2 test for categorical data, where appropriate.
†High values indicate a more active disease/more problems.
‡Educational level in two categories: low level means less than secondary school; high level means at least secondary education.
for functional disability [measured with a validated
Dutch version of the Health Assessment Questionnaire
(HAQ)] [16 ], joint score according to Thompson [17],
pain (measured on a 100 mm visual analogue scale)
and erythrocyte sedimentation rate (ESR). Mean disease duration, age, sex, educational level and marital
status did not differ between patients with high and
low costs. Rheumatoid factor status (a positive test
result ever vs never a positive test result) also did
not differ between patients with high or lower costs.
Radiological damage, measured in the year over which
costs were reported, also did not differ between patients
with high or lower costs.
The multiple logistic regression model for low vs
VAN JAARSVELD ET AL.: ANNUAL DIRECT COST OF RA IN DUTCH PATIENTS
high costs, using socio-demographic and clinical data,
is shown in Table VI. The model included two predictor
variables. Functional disability correlated best with
costs and was the first predictor in the model. Other
parameters of disease activity were not significant
predictors in addition to functional disability.
Although age does not correlate with cost in Table V,
it was entered as the second parameter in the logistic
model since, after correcting for functional disability,
lower age correlated with higher costs. The parameter
estimates were 1.5939 and −0.0260, respectively.
Therefore, one unit increase in the functional disability
score (which could range from 0 to 3) increased the
log odds for high direct costs by 1.5939; in contrast,
an increase in age by one unit (1 yr) decreased the log
odds for high direct costs by 0.0260. Clearly, the
probability of high costs increased when functional
disability was high. Interestingly, the probability of
high costs increased when age was low, after correction
for functional disability.
DISCUSSION
In this cross-sectional study of 363 Dutch patients
with RA of ∏6 yr duration, we examined the annual
direct costs due to RA. The three central questions of
this study, mentioned in the Introduction, will be
discussed.
What is the estimated annual direct cost per RA
patient?
The mean annual direct cost was Dfl. 11 550 per
patient (i.e. £3680). Medical costs accounted for Dfl.
6198 (55%) and non-medical costs for Dfl. 5352 (45%).
Out of the seven cost categories distinguished, devices
caused the highest cost (33%): an average of Dfl. 3755
per RA patient per year during the first 6 yr of
the disease. Some of these costs were paid by the
patient and some by health insurance companies or
special foundations (in The Netherlands, for example,
the Dutch Arthritis Foundation or ‘Nationaal
Reumafonds’). The costs of some devices are frequently
refunded by this foundation, including expensive
adaptations in the home. Most household appliances
are not refunded. Although many costs are not paid
directly by the patients, the disease still has an impact
on their financial situation. A Dutch study showed
that diabetic and rheumatic patients have the highest
disease-related expenses [18]. In the present study, we
investigated the total direct cost from a societal per-
843
spective, meaning that all direct costs due to RA were
included, irrespective of who actually paid the bills.
The calculated mean direct cost is a rough estimation
and should be interpreted as mean cost at the group
level, instead of mean cost at the individual level, since
the standard deviations of the estimations were large.
We believe that this estimation is representative for the
total population of RA patients with a maximum
disease duration of 6 yr, since our patients were drawn
from a population-based study. All recent-onset RA
patients, attending one of the six rheumatology centres
in the Utrecht region, were asked to participate in the
study on therapeutic strategies. Comparison of sociodemographic and baseline clinical data on patients
who refused to participate with those on participants
revealed no differences. This cost-of-illness study
encompassed data on 86% (363 of 424) of these
patients from the study on therapeutic strategies. For
a study based on information from a self-reporting
questionnaire, this was a high percentage. Selection
bias cannot be completely ruled out, however, especially since a questionnaire on financial aspects could be
interpreted as a violation of privacy by a selected
group of patients.
