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Impact of a Medicare MTM Program: Evaluating Clinical and Economic Outcomes | Page 2

Published Online: February 25, 2014
Rita L. Hui, PharmD, MS; Brian D. Yamada, PharmD; Michele M. Spence, PhD; Erwin W. Jeong, PharmD; and James Chan, PharmD, PhD
Descriptive statistics, including x2, t test, and Wilcoxon rank sum test, were used to compare baseline characteristics. In order to identify the direct impact MTM services had on the outcomes of interest, multiple logistic regressions were used to analyze proportion of patients who were hospitalized or who visited the ED; the Cox proportional hazards model was used to analyze death rate; and multiple ordinary least squares modeling was used to analyze changes in daily medication costs. Except for the Cox proportional hazards model, each model was adjusted for age, gender, region, CCI, and prior utilization of the same outcomes. All outcomes, except changes in daily medication costs, were analyzed as dichotomous variable. Changes in medication costs were analyzed as continuous variable. Test for proportional hazards assumption was assessed for the Cox proportional hazards models. Identical and separate analyses were done on study groups that were enrolled in 2010 because of the substantial changes in enrollment criteria. All analyses were performed using SAS 9.1.3 (SAS Institute, Cary, North Carolina).

RESULTS

During the study period from 2006 to 2010, a total of 46,734 MPD members had received an MTM comprehensive medication review. After applying the matching and exclusion criteria, 34,532 members receiving MTM services were identified and matched to 138,128 control members in a 1:4 ratio (Figure) based on age, gender, geographic location, and DxCG risk score. Over 81% of the members in both groups had a 1-year follow-up period. It represented 31,549 personyears in the study group and 124,546 person-years in the control group. Study enrollment rate was similar during 2006 to 2009, however, enrollment significantly increased in 2010, due to CMS-mandated changes, and these enrollees comprised 39% of the entire study cohort (MTM: 13,402; control: 53,608). The study population had a mean age of 75 ± 8 years, 58% were female, and the median DxCG score was 1.5 (IQR 0.8-2.5). Based on the 12-month data prior to enrollment to MTM services, the study group had a significantly higher CCI (a score that predicted the relative risk of death from prognostic clinical covariables), a higher rate of inpatient hospitalizations and ED usage, and higher daily medication costs than the matched controls (Table 1).

Unadjusted observed outcomes rates are presented in Table 2 for the entire cohort and in Table 3 for members that were enrolled in 2010. No differences were found in the unadjusted all-cause mortality rate between the 2 groups (5.7% in study group vs 5.6% in matched group), while the same mortality rate was significantly lower in the MTM group for the cohort enrolled in 2010 only (4.3% vs 5.0%, P <.001). In the pre-intervention period, the MTM group had a higher percentage of hospitalization compared with the control group (absolute between-group difference of +5.75%) and a higher percentage of ED visits (absolute difference of +9.3%) (Table 1). In the postintervention period, the MTM groups showed an absolute reduction in hospitalization of 4.1% while the control group showed an increase of 2.1% (absolute between-group differences of + 0.5%). Similar change was seen with ED visits with an absolute between-group difference of 6.2%, down from 9.3%. In the 2010 cohort, a significantly lower proportion of the MTM group was hospitalized (Table 3: 24.1% vs 24.9%), despite higher percentage of hospitalization in pre-period (27.3% vs 22.1%). We also observed a narrowing in the absolute difference in the percentage of ED visits (3.4% during study vs 7.7% before study). A difference in change of daily median prescription cost was also observed between the 2 study groups, with a median decrease of $0.39 for the MTM group and a median increase of $0.10 for the matched group (P <.001).

The adjusted outcomes comparing the MTM group with the matched group are presented in Table 4. The adjusted proportional hazard ratio for mortality was significantly lower at 0.86 (confidence interval [CI], 0.84-0.88, P <.001) for the entire cohort and at 0.71 (CI, 0.68-0.75, P <.001) for the 2010 cohort. The adjusted logistic regression analysis shows a significantly lower odds of hospital admission in the MTM group (odds ratio [OR] = 0.97 [CI = 0.94-0.99, P = .016] for the entire cohort and OR = 0.91 [CI 0.87-0.95, P <.001] for the 2010 cohort). The OR of ED visits was significantly higher in the MTM group. The change in daily medication costs for the MTM group was not different from the matched group.

DISCUSSION

In this large, retrospective, matched cohort study, we observed a 14% reduction in the risk of mortality, a 3% reduction in the risk of hospitalizations, 17% increased risk for ED visits, and no differences in change in median daily medication costs for MPD beneficiaries within 12 months after receiving MTM services, compared with a matched group of Medicare patients who did not receive MTM services. The same trend, but with a more profound magnitude, was observed in the subgroup enrolled in 2010 when the criteria for MTM services had changed. The improvement in patient outcomes may be due to a combination of services and interventions provided by MTM ambulatory care pharmacists. These interventions included optimizing medication regimens under physician-approved protocol, providing education on medication use to enhance patient understanding and appropriate use which may lead to increased adherence, ordering necessary laboratory testing, and coordination of care. Optimizing drug therapy by the pharmacist usually consisted of simplifying treatment regimens, titrating existing medication regimens to achieve therapeutic goals or reduce the likelihood of adverse reactions, initiating new medications when gaps in therapy were identified, discontinuing duplicate or unnecessary therapies, including drugs on the Beer’s List recommended to be avoided in the elderly; and switching drug therapy to avoid drug-drug interactions. These interventions may help achieve targeted clinical goals that benefit the patient’s health status.3,4,6,7 Lastly, participating MPD beneficiaries and plans providing MTM services can benefit economically by managing prescription drug costs through appropriate drug use, use of generics, and elimination of unnecessary medications. 6,8 These measures may reduce total drug spending and delay the time for MPD beneficiaries to reach the coverage gap (donut hole) and incur out-of-pocket costs. Although we did not observe a significant decrease in change of daily medication costs in this study, we were able to find improvement in other outcomes without an increase in medication costs. We do not have data on the number or type of interventions outlined above during 2006 to 2009 as they were not recorded in an analyzable format. In 2010, there were a total of 51,732 interventions recorded by the MTM program. The impacts of specific types of interventions warrant future study.

The results of this study support findings reported in the available literature. In a study by Welsh et al,10 a reduction in mortality risk was observed in patients enrolled in an MTM program (OR 0.5; 95% CI, 0.3-0.9). The results of our study did not show as great a decrease in mortality for the entire study population or the 2010 subgroup. This may be due to differences in study design between the 2 studies. Our study design included matching, with the intention of obtaining groups with similar cost burden using DxCG scores. Conversely, the study by Welsh et al compared patients who agreed to enroll in the MTM program with those who declined participation.

A mixed impact of the MTM programs on hospital admissions and ED visits was observed in the literature. Some studies have shown no difference or a reduction in hospital admissions, while others have shown an increase associated with MTM programs.8,10,14,22 Explanations for the reduction in proportion of patients being hospitalized include improved medication management, while the increase in hospitalizations may be due, in part, to a reduction in mortality. Our study demonstrated that there was a reduction in hospital admission but an increased rate of ED visits in a sicker MTM study population compared with a control group.

Similarly, studies have shown the impact of MTM on medication costs can vary due to a multitude of reasons.6-8,10 Reductions in medication costs include discontinuation of duplicate medications and those to be avoided in the elderly, and medications with an inappropriate indication. Increased medication costs may be due to the addition of medications identified as gaps in therapy, titrating of medications, and increased adherence.

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Issue: February 2014
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