Kent H Summers

Analysis Group, Boston, Massachusetts, United States

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Publications (15)23.27 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: Chronic pain patients may be subject to polypharmacy because of long-term pharmacological pain treatment and additional comorbidities. Many chronic pain patients expose themselves to potential drug-drug interactions (DDIs) and these interactions can have unintended and severe consequences. Prevalence and costs associated with DDIs are inconsistent and has led to an inadequate level of awareness among the medical community; therefore, it has become necessary to re-evaluate the rates of DDIs in chronic pain patients. Utilizing medical and prescription claims databases, five studies were conducted to assess the health care utilization of and associated financial payments for patients >18 years with chronic noncancer pain. The studies evaluated drug-drug exposures with the potential to cause DDIs specifically occurring through the CYP450 enzyme system. The studies reported that drug-drug exposures are prevalent, costly and can occur in any age group and that physicians should consider ways to limit their patients' exposure to potential DDIs.
    Expert Review of Pharmacoeconomics & Outcomes Research 12/2013; 13(6):725-34. · 1.67 Impact Factor
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    ABSTRACT: Compare direct and indirect costs of oxymorphone extended-release ('oxymorphone') and oxycodone controlled-release ('oxycodone') users. Patients, aged 18+, with ≥1 claim for oxymorphone/oxycodone, Q2:2006-Q4:2009, were selected from a de-identified private payer claims database and observed from the first such claim ('index date') until the earliest of: use of comparator drug; end of continuous eligibility; 12 months ('study period'). Patients with claims for any formulation of the comparator drug during the first 30 days of the study period were excluded. Direct (medical and drug) costs paid by private insurers were reported for patients aged 18-64 (n = 8354) and 65+(n = 3515), as well as sub-sets without cancer (n = 7090 and n = 2444, respectively). Indirect costs (medically-related absenteeism and disability) were reported for all employees, aged 18-64 (n = 1313), and employees without cancer (n = 1146). Multivariate models were used to estimate risk-adjusted costs controlling for patient characteristics. Oxymorphone users, aged 18-64, had lower drug costs ($693 vs $763, p = 0.0035) and similar medical costs ($1875 vs $1976, p = 0.3570) per patient-month compared with oxycodone users (mean follow-up 236 and 280 days, respectively). Indirect costs were not different ($662 vs $670, p = 0.9370). Oxymorphone users, aged 65+, had similar Medicare supplemental drug costs ($533 vs $588, p = 0.0840) and lower medical costs ($459 vs $747, p < 0.0001). Results were comparable for subsets without cancer. Patients with concomitant use of oxymorphone and oxycodone were excluded. Oxymorphone users incur lower risk-adjusted costs in several cost categories, compared with oxycodone users, and no higher costs in any of the examined categories.
    Journal of Medical Economics 01/2012; 15(1):87-95.
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    ABSTRACT: Patients with osteoarthritis (OA) taking at least one CYP450-metabolized opioid concurrently with another CYP450-metabolized medication experience a drug-drug exposure (DDE), which puts them at risk of a pharmacokinetic drug-drug interaction (PK DDI). This study compared patients with and without such an incident DDE to determine healthcare utilization and associated payments. Using a retrospective database analysis, the impact of DDEs was evaluated in terms of associated clinical events, healthcare services utilization (office visits, outpatient visits, ED visits, hospitalization), and payments in patient populations based on age (those under age 65 and those 65 years of age and older), during the 6 months after exposure. DDE patients had significantly more inpatient hospitalizations than no-DDE patients. Mean total payments at 6 months were significantly higher for both younger and older patients with DDE compared to similar patients without DDE ($9,469, SD = $12,192 vs. $8,382, SD = $14,078, respectively, for younger patients, resulting in a difference of $1,087, P < 0.004, and $9,829, SD = $11,721 vs. $8,622, SD = $10,131, respectively, for older patients, resulting in a difference of $1,207, P = 0.001). In both age groups, DDE patients had significantly higher payments for nonopioid prescription drugs ($1,824 SD = $2,420 vs. $1,362, SD = $1,891, respectively, for younger patients, resulting in a difference of $462, P < 0.001, and $2,197 SD = $2,332 vs. $2,013, SD = $2,437, respectively, for older patients, resulting in a difference of $184, P = 0.020). Overall, patients with OA who experienced DDEs had significantly greater utilization rates of healthcare resources and higher associated payments in the 6-month observation period following the exposure, compared to patients without DDEs, consistent with the risk of PK DDIs associated with DDEs.
