Optimizing adherence in hypertension: a comparison of outcomes and costs using single tablet regimens vs individual component regimens

Figures & data

Table 1.  Payment by results tariff prices used in this analysis14.

Event	HRG code	HRG description	Cost applied
Myocardial infarction	EB10Z	Actual or suspected myocardial infarction (non-elective)	£3841
Coronary artery bypass graft	EA14Z	Coronary artery bypass graft (first time) (elective)	£7318
Percutaneous revascularization	EA32Z	Percutaneous coronary intervention (0–2 stents) and catheterization (elective)	£3676
Acute coronary syndrome/unstable angina	EB01Z	Non-interventional acquired cardiac conditions 19 years and over (non-elective)	£802
Stroke	AA22Z	Non-transient stroke or cerebrovascular accident, nervous system infections or encephalopathy (non-elective)	£4264
Transient cerebral ischemia	AA29Z	Transient ischemic attack (non-elective)	£1307
Out-patient attendance	WF01B	First attendance—single professional	£214

Table 2.  Baseline characteristics.

	Group A (single tablet regimens)	Group B (individual components)	p-value (A vs B)
Number of patients	9929	18,665	–
Diagnosis of hypertension	100%	100%	1.0
% Male	44.0%	43.4%	0.80
Age at first prescription (mean + SD)	61.2 [11.3]	62.5 [11.1]	<0.0001
Age at first prescription (range)	22–95	24–95	–
Systolic BP before treatment (mean + SD)	159.7 [17.4] (18% had no BP recorded)	154.9 [24.3] (36% had no BP recorded)	<0.0001
Diastolic BP before treatment (mean + SD)	91.5 [9.1] (18% had no BP recorded)	90.5 [12.8] (36% had no BP recorded)	< 0.0001
Systolic BP after treatment (mean + SD)	147.8 [12.5] (0.9% had no BP recorded)	148.2 [13.0] (0.3% had no BP recorded)	0.011
Diastolic BP after treatment (mean + SD)	82.4 [7.5] (0.9% had no BP recorded)	82.7 [7.1] (0.3% had no BP recorded)	0.001
Target achievement (NICE) Based on mean BP achieved post-treatment against 140/90 target	24.9%, at or below target 74.2%, above target 0.9%, no post-treatment BP	23.8%, at or below target 75.9%, above target 0.3%, no post-treatment BP	0.04
Target achievement (QoF) Based on mean BP achieved post-treatment against 150/90 audit target	56.0%m at or below target 43.1%, above target 0.9%, no post-treatment BP	52.9%, at or below target 46.9%, above target 0.3%, no post-treatment BP	<0.0001

Figure 1.  Cox proportional hazards survival analysis (corrected). Censored at 10 years.

Table 3.  First cardiovascular events.

	Group A—STRs (n = 9929)	Group B—Individual components (n = 18,665)
Any event	2173 (21.9%)	6285 (33.7%)
<1 month	39 (0.4%)	190 (1.0%)
1 month–1 year	155 (1.6%)	550 (2.9%)
2–5 years	626 (6.3%)	1800 (9.6%)
0–5 years	820 (8.3%)	2540 (13.6%)
5 years+	1353 (13.6%)	3745 (20.1%)

Table 4.  Breakdown of first event by sub-type.

Event*	Group A—STRs (n = 9929)	Group B—Individual components (n = 18,665)
Myocardial infarction	149 (1.5%)	570 (3.1%)
Stroke	156 (1.6%)	360 (1.9%)
Death	5 (<0.1%)	42 (0.2%)
Heart failure	169 (1.7%)	649 (3.5%)
Acute coronary syndrome	58 (0.6%)	199 (1.1%)
Transient ischemic attack	177 (1.8%)	369 (2.0%)
Coronary artery bypass	62 (0.6%)	257 (1.4%)
Percutaneous angioplasty	44 (0.4%)	94 (0.5%)
Any qualifying event	820 (8.3%)	2540 (13.6%)

*First event occurring over 5 years following initial anti-hypertensive prescription.

Table 5.  Referrals to hypertension, cardiology, or general medical OPD.

	Group A—STRs (n = 9929)	Group B—Individual components (n = 18,665)
Any referral	1869 (18.8%)	4429 (23.7%)
<1 month	25 (0.3%)	33 (0.2%)
1 month–1 year	131 (1.3%)	209 (1.1%)
2–5 years	603 (6.1%)	894 (4.8%)
0–5 years	759 (7.6%)	1136 (6.1%)
5 years+	1110 (11.2%)	3293 (17.6%)

Table 6.  Total direct costs incurred.

Total costs	Group A—STRs (n = 9929)		Group B—Individual components (n = 18,665)
	Year 1	Year 2–5	Year 1	Year 2–5
Admissions	£632,623	£2,430,265	£2,296,276	£7,525,035
Out patients	£33,384	£129,042	£51,788	£191,316
Drug costs*	£1,248,572	£5,032,712	£1,325,962	£6,280,959
Total	£1,914,579	£7,592,019	£3,674,026	£13,997,310

*Includes basic NHS cost + dispensing fee.

Table 7.  Mean costs per patient per year.

Mean cost per patient per year (SD)	Group A—STRs (n = 9929)		Group B—Individual components (n = 18,665)
	Year 1	Year 2–5	Year 1	Year 2–5
Admissions	£63.71 (302.15)	£61.19 (294.77)	£123.03 (402.48)	£100.79 (358.87)
Outpatients	£3.36 (15.01)	£3.25 (14.22)	£2.77 (14.75)	£2.56 (13.50)
Drug costs*	£125.75 (106.20)	£126.72 (102.94)	£71.04 (75.34)	£84.13 (72.11)
Total	£192.82 (326.22)	£191.16 (318.05)	£196.84 (410.04)	£187.48 (401.56)

*Includes basic NHS cost + dispensing fee.

Department of Health. 2011-12 Tariff for admitted patient care & outpatient procedures. 2011; http://www.dh.gov.uk/prod_consum_dh/groups/dh_digitalassets/documents/digitalasset/dh_125398.xls. Accessed 24 January 2012

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