A Comparison of Daily Average Consumption
`Of Oxycodone Controlled Release (OxyContin CR)
`And Oxymorphone Extended Release (Opana ER)
`In Patients With Low Back Pain
`
`Todd Berner, MD; Heather Thomson, MBA, MS; Ann Hartry, PhD; R. Amy Puenpatom, PhD;
`Rami Ben-Joseph, PhD; and Sheryl L. Szeinbach, PhD, MS, BS Pharm
`
`ABSTRACT
`Objective: Our goal was to examine the daily average con-
`sumption (DACON) of oxycodone controlled-release tablets
`(OxyContin CR)and oxymorphone extended-release tablets
`(Opana ER) in patients with low back pain.
`Study Design: An observational, retrospective cohort study
`enrolled patients with multiple prescriptions for oxycodone CR
`or oxymorphone ER tablets. These patients also had Inter -
`national Classification of Diseases, Ninth Revision, Clinical
`Modification (ICD-9-CM) codes for low back pain. Pharmacy
`prescription medication claims data were obtained from a
`large commercially insured health plan in the U.S. Mean daily
`consumption was calculated for a 90-day period.
`Methods: We used descriptive statistics to evaluate patient
`demographics and health plan characteristics. Univariate analy-
`ses were used to examine the data as observed. A generalized
`linear model with a gamma distribution and log-link function
`provided a sensitivity measure, adjusting for heterogeneity
`among patients and the skewed nature of the DACON variable.
`Results: A total of 4,023 patients received oxycodone CR,
`and 374 patients received oxymorphone ER. The mean age of
`patients (standard deviation, SD) was 49.0 (11.6) years for
`oxycodone CR and 47.3 (10.6) years for oxymorphone ER.
`DACON of oxycodone CR was 3.2 tablets per day, and DACON
`of oxymorphone ER was 2.7 tablets per day (P < 0.01). Uti-
`lization of maximum-strength tablets of oxycodone CR 80 mg
`was 3.9 tablets per day, which was significantly higher, by one
`tablet per day, than the utilization of equipotent oxymorphone
`ER maximum-strength tablets of 40 mg at 2.9 tablets per day
`(P < 0.01).
`Conclusion: The use of oxycodone CR, measured as mean
`daily consumption over a 90-day period, was significantly
`higher than that for oxymorphone ER in these patients, a find-
`ing that could have financial implications for health care sys-
`tems.
`
`Dr. Berner and Ms. Thomson are Senior Field Scientists; Dr. Hartry
`is a Field Scientist; Dr. Puenpatom is Analytics Associate Director;
`and Dr. Ben-Joseph is Vice President, all in Health Outcomes and
`PharmacoEconomics (HOPE) at Endo Pharmaceuticals in Chadds
`Ford, Pa. Dr. Szeinbach is a Professor in the College of Pharmacy,
`Division of Pharmacy Practice and Administration, at Ohio State
`University in Columbus, Ohio.
`
`Accepted for publication October 18, 2010.
`
`INTRODUCTION
`Opioid analgesics have long been used to treat moderate-
`to-severe pain for a variety of non–cancer-related conditions,
`including those affecting the musculoskeletal system.1–4 The
`Federation of State Medical Boards has adopted guidelines to
`promote access to opioid analgesics,5 and the current guide-
`lines of the American Society of Anesthesiologists Practice
`Guidelines for Chronic Pain Management 6 have identified
` extended-release opioids as part of a multimodal pain man-
`agement strategy for patients with neuropathic pain or back
`pain. In the previous decade, there was an increase in the fre-
`quency of diagnosis of non-cancer pain conditions and greater
`use of opioids to treat them.7
`Low back pain occurs in approximately 28% of adults 18
`years of age or older and accounts for the second most com-
`mon symptom reported by individuals during physician office
`visits.8,9 In one study examining data from 1992 to 2001, opioids
`were prescribed by primary care physicians 53% of the time for
`patients with a confirmed diagnosis of back pain, arthritis, or
`acute musculoskeletal conditions.10 Although opioids do relieve
`low back pain,11,12 patient management can be complicated by
`the risk of abuse. A meta-analysis of studies published in 2007
`reported that the prevalence of current substance use dis -
`orders in chronic back pain patients receiving opioids ranged
`from 3% to 43%, with a lifetime prevalence as high as 54%.13
`The prevalence of low back pain and the frequency with
`which opioids are prescribed combine to make opioid an -
`algesics a significant contributor to costs of care. In one study,
`the cost of opioids to treat patients with low back pain repre-
`sented 48% of the $1,795,375 total cost of the opioid class of
`drugs for a university-based health plan.14
`There has been concern about overutilization of opioid
` analgesics in the U.S.;15 however, little research to date has ex-
`amined the real-world use of different long-acting opioids. Yet
`recent evidence suggests that changes in pharmacy policy
`have mixed success in reducing utilization of oxycodone (Oxy-
`Contin, Purdue Pharma).16–18 Patterns of use for long-acting
` opioids have potential clinical and financial implications as
`physicians, payers and patients attempt to manage risks and
`
`Disclosure. Dr. Berner, Ms. Thomson, Dr. Hartry, Dr. Puenpatom, and
`Dr. Ben-Joseph are employed at Endo Pharmaceuticals and report that
`they have received assistance from the company in preparing the arti-
`cle. Dr. Szeinbach reports that she received financial support from Endo
`in drafting portions of the manuscript.