    Pain Practice 09/2011; 12(1):33-44. · 2.61 Impact Factor
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    ABSTRACT: Chronic low back pain (cLBP) patients who take at least 1 CYP450-metabolized opioid analgesic agent concurrent with at least 1 other CYP450-metabolized medication experience a drug-drug exposure (DDE), which puts them at risk for a pharmacokinetic drug-drug interaction (PK DDI). This study compared utilization of healthcare resources and associated payments in cLBP patients with and without incident DDEs with the potential to cause PK DDIs. A retrospective database analysis examined the associated clinical events, healthcare utilization (measured in terms of claims for office visits, outpatient visits, emergency department visits, and hospitalization), and cost to the health plan, as defined as the sum of health plan payments for resources used. Patients were grouped into 2 cohorts by age (those under 65 and those 65 years and over). In the 6 months after exposure, total healthcare payments were significantly higher for DDE patients than those without DDEs (no-DDE), in both in the younger ($7,086, SD = $8,370) and $6,353, SD = $8,352, respectively, P < 0.001) and the older cohorts ($7,806 vs. $7,043, respectively, P = 0.013). Younger and older patients with DDE had significantly higher prescription payments than those without DDE ($2,041, SD = $2,706 vs. $1,565, SD = $2,349, respectively, P < 0.001 for younger and $2,482, SD = $2,481 vs. $2,286, SD = $2,521, respectively, P = 0.044 for older patients). Both older and younger patients with DDE had significantly more claims for office visits and higher associated payments than similar patients without DDE. Patients in the study who experienced DDEs that placed them at risk for PK DDIs had significantly greater utilization rates of healthcare resources and higher associated payments in the 6-month observation period following exposure.
    Pain Practice 09/2011; 12(1):45-56. · 2.61 Impact Factor
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    ABSTRACT: The utilization of high-potency opioids is an important component of chronic pain management, and appropriate utilization of these medicines is a common concern of payers. Two of the most commonly prescribed oral long-acting opioids, oxycodone controlled-release (CR) and oxymorphone extended-release (ER), are FDA-approved for twice-daily dosing, which equates to a theoretical average consumption (DACON) of 2 tablets per day. DACON values greater than 2 have budget and policy implications for managed care pharmacists. To assess from the perspective of the pharmacy benefit decision maker the DACONs of oxycodone CR and oxymorphone ER. The main outcome measure for the analysis was DACON. Pharmacy and medical claims data from a large commercially insured population (i3 InVision Data Mart database) were analyzed to identify patients with at least 1 pharmacy claim for either oxycodone CR or oxymorphone ER from July 1, 2007, to September 30, 2009. After an initial 30-day titration period, all subjects included in the study had 1 or more claims totaling at least a 90-day supply of either study drug during the subsequent 90 days (DACON measurement period). Patients were excluded if there was evidence of a switch from one to the other study opioid during the 90-day measurement period. There were no limitations on the use of other opioids, either short- or long-acting, during either the DACON measurement period or the previous 6 months (baseline period). In addition, patients were excluded if the enrollee was younger than 18 years old, pregnant, did not have continuous insurance coverage for the 6 months before and after the start of the 90-day DACON measurement, or were enrolled in an HMO plan. Bivariate analyses were performed with between-group differences in DACON values assessed using t-tests and Wilcoxon rank sum tests. Patient characteristics including age, sex, geographic location, and baseline Charlson Comorbidity Index (CCI) for each drug group were evaluated descriptively using either the Pearson chi-square test or t-test. Multivariate analyses were conducted using generalized linear models (GLM) to adjust for the observed heterogeneity among patients in the observational database. For the GLMs, the gamma distribution and log link function were chosen to account for non-normal distributions of DACON. Independent variables included study drug, tablet strengths, age, sex, CCI, the maximum days gap between prescription refills during the DACON measurement period, and other opioid medication use. Several sensitivity analyses were conducted to verify all findings. The final analyses were conducted on 6,567 oxycodone CR patients and 796 oxymorphone ER patients. The unadjusted DACON mean value for the highest strength of oxycodone CR 80 milligrams (mg) was 3.9, compared with 2.9 for oxymorphone ER 40 mg (P < 0.001); mean DACON values were 3.0 versus 2.4, respectively, for lower strengths (P < 0.001) and 3.1 versus 2.5 for all strengths (P < 0.001). After adjusting for age, sex, CCI, maximum gap days, and other opioid medication use, a risk-adjusted mean difference in DACON remained, with oxycodone CR patients receiving on average 0.6 tablets more per day than those dispensed oxymorphone ER (P < 0.001). The direction, magnitude, and statistical significance of these differences were essentially unchanged in sensitivity analyses. On average during a 90-day time period, patients taking oxymorphone ER consumed 0.6 fewer tablets per day than did patients taking oxycodone CR. Further research is necessary to see if this difference amounts to cost savings for health plans that provide prescription reimbursement for patients with chronic pain syndromes.
