ADHD medication use, adherence, persistence and cost among Texas Medicaid children

OBJECTIVES

(1) Describe ADHD medication use, adherence and persistence. (2) Determine factors (e.g., medication type, demographics, concomitant medication use) associated with ADHD medication adherence and persistence. (3) Compare ADHD medication costs.

METHODS

Continuously enrolled Texas Medicaid children (3-18 years) with ≥ 2 ADHD prescription claims (July 2002-December 2008) were included. Prescription claims were grouped by medication type (i.e., immediate-release, extended-release, prodrug, non-stimulant); medication class (i.e., stimulant, non-stimulant); and duration of action (i.e., long-acting, short-acting). Adherence, using medication possession ratio, was measured continuously and dichotomously (80% cut-off). Persistence was days of continuous therapy without a 30-day gap and medication costs were reimbursement amount paid to dispensing pharmacies.

RESULTS

The study sample (n = 62,789) was primarily 6-12 years (61.7%) and male (69.2%). The majority of the subjects were prescribed extended-release agents (70.3%), stimulant agents (86.4%), and long-acting agents (84.5%). Adherence and persistence (adherence mean ± SD; adherence dichotomous; persistence mean ± SD) varied among medication type and was highest for non-stimulants (52.5 ± 30.9; 25.8%; 153.3 ± 124.3), followed by extended-release stimulants (52.1 ± 30.2; 24.1%; 143.7 ± 120.8), prodrug stimulants (47.6 ± 30.9; 21.1%; 113.3 ± 100.5) and immediate-release stimulants (37.2 ± 27.1; 9.8%; 95.4 ± 92.6). Logistic regression showed immediate-release stimulant users were 67% less adherent than non-stimulant users (p < 0.0001) and linear regression showed immediate-release, extended-release and long-acting users (p < 0.0001) were significantly less persistent than non-stimulant users. Females, increase in total number of medications, and comorbid medications were associated with better adherence and persistence. Non-stimulant agents ($4.04 ± $2.15) had the highest mean medication cost per patient per day and immediate-release stimulants had the lowest ($1.24 ± $0.97).

CONCLUSIONS

ADHD medication adherence and persistence was suboptimal. Although there was no difference in adherence between long-acting stimulant and non-stimulant users, non-stimulant users were more persistent compared to stimulant users. This study was limited due to the use of retrospective prescription claims data, which cannot capture actual patient use patterns, ICD-9 diagnoses, family history and support, or side effect profiles. Because ADHD can be effectively treated with pharmacotherapy, providers should be proactive in identifying patients with poor adherence and intervene to address barriers to medication adherence and persistence.

Costs and effectiveness of ximelagatran for stroke prophylaxis in chronic atrial fibrillation

CONTEXT

Recent trials have found that ximelagatran and warfarin are equally effective in stroke prevention for patients with atrial fibrillation. Because ximelagatran can be taken in a fixed, oral dose without international normalized ratio monitoring and may have a lower risk of hemorrhage, it might improve quality-adjusted survival compared with dose-adjusted warfarin.

OBJECTIVE

To compare quality-adjusted survival and cost among 3 alternative therapies for patients with chronic atrial fibrillation: ximelagatran, warfarin, and aspirin.

DESIGN

Semi-Markov decision model.

PATIENTS

Hypothetical cohort of 70-year-old patients with chronic atrial fibrillation, varying risk of stroke, and no contraindications to anticoagulation therapy.

MAIN OUTCOME MEASURES

Quality-adjusted life-years (QALYs) and costs in US dollars.

RESULTS

For patients with atrial fibrillation but no additional risk factors for stroke, both ximelagatran and warfarin cost more than 50,000 dollars per QALY compared with aspirin. For patients with additional stroke risk factors and low hemorrhage risk, ximelagatran modestly increased quality-adjusted survival (0.12 QALY) at a substantial cost (116,000 dollars per QALY) compared with warfarin. For ximelagatran to cost less than 50,000 dollars per QALY it would have to cost less than 1100 dollars per year or be prescribed to patients who have an elevated risk of intracranial hemorrhage (>1.0% per year of warfarin) or a low quality of life with warfarin therapy.

