Health economics June 15th. 2011 Merethe Ørtoft and Ulla Due

1. Cost-effectiveness analysis (CEA) ofa nurse-led intervention aiming to reduce high blood pressure in stroke patients Health economics June 15th. 2011 Merethe Ørtoft and Ulla Due

2. Agenda • Objective • Methods and outcome measures • Background • Intervention • Choice of model • Analysis of costs • Results • Discussion

3. Objective • To carry out a cost effectiveness analysis (CEA) of a nurse-led intervention for stroke patients with the primary objective of reducing high blood pressure (BP)

4. Metods and outcome measures Cost effektiveness analysis (CEA): • Direct costs related to the intervention • Effect of intervention in reducing recurrence of stroke • Effect of intervention on life-years gained • Cost-effectiveness Ratio (CER) Population • 832 new strokes at Herlev Hospital every year Outcome measures • Reduction in recurrence of stroke • Reduction of death because of recurrence

5. Definition of stroke • Stroke caused by infarction: Infarct in the arteries of the brain lasting more than 24 hours • Transient ischemic attack (TIA): Periodic reduction of blood supply to the brain for less than 24 hours followed by full recovery (remission) • Stroke caused by hemorrhage: Bleeding in the brain

6. Incidence • Stroke is a substantial National health problem • Every year 12.000 Danes will suffer a stroke caused be an infarction or a hemorrhage • Around 85% will be caused by infarction, 10 % by hemorrhage and 5 % by other bleedings in the brain • It is estimated that 30.000 to 40.000 people are living with dissabilities caused by stroke (LPR)

7. Mortality • 17% - will die after one month • 29% - will die after one year • 54% - will die after five years (Vernino 2003) • Stroke is the third most frequent cause of death in Denmark(National Discharge registry)

8. Prediction of progress • Depends on localisation of infarct, size of the infarct and age of the patient • Among 20 to 30 % progression of symptoms occur within the first 24 hours • Acute mortality within 30 days is NOW 10 to 20%. • Approximately 40 % will recover to a state of independence while the rest will need daily help (NIP)

9. Frequency of recurrence of stroke Recurrence of stroke: • 3% within 30 days • 9% within six months • 7-13% within one year • Between 16% to 29% within 5 years • 25% of admissions to hospital because of acute stroke is caused by a recurrence of stroke • Recurrent strokes are often mortal or related to severe dissabilities

10. Risk factors • Basic: Increasing age, male sex, low educational level, low income • High blood pressre (BP) is the most dominant risk factor. High blood pressure is defined as blood pressure of 140/90 mm Hg. 10 - 20 % of the population has a too high blood pressure. • People with high BP have more than tripled risk of getting a stroke compared to people with normal blood pressure • Smoking • A high consumption of alcohol increases risk of stroke • General health: (High BP) diabetes cardiovascular diseases, atrial fibrillation, reduced respiratory capacity, TIA, former stroke, hypercholesterolemia. (NIP)

11. Direct costs • The total direct costs of stroke are estimated to be 2,7 billions a year d.kr corresponding to 4% af the total cost of the Danish health service. • If disease related expenses such as pensions, home care, medicine, nursing home admittance etc. are included stroke is estimated to cost the society around 7 billion d.kr a year(NIP and (Referenceprogramme for acute stroke)

12. Background for intervention • Hypertension is the most important factor in reducing recurrence of stroke and thereby death caused by recurrence • In the PROGRESS study it was found that reducing high BP alone could prevent fatal or severe stroke in one out of 11 • More than 70% of stroke patients are discharged from hospital with hypertension and that they still have hypertension one year after discharge despite medical treatment

13. The intervention • Early follow up after discharge in out-patient clinic for neurological patients • More frequent control and adjustment of medication • Studies have shown that using special trained nurses for the hypertension regulation treatment will result in better patient compliance and better BP regulation

14. Death Recurrence of stroke screening Stroke 3 months follow up, control Decision tree - Time line 3 months follow up, intervention normal normal normal Interven- tion group screening screening High BP High BP High BP Control group

15. Cost analyis • Based on costs and economical effect within the hospital sector • Does not include costs for pensions, primary sector health care sevice or GP service

16. Cost analysis Present expenses: • 832 stroke patients receive one control visit with a nurse three months after discharge • One visit lasting one hour costs:

17. Costs related to intervention The intervention includes: • 832 patients • In average every patient is seen three hours in the out-patient clinic within six months meaning three to 7 visits depending on BP • Total amount of visiting time is calculated as follows: • three hours x 832 patients = 2496 hours

18. Cost analysis - Intervention

19. Estimated costs for intervention Difference in costs between new intervention and present intervention: Costs of intervention kr.1.693.604 Present costs kr. 615.680 Increased costs kr.1.077.924

20. Effect on health • Studies have shown that 7,1% will have a new stroke with the first year In our case that will mean 59 recurrent strokes • We believe that the intervention will reduce this figure with 28% = 16, 54 recurrent strokes (Mohan 2009) • Every new stroke will cost society 175.000 d.kr. in the first year, but to be consistent we only include hospital costs which are 44.000 d.kr for each patient

21. Cost effectiveness analysis (CEA) CEA is calculated as follows: Costs for intervention - saved costs by preventing x 16,54 recurrent strokes _______________________________________________________ = the cost per Number of recurrent strokes prevented prevented stroke 1.077.924 kr. – (16,54 x 44.000 kr.) = _______________________________________________________ 21.170 kr. the cost per 16,54 prevented stroke

22. Calculation of cost effectiveness ratio • We expect to be able to prevent 16,54 cases of recurrent stroke • The risk of death after a second stroke is 28% and as follows the intervention will prevent 4,6 deaths • Average age for recurrency of stroke is 75 years • Expected lifetime for a Danish citizen is 78,6 year. This means that lifetime can be extended with 4,6 x 3,6 years = 16,56 years • Costs of intervention divided with 16,56 gives the costs of one extra life year gained =direct costs, pensions etc. excluded

23. Costs for one life-year gained 1.077.924 D.kr. – (16,54 x 44.000 d.kr.) _____________________ = 21.145 kr. for one life-year gained 16,56 life-years In this calculation we have only included hospital costs in relation to life-years gained

24. Discussion • In our analysis we have calculated the cost effectiveness of a BP reducing intervention in a hospital setting • The intervention for reducing high BP is part of a larger study with other preventive interventions included. We believe that more recurrent strokes will be prevented when all these aspects are considered together • We do not have enough data to discuss this aspect • Neither do we have enough data to be able to discuss our CEA in a larger health economic perspective