General Practice

Randomised controlled trial comparing hospital at home care with inpatient hospital care. II: cost minimisation analysis

BMJ 1998; 316 doi: http://dx.doi.org/10.1136/bmj.316.7147.1791 (Published 13 June 1998) Cite this as: BMJ 1998;316:1791
  1. Sasha Shepperd (Sasha.Shepperd{at}dphpc.ox.ac.uk), research officera,
  2. Diana Harwood, lecturer in medical statisticsb,
  3. Alastair Gray, directorc,
  4. Martin Vessey, professor of public health and head of departmenta,
  5. Patrick Morgan, consultant in public health medicined
  1. aDivision of Public Health and Primary Health Care, University of Oxford, Institute of Health Sciences, Headington, Oxford OX3 7LF,
  2. bHealth Services Research Unit, Division of Public Health and Primary Health Care, University of Oxford, Institute of Health Sciences,
  3. cHealth Economics Research Centre, Division of Public Health and Primary Health Care, University of Oxford, Institute of Health Sciences,
  4. dNorthamptonshire Health Authority, Northampton NN1 5DN
  1. Correspondence to: Sasha Shepperd
  • Accepted 15 April 1998

Abstract

Objectives:To examine the cost of providing hospital at home in place of some forms of inpatient hospital care.

Design: Cost minimisation study within a randomised controlled trial.

Setting: District general hospital and catchment area of neighbouring community trust.

Subjects: Patients recovering from hip replacement (n=86), knee replacement (n=86), and hysterectomy (n=238); elderly medical patients (n=96); and patients with chronic obstructive airways disease (n=32).

Interventions: Hospital at home or inpatient hospital care.

Main outcome measures: Cost of hospital at home scheme to health service, to general practitioners, and to patients and their families compared with hospital care.

Results: No difference was detected in total healthcare costs between hospital at home and hospital care for patients recovering from a hip or knee replacement, or elderly medical patients. Hospital at home significantly increased healthcare costs for patients recovering from a hysterectomy (ratio of geometrical means 1.15, 95% confidence interval 1.04 to 1.29, P=0.009) and for those with chronic obstructive airways disease (Mann-Whitney U test, P=0.01). Hospital at home significantly increased general practitioners' costs for elderly medical patients (Mann-Whitney U test, P<0.01) and for those with chronic obstructive airways disease (P=0.02). Patient and carer expenditure made up a small proportion of total costs.

Conclusion: Hospital at home care did not reduce total healthcare costs for the conditions studied in this trial, and costs were significantly increased for patients recovering from a hysterectomy and those with chronic obstructive airways disease. There was some evidence that costs were shifted to primary care for elderly medical patients and those with chronic obstructive airways disease.

Key messages

  • Hospital at home schemes are a popular alternative to standard hospital care, but there is uncertainty about their cost effectiveness

  • In our randomised controlled trial we compared the cost of hospital at home care with that of inpatient hospital care for patients recovering from hip replacement, knee replacement, and hysterectomy; elderly medical patients; and those with chronic obstructive airways disease

  • There were no major differences in health service costs between the two arms of the trial for patients recovering from hip or knee replacement and elderly medical patients

  • Hospital at home care increased healthcare costs for patients recovering from hysterectomy and for those with chronic obstructive airways disease

  • Hospital at home care resulted in some costs shifting to general practitioners for elderly medical patients and those with chronic obstructive airways disease

Editorial by IliffeGeneral practice p 1686, 1696, 1802

Introduction

There is little evidence to justify the widespread adoption of hospital at home on the basis of cost. A review of the subject identified only one randomised controlled trial that compared the cost of hospital at home with inpatient hospital care.1This trial, based in the United States, recruited patients with a terminal illness and found no difference in overall healthcare costs.2 There is conflicting evidence from non-randomised studies. 3 4

We report the results of a prospective economic evaluation, in the context of a randomised controlled trial, of the cost of providing hospital at home as a substitute for some forms of inpatient hospital care. The three questions addressed by the economic evaluation were

  • Does substituting hospital at home care for hospital care result in a lower cost to the health service?

  • Does hospital at home care, compared to hospital care, increase the cost to general practitioners?

  • Does hospital at home care increase the cost borne by the patients and their families compared with hospital care?