`
`Vol. 36 No. 3 (cid:129) March 2011 (cid:129) P&T® 139
`
`ENDO - Ex. 2058
`Amneal v. Endo
`IPR2014-00360
`
`

`

`Consumption of Oxycodone CR and Oxymorphone ER for Low Back Pain
`
`costs of therapy while achieving effective pain relief.
`One common measure of utilization is daily average con-
`sumption (DACON), which has been used to assess medica-
`tions for diseases such as diabetes,19,20 hypertension,21 and
`arthritis.22 DACON can be defined as the number of tablets per
`day that are dispensed to a patient over a defined period of time.
`This measure does not necessarily correlate with adherence
`to therapy, but it can reveal patterns of use in specified popu-
`lations.
`For this study, the measure of DACON provided an oppor-
`tunity to examine how two opioids in long-acting formulations,
`with the same prescribing information for twice-daily dosing,
`differ with respect to usage in patients with low back pain. If
`utilization is not similar, there could be, at a minimum, eco-
`nomic consequences for pharmacy costs to patients and pay-
`ers. The objective was to quantify the differences in utilization
`between controlled-release oxycodone (OxyContin CR) and ex-
`tended-release oxymorphone (Opana ER, Endo) in a popula-
`tion of patients with low back pain.
`
`METHODS
`Scope of the Study
`We conducted a retrospective, observational study of com-
`mercially insured patients taken from a large managed health
`care plan in the U.S. Data regarding the study population were
`drawn from the i3 InVision Data Mart data set, which contained
`aggregated medical claims and prescription drug information
`reported to United Healthcare for the period January 1, 2006,
`through September 30, 2009. The number of covered lives
`during the 36-month period at any particular point in time was
`approximately 15 million. The population was diverse geo-
`graphically across the U.S.
`Coverage included medical and pharmacy benefits, as well
`as plan options that allowed for different levels of copayments
`and deductibles, but both oxycodone CR and oxymorphone ER
`were subject to the same formulary tier status and quantity lim-
`its. De-identified patient data were used in accordance with the
`Health Insurance Portability and Accountability Act (HIPAA).
`Approval by the institutional review board was not required.
`
`Sample Selection and Characteristics
`As shown in Figure 1, an index date for each patient was de-
`fined as the date of the first prescription claim for either oxy-
`codone CR or oxymorphone ER; patients had to have at least
`a 30-day supply of the study drug at least one month before the
`DACON observation period in order to avoid capturing titra-
`tion utilization patterns at the initiation of therapy. Prescription
`claims totaling a minimum of a 90-day supply of the study
`drug were required during the DACON observation period, as
`three months is consistent with definitions for chronic pain.23,24
`Thus, utilization would be within the labeled indication for
`both opioids of “use for an extended period of time.”25,26
`Patients included in the analysis had to have continuous
` insurance coverage for the six months before and after the start
`of the DACON observation period for the purpose of identify-
`ing exclusion criteria diagnoses. They also had to have at least
`one diagnosis of low back pain during that time, following the
`list of International Classification of Diseases, Ninth Revision,
`Clinical Modification (ICD-9-CM) codes, developed at the Uni-
`
`140 P&T® (cid:129) March 2011 (cid:129) Vol. 36 No. 3
`
`versity of Washington in Seattle (Table 1).10
`Patients were retained in the study cohort only if they did
`not switch to the other study drug during the 90-day DACON
`observation period. There were no other limitations on the use
`of other short-acting or long-acting opioids.
