Abstract

Introduction

In 2020, approximately 1 in 5 adults in the United States were living with a psychiatric disorder, which translates to approximately 52.9 million individuals.¹ Additionally, an average of 17% of young people experience an emotional, mental, or behavioral disorder.² Psychotropic medications make up nearly 20% of the treatment approaches for psychiatric disorders.³ Therefore, optimizing the safe and effective use of psychiatric medications is paramount. Pharmacists focusing on psychotropic medications and practicing across a wide variety of healthcare settings have significantly improved patient-level outcomes, including attaining therapeutic goals, improving medication adherence, managing adverse effects, and avoiding hospitalizations.⁴ In 1996, the Board-Certified Psychiatric Pharmacist (BCPP) credential was established, further demonstrating pharmacists’ expertise with appropriate training in managing these disorders.

Abundant evidence exists regarding pharmacist practices and their impact on patient care in psychiatric and neurologic settings. The American Association of Psychiatric Pharmacists (AAPP) Systematic Literature Review Committee developed a methodology to review articles highlighting psychiatric pharmacists’ impact on medication-related outcomes. The methodology provides a mechanism to identify newly published literature to continuously add to the current research outcomes, further supporting the impact of psychiatric pharmacists in a systematic approach.

This project aimed to identify, review, and evaluate primary literature published up to December 31, 2022, highlighting the improved patient-level, medication-related outcomes psychiatric pharmacists achieve as a part of the healthcare team.

Methods

A systematic search of literature published from January 1, 1961, to December 31, 2022, was conducted using PubMed. Limiting articles to PubMed ensured that all relevant studies were found in journals that abide by specific quality standards. PubMed also supports complex search queries and can export all results in a structured format; articles dating only as far back as 1961 were returned in the match. Other databases were excluded because the output required to review these additional articles would result in diminishing returns.

The search terms from the previous AAPP literature review⁴ were expanded to include disease-state terms associated with all categories of major psychiatric disorders and select major neurologic disorders with psychiatric manifestations that are primarily or secondarily treated with psychotropic medications (Table 1).⁴ The search was limited to papers with at least 1 “pharmacist” and 1 “psychiatric” term. Articles were additionally excluded based on article type and title keywords that strongly indicated that the article was not original clinical research. Terms such as “pain” were omitted from the query, such that pain studies were only included when they involved psychiatric comorbidity(ies).

TABLE 1 PubMed search criteria

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A final search of PubMed was performed on January 10, 2023, with a publication date filter of December 31, 2022. The results from PubMed were loaded into a spreadsheet to track inclusion and exclusion. The author group completed manual reviews of each article and documented inclusion or exclusion on the spreadsheet. Any questionable articles were brought to the group for further discussion. An article was manually excluded if it met any of the following 6 criteria:

• No pharmacist intervention

• No treatment of psychiatric disorder

• No clinical outcomes

• Not original research

• No full-text access

• No English-language version

A second reviewer evaluated at least 5% of excluded articles, predetermined by the authors, to confirm the accuracy and appropriateness of the exclusion. Publications with results describing patient-level outcomes associated with pharmacist provision of care in psychiatric/neurologic settings and/or in relation to psychotropic medications were included. Table 2 lists each study evaluator’s characterization and description of the study design and outcome measures. The quadruple aims, which include improved care, reduced healthcare costs, improved patient experience, and improved healthcare provider well-being, were also tracked for included articles to enhance outcomes data.

TABLE 2 Study characteristics

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Results

The Figure depicts the article identification, screening and eligibility, and total articles selected. A total of 4270 articles were pulled for review via PubMed. The study authors excluded 4072 articles based on title, abstract, and/or full text in the initial pass, with 208 articles selected for inclusion. The authors completed a second review of 7.5% of the articles, rather than the planned 5%. After a secondary review, 11 articles initially included were excluded, and 5 of 307 articles excluded were included, leaving a final total of 202 articles meeting the inclusion criteria (see Appendix). The top 6 journals by article count were the Journal of the American Pharmacists Association (14), the Mental Health Clinician (11), the American Journal of Health-System Pharmacy (8), the American Journal of Hospital Pharmacy (6), the Annals of Pharmacotherapy (6), and Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy (6). Over half of these articles were published in the United States. Patient demographics and other study characteristics are presented in Table 2.

