Objectives:

To describe intervention components and implementation features (Key Question [KQ]1) for outpatient medication therapy management (MTM) interventions with comprehensive medication review, followup, education, and care coordination; assess the effectiveness of these MTM interventions on intermediate, patient-centered, or resource utilization outcomes (KQ 2); identify intervention features (KQ 3) and patient characteristics (KQ 4) that moderate the effect of an intervention on outcomes; and assess harms associated with interventions (KQ 5).

Data sources:

MEDLINE^®, Cochrane Library, International Pharmaceutical Abstracts, gray literature, additional studies from reference lists and technical experts

Review methods:

Two trained reviewers selected, extracted data from, and rated the risk of bias of relevant trials and cohort studies. We used random-effects models to estimate pooled effects for outcomes with three or more similar studies with a low or medium risk of bias. For other outcomes, we synthesized the data qualitatively.

Results:

We included 44 eligible studies (21 randomized controlled trials, 4 controlled clinical trials, and 19 cohort studies) reported in 61 articles, described in detail in the report (KQ 1). Evidence was insufficient on the effect of outpatient MTM interventions on most outcomes (KQ 2). In a few instances, described below, the evidence led us to conclude benefit or lack of benefit. Specifically, we found evidence that MTM results in improvement when compared with usual care for some measures of medication adherence and appropriateness; medication dosing; health plan expenditures on medication costs; and, for patients with diabetes, the proportion hospitalized and costs of hospitalization. Similarly, we conclude, based on a low strength of evidence, that MTM confers no benefit for patient satisfaction and most measures of health-related quality of life.

We found evidence on five intervention components and intervention features (KQ 3). One study provided information on each feature and yielded insufficient evidence for most outcomes, with the following two exceptions. An MTM program with pharmacist access to brief clinical summaries from the medical record reduces the mean number of adverse drug events when compared with a basic MTM program without such access (low strength of evidence). Community pharmacists increase the generic dispensing ratio more than call-center–based pharmacists (low strength of evidence). We found no relevant studies on patient characteristics moderating the effect of MTM interventions (KQ 4). Similarly, the evidence on harms associated with MTM was limited to one study on inconvenience and was rated as insufficient (KQ 5).

Conclusions:

The evidence base offers low evidence of benefit for a limited number of intermediate and health utilization outcomes. We graded the evidence as insufficient for most other outcomes because of inconsistency in direction, magnitude, and precision, rather than lack of evidence. Wide variations in populations and interventions, both within and across studies, likely explain these inconsistencies. Given the widespread implementation of MTM and urgent need for actionable information, optimal investments in new research require a process of research prioritization in which the value of information from each proposed study is carefully considered. Studies designed to identify causal relationships between MTM interventions and their outcomes require adequate controls for confounding but may offer limited information on the factors that explain program success or failure. Studies designed to explore the reasons for program success or failure using qualitative or single-arm designs may offer hypotheses-generating rather than hypotheses-confirming insights on MTM effectiveness. New research, regardless of specific focus, will likely continue to find inconsistent results until underlying sources of heterogeneity are accounted for.