Making the case for insulin pump therapy

Transcription

1 T Ulahannan*, NN Myint, KF Lonnen Introduction Previously used economic models of continuous subcutaneous insulin infusion (CSII/insulin pump therapy) projected long-term costs and outcomes compared to multiple daily injections (MDIs) in patients with type 1 diabetes. 1 4 These models have used a variety of simulation techniques to estimate the long-term incidence and progression of diabetes-related complications. Typical measures have included quality adjusted life expectancy (QALE), incremental cost-effectiveness ratio (ICER) and quality-adjusted life year (QALY). 5 A common assumption is that improvements in glycaemic control associated with CSII 6 8 lead to improved QALE by reduced incidence of diabetes-related complications. 9 An ICER of per QALY gained is considered to represent good value for money by current standards in the UK. However, the local population and clinical conditions in which a pump service operates may differ significantly from those assumed in the models, or cost savings from avoidance of complications of diabetes may take years to realise. Demonstrating short-term benefits to the local health care system provides a powerful argument in favour of the provision of pump therapy. In addition, front line clinicians and managers may not always be familiar with the calculation and subtleties of economic modelling and measures such as QALE, ICER and QALY. As an alternative to economic models, we directly monitored the effects of CSII introduction on relevant and important health care usage using the NHS national tariffs 1 in a single district ABSTRACT It is assumed in economic models that insulin pump therapy produces long-term reductions in complications which offset the short-term costs. It is not always apparent that there may also be short-term resource benefits of relevance to a local health community. We retrospectively observed patients use of primary and secondary care health services before and after initiation of insulin pump therapy in our locality. Data on emergency admissions, outpatient appointments, HbA1c, lipids, weight and blood pressure were collected on 34 patients, up to five years before and five years after insulin pump therapy was commenced. Data regarding primary care contacts were also available for 17 patients for a period of two years before and after initiation of pump therapy. Significant reductions in consultant hospital diabetes outpatient visits (.2 vs.11 appointments per month, p<.1), reductions in hospital admissions (.3 vs admissions per month, p<.2), and similar reductions in total primary care contacts, following initiation of pump therapy were demonstrated. We estimated that these reductions in service use for 1 pump patients equate to per year at current NHS tariffs. Clinical measures of HbA1c (8.84 vs 7.62%, p<.1) and total cholesterol (5.12 vs 4.45mmol/L, p<.1) also showed improvement after insulin pump therapy. By showing benefits on health service utilisation in the short term, to both primary and secondary care, we have strengthened the local case for supporting insulin pump therapy in our service. The calculation of total annual saving per 1 patients treated is an easily understood representation of cost savings which can be set against treatment costs. The methods used could be of value to other diabetes departments considering starting a pump service or wishing to evaluate their current provision. Copyright 27 John Wiley & Sons. Practical Diabetes Int 27; 24(5): KEY WORDS insulin pump therapy; cost savings; NHS national tariff prices general hospital and local primary care practices. Patients and methods Secondary care Patients commencing CSII over a five-year period, between June 2 and June 25 inclusive, were seen in a single district general hospital by one pump team, consisting of a consultant physician, diabetes dietitian and diabetes specialist nurse. Patients were selected for CSII according to National Institute for Health and Clinical Excellence (NICE) criteria 11 after these were available. Prior to NICE guidance, patients with type 2 diabetes were not excluded from consideration. All patients received intensive general diabetes education and carbohydrate counting training, initially on a one-to-one basis, and latterly using the REACCT (Re-Education And Carbohydrate Counting Training) programme. 12 Suitability for a trial on pump therapy was decided jointly by the pump team if stable glucose control was not achieved despite intensive education and use of basal-bolus insulin regimens including insulin analogues where applicable. Patients not willing to comply with recommendations were not considered further for Thomas Ulahannan, BSc, FRCP, Consultant Physician Nyo Nyo Myint, MBBS, Clinical Observer Kathryn F Lonnen, MRCP, Specialist Registrar Department of Diabetes and Endocrinology, Gloucestershire Royal Hospital, Gloucester, UK *Correspondence to: Dr Thomas Ulahannan, FRCP, Consultant Physician, Department of Diabetes and Endocrinology, Gloucestershire Royal Hospital, Great Western Road, Gloucester GL1 3NN; thomas.ulahannan@glos.nhs.uk Received: 13 February 27 Accepted in revised form: 2 April Pract Diab Int June 27 Vol. 24 No. 5 Copyright 27 John Wiley & Sons

