Introduction

Admission to hospital for treatment of active rheumatoid arthritis has been shown in controlled trials to be more effective than intensive outpatient care.^1-4 The information available, however, is insufficient to assess whether inpatient care is more cost effective than management strategies that use outpatient or day care.

In an earlier pilot study we showed that day care, which preserves the benefits of multidisciplinary care, is acceptable to patients and might be less costly than inpatient care.⁵ The study was too small to draw firm conclusions regarding differences in clinical outcome, but the results suggested that day care did not compromise outcome.

Using a randomised controlled clinical trial with an integrated cost minimisation economic evaluation, we tested the hypothesis that inpatient and day care management of patients with uncomplicated active rheumatoid arthritis are clinically equivalent and that the resources needed are equivalent.

	Subjects and methods

Subjects
A total of 118 consecutive patients attending the rheumatic diseases unit, for whom admission for management of active rheumatoid arthritis was indicated, were randomised to either day care or inpatient care. The basic criterion for admission was active rheumatoid arthritis, defined as deteriorating functional status, active synovitis, the need for review of second line drug regimen, and the need for physical or psychological treatment.

Patient management protocols
Multidisciplinary care and medication were left to the discretion of the attending doctor. Whereas inpatients were treated during one continuous episode until discharge, day patients received treatent in hospital between 10 am and 4 pm, interspersed with periods at home, where they followed prescribed treatment. Patients were assessed twice each week, and treatment ended when there was no further clinical improvement. The intensity of hospital based and primary care intervention was recorded. If subsequently there was relapse of disease requiring admission, the patient remained in his or her original group and resumed treatment. At the conclusion of the study all patients were requested to state whether they would prefer day care or inpatient care for future flares of active rheumatoid arthritis.

Clinical assessments
Disability, measured with the modified health assessment questionnaire,⁷ the Ritchie index,⁸ and erythrocyte sedimentation rate (Westergren method); psychological status, measured with the hospital anxiety and depression scale⁹; and Steinbrocker functional class¹⁰ were recorded on admission, discharge, and 12 month follow up. Secondary outcome measures were health utility, measured using the method of time trade off¹¹ and the quality of well being scale.¹²

Economic assessments
Costs were measured from the perspective of the health service and the patient. They comprised the direct costs of hospital based and community care intervention, transport costs, and the indirect costs incurred by patients involving forgone production as measured by cost of wages.⁵ A unit cost per day was calculated for each group; this consisted of patient care costs (salaries, medication and investigations), patient services (catering, laundry), overheads (energy consumption, capital charge, maintenance), and opportunity cost. The total hospital cost was then derived by multiplying the number of days of hospital treatment by the appropriate unit cost. Community costs consisted of costs of attending the general practitioner's surgery, practice or district nursing, and paramedical services; for social support and domestic help; and for drugs not supplied on prescription. Transport details, including distance from home to hospital and to the surgery, number of journeys made, and method of travelling were recorded. Costs were based on total distance by ambulance car. Use of resources in the community and changes in employment status reported by the patient were verified by interviewing all patients. Primary care records were checked on a random sample of 10 patients in each group.

Statistical and economic analysis
To test clinical equivalence, the largest acceptable clinical differences in outcome between groups were chosen as >0.25 points on the health assessment questionnaire (the main outcome measure), >20 mm/h difference in erythrocyte sedimentation rate, or >3 points on either the anxiety or depression scale of the hospital anxiety and depression scale. A total sample size of 105 patients was required to detect this difference in the health assessment questionnaire, between unpaired groups, with a power of 90% at the P<0.05 level (two tailed test).

	Results

Analysis of admissions
Between May 1993 and January 1995, 557 rheumatology outpatients who required admission to hospital and were screened for the study. Of the 200 patients with active rheumatoid arthritis, 118 satisfied the entry criteria and were randomised to receive day care (59 patients) or inpatient care (59 patients). Sixty patients were unable to travel and 22 had medical complications. In each group, 51 patients completed the trial and eight were lost to follow up. During the study 11 day patients transferred to inpatient care, five owing to travelling difficulties, two for clinical reasons, two for domestic reasons, and two out of preference. Two inpatients requested day patient care and were transferred. The groups did not differ significantly in the baseline clinical and socioeconomic characteristics (table 1).