Method

We describe patient recruitment and randomisation in our accompanying paper.5 This economic evaluation took the form of a cost minimisation analysis, as the health outcomes of the two arms of the trial did not differ. Our primary interest was the cost to the health service, but we also examined the costs incurred by patients and families, as they could influence the acceptability of a hospital at home scheme.

We recruited five groups of patients: patients recovering from a hip replacement, a knee replacement, or a hysterectomy; patients with chronic obstructive airways disease; and elderly patients with a mix of medical conditions. All patients were aged 60 years or over, except those recovering from a hysterectomy, who were aged 20-70 years.

Data collection

The box lists the uses of health service resources on which data were collected. We obtained cost data for hospital care and hospital at home care from the respective trusts' finance departments for the financial year 1994-5, apportioned on the basis of activity for 1993-4. Details of the unit costs are available from the authors.

Uses of health service resources that were recorded for cost minimisation analysis

Hospital care

  • Number of inpatient days

  • Number of inpatient days due to a hospital readmission related to the trial diagnosis

  • Medication

Hospital at home care

  • Number of hospital at home days

  • Number of hospital at home visits (including duration of visit and grading of staff)

  • Medication

Hospital transport

  • Number of journeys made by ambulance or a health service car

General practitioner visits

  • Number of visits to doctor's surgery

  • Number of home visits

Hospital costs

The cost of hospital care included staffing costs, all non-staff running costs, and capital costs. Patient dependency scores were developed by hospital nursing and medical staff to reflect the marginal costs incurred during a patient's episode of hospital care (and hence the marginal savings of early discharge). 3 6 These scores were used to weight the costs for each day that a patient was in hospital. The costs of physiotherapy and occupational therapy were calculated according to the amount of time spent with a typical patient for each clinical group, and included a cost for non-contact time. Equipment costs (based on ward records), the cost of items not directly related to levels of patient care, and capital charges for land and buildings (based on valuation and including interest and depreciation) were divided by the number of ward bed days for the year 1994-5 to arrive at a charge per bed day. The cost of prescribed drugs was obtained from the hospital pharmacy department.

The time profile for costing hospital care differed for each clinical group. The costs for surgical patients excluded the costs of the operation, as these costs do not alter with different rehabilitative care. For patients having a hip or knee replacement, costs were calculated from the fourth postoperative day. For patients having a hysterectomy, costs were calculated from the first postoperative day. Cost data for medical patients were collected for the duration of their hospital stay.

Hospital at home costs

The cost of hospital at home care included all staffing and non-staff running costs. The costs of nurses, physiotherapists, and occupational therapists were based on the amount of time spent with patients, and included a cost for non-contact time. The following non-staff costs were included: central administration, travel, training, telephones and pagers, equipment, and office space. Medical supplies and equipment costs were depreciated over a 10 year period with a discount rate of 6%.7 These costs were apportioned on an equal basis to each patient receiving hospital at home care, assuming costs were payable in advance at the start of the year. Administration and travel costs were apportioned according to the volume of patients. The cost of prescribed drugs was obtained from the hospital's pharmacy department.

General practitioner costs

Research nurses visited each practice to record the number of general practitioners' home visits and number of patients' visits to the surgery. The community trust providing the hospital at home care reimbursed general practitioners visiting hospital at home patients at a rate of £100 per patient and £25 for each visit. General practitioner costs for the hospital care group were calculated with unit costs developed by the Personal Social Services Research Unit, Kent.8

Carer costs

Carers were asked to record all expenditures related to the trial diagnosis (including equipment and adaptations, consumables, and travel) in a diary for one month, and any loss of earnings and days off work due to caring for their patient. Carers were also asked to record the number of hours a day they spent caring for the patient.

Statistical analysis

We describe the sample size calculations in our accompanying paper.5 Analysis was done on an intention to treat basis. When appropriate, data with non-normal distribution was log transformed before further parametric analysis was done. The Mann-Whitney U test was used for continuous variables that did not approximate a normal distribution after log transformation.

Sensitivity analyses were conducted for areas that could possibly restrict the generalisability of the trial results. These were the trial rate of reimbursing general practitioners, patients' duration of hospital at home care observed in the trial, and the use of average costs per inpatient day instead of dependency adjusted hospital costs.