`Patients were excluded from the study if they were younger
`than 18 years of age or pregnant (ICD-9-CM 761.5x, V22.xx,
`V72.40, and V2.32), given that opioid utilization might be more
`limited in these populations. Patients with cancer (ICD-9-CM
`140-239) were also excluded because of the potential for in-
`creased opioid utilization unrelated to back pain.
`
`Average Daily Opioid Consumption
`DACON for each patient was calculated by dividing the
`number of tablets dispensed during the 90-day observation
` period by 90. From these amounts, overall DACON for each
`of the two opioids was calculated, as was that for the highest
`dosage strength and all lower dosage strengths for each opi-
`oid. This approach allowed the separation of prescribed doses
`that would require multiple tablets of the highest dosage
`strength from doses that could be achieved with a single tablet.
`Comparing the utilization of the highest tablet strengths of
`each opioid requires that these highest strengths be equipo-
`tent. We determined the equivalence of potency of the oxy-
`codone CR 80-mg tablet and the oxymorphone ER 40-mg tablet
`on the basis of the 2:1 (oxycodone CR/oxymorphone ER)
`
`Baseline Period
`(6 months)
`
`Index
`Date
`
`30 days
`
`90-day DACON
`Observation period
`
`Figure 1 Study time line. DACON = daily average
` consumption.
`
`Table 1 Classification of Patients With Low Back Pain
`
`Patients with low back pain were identified using International
`Classification of Diseases, Ninth Revision, Clinical Modification
`codes (ICD-9-CM) as follows:
`
`(cid:129) Group I: back pain with no neurological findings (ICD-9-
`CM codes 724.2, 724.5, and 846.0–846.9)
`(cid:129) Group II: back pain with neurological findings (ICD-9-CM
`codes 721.42, 721.91, 722.73, 722.80, 724.3, and 724.4)
`(cid:129) Group IIIa: congenital lumbar spine structural disorders
`(ICD-9-CM codes 737.1, 737.20, 737.3, 739.3, 739.4, and
`756.13–756.19)
`(cid:129) Group IIIb: acquired lumbar spine structural disorders
`(ICD-9-CM codes 721.5–721.90, 722.10, 722.2, 722.30,
`722.32, 722.52, 722.6, 722.90, 722.93, 724.00, 724.02,
`724.09, 738.4, and 756.12)
`(cid:129) Group IV: other (ICD-9-CM codes 307.89, 722.83, 724.6,
`724.8, 724.9, 756.10, 805.4, 805.6, 805.8, and 996.4).
`
`

`

`Consumption of Oxycodone CR and Oxymorphone ER for Low Back Pain
`
`Table 2 Demographic and Plan Characteristics
`
`Characteristic
`
`Oxycodone Oxymorphone
`CR Group
`ER Group
`(n = 4,023)
`(n = 374)
`
`P Value*
`
`Mean (SD) age on index date:
`Women n (%)
`Region n (%)
`Northeast
`Midwest
`South
`West
`Health Plan n (%)
`HMO
`PPO
`POS
`Others
`Charlson Comorbidity Index n (%)
`CCI = 0
`CCI = 1
`CCI = 2
`CCI ≥ 3
`* Pearson chi-square and t-tests were used to compare proportions by drug groups and mean
`difference, respectively.
`CR = controlled release; ER = extended release; HMO = health maintenance organization;
`PPO = preferred provider organization; POS = point of service; SD = standard deviation.
`
`49.0 (11.6)
`1,986 (49.4)
`
`383 (9.5)
`1,016 (25.3)
`1,808 (44.9)
`816 (20.3)
`
`497 (12.4)
`428 (10.6)
`2,436 (60.6)
`816 (20.3)
`
`1,290 (32.1)
`359 (8.9)
`1,169 (29.1)
`1,205 (30.0)
`
`47.3 (10.6)
`195 (52.1)
`
`<0.01
`0.31
`
`24 (6.4)
`78 (20.9)
`212 (56.7)
`60 (16.0)
`
`51 (13.6)
`42 (11.2)
`229 (61.2)
`52 (13.9)
`
`116 (31.0)
`43 (11.5)
`118 (31.6)
`97 (25.9)
`
`<0.01
`
`0.58
`
`0.16
`
`dosage conversion ratio. The ratio was
`derived from a study of patients with
`low back pain that examined the effi-
`cacy and safety of oxymorphone ER
`compared with placebo. Oxycodone CR
`was the active control.12 Both drugs
`demonstrated similar analgesia that
`was superior to that of placebo. The rel-
`ative dose of oxymorphone ER (79.4
`mg/day) was approximately half that of
`oxycodone CR (155 mg/day).