    Journal of managed care pharmacy: JMCP 06/2011; 17(5):367-76. · 2.41 Impact Factor
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    ABSTRACT: Patients managing chronic non-cancer pain with cytochrome P450 (CYP450)-metabolized opioid analgesics who concurrently take another CYP450-metabolized medication experience a drug-drug exposure (DDE), which puts them at risk for a pharmacokinetic drug-drug interaction (PK DDI). This study examined the economic impact of incident DDEs with the potential to cause PK DDIs compared to similar patients without such exposure. This retrospective analysis used paid claims from a large, commercially insured population during January 1, 2004 through December 31, 2008. Propensity matching was used to control for baseline differences in comparisons between 85,043 exposed and 85,043 non-exposed patients. Comparisons yielded mean total costs 6 months after the DDEs that were significantly higher in subjects with DDE versus matched subjects without DDE [$8165 (SD $11,357) vs. $7498 (SD $11,668), respectively, p<0.01] resulting in a difference of $667. This was driven by medical costs [$5520 (SD $10,505) vs. $5222 (SD $10,689), respectively, p<0.01] a $298 difference, and total prescription costs [$2646 (SD $3262) vs. $2276 (SD $3907), respectively, p<0.01] a $369 difference. The study design demonstrates associations only and cannot establish causal relationships. Further, relevant DDEs were not included if concurrent consumption occurred outside the index period and when CYP450 substances were consumed that are not reflected in pharmacy claims (herbals, over-the-counter medications). Since concurrent exposure to DDEs with the potential to cause PK DDIs may be relatively common, policy decisions-makers should consider the use of long-acting opioids that are not metabolized through the CYP450 pathway.
    Journal of Medical Economics 05/2011; 14(4):390-6.
  • Value in Health 01/2011; 14(3). · 2.19 Impact Factor
  • Value in Health 01/2011; 14(3). · 2.19 Impact Factor
  • Value in Health 01/2011; 14(3). · 2.19 Impact Factor
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    ABSTRACT: Patients taking more than one drug metabolized through the cytochrome P450 (CYP450) enzyme system experience a drug-drug exposure (DDE), which puts them at risk for a potential pharmacokinetic drug-drug interaction (DDI), defined as two or more drugs interacting in such a way that the effectiveness and/or toxicity of one or all drugs are changed. Any patient subjected to a DDE is at risk for a potentially serious DDI, the epidemiology of which has not been thoroughly studied. Many drugs are metabolized primarily via the CYP450 enzyme system, including certain opioids used to manage moderate to severe chronic pain. We conducted a retrospective analysis of a large commercial claims database and a Medicare database to assess the prevalence of DDEs among patients with osteoarthritis taking CYP450-metabolized opioids. The overall prevalence of DDEs in this population was 26%, with females more likely to experience DDEs than males (28.4% vs. 21.0%, respectively). The number of unique concurrent prescriptions at baseline, gender, age, and Charlson Comorbidity Index were statistically significant predictors of DDEs (P < 0.05). This study challenged previous assumptions about DDEs in that advanced age was not positively associated with the risk of DDE. However, the number of prescriptions the patient received in the 90-day window prior to the index date was a risk factor. For patients taking at least two medications in the 90-day period prior to the index date, every additional prescription taken increased their risk for a DDE during the observation period by 138% (on average). The risk of DDE during the study period was threefold greater for patients with one medication in the 90-day period before index date compared with similar patients with no prescriptions in that same period before the index date. DDEs are more common than may be generally believed in patients with osteoarthritis, regardless of age, and can occur even in patients taking few medications. When selecting an opioid analgesic to treat osteoarthritis, physicians should consider the potential for exposure of these patients to drugs that could interact unfavorably. 
    Pain Practice 12/2010; 11(4):325-36. · 2.61 Impact Factor
  • Journal of Pain - J PAIN. 01/2010; 11(4).
