Impact of an Educational Intervention for Secondary

MANAGERIAL

Impact of an Educational Intervention for Secondary Prevention of Myocardial Infarction on Medicaid Drug Use and Cost Ilene H. Zuckerman, PharmD; Sheila R. Weiss, PhD; Diane McNally, BPharm, MS; Barbara Layne, RN; C. Daniel Mullins, PhD; and Junling Wang, MS Objectives: The objectives of this drug utilization review program were (1) to increase β-blocker prescribing to fee-for-service post-acute myocardial infarction (AMI) Medicaid patients; (2) to improve compliance among patients who were prescribed βblockers post-AMI; and (3) to evaluate the economic implications of increased β-blocker prescribing. Study Design: Pre-post nonequivalent group design. Patients and Methods: The intervention targeted physicians of Pennsylvania Medicaid recipients who had an AMI between November 1, 1998, and November 1, 1999. Educational materials were sent to the physicians of post-AMI patients not receiving βblockers. Preintervention and postintervention rates of β-blocker prescribing in the Medicaid program within 7 and 30 days of discharge after an AMI hospitalization were compared. Similarly, preand postintervention compliance rates were compared for AMI patients who were prescribed β-blockers. Cost savings and number of avoided deaths also were calculated. Results: There was a 5.5% to 6.9% increase in β-blocker prescribing after the intervention, depending on the follow-up period. Postintervention AMI patients were 16% more likely to be prescribed a β-blocker. There was an 8.3% increase in patient compliance with β-blocker therapy from preintervention to postintervention. In the first 2 years of the intervention, the estimated cost savings to the Pennsylvania Medicaid program ranged from $71 970 to $76 678, respectively. An estimated 3 deaths were avoided. Conclusions: The intervention resulted in increased appropriate prescribing and compliance with β-blockers among post-AMI patients. There also were estimated cost savings to Pennsylvania Medicaid as a result of reduced hospitalization, and fewer deaths. (Am J Manag Care. 2004;10:493-500)

atients who survive an acute myocardial infarction (AMI) are at an increased risk for sudden death, nonsudden death, and reinfarction.1 In the past 2 decades, numerous trials have demonstrated that β-blockers can improve survival and reduce the rate of reinfarction in patients with AMI.2-8 However, published reports indicate that β-blockers are underutilized.9-25 Most educational programs targeting hospital physicians have successfully increased β-blocker prescribing during hospitalizations for AMI.26-29 These examples show that intensive educational programs can influence prescriber behavior and increase the proportion of

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patients who receive β-blockers after an AMI. However, these interventions were directed at hospital physicians. How these results might apply to a less intensive education program targeting ambulatory care physicians is unclear. Once AMI patients are prescribed a β-blocker, therapy should continue indefinitely, unless a complication arises. Therefore, compliance becomes an issue. In the Beta-Blocker Heart Attack Trial, investigators found that patients who took ≤75% of their prescribed βblocker regimen were 2.6 times more likely to die within the first year of follow-up than more compliant patients.30 Clinical data relative to long-term use of lifesaving drugs in 156 survivors of definite myocardial infarction at a government, university-affiliated teaching hospital were analyzed over a 24-month follow-up period. Among post-AMI patients who were discharged home with a β-blocker prescription, only 71% remained on their β-blocker medication at 24 months.31 Among intervention programs to increase the use of β-blockers after AMI, economic evaluations have not been done to our knowledge. Bradford et al believed that there are 3 types of costs associated with underutilization of β-blockers: (1) costs due to higher mortality or morbidity (reduced health) attributed to suboptimal care; (2) increased use of medical resources (eg, hospital admissions, physicians visits) because of less appropriate treatment; and (3) costs of less effective therapies.32 Due to the paucity of literature on cost implications of β-blockers, Bradford and colleagues could only calculate the first type of costs: years of life lost due to underutilization of β-blockers in the United States and the associated dollar value of the loss.

From the Center on Drugs and Public Policy, University of Maryland School of Pharmacy, Baltimore, Md (IHZ, SRW, DM, CDM, JW); and the Center for Professional Drug Education, Pennsylvania Medical Society, Harrisburg, Pa (BL). This study was supported by the Commonwealth of Pennsylvania’s Department of Public Welfare, Office of Medical Assistance Programs. Address correspondence to: Ilene H. Zuckerman, PharmD, Center on Drugs and Public Policy, University of Maryland School of Pharmacy, 515 W Lombard St, 2nd Floor, Baltimore, MD 21201. E-mail: [email protected].

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MANAGERIAL Soumerai et al estimated that β-blockers could reduce the risk of readmission to hospitals for all cardiac events by 22%.33 However, the cost consequences of cardiac events can vary significantly, which hinders the attachment of a dollar value to the reduction in hospital admissions. Goldman et al, in a widely cited article, examined the cost of β-blockers per year of life saved.34 Phillips et al used a computer-simulation Markov Model to estimate that the incremental cost per qualityadjusted life-year gained would always be less than $11 000.35 However, the cost implications in terms of life-years saved often are not the primary concern of intervention programs. On the contrary, the intervention programs are most interested in the cost savings to the payers. The overall goal of this educational intervention program was to increase the prescribing of β-blockers to fee-for-service Medicaid patients immediately after a hospitalization for AMI. A secondary project aim was to improve compliance among patients who were prescribed β-blockers post-AMI, but who were refilling their prescriptions at intervals that suggested poor compliance. The third aim was to evaluate the economic implications of an increase in β-blocker prescribing.