Comparison of our data with results of other costof-illness studies on RA or other diseases could be
misleading because often the categories of cost and
methods used differ markedly. However, a few links
to other studies can be made, bearing in mind that the
results are not exactly comparable. In a review of
American cost-of-illness studies, the direct cost of RA
was found to average $6000 (i.e. Dfl. 11 800 or £3800)
[3]. In that article, several studies of RA patients with
early as well as prolonged RA were combined, since
no major differences in direct costs were found for
groups with different disease duration. In England, the
total direct cost for all 232 825 RA patients was
estimated to be £604.6 million in 1992 by McIntosh
[4], corresponding to £2597 (or Dfl. 8116) per RA
patient. Our estimate of direct costs for patients with
early RA (0–6 yr) was Dfl. 11 500, indicating that
direct costs are already high in the first few years of
the disease. The total direct cost of illness in The
Netherlands was estimated to be 39.8 billion in 1988
for all diseases [19]. Ranking according to major
disease categories revealed that mental disorders
account for the highest proportion of costs (20%),
followed by disorders of the circulatory system (9%)
and diseases of the digestive system (8%); fourth were
TABLE VI
Multiple logistic regression model for low (∏Dfl. 10 000) vs high (>Dfl. 10 000) total annual direct costs*
Parameter
Estimate ( b)
.. (b)
P
eb (= OR)
95% CI of OR
Disability
Age
Constant
1.5939
−0.0260
−1.4868
0.2092
0.0097
0.5671
0.0000
0.0076
0.0087
4.9228
0.9744
3.27–7.42
0.96–0.99
*Estimate ( b) = regression coefficient; .. ( b) = standard error of regression coefficient; P for the test that b = 0; eb = factor by which the
odds change when the parameter increases by one unit (odds = the ratio of the probability that a person has high costs to the probability that
a person has low costs); 95% CI of OR = 95% confidence interval of odds ratio (= eb ± 1.96 × S.E.(b)).
844
BRITISH JOURNAL OF RHEUMATOLOGY VOL. 37 NO. 8
rheumatic disorders (7%), including RA. The lifetime
medical cost after a cerebral vascular incident is estimated to be Dfl. 78 000 in The Netherlands [20]. The
costs are highest in the first year, Dfl. 28 000, and
lower in subsequent years. In our study, the mean
medical cost was Dfl. 9882 per RA patient in the first
year of the disease.
Is there a trend in direct annual cost with increasing
disease duration?
Since RA is a chronic disease, leading to progressive
disability over the years, we calculated the direct cost
for six groups of patients with increasing disease duration. A longitudinal study, in which a group of patients
is followed for several years, provides the best trend
analyses; however such a study takes years. The present
study was cross-sectional, i.e. data on patients with
different disease duration were compared. In this
manner, one might introduce a ‘cohort bias’, meaning
that the cost for the patients with RA of 5–6 yr
duration will differ from the cost 5 yr later for patients
with <1 yr RA. Such a cohort difference is due to
changes over time in, for example, treatments.
Although this is a known bias, we believe that it will
not be a problem in our study since all patients were
treated according to the protocol. Taking this into
account, we tried to find a possible trend in the costs
over time. Such a trend was not obvious ( Fig. 1).
According to estimations of the mean, the direct costs
appeared to be high in the first 2 yr of the disease. In
the subsequent 2–3 yr, the direct costs due to RA were
lower, but after 4 yr they increased once again. There
was not a statistically significant trend however.
Which socio-demographic or clinical characteristics
separate patients with relatively high costs from
patients with lower costs?
Direct cost due to RA exhibited a skewed distribution ( Fig. 2). Table IV showed that hospitalized
patients also encountered higher ‘other’ medical and
non-medical costs than non-hospitalized patients. For
the majority of patients, namely 75%, the total direct
cost was below Dfl. 10 000 (i.e. £3200); for the other
25%, it was much higher (up to Dfl. 145 000). Patients
with a high cost did not differ in socio-demographic
characteristics, disease duration or rheumatoid factor
test from patients with a cost below Dfl. 10 000. On
the other hand, mean disease activity during the year
was higher for patients with high costs compared to
patients with lower costs ( Table V ). The multiple
logistic regression model was determined by mean
functional disability during the last year and age
( Table VI ). High functional disability and low age
increased the probability of high costs. Relatively
young patients had high expenses specifically for
devices and adaptations in the home. Young patients
might place higher demands on their living standard.