`
`Statistical Analysis
`We analyzed demographic variables
`for age and sex of the patients, as well
`as plan type and region in each group,
`descriptively using either chi-square
`tests or an independent t-test. Univari-
`ate analyses to compare mean differ-
`ences between oxycodone CR and oxy-
`morphone ER use were conducted with
`t-tests. We performed multivariate
`analyses using generalized linear mod-
`els with a gamma distribution and log-
`link function to adjust for the observed
`heterogeneity among patients. The de-
`pendent variable was DACON.
`Explanatory variables included the
`study drug, tablet strengths, age, sex,
`and the Charlson Comorbidity Index (CCI), a proxy measure
`that assigns weights for 19 chronic conditions.27,28 SAS version
`9.1 (SAS Institute, Inc., Cary, N.C.) and Stata version 10.1
`(StataCorp, College Station, Tex.) were used to analyze the
`data.
`
`difference for all strengths was 0.5 more tablets of oxycodone
`CR dispensed per day.
`A generalized linear model was applied to measure any
` effect of the demographic variables in conjunction with the
`choice of drug and tablet strength. The bias-adjusted means
`and standard deviations (SDs) were consistent with the uni-
`variate data analysis (Table 4). This modeling confirms
`that DACON was not affected by age, sex, or the Charlson
`
`Low Back Pain (LBP) Patients
`(n = 2,268,688)
`
`LBP patients with at least one Rx
`of any opioid
`(n = 1,297,532)
`
`LBP Patients with at least one Rx
`of oxycodone CR or oxymorphone ER
`(n = 32,325)
`
`RESULTS
`We identified a total of 2,268,688 patients with low back pain
`(Figure 2). Applying the inclusion and ex-
`clusion criteria produced final cohorts of
`4,023 patients in the oxycodone CR group
`and 374 patients in the oxymorphone ER
`group (see Figure 2). Demographic find-
`ings (Table 2) revealed no significant dif-
`ferences between the groups; however, the
`mean age of oxycodone CR patients was
`1.7 years older than that of the oxymor-
`phone ER patients (P < 0.01), and geo-
`graphical distribution reflected that of the
`patients in the database, favoring the south-
`ern region of the U.S. (P < 0.01).
`DACON of oxycodone CR was higher
`than that for oxymorphone ER in all com-
`parisons (Table 3). Mean DACON values
`ranged from 2.7 for oxymorphone ER at
`the lower strengths to 3.9 for oxycodone CR
`at the highest strength. The greatest dif-
`ference between drugs was at the highest
`tablet strength; patients used one more
`tablet of oxycodone CR per day. The mean
`
`Patients with more than one Rx of
` oxycodone CR (no oxymorphone ER
` during 120 days) (n = 4,023)
`
`Patients with more than one Rx of
`oxymorphone ER (no oxycodone CR
` during 120 days) (n = 374)
`
`Figure 2 Schematic depicting the sample selection process. CR = controlled
` release; ER = extended release; Rx = prescription.
`
`Vol. 36 No. 3 (cid:129) March 2011 (cid:129) P&T® 141
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`

`

`Consumption of Oxycodone CR and Oxymorphone ER for Low Back Pain
`
`Comorbidity Index, but it was
` positively associated with the
`choice of oxycodone CR (P <
`0.01) and with the use of the
`highest tablet strength (P <
`0.01) (Table 5).
