Sequential drug decision problems in long-term medical conditions: a case Study of Primary Hypertension Eunju Kim ba, ma, msc

5.6.8Costs

As antihypertensive treatment is lifelong treatment, it was assumed that the patients took antihypertensive drugs for the remainder of their lives. Annual drug costs came from the NICE hypertension model^[63]. NICE calculated the drug costs per year based on the prices quoted in the British National Formulary 60 (September 2010). The optimal doses were provided by clinical members of the Guideline Development Group (GDG). The costs of base-case represent the cost for the most commonly used drug in each class based on the 2008 NHS Prescription Cost Analysis.

As recommended in the NICE guideline, it was assumed that both the controlled and uncontrolled patients had an annual GP check-up, which included physical examination, routine laboratory tests and other diagnostic procedures^[63]. The estimated cost for the annual check-up in the NICE hypertension model, which was £56, was converted to 2011/12 value using the Personal Social Services Research Unit (PSSRU) 2011 inflation indices^[335].

Table ‎5.. Antihypertensive drug costs per year

	Base-case (£)	Cheapest drug (£)	Most expensive drug (£)
Ds	11.86	11.86	50.74
BBs	13.17	13.17	485.45
CCBs	18.64	18.64	431.22
ACEIs	20.73	20.71	163.08
ARBs	25.94	25.94	263.71

Annual costs of each CVD estimated in the ScHARR statin model were also adjusted to 2011/2012 value using the Unit Costs of Health and Social Care 2011 inflation indices^{[286, 335]}. Those costs include the overall expenses related to drug, GP contact, hospitalisation and surgical procedure for appropriate patients. Subsequent year costs of each CVD were applied to the post-CVD states (see Table ‎5.).

As the costs for HF and DM were not included in the ScHARR statin model^[286], they came from the financial analysis of HF community services of South London Cardiac and Stroke Network^[336] and Currie et al’s study, which estimated primary care treatment costs for people with type 1 and type 2 DM in the United Kingdom^[337]. All the annual costs were converted to 3-month basis. 3.5% of discount rate was applied to costs. The threshold of the incremental cost-effectiveness ratio (ICER) was assumed to be £30,000.