Medical cost savings associated with an extended-release opioid with abuse-deterrent technology in the US

Figures & data

Table 1. Changes in rates of abuse among continuous ERO users following the introduction of reformulated ER oxycodone.

Population	Continuous users of EROs (pre-reformulation)		Continuous users of reformulated ER oxycodone (post-reformulation)		Relative change in rates of abuse
	n	Rate of abuse [A]	n	Rate of abuse [B]	([B] − [A])/[A]	95% CI	p Value
Commercial	69,315	3.6%	14,480	2.8%	−22.7%	(−31.2%, −14.3%)	<0.001
Medicare-eligible	17,899	1.2%	3680	1.3%	6.1%	(−27.8%, 40.0%)	0.707
Medicaid	11,883	6.2%	2490	5.1%	−18.0%	(−34.0%, −2.0%)	0.034

Due to rounding, the differences may not exactly equal the estimates implied by the rounded numbers presented in the table. Chi-squared tests were used to test differences in rates of abuse between continuous users of EROs (pre-reformulation) and continuous users of reformulated ER oxycodone (post-reformulation).

Table 2. Baseline characteristics of abusers and non-abusers.

Characteristics	Unmatched			Matched
	Abusers	Non-abusers	p Value	Abusers	Non-abusers	p Value
I. Commercially-insured patients
n	2532	61,421		2510	2510
Age on index date, mean (SD)	47.9 (10.2)	51.2 (9.1)	<0.001	48.0 (10.1)	48.0 (9.9)	0.937
Male, %	47.2%	43.9%	0.001	47.1%	48.5%	0.287
Charlson Comorbidity Index (CCI), mean (SD)	0.7 (1.3)	0.9 (1.5)	<0.001	0.69 (01.3)	0.72 (01.3)	0.307
Select co-morbidities
Lower back pain, %	72.9%	67.5%	<0.001	72.9%	73.4%	0.722
Arthritis, %	59.8%	55.3%	<0.001	59.6%	59.8%	0.931
Psychiatric disorders, %	44.7%	29.3%	<0.001	44.5%	35.3%	<0.001
Trauma or accidental injury, %	25.7%	19.0%	<0.001	25.4%	24.3%	0.358
Neuropathic pain, %	19.2%	17.1%	0.005	19.2%	18.0%	0.295
Fibromyalgia, %	17.5%	15.0%	<0.001	17.5%	17.9%	0.741
ERO days supply, mean (SD)	177.5 (117.6)	151.2 (93.0)	<0.001	174.6 (96.8)	173.7 (102.5)	0.256
II. Medicare-eligible patients
n	272	19,564		268	268
Age on index date, mean (SD)	74.1 (6.7)	76.9 (7.9)	<0.001	74.2 (6.7)	74.3 (7.3)	0.850
Male, %	30.5%	33.3%	0.333	30.6%	29.1%	0.705
Charlson Comorbidity Index (CCI), mean (SD)	1.4 (1.5)	1.6 (1.9)	0.249	1.41 (01.5)	1.28 (01.4)	0.494
Select comorbidities
Lower back pain, %	73.9%	57.6%	<0.001	73.5%	73.9%	0.916
Arthritis, %	62.1%	58.8%	0.267	61.6%	60.4%	0.785
Psychiatric disorders, %	38.2%	20.3%	<0.001	38.1%	25.4%	0.003
Trauma or accidental injury, %	30.9%	22.4%	<0.001	31.3%	24.3%	0.069
Neuropathic pain, %	22.1%	16.1%	0.008	21.6%	21.6%	1.000
Fibromyalgia, %	11.4%	6.9%	0.004	10.8%	10.1%	0.785
ERO days supply, mean (SD)	173.3 (83.6)	138.6 (84.1)	<0.001	172.7 (83.1)	167.8 (86.7)	0.185
III. Medicaid patients
n	548	7770		536	536
Age on index date, mean (SD)	46.9 (9.6)	48.9 (9.6)	<0.001	47.1 (9.5)	47.5 (9.8)	0.386
Male, %	37.8%	40.2%	0.259	38.2%	36.0%	0.446
Charlson Comorbidity Index (CCI), mean (SD)	1.5 (2.1)	1.7 (2.0)	0.004	1.49 (02.1)	1.42 (1.8)	0.755
Select comorbidities
Lower back pain, %	75.9%	66.9%	<0.001	75.7%	76.7%	0.692
Arthritis, %	69.0%	64.5%	0.033	68.7%	69.4%	0.786
Psychiatric disorders, %	65.0%	52.5%	<0.001	64.7%	57.1%	0.008
Trauma or accidental injury, %	30.5%	25.4%	0.008	30.4%	28.0%	0.366
Neuropathic pain, %	24.8%	22.0%	0.119	24.3%	23.7%	0.824
Fibromyalgia, %	17.2%	15.3%	0.253	17.0%	17.2%	0.936
ERO days supply, mean (SD)	175.0 (94.2)	148.4 (100.4)	<0.001	173.3 (93.2)	179.6 (104.8)	0.597