Results

Results are presented by clinical condition for both arms of the trial. Inpatient hospital care and hospital at home care accounted for most of the healthcare costs. Tables Table 1, Table 2, and Table 3 show health service resources and costs for each patient group.

Early discharge of patients after elective surgery

Patients allocated to hospital at home care after a hip or knee replacement or a hysterectomy spent significantly fewer days in hospital (tables Table 1 and Table 2). However, they received significantly more days of health care with the addition of hospital at home. For patients recovering from a hip or knee replacement, the total costs to the health service were not significantly different between the two groups. For patients recovering from a hysterectomy, total health service costs were significantly higher for those allocated to hospital at home care. Of the total numbers of patients undergoing these procedures during the study period, we recruited about 20% of all those having hip replacements, 25% of those having knee replacements, and 35% of those undergoing hysterectomy.

Table 1.

Health service resources and costs consumed at 3 months after hospital admission by patients allocated to hospital at home care or inpatient hospital care: orthopaedic patients recovering from hip or knee replacement

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Table 2.

Health service resources and costs consumed at 3 months after hospital admission by patients allocated to hospital at home care or inpatient hospital care: patients recovering from hysterectomy

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Elderly medical patients and patients with chronic obstructive airways disease

No significant difference was detected between the two groups of elderly medical patients in the number of days spent in hospital, but, with the addition of hospital at home care, the total days of health care for the hospital at home group was significantly higher (table Table 3). Patients with chronic obstructive airways disease in the hospital at home group spent significantly fewer days in hospital, but this reduction was offset by the time spent in hospital at home care so there was no significant difference between the two groups for the total days of health care (table Table 3). For elderly medical patients, total costs to the health service were not significantly different between the two groups. Patients with chronic obstructive airways disease allocated to hospital at home care incurred significantly greater healthcare costs than did those receiving only hospital care. About 1% of all patients admitted for medical conditions during the study period were recruited to either the elderly medical or chronic obstructive airways disease groups. Nineteen of these patients were recruited by general practitioners, of whom nine were allocated to hospital care. However, only two of these patients received acute hospital care.

Table 3.

Health service resources and costs consumed at 3 months after hospital admission by patients allocated to hospital at home care or inpatient hospital care: elderly medical patients and patients with chronic obstructive airways disease

View this table:
Table 4.

Sensitivity analysis: comparing costs of hospital care, dependency adjusted costs and average costs, with costs of hospital at home care after reducing lengths of stay by one or two days

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General practitioner costs

For patients discharged early after elective surgery, no significant differences in general practitioner costs were detected between the two groups. However, for elderly medical patients and those with chronic obstructive airways disease, the costs of general practitioner services were significantly higher for the patients allocated to hospital at home care compared with those in the hospital groups.

Costs to patients and carers

Patients' and carers' expenses made up a small proportion of total costs. There were no significant differences between the two groups for any of the categories of patients, and inclusion of these costs did not alter the results. The median cost for all patient groups was £0. The greatest expense was incurred by patients with chronic obstructive airways disease: median cost for the hospital at home group was £0 (interquartile range £0-£19.8) and for the hospital group was £0 (£0-£0). There were no significant differences between the two groups of carers in the time spent caring for the patient, although this was a substantial element in both groups. Few carers reported loss of earnings from caring for the patient, as most of the carers were retired. Further details of these costs will be published elsewhere.

Sensitivity analysis

Table Table 4 shows the results of the sensitivity analyses. Reducing length of stay in hospital at home care changed the difference in total healthcare costs for patients recovering from a hysterectomy and for those with chronic obstructive airways disease. A one day reduction eliminated the difference in cost for patients recovering from a hysterectomy, while a two day reduction altered the results so that hospital at home care became significantly less costly than hospital care for these patients. Costs remained significantly more expensive for patients with chronic obstructive airways disease when duration of hospital at home care was reduced by one day, but a reduction of two days resulted in a non-significant difference between the two groups.

Using average hospital costs instead of dependency adjusted costs reduced the difference in cost between hospital at home care and hospital care for all groups of patients except for the elderly medical patients. Using standard general practitioner costs8 for both arms of the trial altered the results only for patients recovering from a hip replacement, and general practitioner costs for these patients became significantly more expensive (Mann-Whitney U test P=0.03).