These higher demands are not due to more functional
disability, since the multiple regression model corrected
for functional disability as the first factor in the model.
Functional disability was the best predictor in the
model. Other studies also concluded that functional
disability is a major determinant of costs [3, 21].
Several studies have shown that functional disability
measured by the HAQ or the Dutch version ( VDF ) is
influenced by disease activity [16, 22, 23]. Controlling
disease activity, therefore, seems to be an important
factor in controlling the direct cost due to RA.
A cost-of-illness study in which all costs due to the
disease are included is almost impossible. These studies
therefore have their limitations. Comparison of several
cost-of-illness studies is difficult, since the methods
used differ in most cases. Moreover, differences in
health care systems must be taken into account. Several
assumptions were made in this cost-of-illness study,
three of which are discussed below. First, one item of
the questionnaire was the number of contacts with
health care workers during the past 3 months. We did
not ask about the past 12 months, because one cannot
expect a person to remember exactly the number of
contacts in the course of 12 months. This would
introduce a ‘memory bias’, meaning that patients with
a poor memory cannot give reliable information. The
number of contacts with health care workers in the
past 3 months is multiplied by four to obtain
the number of contacts in 1 yr. Thus, we assumed that
the number of contacts during 3 months reflects the
annual number of contacts. However, the number of
contacts with a health care worker might fluctuate in
a year, since RA is characterized by periods of remission and flare-up. Therefore, in some cases, the number
of contacts during the past 3 months might lead to
overestimation of the annual number and in other
cases to underestimation. This might introduce a bias.
However, since the number of patients in our study is
quite large, it can be assumed that the cases of overestimation will neutralize the cases of underestimation.
Secondly, costs of care facilities and health care
workers were estimated using national data. Tariffs for
care facilities and health care workers exist, but were
not used, since tariffs often deviate from actual costs
and are not specific for RA patients. Our estimations
are also not specific for RA, yet they resemble the
actual costs better than tariffs.
Thirdly, medical management of RA involves frequent monitoring of disease activity, including radiographs and blood studies. In the present study, only
the cost of standard monitoring for side-effects of antirheumatic drugs was included. The cost of monitoring
disease activity was not included as a separate category
since it was already included in the cost of a day spent
in a hospital. The total cost of hospitals used to
estimate the cost of a nursing day includes all costs of
radiographs and blood studies. As a result, the cost of
monitoring disease activity is only included for the few
patients who were hospitalized, whereas all patients
have these costs. However, it would be counted twice
if it were to be included as a separate category. We
only included the cost of monitoring for side-effects in
order to gain information on the magnitude of these
costs. The estimated cost of monitoring is an underestimation of the real cost, since only standard moni-
VAN JAARSVELD ET AL.: ANNUAL DIRECT COST OF RA IN DUTCH PATIENTS
toring was considered; more frequent monitoring can
be expected when side-effects occur.
CONCLUSION
The mean annual direct cost of RA during the first
6 yr of disease is estimated to be Dfl. 11 550 per patient.
A few patients generate very high costs, while 75%
have lower costs (∏Dfl. 10 000). Almost one-third of
the total represents the costs of devices and adaptations
in the home. Like disease course and treatment effects,
direct costs also show huge variability between patients.
The aggregated results of such a heterogeneous group
are of limited value for decision making. However, our
results indicate that direct costs are already high in the
very first years of the disease, and these costs correlate
best with functional disability. Therefore, early control
of disease activity might be an important factor in
diminishing the direct costs of RA for both patients
and society.
A
The authors thank G. A. van Albada-Kuipers,
A. A. M. Blaauw, C. van Booma-Frankfort, E. J. ter
Borg, H. L. M. Brus, D. M. Hofman, A. A. Kruize,
Y. Schenk and M. J. van der Veen, rheumatologists of
the departments of rheumatology of University
Hospital Utrecht, Sint Antonius Hospital Nieuwegein,
Diakonessen Hospital Utrecht, Eemland Hospital
Amersfoort, Hospital Hilversum and Sint Jansdal
Hospital Harderwijk, The Netherlands, for their contributions to this paper. Supported by a grant from the
Dutch League against Rheumatism (Het Nationaal
Reumafonds).