This table shows a selection of baseline characteristics. The full set of baseline characteristics is available upon request. For categorical variables, differences between abusers and non-abusers were assessed using chi-squared tests (pre-match) and McNemar tests (post-match). For continuous variables, differences between abusers and non-abusers were assessed using Wilcoxon rank-sum tests (pre-match) and Wilcoxon signed-rank tests (post-match).

Table 3. Excess medical and prescription drug costs associated with diagnosed opioid abuse among continuous ERO users.

Population (n for abusers)	Abusers [A]	Non-abusers [B]	Excess costs (difference)		p Value
			[A] − [B]	95% CI
I. Annual medical costs, mean (SD)
Commercial (n = 2510)	$37,846 ($53,282)	$28,390 ($50,575)	$9456	($6648, $12,264)	<0.001
Medicare-eligible (n = 268)	$34,965 ($44,885)	$24,920 ($44,423)	$10,046	($2565, $17,527)	0.009
Medicaid (n = 536)	$34,607 ($44,852)	$23,106 ($39,096)	$11,501	($6632, $16,369)	<0.001
II. Annual prescription drug costs, mean (SD)
Commercial	$11,230 ($13,784)	$11,529 ($14,155)	−$299	(−$1060, $461)	0.440
Medicare-eligible	$10,649 ($9387)	$12,152 ($19,769)	−$1504	(−$4113, $1106)	0.258
Medicaid	$12,851 ($24,320)	$12,165 ($11,994)	$686	(−$1580, $2953)	0.552

All costs are reported in 2011 US dollars. The sample sizes provided in the first column refers to the sample sizes for abusers by payer; there are identical sample sizes for the matched non-abusers by payer (e.g., the commercially-insured population includes 2510 abusers and 2510 non-abusers). Due to rounding, the differences may not exactly equal the estimates implied by the rounded numbers presented in the table. Paired t-tests were used to test differences in costs between abusers and non-abusers.

Table 4. Calculations for medical cost savings at the US level.

Population	Reduction in number of abusers	Annual medical cost savings (2011 USD)
		Per patient	Total
I. Diagnosed abusers
Commercially-insured	3673	$9456	$34,730,641
Medicare-eligible	0	$10,046	$0
Medicaid	1371	$11,501	$15,769,878
Uninsured	3079	$11,501	$35,408,151
Sub-total for diagnosed abusers			$85,908,669
II. Undiagnosed abusers
Commercially-insured	18,364	$7565	$138,922,564
Medicare-eligible	0	$8036	$0
Medicaid	6856	$9200	$63,079,510
Uninsured	15,394	$9200	$141,632,603
Sub-total for undiagnosed abusers			$343,634,677
Total			$429,543,346

All costs are reported in 2011 US dollars.