`
`Table 3 Univariate Analysis
`
`Low Back Pain,
`Mean (SD), Tablets*
`
`n
`
`Mean (SD)
`
`Oxycodone CR
`
`Oxymorphone ER
`
`n
`
`91
`283
`374
`
`Mean (SD)
`
`2.9 (1.3)
`2.6 (1.2)
`2.7 (1.2)
`
`Difference
`in DACON
`(Tablets/Day)
`
`1.0
`0.5
`0.5
`
`Highest strengths†
`Lower strengths†
`Overall†
`
`688
`3,335
`4,023
`
`3.9 (2.4)
`3.1 (1.6)
`3.2 (1.8)
`
`DISCUSSION
`Our study examined varia-
`tions in daily average con-
`sumption (DACON) of oxyco-
`done CR and oxymorphone
`ER tablets in a large health
`care insurance plan. DACON
`is a simple utilization meas-
`urement calculated in terms of
`tablets per day, and it varies
`with respect to manufacturer dosing recommendations
`and physician prescribing practices. In this case, both
`oxycodone CR and oxymorphone ER are recommended
`at twice-daily dosing; thus, the expected DACON would
`theoretically be two tablets. The mean DACON calcu-
`lations for both of these opioids at all dosage strengths
`exceeded two tablets per day; however, the calculated
`value for oxymorphone ER was closer to the expected
`level, with patients using 0.5 tablet more of oxycodone
`CR per day than oxymorphone ER for all strengths.
`Prescribed doses higher than oxycodone CR 80 mg
`or oxymorphone ER 40 mg would require multiple
`tablets and could therefore exceed a DACON of two
`tablets while remaining consistent with the prescribing
`information. For this reason, the highest tablet strengths
`were analyzed separately from the lower strengths. At
`these equipotent highest strengths, patients used one
`more oxycodone CR tablet per day.
`Because the dose of an opioid analgesic must be individu-
`alized for each patient, the variance in DACON from two tablets
`could reflect an individual patient’s titration phase. However,
`clinical trials with these drugs have generally permitted one
`month or less for titration.29,30 For this reason, a one-month run-
`in period was built into the study to avoid capturing initial
` dosing titration. In this analysis, a prescribed asymmetrical
` dosing regimen of two tablets in the morning and one at night
`would be reflected as a DACON of three tablets.
`There are several theoretical explanations as to why
`DACON exceeded two tablets per day and why it was higher
`for oxycodone CR than for oxymorphone ER. First, there is
`variability in the analgesic duration of effect based on differ-
`ences in release characteristics. Although pharmacokinetic
`evaluations of the two drugs have been designed differently,
`a pharmacokinetic study of oxycodone CR produced a bi phasic
`curve in which 38% of the drug was released in the first
`37 minutes;31 this phenomenon has not been observed for
`oxymorphone ER.32
`Research published in 2010 also indicates a difference in sub-
`jective effects (e.g., euphoria) between these two drugs,33
`which may lead to differences in noncompliant use by patients
`or others, as the abuse and diversion of opioids, especially oxy-
`codone CR, are well documented.33,34
`
`* Highest tablet strength: oxycodone CR = 80 mg and oxymorphone ER = 40 mg; lower tablet
`strengths: oxycodone CR < 80 mg and oxymorphone ER < 40 mg.
`† t-tests established statistically significant differences in daily average consumption (DACON) between
`oxycodone CR and oxymorphone ER across all categories (P < 0.01).
`CR = controlled release; DACON = daily average consumption; ER = extended release; SD = standard
`deviation.
`
`Table 4 Generalized Linear Model, Adjusted by Age,
`Sex, and Comorbidities
`
`Low Back Pain
`Population
`
`Highest strength*†
`Lower strengths†
`Overall†
`
`Oxycodone CR
`(n = 4,023)
`
`Oxymorphone ER
`(n = 374)
`
`Mean
`
`3.9
`3.1
`3.2
`
`SD
`
`0.1
`0.0
`0.3
`
`Mean
`
`3.2
`2.5
`2.7
`
`SD
`
`0.0
`0.0
`0.3
`
`* Highest tablet strength: oxycodone CR = 80 mg, oxymorphone ER =
`40 mg; lower tablet strengths: oxycodone CR < 80 mg, oxymorphone ER <
`40 mg.
`† Statistically significant differences across all tablet strengths for utilization
`between oxycodone CR and oxymorphone ER (P < 0.01).
`CR = controlled release; ER = extended release; SD = standard deviation.
`
`Finally, differences in utilization could reflect the effect of
`polymorphisms or drug–drug interactions in drug metabo-
`lism. Oxycodone is eliminated through the cytochrome P450
`(CYP) 2D6 pathway,25 whereas oxymorphone’s biotransfor-
`mation occurs via glucoronidation.26 A retrospective study
`found a 26% prevalence of CYP 2D6 drug–drug exposures
`among ambulatory osteoarthritis patients using oxycodone
`
`Table 5 Results of the Generalized Linear Model
`
`Coefficient
`
`Standard
`Error
`
`1.145
`0.197
`–0.222
`–0.001
`
`Constant
`Drug
`Tablet strength
`Years of deviation
`from mean age
`Sex
`CCI = 1
`CCI = 2
`CCI ≥ 3
`CCI = Charlson Comorbidity Index.