CONCLUSION

Assuming equal effectiveness in stroke prevention and decreased hemorrhage risk, ximelagatran is not likely to be cost-effective in patients with atrial fibrillation unless they have a high risk of intracranial hemorrhage or a low quality of life with warfarin.

Cost-benefit analysis of capecitabine versus 5-fluorouracil/leucovorin in the treatment of colorectal cancer in the Netherlands

BACKGROUND

Capecitabine is an oral prodrug of 5-fluorouracil and has been studied for the treatment of colorectal cancer. In 2 Phase III trials, capecitabine was at least as effective as 5-fluorouracil plus leucovorin and had a more favorable toxicity profile.

OBJECTIVE

A cost-benefit analysis was used to assess the pharmacoeconomic profile of capecitabine compared with 5-fluorouracil/leucovorin, given according to the Mayo regimen, for colorectal cancer patients treated in the Netherlands.

METHODS

The medical files of patients treated for colorectal cancer at a single center from 1999 to 2002 were examined to determine the numbers of outpatient visits for 5-fluorouracil/leucovorin administration, health care use and medication to manage adverse effects, and travel distance to and from the hospital. The costs of capecitabine treatment were simulated by assuming that the same patients were treated with capecitabine instead of 5-fluorouracil/leucovorin. Toxicity data for capecitabine were derived from 2 Phase III studies that compared capecitabine and 5-fluorouracil/leucovorin.

RESULTS

The files of 65 patients were reviewed. Thirty-two patients received adjuvant treatment and 33 patients were treated palliatively for metastatic disease. The mean total costs of palliative treatment were Euro 4004 with capecitabine and Euro 5614 with 5-fluorouracil/leucovorin. These results were robust in sensitivity analyses. The cost savings were primarily related to the number of outpatient visits for capecitabine versus the number of day-care treatment days for 5-fluorouracil/leucovorin, despite the higher acquisition costs of capecitabine.

CONCLUSIONS

Based on this analysis, treatment of colorectal cancer with oral capecitabine is cost saving in the Netherlands compared with 5-fluorouracil plus leucovorin administered according to the Mayo regimen. Baseline savings were estimated at Euro 1610 for palliative treatment and Euro 934 for adjuvant treatment.

The economic value of valacyclovir prophylaxis in transplantation

Cytomegalovirus (CMV) infection and disease, with its extensive direct and indirect consequences, adds considerably to the cost of patient management in both solid organ and bone marrow transplantation. Antiviral prophylaxis for CMV infection can offer cost advantages over preemptive therapy and "wait-and-treat" approaches. Valacyclovir has demonstrated efficacy for CMV prophylaxis in renal, heart, and bone marrow transplantation and is cost-effective when compared with placebo in renal transplant recipients at high risk of CMV infection. In reducing CMV infection and disease, valacyclovir prophylaxis appears to be associated with reductions in indirect effects of CMV (acute graft rejection, other opportunistic infections) and, if these effects are considered, the potential exists for even greater savings to be made with valacyclovir therapy. Benefits of valacyclovir in transplantation extend beyond CMV to other herpesviruses and may be increased in some clinical situations by prolonging prophylaxis beyond 3 months.

Inappropriate fosphenytoin use in the ED

The objective of the study was to evaluate how often intravenous (IV) fosphenytoin is used when oral phenytoin loading is possible. The methods included a retrospective chart review of all patients receiving IV fosphenytoin in the emergency department. We prospectively derived criteria that identify patients with seizures who could receive oral phosphenytoin loading (awake on arrival, alert, no emesis, and lack of endotracheal intubation, repeated seizures, or status epilepticus after arrival). The setting of the study was at an urban, university hospital emergency department with an annual census of 55,000 patients. The outcomes included the number of patients receiving IV fosphenytoin who could have received oral phenytoin loading. From February 1997 to June 1999, 55 patients received IV fosphenytoin. Thirty of these patients (55%, 95% confidence interval 41%-68%) were felt to have received fosphenytoin appropriately. The remaining 25 (45%, 95% confidence interval 32%-59%) patients could have been loaded orally with phenytoin. In a single institution, fosphenytoin administration is inappropriate almost half the time. Oral phenytoin loading is less expensive and safe.