2 Table 1. Clinical variables of patients before and after pump initiation. (Data presented as means ± standard deviation) Clinical variable p-value HbA1c (%) 8.8± ±.8 <.1 Total cholesterol (mmol/l) 5.1±.8 4.4±.8 <.1 HDL cholesterol (mmol/l) 1.5±.3 1.3±.4.17 Weight (kg) 73.7± ± Systolic blood pressure (mmhg) 134.8± ± Diastolic blood pressure (mmhg) 77.3± ± pump therapy. After three months, patients were reassessed and, if it was agreed by the pump team that the therapy was of benefit to the patients, they remained under the care of the same specialist team for pump therapy. Health care resource utilisations before and after CSII initiation were compared. Data were collected for a maximum time of 6 months (five years) before and 6 months after CSII Figure 1a and 1b. Clinical variables before and after pump initiation. (Data are presented as mean ± standard deviation error bars) A B p<. p<. p=.2 HbA1c (%) Total cholesterol HDL cholesterol (mmol/l) (mmol/l) p=.12 p=.28 p=.47 Weight (kg) Systolic blood Diastolic blood pressure (mmhg) pressure (mmhg) initiation on 34 patients. Routine hospital data were obtained on outpatient appointments in diabetes clinics to see consultants or diabetes specialist nurses and appointments in other departments. Hospital admission and discharge data were also reviewed to obtain information on admissions for primary diabetes and other conditions. As the followup time varied before and after pump therapy, the numbers of appointments or admissions were then averaged per month before and after pump initiation. National tariff charges 1 were applied to outpatient and admission data in order to calculate cost savings. Clinical information routinely collected such as HbA1c, cholesterol, weight and blood pressure was also collected for the two time periods before and after pump initiation, and the results over the two time periods were averaged. Primary care The general practitioners of patients on CSII were contacted, with patients consent, for their records of any home or surgery visit, phone call or out-of-hours contact which were defined as patient contact. Analysable data were received on 17 patients for a period of two years before and two years after pump therapy was commenced. Data analysis The data were analysed using SPSS version 11. Parametric data such as clinical variables were compared using the paired t-test, and non-parametric data such as hospital admissions were analysed using the Wilcoxon signed rank test. For all statistical analysis a p-value of <.5 was taken as significant. The results are expressed as mean ± standard deviation or median (range) as appropriate. Results Demographic data Hospital data were obtained for 34 patients commenced on CSII between June 2 and June 25 inclusive. There were 16 male and 18 female patients, with ages ranging from years (mean age 45.3±13.5 years) at the time of the Pract Diab Int June 27 Vol. 24 No. 5 Copyright 27 John Wiley & Sons 253

3 insulin pump initiation. The average length of follow up was 31.±15.9 months prior to commencement of pump therapy and 33.9±17.6 months after. Clinical data Table 1 shows the clinical data obtained before and after pump initiation. There was a significant improvement in HbA1c (8.84±1.5 vs 7.62±.76%, p<.1, paired t-test) following pump initiation and in cholesterol profile (total cholesterol 5.12±.84 vs 4.45±.79mmol/L, p<.1, and cholesterol/hdl ratio 3.66±.83 vs 3.32±1.2mmol/L, p=.5, paired t-test). There was no significant difference in weight or blood pressure following pump therapy. These results are represented graphically in Figure 1a and 1b. Table 2. Appointments to see diabetes consultants, diabetes nurses and other specialties, and admissions to hospital for diabetes or other causes according to hospital Patient Administration Systems data before and after CSII therapy Appointments p-value (per month) Consultant diabetologist.2 (.1.8).11 (.3) <.1 Diabetes specialist nurse.4 ( 1.5).44 ( 1.).66 Diabetic admission (.1) ( ).28 Other clinic.146 ( 2.7).162 ( 1.).82 Other admission.4 (.2) (.3).6 Data in table presented as medians (range in brackets). Effects on secondary care utilisation The reductions in hospital admissions and consultant outpatient appointments are shown in Table 2. There was a significant reduction in consultant outpatient appointments (.11 vs.2 appointments per month, p<.1, Wilcoxon rank sum test), although there was no significant difference in nurse outpatient visits (.4 vs.44 appointments per month, p=.66, Wilcoxon rank sum test). There were also reductions in hospital admissions, both for diabetes-related problems (p=.28) and other admissions (p=.6). On NHS national tariffs 1 each follow-up diabetes appointment costs 88. In our cohort of 34 patients, there were an average of 1.44 appointments saved per patient per year, which would equate to per 1 patients per year. (Table 3.) Similarly, both diabetes and other admissions were reduced after pump therapy. Specific information was not obtained regarding the nature of admission other than a division into diabetes or other cause, but the main cause of diabetes hospitalisation for non-pump patients was, based on previous experience, thought to be severe hypoglycaemia. Therefore, costs were calculated based on national tariffs for admissions for hypoglycaemia as well as simply on the midpoint of the national tariff scale for all types of diabetes admission. Based on admissions solely for hypoglycaemia emergency (<7 years of age without complicating conditions), there would be cost savings of per 1 patients per year and, if costs were taken