`
`–0.004
`0.004
`0.007
`0.028
`
`0.036
`0.029
`0.021
`0.001
`
`0.016
`0.032
`0.021
`0.024
`
`P Value
`
`< 0.01
`< 0.01
`< 0.01
`0.149
`
`0.824
`0.909
`0.756
`0.243
`
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`Consumption of Oxycodone CR and Oxymorphone ER for Low Back Pain
`
`CR.35 Any of these possibilities or a combination of factors
`might help to explain the elevated levels of oxycodone utiliza-
`tion.
`
`STUDY LIMITATIONS
`Our findings should be considered within the context of
`several limitations. The sample size of patients receiving oxy-
`morphone ER was substantially smaller than that for oxy-
`codone CR, reflecting the relative market shares for the two
`drugs within the health plan from which the data were ana-
`lyzed.
`The research objectives covered 90 days, but observed
`DACON levels might change from the initiation of therapy to
`points further along the continuum of care. In addition, data
`extracted from a large database and compiled from several
` insurance products in the U.S. can be subject to errors, in-
`cluding omissions, inaccurate information, and other possible
`mistakes.
`As with all retrospective claims database analyses, there
`was no randomization of the oxycodone CR and oxymorphone
`ER patient populations studied within the i3 InVision Data
`Mart database. Further, despite the use of multivariate analy-
`ses to correct for differences in patient characteristics, such
`as demographics and comorbidities between the two groups,
`other differences may exist.
`The study could not evaluate patients’ experience of pain,
`and no comparison of the effectiveness of the two products
`could be made from these results. The additional use of mul-
`tiple, long-acting tablets to conduct dose escalations in re-
`sponse to increasing pain severity or tolerance would not be
`separable in this analysis.
`Given these limitations, the fact that utilization of two long-
`acting opioids can differ in a patient population for whom opi-
`oid analgesics are a frequent therapeutic choice implies that
`assumptions about equivalent utilization should not be made
`for the class.
`
`RECOMMENDATIONS FOR FUTURE STUDY
`Areas for future research could include examining the im-
`pact that differences in utilization levels might have on clini-
`cal outcomes and health care expenditures. Although our
`study did not measure health outcomes, an emerging body of
`research has tied increased medical consequences and costs
`to daily consumption of higher doses of opioids among patients
`receiving chronic opioid therapy.36,37
`From a cost-of-therapy perspective, switching the 688
` patients in this study from the highest strength of oxycodone
`CR to the equivalent highest strength of oxymorphone ER
`would generate $217,985 per month in savings at wholesale
` acquisition costs (Table 6).
`Additional research could focus on evaluating the full costs
`and outcomes of treatment for a defined population using
`claims data to be supplemented with information from patient
`medical charts or electronic medical records.
`
`CONCLUSION
`Daily average consumption (DACON) of oxycodone CR
`was one tablet per day more at the highest tablet strengths
`compared with oxymorphone ER in patients with low back
`
`Table 6 Calculations of Cost Differences
`For Highest Strengths of Oxycodone CR
`And Oxymorphone ER per Month
`In the Univariate Analysis*
`
`688 patients received oxycodone CR 80 mg
`× DACON of 3.9
`× 30 days
`× wholesale acquisition cost, $10.83
`TOTAL = $874,007
`
`688 patients switched to oxymorphone ER 40 mg
`× DACON of 2.9
`× 30 days
`× $10.96
`TOTAL = $656,022
`
`$874,007 − $656,022 = $217,985
`
`* First Databank wholesale acquisition costs per tablet, as of April
`10, 2010, were $10.83 for oxycodone CR 80 mg and $10.96 for oxy-
`morphone ER 40 mg.
`DACON = daily average consumption.
`
`pain. Chronic opioid therapy for non-cancer pain continues to
`exert significant pressure on health care costs; therefore, care-
`ful assessment by prescribers of the utilization patterns and
` attributes of individual long-acting opioids is merited, just as
`it is for decision-makers responsible for pharmacy policy.
`
`Acknowledgment: We wish to thank Pi-Chin Lai, MS, for
`programming contributions; Chunmay Fu, MS, for quality
`control support; and Kent Summers, PhD, for valuable com-
`ments in the preparation of the manuscript.
`
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