Cost-minimization analysis of phenytoin and fosphenytoin in the emergency department

STUDY OBJECTIVE

To determine the value of fosphenytoin compared with phenytoin for treating patients admitted to an emergency department following a seizure.

DESIGN

Cost-minimization analysis performed from a hospital perspective.

SETTING

Hospital emergency department.

PATIENTS

Two hundred fifty-six patients participating in a comparative clinical trial.

INTERVENTION

Estimation of adverse event rates and resource use.

MEASUREMENTS AND MAIN RESULTS

In our base case, phenytoin was the preferred option, with an expected total treatment cost of $5.39 compared with $110.14 for fosphenytoin. One-way sensitivity analyses showed that the frequency and cost of treating purple glove syndrome (PGS) possibly could affect the decision. Monte Carlo simulation showed phenytoin to be the preferred option 97.3% of the time.

CONCLUSION

When variable costs of care are used to calculate the value of phenytoin compared with fosphenytoin in the emergency department, phenytoin is preferred. The decision to administer phenytoin was very robust and changed only when both the frequency and cost of PGS was high.

Fosphenytoin. Pharmacoeconomic implications of therapy

Advantages and disadvantages of Fosphenytoin. Advantages. More rapid intravenous administration than phenytoin and no need for an in-line filter. May be administered by intramuscular injection. Lower potential for local tissue and cardiac toxicity than phenytoin. Associated with less pain and phlebitis at the injection site, fewer reductions in infusion rate and fewer changes of administration site because of injection site complications than phenytoin. Benefits in terms of ease of administration and improved tolerability vs phenytoin have pharmacoeconomic implications which may translate into an overall cost advantage. Disadvantages. Approximately 10-fold higher acquisition cost vs phenytoin. Fosphenytoin is a parenterally administered prodrug of phenytoin, used in the treatment of patients with seizures. Advantages of fosphenytoin over phenytoin include more rapid intravenous administration, no need for an intravenous filter, and a lower potential for local tissue and cardiac toxicity. Unlike phenytoin, fosphenytoin may also be administered by intramuscular injection. Pharmacoeconomic data from a small study of patients with acute seizures in a US emergency department showed an overall cost advantage of fosphenytoin over phenytoin, despite a considerably greater acquisition cost of fosphenytoin. The main cost drivers for phenytoin therapy were treatment costs associated with adverse events. In view of the limited pharmacoeconomic data currently available, it is in the interests of individual institutions to conduct their own formal pharmacoeconomic studies applying local cost data and patterns of clinical practise to determine whether fosphenytoin should replace phenytoin on their formularly list.

Economic evaluation of famciclovir in reducing the duration of postherpetic neuralgia

The economic impact of famciclovir therapy for postherpetic neuralgia (PHN) in patients with acute herpes zoster was studied. A decision-analytic model of the treatment of herpes zoster and PHN was used to compare the cost of PHN between patients treated with oral famciclovir 500 mg three times daily for seven days and patients not receiving any antiviral therapy. The effects of famciclovir on PHN in the model were based on the results of a randomized, double-blind trial in 419 adult outpatients. The cost of the course of famciclovir therapy (21 tablets) was estimated as the sum of the drug's wholesale acquisition cost and the pharmacy dispensing cost. The cost of treating PHN (physician visits, medications, and miscellaneous nondrug therapy) was estimated by consulting a panel of physicians. According to the model, the cost of treating PHN was $85 lower per famciclovir recipient ($294 for famciclovir versus $379 for no antiviral therapy). The net cost of famciclovir therapy was $23 per patient ($108 for acquisition and dispensing minus the $85 savings). Among patients 50 years of age or older, famciclovir reduced the average cost of PHN by $155 ($414 for famciclovir versus $569 for no antiviral therapy) and yielded a net savings of $7 per patient. A model for the use of famciclovir to treat acute herpes zoster showed that the cost of such therapy was largely offset by savings in the cost of treating this complication.