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    ABSTRACT: To compare demographic and comorbidity profiles and healthcare costs of Medicaid patients with postherpetic neuralgia (PHN) treated with lidocaine patch 5% (lidocaine patch) versus patients not treated with the lidocaine patch. Repeat comparison for the subset of patients treated in long-term care (LTC) settings. Patients, age≥18 years, with PHN diagnosis, or PHN-likely patients with herpes zoster diagnosis and ≥30 days of PHN-recommended treatment, were identified in Medicaid claims from Florida, Iowa, Missouri, and New Jersey (1999-2007). Patients had continuous eligibility 6 months before (baseline) and 12 months after (study period) the PHN index date. Patients with ≥1 claim for a lidocaine patch during the study period (n=872) were compared to patients without a lidocaine patch claim (comparison group). Baseline characteristics, study period treatment and healthcare costs (reimbursements by Medicaid for medical services and prescription drugs) were compared between groups using univariate analyses. PHN patients in the lidocaine patch group were older (64.5 vs. 62.2 years; p=0.002) and had higher rates of pain-related comorbidities (e.g., back/neck pain, osteoarthritis) than comparison patients. Average PHN-related drug costs per patient were higher ($1994 vs. 1137; p<0.0001) among lidocaine patch patients, with lidocaine patch accounting for $505 of the difference. PHN-related medical costs appeared lower in the lidocaine patch group, although not statistically significant ($983 vs. 1294; p=0.1348). No significant differences were found in total healthcare costs ($20,175 vs. 19,124; p=0.3720) across groups, despite higher total prescription drug costs among lidocaine patch patients. A similar pattern was observed among LTC patients. Despite higher rates of comorbidities and prescription drug costs, lidocaine patch patients had similar study period healthcare costs as comparison patients. The cost of the lidocaine patch represented a small fraction of overall costs incurred over the study period. Findings are based on a Medicaid sample and may not be generalizable to all PHN patients.
    Journal of Medical Economics 01/2010; 13(3):472-81.
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    ABSTRACT: Drug-drug interactions (DDIs) have been defined as two or more drugs interacting in such a way that the effectiveness and/or toxicity of one or all drugs are changed. Patients taking more than one drug metabolized through the cytochrome P450 (CYP450) enzyme system, including some, but not all, opioids experience a drug-drug exposure (DDE), which may result in a potentially dangerous DDI. Using a retrospective analysis of a large commercial claims database and a Medicare database, we evaluated DDEs that have the potential to cause DDIs among chronic low back pain (cLBP) patients on long-term opioid analgesia, which metabolizes through the CYP450 enzyme system, concomitant with other CYP450-metabolized drug(s). The overall prevalence of DDEs among cLBP patients was 27%. Women had a higher prevalence of DDEs (30.6% vs. 22% for men). Patients aged 45 to 55 and 56 to 64 years had the highest prevalence of DDEs (30.4% and 29.8%, respectively), followed by patients 34 to 45 years (27.9%). For patients>65 years, the prevalence of DDEs was 23.1%. In general, the prevalence of DDEs was fairly consistent across age ranges in this population. This study suggests that DDEs are common in the cLBP population. When selecting an opioid to treat cLBP, physicians should consider the potential for exposure of these patients to drugs that might unfavorably interact and, for that reason, the use of opioids that do not rely on the CYP450 system as their primary means of metabolism might be worthy of consideration.
    Pain Practice 01/2010; 11(3):230-9. · 2.61 Impact Factor
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    ABSTRACT: To compare healthcare resource utilization and costs of postherpetic neuralgia (PHN) patients initiating lidocaine patch 5% (lidocaine patch) or oral gabapentin/pregabalin. Patients with PHN diagnosis, or herpes zoster diagnosis and ≥30 days PHN-recommended treatment were selected from de-identified Medicaid claims data from Florida, Iowa, Missouri, and New Jersey, 1999-2007. Patients initiated monotherapy with lidocaine patch or gabapentin/pregabalin after PHN diagnosis, had continuous eligibility 6 months before (baseline) and 6 months after (study period) medication index date, and were ≥18 years old. Lidocaine patch patients were matched to gabapentin/pregabalin patients based on their propensity to initiate treatment. Study period resource utilization and costs from a Medicaid perspective were compared between treatment groups using univariate analysis. Matched patients were on average 61.3 years old, approximately 73% were women, and 55% had other painful conditions during the baseline period. 6-month per patient PHN-related prescription drug costs were similar for matched lidocaine patch (n=312) and gabapentin/pregabalin (n=312) patients ($854 vs. 820, p=0.75), while PHN-related medical costs appeared lower in the lidocaine patch group ($145 vs. 353, p=0.12). Furthermore, there were no statistically significant differences between treatment groups during the observation period in overall resource utilization, total prescription drug costs, and total medical costs per patient. In spite of higher list prices, PHN patients treated with lidocaine patch cost no more than patients treated with gabapentin or pregabalin in terms of overall healthcare costs over the 6-month study period. The study suggests that PHN-related medical costs may be lower among lidocaine patch patients. Findings are based on a Medicaid sample and may not be generalizable to all PHN patients.
    Journal of Medical Economics 01/2010; 13(3):482-91.
  • Value in Health 01/2008; 11(6). · 2.19 Impact Factor

Publication Stats

33 Citations
5 Downloads
713 Views
23.27 Total Impact Points

Institutions

  • 2010–2012
    • Analysis Group
      Boston, Massachusetts, United States
  • 2011
    • Endo Pharmaceuticals
      Philadelphia, Pennsylvania, United States
  • 2010–2011
    • Johns Hopkins University
      • Department of Medicine
      Baltimore, MD, United States