on the midpoint of the tariff scale, would be saved per 1 patients per year. Thus, the total direct diabetes savings in secondary care per 1 patients per year would be ( ). Based on an average length of stay for diabetic admissions of 1.7 days in this hospital, the annual estimated total bed days saved was 48 days. Savings for non-diabetic admissions are likely to be at least as great as for the diabetic admissions but, as details regarding reason for admissions to other specialities were not collected, it was not possible to quantify the saving using the national tariff scale. Effects on primary care utilisation Primary care contacts were effectively halved in the two years after pump initiation (11 vs six appointments per year, p=.1, Wilcoxon rank sum test) compared to the two years prior. This is demonstrated graphically in Figure 2. The annual reduction in primary care contacts was 6.52 per patient. General practitioners benefit directly from the additional 1 patients (29.4% of patients) who achieved an HbA1c of 7.4% after CSII, since patients achieving an HbA1c of 7.4% attract the maximum of 16 quality framework points in performance-related payments. Overall, taking into account both primary and secondary care, the estimated value of appointments/ admissions saved per 1 patients per year would be in the range of plus any savings from reduced primary care contacts. This does not include savings from non- Table 3. Tariff values of appointments/admissions reductions Secondary care Mean no. of Annual total costs (national appointments/ per 1 tariff rate) admissions saved patients (per patient per year) per year Diabetes consultant appointments ( 88) Diabetes admissions.132 If hypoglycaemic emergency ( 757) If midpoint of scale ( ) 254 Pract Diab Int June 27 Vol. 24 No. 5 Copyright 27 John Wiley & Sons

4 Figure 2. Appointments in primary care in the two years before and after initiation of pump therapy Average no. of appointments per year Patient no. diabetic admissions, as explained above, nor additional elective income which could be obtained from inpatient beds not used for acute admissions. Discussion NICE s Technology Appraisal No. 57 Guidance on the use of continuous subcutaneous insulin infusion for diabetes recommended CSII as an option for people with type 1 diabetes provided that MDI therapy (including, where appropriate, the use of insulin glargine) has failed, and those receiving the treatment have the commitment and competence to use the therapy effectively. 11 The additional cost of CSII therapy compared with MDI therapy was considered by NICE to be in the region of per year, depending on the cost of the pump and the expected length of its life. Cost offsets (comprising reduced insulin costs and lower medical costs for adverse events) were estimated to be about 13 per year. With careful selection, the costs of appointments and admissions avoided to primary and secondary care may be of the order of 95 per patient per year. This alone, in addition to the 13 reduced insulin costs, almost offsets the running costs of the pump therapy. This is without taking into consideration the benefits to primary care from achieving extra quality framework points, savings from non-diabetic admissions or emergency admission bed savings. This work was observational and used only data routinely collected in normal clinical activities. It is likely that some of the benefits seen, particularly in terms of improved glycaemic control, may have resulted from the increased knowledge and understanding obtained from taking part in the REACCT course, as previous studies have demonstrated that courses promoting dietary freedom in type 1 diabetes lead to both improvements in quality of life and glycaemic control. 13,14 However, it is unlikely to be the full answer as not all patients previously receiving this training had seen such benefit. Moreover, some patients did not attend the REACCT programme and some underwent part of their pump training by outside trainers. Our findings are in agreement with other studies which showed improvements in glycaemic control after CSII. 3,4,6 In this respect, the consistency of our results with previous work shows that the reductions in appointments and admissions which we observed are due to improved diabetes control in our patients, not rationing of appointments. The improvement we saw in the lipid profile with a reduction in total cholesterol and HDL:total cholesterol ratio has probably resulted from a combination of factors, unrelated to pump therapy per se, as other studies have not documented such an improvement. 3 Firstly, the improvement in glycaemic control in these patients and, secondly, the greater use of statins over the last five years may be more probable explanations. Weight gain has been shown in other studies which have used intensified insulin regimens, 9 but not in our study, probably because of the reduced rather than increased doses of insulin required with pump therapy. Many of the previous studies that projected long-term cost benefits and outcomes of CSII in patients with type 1 diabetes have used complex simulation techniques to estimate the long-term incidence and progression of diabetes-related complications, assuming that by improving glycaemic control diabetic complications will be reduced and hence QALE would be improved. While the economic modelling approach is valuable at the national policy level, there