Cost saving of 5-day therapy with cefpodoxime proxetil versus standard 10-day beta-lactam therapy for recurrent pharyngotonsillitis in adults. A prospective general practice study

A prospective economic evaluation was undertaken as part of a randomised clinical trial conducted in French general practice. Its aim was to compare the costs and therapeutic outcomes of a 5-day course of cefpodoxime proxetil 100 mg twice daily with 10-day courses of phenoxymethylpenicillin (penicillin V) 1 MIU 3 times daily and amoxicillin-clavulanic acid 500/125 mg 3 times daily for the treatment of recurrent pharyngotonsillitis in 575 adults. Over the 6-month study period, the total cost to society per patient treated with cefpodoxime proxetil was 123 French francs (FF; 1993 values) lower than that for patients treated with phenoxymethylpenicillin and FF227 lower than that for patients treated with amoxicillin-clavulanic acid. This cost saving was primarily attributable to a lower initial drug acquisition cost, and a reduction in the cost associated with lost productivity and general practitioner consultations. Furthermore, as a consequence of a lower relapse rate, the cost-saving ratio for cefpodoxime proxetil, expressed as FF per month free of recurrence, was FF50 less than for phenoxymethylpenicillin and FF60 less than for amoxicillin-clavulanic acid. Thus, a 5-day course of cefpodoxime proxetil is likely to be less costly for treatment of pharyngotonsillitis in the general practice setting than standard 10-day courses of phenoxymethylpenicillin and amoxicillin-clavulanic acid.

Fosphenytoin: a novel phenytoin prodrug

Fosphenytoin is a phenytoin prodrug that received an approvable letter from the Food and Drug Administration in February 1996. It was designed to overcome many of the shortcomings associated with parenteral phenytoin sodium. Specifically, fosphenytoin is a highly water-soluble, phosphate ester of phenytoin that has no known pharmacologic activity before its conversion to phenytoin. Dosing of fosphenytoin uses phenytoin equivalents (PE) to minimize dosage errors when converting from the conventional formulation. Pharmacokinetic studies documented that the agent is rapidly and completely converted to phenytoin after intravenous and intramuscular dosing. Reported conversion half-lives after intravenous administration range from 8-15 minutes. The absorption rate appears to be the rate-limiting step in the conversion of fosphenytoin to phenytoin after intramuscular administration (half-life range 22-41 min). Bioavailability of phenytoin derived from both intravenous and intramuscular fosphenytoin is essentially 100%. As a consequence of concentration-dependent protein binding, fosphenytoin is bioequivalent to phenytoin sodium at intravenous infusion rates of 100-150 mg PE/minute and 50 mg/minute, respectively. In clinical studies to date, fosphenytoin is safe and significantly better tolerated than phenytoin sodium when administered intravenously. It is also well tolerated when given intramuscularly, and this is a valuable alternative route of administration when intravenous access or cardiographic monitoring is unavailable. Its pharmacoeconomic advantages over phenytoin have not been documented in formal studies to date, although the likelihood of savings based on cost-effectiveness analyses is high. Hence, fosphenytoin has the potential as a safe, well-tolerated, and effective means of delivering phenytoin parenterally in a variety of clinical settings.