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BRITISH JOURNAL OF RHEUMATOLOGY VOL. 37 NO. 8
APPENDIX 1
Mean number of contacts and cost of health care workers
Patients with
at least
1 contact
Care worker
n
(%)
Mean contacts
(by n patients)
in 3 months
Mean contacts
for total group
in 3 months (Dfl.)
Cost per
contact
(Dfl.)
Annual cost
per patient
(Dfl.)*
Annual cost
363 patients
(Dfl.)*
Primary health care
General practitioner
Physiotherapist
Occupational therapist
67
87
36
(19)
(24)
(10)
4 (n = 67)
13 (n = 87)
5 (n = 36)
0.7
3.1
0.5
39.50†
53
53
113
666
101
40 900
241 900
36 700
Hospital care
Rheumatologist
Rheumatology nurse
Rehabilitation doctor
326
91
3
(90)
(25)
(1)
2 (n = 326)
2 (n = 91)
1 (n = 3)
1.8
0.5
0.01
81
75
81
580
162
4
210 000
58 800
1300
Other
Home help
Company doctor
Personnel officer
District nurse
Social worker
Priest
Psychologist
Other
49
16
12
8
7
3
1
42
(14)
(4)
(3)
(2)
(2)
(1)
(0.3)
(12)
15 (n = 49)
2 (n = 16)
1.5 (n = 12)
30 (n = 8)
2 (n = 7)
2 (n = 3)
3 (n = 1)
3 (n = 42)
2.0
0.9
0.1
0.7
0.4
0.03
0.01
0.3
30
81
81
30
30
81
81
81
244
30
18
80
4
9
3
108
88 700
11 000
6500
29 000
1600
3200
1000
39 200
Total
341
(94)
2122
769 800
11
*Obtained by multiplying the mean number of contacts presented in this table with the cost per contact; the total annual cost may be
slightly different from the cost presented in the table, since the calculations were completed to the second decimal place.
†Method of estimation of cost of one contact with health care workers:
Total cost (million)
Medical specialist
General practitioner
Number of contacts (million)
Dfl. 2216.7
Dfl. 2260.9
27.5
57.2
Total cost (million)
Physiotherapist
Social worker
Cost per contact
Dfl. 81
Dfl. 39.50
Number of workers
Cost per h‡
11 384
53 808
Dfl. 53
Dfl. 30
Dfl. 1264
Dfl. 3312
‡Total working hours per health care worker = 52 weeks × 40 h a week = 2080 h a year.
Data from 1995 [8, 10].
APPENDIX 2
Cost of medication (summary of most frequently used medication according to the study population)
Medication
Standard dose
Slow-acting anti-rheumatic drugs
Methotrexate (LedertrexateA) (oral )
Sulphasalazine (SalazopyrineA)
Hydroxychloroquine (PlaquenilA)
Cyclophosphamide ( EndoxanA)
Methotrexate (LedertrexateA) (parenteral )
Aurothioglucose (AuromyoseA)
-Penicillamine ( KelatinA)
Azathioprine (ImuranA)
Auranofin (RidauraA)
7.5 mg weekly
2000 mg daily
400 mg daily
150 mg daily
7.5 mg weekly
50 mg weekly
500 mg daily
150 mg daily
6 mg daily
Non-steroidal anti-inflammatory drugs†
Corticosteroids
Prednisolone (oral )
Triamcinolone (oral )
Intra-articular corticosteroids (triamcinolone)
Pulse i.v. or i.m. corticosteroids
Standard daily dose
10 mg daily
8 mg daily
1 injection
3 × 200 mg
Standard cost per
month (Dfl.)*
10.50
31.30
36.00
38.30
40.00
75.10
80.80
105.80
125.70
41.00
4.90
16.50
35.00 per injection
495.00 per pulse therapy
VAN JAARSVELD ET AL.: ANNUAL DIRECT COST OF RA IN DUTCH PATIENTS
847
APPENDIX 2 (continued )
Medication
Standard dose