Discussion

Many believe that hospital at home schemes will contain healthcare costs by reducing the demand for acute hospital beds. Our findings indicate that this is not the case. Instead, hospital at home care increased health service costs for some groups of patients, while for others there were no net differences in costs. This is perhaps not surprising, as patients who were discharged early to hospital at home care went home when their hospital care was least expensive. Once in hospital at home care some patients, particularly elderly patients with a medical condition, required 24 hour care. Furthermore, hospital at home increased the overall duration of an episode of health care. This pattern has been observed elsewhere.4 It may be possible to decrease the amount of time patients spend in hospital at home, and thus reduce cost. However, this could have an adverse effect on patient outcomes. For elderly medical patients and those with chronic obstructive airways disease, hospital at home care increased general practitioner costs, providing evidence that some costs were shifted within the health service.

Perhaps surprisingly for a service that is intended to reduce the pressure on acute hospital beds, the proportion of patients eligible for hospital at home care was low. Other evaluations have also described a relatively low volume of eligible patients. 2 4 9 10 1112 This contrasts with the numbers described by some service providers (Harrison V, Intermediate Care Conference, Anglia and Oxford NHS Executive, Milton Keynes, October, 1997). An increased volume of patients would not, however, alter the costs substantially as only a small proportion of hospital at home costs are fixed. It is possible that patients who would otherwise agree to use hospital at home are deterred by an evaluation. An alternative explanation may be that hospital at home provides extra care in the community but not necessarily care that would otherwise be carried out in a hospital setting.

Just as inappropriate admissions are a problem for acute hospitals, there is no reason to believe they do not pose a problem for services such as hospital at home. We found that some patients allocated to hospital care were never admitted to hospital and stayed at home with no extra services. This has been found elsewhere (A Wilson, personal communication) and suggests that hospital at home schemes could potentially provide care to patients who would otherwise not be receiving healthcare services. Alternatively, hospital at home may be viewed as supplementing existing services, which may be an acceptable policy option for some groups of patients, particularly elderly medical patients who prefer this form of care.

The extent to which hospital at home care can substitute for hospital care in the United Kingdom is limited. This can partly be explained by the speed at which hospital at home schemes have been set up. Purchasers and providers have responded quickly to initiatives, usually supported by “ring fenced” monies, designed to ease the pressure on hospital beds. Schemes have usually been grafted onto primary care services, with minor alterations to the mix of skills already available. They may become out of date with changes in hospital practice. This is a particular problem for schemes admitting patients who are discharged early from hospital. As hospital lengths of stay decrease, the number of days that can be transferred into the community is correspondingly reduced.

Conclusions

The results of this trial suggest that simply shifting services from one location to another is unlikely to reduce health service costs. Patients discharged early after elective surgery go home at a time when they use least resources. When an inpatient stay involves relatively high nursing costs, as with elderly medical patients, early discharge to hospital at home is unlikely to be significantly cheaper than hospital based care as most of these nursing costs still have to be incurred. Hospital at home care may be cost effective for patients who are relatively independent but who require technical support, such as those receiving intravenous antimicrobial therapy. However, there is little evidence to support or refute this.13 Service developments, as much as clinical interventions, need to be evidence based. Arguments for diverting resources away from hospital beds should be viewed in the light of the available evidence.

Acknowledgments

We thank the Rockingham Forest NHS Trust, Kettering General Hospital NHS Trust, Northamptonshire Health Authority, and local general practitioners for supporting this research. We also thank Jean Pugh and Angela Howe for their diligent work as research nurses, Helen Doll for statistical advice, and Dr Henry McQuay and Dr J A Muir Gray for their support during the planning of this trial.

Contributors: SS defined the research question, collaborated in designing the trial, coordinated the trial, analysed the data, and was the principal writer of the paper. DH contributed to the running of the trial, maintained the databases, and helped with writing the paper. AG discussed core ideas and participated in analysing and interpreting the data and writing the paper. MV collaborated in designing the trial, solving problems that occurred during the trial, and writing the paper. PM assisted with the study design, implementing the trial, and writing the results. SS is guarantor for the paper.

Funding: R&D Programme NHS Executive Anglia and Oxford and the National R&D Programme, Primary Secondary Care Interface, NHS Executive North Thames.

Conflict of interest: None.

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