METHODS Educational materials were produced and distributed specifically for this project by the Pennsylvania Medical Society’s Center for Professional Drug Education. Physicians for the intervention were identified based on claims data. They were put into 1 of 3 groups: (1) those with post-AMI patients who were noncompliant with βblocker therapy; (2) those with post-AMI patients who had not been prescribed a β-blocker; and (3) all other physicians with a specialty identified by the Pennsylvania Medical Society that had the potential to treat a post-AMI patient (eg, internal medicine, family medicine). Cardiologists were excluded from the first 2 intervention groups because it was assumed that most patients were followed by their primary care physician after discharge from the hospital, and that cardiologists were more likely to prescribe β-blocker therapy when appropriate.36 In the first group, prescribing physicians were identified for those patients who had 1 or more β-blocker prescriptions, but had β-blocker availability rates below 80%. Beta-blocker availability rates were defined as the percentage of time when β-blockers were available for the patients after the initiation of β-blocker use postAMI. It was calculated by dividing the β-blocker available days by episode days for all recipients with 1 or more β-blocker claims after their index AMI hospital-

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ization. Beta-blocker available days were determined by counting days of drug availability based on the days supply from the dispensing date forward. Episode days were the number of days from the first β-blocker prescription after the AMI through termination of Medicaid fee-forservice eligibility, or the end of the study period, if earlier. Days hospitalized were subtracted from the denominator and patients with negative β-blocker availability rates due to extended hospitalizations were excluded. Compliance was defined as having β-blocker availability rates equal to or above 80%. Patients with βblocker availability rates below 80% were considered noncompliant. Patient drug history profiles were created for those patients for whom compliance was an issue. A case-bycase review of the profiles was conducted to exclude false-positives, which were patients who were labeled “positive” but who were in fact compliant based on implicit review by Pennsylvania Medical Society staff. These false-positives were probably due to administrative or data entry errors. From 309 “positive” patients, 135 were excluded. Two intervention educational packets were developed and administered. One packet was mailed to the physicians whose patients were identified as noncompliant. The educational materials included an introduction letter, the Counter Details newsletter, a Medicaid patient report, a response form, and each patient’s drug history profile. The introduction letter discussed the review aims and reported the overall post-AMI β-blocker prescribing and compliance rates in Pennsylvania Medicaid. The Counter Details newsletter, which offered continuing medical education credit, included current strategies in the treatment of myocardial infarction, identified the factors contributing to compliance problems among patients, and laid out actions that physicians need to take to increase patient compliance rates. The Medicaid patient report listed the physician’s noncompliant patients. In the drug history profiles, β-blocker prescriptions were grouped separately and listed first. The physician response form was included with the educational materials to assess the acceptance of the intervention by the physicians. The other packet was mailed to physicians whose patients were identified by the underutilization criterion. These physicians received an introduction letter and the Counter Details newsletter. If a physician had patients who met both criteria, they only received the compliance educational packet. In total, 328 physicians received “underutilization packages,” 157 physicians received “noncompliant packages,” and 10 972 physicians (the third group of physicians) received only the


JULY 2004

Secondary Prevention of MI Counter Details newsletter. We were unable Figure. Decision Tree of the Effects of the Intervention Program to determine what percentage of AMI patients saw these physicians in the postinSudden death tervention period. 3.6% The timeline of the study was as folNonsudden death lows: (1) Physicians were identified from 4.1% β-blocker November 1, 1998, through November 31, Nonfatal reinfarction 49.6%* 1999. (2) The intervention packages were 5.7% 64.7%† mailed to them on April 28, 2000. (3) Two Other weeks later a follow-up certified letter was 86.6% Postintervention sent to each nonresponder. (4) General mailSudden death ing of Counter Details newsletters to physi5.2% cians in the third group took place on May 1, Nonsudden death 2000. 4.6% Control To evaluate the impact of the educational Nonfatal reinfarction 50.4%* program on the prescribing of β-blockers † 7.5% 35.3% post-AMI, we calculated the proportion of Other AMI patients with a paid claim for a β-block82.7% er within 7 and 30 days of discharge. Sudden death Medicaid recipients who were hospitalized 3.6% for an AMI between November 1, 1998, and October 31, 2001, were identified through Nonsudden death Medicaid inpatient administrative claims. 4.1% β-blocker Patients were classified into 1 of 3 periods Nonfatal reinfarction 46.4%* based on the timing of their AMI hospitaliza† 5.7% 61.3% tion with respect to our educational proOther gram: preintervention (November 1, 1998, to Preintervention 86.6% March 31, 2000); during the intervention Sudden death period (April 1, 2000, through May 31, 5.2% 2000); and postintervention (June 1, 2000, Nonsudden death through October 31, 2001). Patients were 4.6% Control excluded if they were less than 21 years old, Nonfatal reinfarction 53.6%* if they died during the first (index) AMI hos7.5% 38.7%† pitalization, or if they had no prescription Other claims during the study period. 82.7% To avoid overestimation of β-blocker use, *7 days after discharge. †30 days after discharge. only the first AMI hospitalization within the study period was selected. Patients with available β-blockers, based on prescription history immediately before the AMI hospitalization, Medicaid eligibility, or an inpatient or psychiatric hoswere counted as receiving β-blockers in both the 7 and pitalization during these postdischarge periods, were the 30-day analyses. Patients without a pharmacy claim excluded from the 7-day and/or 30-day utilization cal100 days before the index AMI hospitalization were culations as appropriate. The economic effects of the intervention program excluded from this analysis to limit analysis to those with prescription benefits. Because this exclusion had were evaluated in terms of (1) cost savings to the such a large effect on the denominator (almost one half Pennsylvania Medicaid fee-for-service program and (2) of the patients were ineligible because they had no prior number of deaths avoided in the Pennsylvania prescriptions), it would tend to result in overestimation Medicaid program. The outcomes of patients who were of the percentage of β-blocker use in the population. discharged from hospitals after AMIs were categorized Because it is applied consistently over each time period, as sudden death, nonsudden death, nonfatal reinfarcit shouldn’t affect the relative difference from 1 period tion, and other, as reported in the Figure (probabili8 to the next. Finally, because of missing pharmacy data, ties were based on the meta-analysis by Yusuf et al ). © patients with fewer than 7 (or 30) days of continuous This figure was generated by using Data, Version 3.5,