is a need to demonstrate value to the local health care system as increased expenditure in a given area may impact on other provision. As there exists considerable flux in the provision of diabetes services, this type of evaluation may enable decisions about the mix of provision in a local district and their location. Complications of diabetes may take years to develop, hence savings from their avoidance may also take several years to realise. As an alternative approach, we directly observed the effects of CSII introduction on health care usage and estimated costs using the NHS national tariffs. We could not include the longerterm savings that might be achieved by avoidance of diabetic microvascular complications as these would occur outside the timeframe of our observations. For example, it would be useful to quantify in a future study the rates of dialysis or laser photocoagulation in pump treated vs other patients in our locality. However, the magnitude of the direct cost savings estimated significantly offsets the additional expendi- Pract Diab Int June 27 Vol. 24 No. 5 Copyright 27 John Wiley & Sons 255

5 ture to the local health care community within the timeframe on therapy, and the savings appear to be shared between primary and secondary care. In future managed care networks, distinctions such as primary and secondary care may not be relevant and the savings would accrue to the system as a whole. However, the approach taken in this service has been cautious and patients have been rigorously selected after maximal conventional therapy and for optimal compliance. Wider application of pump therapy without these limitations may not result in the same outcomes. We have shown that provision of CSII by a single specialist team, with careful patient selection and follow up, has led to directly measurable resource benefits and appears to be a cost effective intervention in our locality. Conflict of interest statement No commercial funding was received in the preparation of this article. Key points Insulin pump therapy (CSII) is assumed to reduce complications in the long term, off-setting short-term costs of treatment Our retrospective audit of pump treated patients showed reductions in the use of primary and secondary care resources on CSII compared to before CSII These patients were given intensive conventional diabetes education and carbohydrate counting prior to CSII Careful selection and training of patients for CSII can yield short-term as well long-term benefits in health service usage both in primary and secondary care References 1. Scuffham P, Carr L. The cost-effectiveness of continuous subcutaneous insulin infusion compared with multiple daily injections for the management of diabetes. Diabetic Med 23; 2: Radermecker RP, Scheen AJ. Continuous subcutaneous insulin infusion with short acting insulin analogues or human regular insulin: efficacy, safety, quality of life and cost effectiveness. Diabetes Metab Res Rev 24; 2: Colquitt JL, Green C, Sidhu M, et al. Clinical and cost effectiveness of continuous subcutaneous insulin infusions for diabetes. Health Technol Assess 24; 8(43): iii, Steindel BS, Roe TR, Costin G, et al. Continuous subcutaneous insulin infusion (CSII) in children and adolescents with chronic poorly controlled type 1 diabetes mellitus. Diabetes Res Clin Pract 1995; 27(3): Roze S, Valentine WJ, Zakrzewska KE, et al. Health-economic comparison of continuous subcutaneous insulin infusion with multiple daily injection for the treatment of Type 1 diabetes in the UK. Diabetic Med 25; 22: Linkeschova R, Raoul M, Bott, U, et al. Less severe hypoglycaemia, better metabolic control and improved quality of life in type 1 diabetes mellitus with CSII therapy; an observational study of 1 consecutive patients followed for a mean of 2 years. Diabetic Med 22; 19: Weinzimer SA, Ahern JH, Doyle EA, et al. Persistence of benefits of CSII in very young children with type 1 diabetes: a follow up report. Paediatrics 24; 114(6): Litton J, Rice A, Friedman N, et al. Insulin pump therapy in toddlers and preschool children with type 1 diabetes mellitus. J Pediatr 22; 141(4): DCCT Research Group. The effect of intensive treatment of diabetes on the development and progression of long term complications in insulindependant diabetes mellitus. N Engl J Med 1993; 329: /13/44/4/ xls 11. NICE. Technology Appraisal No. 57. Guidance on the use of continuous subcutaneous insulin infusion for diabetes. London: National Institute for Health and Clinical Excellence, Feb Ulahannan TJ, Ross W, Davies FC. Carbohydrate counting in type 1 diabetes: time to REACCT. Pract Diabetes Int 27; 24: DAFNE Study Group. Training in flexible, intensive insulin management to enable dietary freedom in people with type 1 diabetes: dose adjustment for normal eating (DAFNE) randomised control trial. BMJ 22; 325(7367): Samann A, Muhlhauser I, Bender R, et al. Glycaemic control and severe hypoglycaemia following training in flexible, intensive insulin therapy to enable dietary freedom in people with type 1 diabetes: a prospective implementation study. Diabetologia 25; 48(1): CONFERENCE NOTICE Clinical Research Nurses Association Annual Conference 4 5 October 27 Cathedral Conference Centre, Canterbury, UK For further information and to register please contact: Elizabeth Denver, Secretary CRNA, e.denver@ucl.ac.uk, website: Pract Diab Int June 27 Vol. 24 No. 5 Copyright 27 John Wiley & Sons