Cefpodoxime proxetil. An appraisal of its use in antibacterial cost-containment programmes, as stepdown and abbreviated therapy in respiratory tract infections

Cefpodoxime proxetil is an orally administered prodrug which is converted in vivo to the third generation cephalosporin cefpodoxime. Cefpodoxime has a similar spectrum of antibacterial activity to the parenteral cephalosporins ceftriaxone and cefotaxime and a long elimination half-life, which allows once- or twice-daily administration. Cefpodoxime proxetil has proven efficacy in the treatment of community-acquired pneumonia and upper respiratory tract, skin and soft tissue and urinary tract infections. It has been evaluated for use in cost-containment programmes, as stepdown (parenteral-to-oral conversion) therapy in the treatment of community-acquired pneumonia and as abbreviated therapy in upper respiratory tract infections. Substituting oral for parenteral therapy can achieve considerable savings (in acquisition, delivery and labour costs). Moreover, oral administration has advantages for the patient in terms of comfort and mobility, avoids the hazards of parenteral delivery and may allow earlier discharge from hospital, or even allow home treatment from the outset in low-risk patients. As hospitalisation is usually the major cost component in treating serious infections, considerable savings can be made in this way. Pharmacy-driven stepdown programmes in 2 US hospitals have achieved cost savings by targeting patients with community-acquired pneumonia for early conversion from intravenous ceftriaxone therapy to oral cefpodoxime proxetil. Costs were compared with those from a control group of patients who continued to receive intravenous ceftriaxone until physicians deemed that oral therapy (with various agents) was appropriate. In one study, duration of parenteral therapy in the cefpodoxime proxetil group was reduced from 6.18 to 3.82 days and duration of hospitalisation was reduced from 10.06 to 6.23 days (p < 0.02), with corresponding hospitalisation cost reductions of $US7300 per patient. However, clinical trial data relating to the efficacy of cefpodoxime proxetil as stepdown therapy in patients initially requiring parenteral antibacterials are lacking. Abbreviated (4-to 7-day) cephalosporin regimens appear to be as effective as traditional 10-day penicillin regimens in the treatment of upper respiratory tract infections. Short regimens may improve patient compliance and tolerability, thereby reducing the costs of adverse effects and treatment failures. Data from preliminary clinical studies suggest that a 5-day course of cefpodoxime proxetil is as effective as an 8-day course of amoxicillin/clavulanic acid in treating either acute otitis media or sinusitis, and as effective as a 10-day course of amoxicillin/ clavulanic acid and more effective than a 10-day course of phenoxymethyl- penicillin in the treatment of pharyngotonsillitis. Cefpodoxime proxetil tended to be better tolerated and was associated with better compliance than penicillin-based regimens. Indeed, a pharmacoeconomic study showed that a 10-day regimen of cefpodoxime proxetil was associated with lower costs for treating adverse effects and treatment failures than a 10-day regimen of amoxicillin/clavulanic acid in the treatment of acute otitis media in children. A 5-day course of cefpodoxime proxetil had a lower cost per patient treated per month free of recurrence than a 10-day course of phenoxymethylpenicillin (non-generic) or amoxicillin/clavulanic acid in the treatment of recurrent pharyngotonsillitis. Thus, evidence to date suggests that cefpodoxime proxetil has potential for use as stepdown therapy in community-acquired pneumonia and in abbreviated therapy courses in upper respiratory tract infections. These preliminary observations require confirmation in well designed studies.

A double-blind randomized trial comparing the efficacy and safety of a 5-day course of cefotiam hexetil with that of a 10-day course of penicillin V in adult patients with pharyngitis caused by group A beta-haemolytic streptococci