Clinical evaluation
On admission the erythrocyte sedimentation rate, Ritchie index, and hospital anxiety and depression scale scores were similar in the two groups, but day patients were slightly more disabled on the health assessment questionnaire score (P=0.04, unpaired t test) (table 3). The erythrocyte sedimentation rate, health assessment questionnaire, and Ritchie index scores differed significantly over time (P<0.0001, analysis of variance) but did not differ significantly between inpatients and day patients. Substantial improvement in disability (health assessment questionnaire), joint score (Ritchie index) and erythrocyte sedimentation rate were seen in both day patients and inpatients between admission and discharge (P<0.0001, analysis of variance). Although small differences were observed in hospital anxiety and depression scale depression scores, these were not considered to be of clinical importance. During follow up after discharge from hospital, the health assessment questionnaire and Ritchie index scores deteriorated significantly in both groups (P<0.0001, analysis of variance), but the erythrocyte sedimentation rate and the hospital anxiety and depression scale score did not (P>0.5). The difference in health assessment questionnaire and Ritchie index remained highly significant after baseline variables were included as covariates in the models (table 3). Thus the groups showed equivalent clinical improvement with the initial hospital treatment and similar deterioration over the next year.

Economic evaluation
The mean hospital cost per patient for day care, £798 (95% confidence interval £705 to £888), was lower than for inpatient care, £1253 (£1155 to £1370), but this difference was offset by higher community, travel and readmission costs. The difference in total cost per patient between day care and inpatient care was therefore small (£1789 (£1539 to £2027) v £2021 (£1834 to £2230)) (table 4).

	Discussion

This study has shown that the clinical outcome of day care for patients with active rheumatoid arthritis is equivalent to that of inpatient care, but there is a small reduction in resource cost. This finding may be relevant to other medical specialties in which day care is a possibility.

Several randomised studies have confirmed the clinical benefit of multidisciplinary inpatient care for active rheumatoid arthritis,^1-3 which was suggested by earlier unrandomised studies.⁴ However, the cost of such treatment has restricted its application, and more cost effective strategies have been sought. Three studies that compared inpatient care with outpatient care concluded that inpatient care gave the better clinical outcome.^2-4 Only one randomised study included a complete economic evaluation, and it found that inpatient care was more cost effective than outpatient care.³

In Canada a randomised controlled trial comparing inpatient with day care for active rheumatoid arthritis used similar inclusion criteria to our own study.²¹ As in our study, functional outcomes were not significantly different between the groups at discharge.

Duration of benefit
There is conflicting evidence regarding the duration of benefit after intensive medical intervention for active rheumatoid arthritis. Our study and most others suggest that improvement is short term. This may reflect inadequate outpatient care rather than a shortcoming of the initial intervention. Nevertheless, for the expenditure on intensive intervention to be economically and clinically worthwhile it is crucial that benefits are maintained for as long as possible. Guidelines on the management of rheumatoid arthritis have been published recently, and these emphasise the importance of regular, long term follow up. ^{22 23} Although implementing these recommendations may require additional resources, failure to preserve the benefits of intensive intervention may also carry heavy financial penalties in terms of greater subsequent demand for health care, particularly orthopaedic surgery, earlier loss of independence, and loss of productivity. Further controlled trials are needed to test the effectiveness of these recommendations.

Financial considerations
Financial rather than clinical considerations have driven many of the recent changes in the delivery of health care in Britain, and it is appropriate to consider whether the benefits of inpatient treatment for active rheumatoid arthritis could be achieved in a more cost effective way.²⁴ This study shows that day care is only slightly more cost effective than inpatient care. It is also uncertain whether the potential savings from implementing a day care facility and freeing beds would be realised in practice; a day patient unit would probably generate additional workload and the spare inpatient capacity would be redeployed.