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MANAGERIAL [1988-1998] Treeage Software, Inc,® of Treeage Inc, Williamstown, Massachusetts, USA.37 When estimated from the perspective of the Pennsylvania Medicaid program, the economic effects of the intervention program could result from the number of nonsudden deaths and number of nonfatal reinfarctions avoided. The total cost savings of the intervention was considered to be the sum of the reduced hospitalization costs for treating fewer patients with nonsudden deaths and the reduced costs for treating fewer patients with nonfatal reinfarctions. The data points were estimated as follows: The rates of nonsudden deaths for patients who were put on βblockers (4.1%) and for those who were not (4.6%), within an average follow-up period of approximately 2 years, were based on an estimate from the meta-analysis by Yusuf et al.8 From the same meta-analysis, the rates of nonfatal reinfarction were estimated to be 5.7% in the β-blocker group and 7.5% in the control group within the same follow-up period.8 The hospitalization cost of nonsudden AMI-related deaths was estimated to be $21 679, which was adjusted to 2001 dollars from a study that reported direct medical costs of treating a fatal AMI.38 The hospitalization cost for a patient who survived an AMI was estimated to be $19 326, which was adjusted to 2001 dollars from a study on the cost of ischemic complications.39 In addition to estimating the cost savings to the Pennsylvania Medicaid program, we also estimated the total number of deaths avoided due to the intervention. The reduction in mortality rates due to increased use of β-blockers was based on the meta-analysis by Yusuf et al, which reported that β-blockers could reduce the mortality rate from 10.0% to 7.9% in the long term.8 The total number of AMI patients considered (4914) was

based on the total number of unique patients with AMI hospitalizations after excluding multiple AMIs. Estimations of cost savings and deaths avoided were calculated for the actual increases seen in β-blocker use at 7 days and 30 days post-AMI. The retrospective drug utilization review program under which this study was conducted was reviewed and deemed to be exempt by the institutional review board of the University of Maryland (IRB protocol #0101412).

RESULTS

There were 5241 AMI hospitalizations during the 3year study period. With exclusions for multiple AMIs during the study period (n = 327), patients with no prescription claims within 100 days before the index AMI (n = 2408), and patients without follow-up time after discharge (n = 1002), the project evaluation was based on the remaining 2543 AMI patients (these categories of patients overlapped). As reported in Table 1, the majority of the patients were classified into the preintervention or postintervention period based on the timing of their AMI hospitalization with respect to our educational program. They were mostly women and more than 50 years of age. Comparing the preintervention and postintervention groups, there were no statistically significant differences in age and sex. However, compared with the preintervention group, the intervention group has a smaller proportion of patients under age 50 (P < .01). In the preintervention period, 46.4% of patients with an AMI hospitalization filled a β-blocker prescription within 7 days and 61.3% within 30 days of discharge (Table 2). These percentages increased to 49.6% of AMI patients at 7 days and 64.7% at 30 days postintervention. These results translated Table 1. Characteristics of the AMI Patients in Pennsylvania to a population-wide 6.9% increase in βMedicaid, November 1998–October 2001* blocker prescribing immediately after an AMI hospitalization (within 7 days of the Characteristic Preintervention† Intervention† Postintervention discharge). However, these increases were not statistically significant (χ2 = 2.35, P = Total 1249 143 1151 0.13, and χ2 = 2.44, P = .12, respectively). No. males (%) 461 (36.9) 49 (34.3) 409 (35.5) Using a multivariate proportional-hazards model to adjust for age group, sex, No. in age group (%) and race, patients with their first AMI in