A 10-day course of penicillin is the antibiotic regimen currently recommended by the American Heart Association (AHA) as treatment for patients with tonsillitis caused by group A beta-haemolytic streptococci (GABHS), with the aim of preventing both the suppurative and non-suppurative complications of this infection. This prospective, multicentre, randomized, double-blind, double-dummy clinical trial was undertaken in order to compare the efficacy of, tolerability of and compliance with a 5-day course of cefotiam hexetil (CTM) 200 mg bd with that of a 10-day course of penicillin V (PEV) 1 megaunit (600 mg) tds, to investigate the significance of recovering GABHS during or after treatment and to evaluate the potential economic advantages of short-term regimens. Two hundred and fifty ambulatory adult patients with a presumptive diagnosis (based on a positive rapid antigen detection test) of GABHS tonsillitis were recruited in 60 centres; the diagnosis was subsequently confirmed by a positive culture of a throat swab. At the time of entry into the trial there was no statistically significant difference between the groups in terms of clinical symptoms. In an intention-to-treat analysis, both the clinical and bacteriological response rates at days 10 and 30 were comparable for each group i.e. 106 of 119 (89.1%) patients and 90 of 109 (82.6%) patients respectively in the CTM group and 103 of 117 (88.0%) patients and 92 of 107 (86.0%) patients respectively in the PEV group. The times until defervescence and resolution of symptoms were also similar. Of the 115 patients in each group who were assessed at day 90, there were three clinical relapses in the CTM group and seven in the PEV group. No non-suppurative complications of GABHS infection were detected. Tolerance was significantly better in the CTM group than in the PEV group, 14 of 119 (11.8%) patients and 26 of 117 (22.2%) patients in the former and latter groups respectively reporting adverse events. In three cases in each group treatment was discontinued prematurely because of adverse events; none of these in the CTM group was serious but one patient in the PEV group experienced a severe allergic reaction. Compliance in both groups was good during the first 5 days of therapy but, by the end of each course, 93.6% of patients in the CTM group had completed treatment, compared with 73.0% in the PEV group.(ABSTRACT TRUNCATED AT 400 WORDS)

Pharmacoeconomic benefit of antibiotic step-down therapy: converting patients from intravenous ceftriaxone to oral cefpodoxime proxetil

OBJECTIVE

To evaluate the economic benefit associated with the early conversion of therapy from intravenous ceftiaxone to the comparable oral third-generation cephalosporin, cefpodoxime proxetil.

DESIGN

Open-label, unblind, nonrandomized clinical trial.

SETTING

A 360-bed Veterans Affairs Medical Center.

PATIENTS

Forty patients who began receiving intravenous ceftriaxone for either a community-acquired pneumonia or a complicated urinary tract infection.

INTERVENTION

twenty patients were selected, based on clinical assessment, to be converted from intravenous ceftriaxone to oral cefpodoxime proxetil. Twenty other comparable patients who would have been appropriate for step-down therapy, did not receive pharmacy intervention and were used as a control group.

MEASUREMENTS

Both groups were assessed and compared for length of ceftiaxone therapy, length of oral follow-up therapy (if any), length of hospitalization, results of culture and sensitivity testing, treatment success and readmissions, and cost of respective therapeutic regimens.

RESULTS

In the cefpodoxime study group, the average time receiving intravenous and oral antibiotics was 9.1 days at a total cost of $3040.26 for the 20 patients. In the control group, the average time receiving intravenous and oral antibiotics was 11.9 days at a total cost of $3961.26. A savings of $46.05 per patient was achieved. Patients receiving step-down therapy averaged 1 fewer day of hospitalization.

CONCLUSION

Pharmacist intervention and cefpodoxime step-down therapy were associated with decreased overall antibiotic costs in our intravenous-to-oral program.

A pharmacoeconomic comparison of amoxicillin/clavulanate and cefpodoxime proxetil in the treatment of acute otitis media

This report describes the results of a review that was done to compare, from the patients' and their parents' perspective, costs involved in treating acute otitis media in children with amoxicillin/clavulanate potassium or cefpodoxime proxetil. The following costs were included in the analysis: average wholesale price of the initial antibiotic prescribed, cost of initial and follow-up physician visits for additional treatment, antibiotics for treatment failures, and medications and products required to manage side effects. The amount of time that parents were required to take off work or school to deal with treatment failures or side effects in their children and the number of times that parents phoned the physician about side effects were also monitored. The acquisition costs of the initial antibiotics were slightly higher for patients who received cefpodoxime proxetil than for those who were given amoxicillin/clavulanate. However, the total costs were greater with amoxicillin/clavulanate therapy. In addition, the time that parents were required to take to deal with treatment failures or side effects in their children was greater in the amoxicillin/clavulanate group. More parents from the amoxicillin/clavulanate group also phoned their physicians about side effects. The results of this review confirm that there are many factors in addition to acquisition cost that must be considered when determining the total cost of treating a patient with a specific drug.