Standard cost per
month (Dfl.)*
Simple analgesics
Acetylsalicylic acid (AcetosalA)
Acetylsalicylic acid (AcetosalA)
Paracetamol/codeine 500/10 mg
Paracetamol/codeine 500/20 mg
Codeine
Dextropropoxyphene (Depronal RetardA)
Paracetamol
Tramadol ( TramalA)
200 mg daily
1500 mg daily
4 caps daily
4 caps daily
120 mg daily
300 mg daily
2000 mg daily
300 mg daily
7.20
11.40
12.77
16.80
29.30
43.80
80.40
142.80
Antacids
Ranitidine (ZantacA)
Cimetidine (TagametA)
Omeprazole (LosecA)
Metoclopramide (PrimperanA)
Cytotec (MisoprostolA)
300 mg daily
800 mg daily
20 mg daily
30 mg daily
400 mg daily
102.00
104.00
139.70
36.80
64.20
Vitamins/minerals
Thiamine (vitamin B )
1
Ferrofumarate (FerumatA)
Pyridoxine (vitamin B )
6
Folic acid (vitamin B )
11
Ferrosulphate (Fero gradumetA)
Calcitriole (vitamin D)
Calcium supplementation (Calcium-SandozA Forte)
Ascorbic acid (vitamin C )
50 mg daily
200 mg daily
160 mg daily
0.5 mg daily
200 mg daily
10 tablets
500 mg daily
500 mg daily
1.80
3.00
3.40
4.70
10.40
18.30
20.21
65.70
*When a double dose is used, the cost per month is doubled.
†Monthly cost of all NSAIDs (standard daily doses) used by patients in this study ranged from Dfl. 38.00 to Dfl. 49.50. A mean cost of
Dfl. 41.00 for standard daily doses was used for the calculation.
APPENDIX 3
Cost of standard monitoring for side-effects of SAARD and NSAID
Medication
-Penicillamine
-Penicillamine + NSAID
Auranofin
Auranofin + NSAID
Hydroxychloroquine
Hydroxychloroquine + NSAID
Sulphasalazine
Sulphasalazine + NSAID
Azathioprine
Azathioprine + NSAID
Methotrexate
Methotrexate + NSAID
Aurothioglucose
Aurothioglucose + NSAID
NSAID
Monitoring*
Cost first
year (Dfl.)
Cost following
year (Dfl.)
1† + 2†
1† + 2† + 3 + 4
1† + 2†
1† + 2† + 3 + 4
6 (start/every year)
6 (start/every year) + 3 + 4
5 (every 6 months) + 1†
5 (every 6 months) + 1† + 3 + 4
1† + 3†
1† + 3† + 4
1† + 3† + 5 (every 6 months) + 7 (start)
1† + 3† + 4 + 5 (every 6 months) + 7 (start)
1 + 2 (before every injection)
1 + 2 (before every injection) + 3 + 4
3+4
110.00
253.00
110.00
253.00
81.00
224.00
120.00
263.00
233.00
269.00
382.00
416.00
951.00
1092.00
35.70
73.00
216.00
73.00
216.00
81.00
224.00
97.00
240.00
156.00
192.00
206.00
240.00
951.00
1092.00
35.70
*Standardized monitoring schedule at University Hospital Utrecht for patients taking the medication [11].
Frequency of monitoring is every 3 months, unless stated otherwise.
†First 3 months: every month, after that every 3 months.
1 = Blood cell count: haemoglobin, white blood cell count (including differential cell ), platelet count (Dfl. 11.50).
2 = Urine for protein (quantitative) (Dfl. 6.80).
3 = Serum transaminases: ASAT (aspartate aminotransferase), ALAT (alanine aminotransferase) (Dfl. 27.20).
4 = Serum creatinine (Dfl. 8.50).
5 = Serum folic acid (Dfl. 25.00).
6 = Ophthalmologic examination (= consultation with a medical specialist: Dfl. 81.00).
7 = X-ray chest (Dfl. 48.30) and lung function test (CO diffusion) (Dfl. 50.00).