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All applicable outcome measures and quadruple aims for each study were included during the study review, resulting in a total percentage exceeding 100 for each of these characteristics. Response to study treatment was the most common outcome measure in 141 total studies (69.5%). Other outcome measures tracked in the order of most to least frequent were medication-based (60 studies), patient experience/adherence (48), resource utilization (47), adverse outcome (24), cost-based (19), time-based (17), and retention/referral (13). Of the studies, 57% had more than 1 applicable outcome measure. Quadruple aims tracked from the most to least frequent were better care (202 studies; 4.5% had negative outcomes), improved patient experience (45), reduced health care costs (27; 3.7% had negative outcomes), and provider well-being (1). Almost one-fourth of the studies (23.8%) had more than 1 applicable quadruple aim.

Tobacco use disorder and major depressive disorder (MDD) were the most frequently assessed disease states, accounting for 38 and 27 included studies, respectively. All other specified disease states accounted for less than 10 included articles each, while a total of 81 (40.1%) did not specify the disease state being evaluated. In the general outpatient and community settings, psychiatric pharmacists increased smoking cessation response rates through methods such as behavioral counseling and/or nicotine replacement therapy.^5–10 Psychiatric pharmacists improved depression symptom scores in various clinical settings. Inpatients demonstrated reductions in the Hamilton Depression Rating Scale and the Patient Health Questionnaire-9 symptom scores.^11,12 Patient Health Questionnaire-9 scores improved for patients in outpatient general, outpatient specialty, and community pharmacy settings when a psychiatric pharmacist was involved in their care. Patients diagnosed with depression had enhanced medication adherence.^13–16 Patients seeking treatment for multiple disease states, including smoking cessation, depression, post-stroke/transient ischemic attack, and neurological disorders, reported better satisfaction and attitudes.^{5,8,10,16–31} Representing 72.8% of authorship, patients in long-term care facilities, outpatient general clinics, inpatient, primary care clinics, and community settings demonstrated improved satisfaction and attitudes when a psychiatric pharmacist was involved in their care.^{14,18,24,32–36} In addition, the presence of a psychiatric pharmacist improved the number of patients seen per month, the hours of direct care provided, the number of patient contacts, rehospitalization rates, the number of medications prescribed, and the length of stay.^37–50

Most of the included studies (83.2%) did not report any Board of Pharmacy Specialties (BPS) certification, including BCPP designation, or other advanced clinical training among the researchers. Some studies without evidence of BPS certification were published before the establishment of BCPP designation. Only 24 (11.9%) articles had at least 1 BCPP mentioned in the body of the paper as a part of the intervention. Eleven (5.4%) included authors with non-psychiatric certifications. The number of BCPPs represented in authorship varied by year, but no trend could be identified. Of the 64 articles from 2020 to 2022, 8 (12.5%) had at least 1 BCPP represented based on details included in the article, and 2 (3.1%) had at least 1 author with a non-psychiatric BPS certification. While BPS may not have been explicitly mentioned in the article, intervention by a “psychiatric pharmacist” was noted based on the description of the pharmacists’ training and/or experience, such as completing a psychiatric pharmacy residency or years of experience in the psychiatric setting.

Discussion

With 4270 articles reviewed, this was the most extensive and comprehensive evaluation of primary literature to date, highlighting the impact of psychiatric pharmacists on patient-level outcomes. The database underscores the wide range of clinical settings psychiatric pharmacists practice as well as the varied outcomes measured by their efforts. Additionally, through medication management, quadruple aims for mental healthcare were included such as improved care, reduced costs, patient experience, and provider well-being.

This review largely aligned with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), which aims to improve the reporting of systematic reviews and meta-analyses. However, there were slight deviations, such as not specifying effect measures because of the heterogeneity of the studies included and lack of certainty or confidence assessment except through a 7.5% rereview process. Although a rereview of all the articles would be ideal for verification, the authors only found a small number of articles either incorrectly included or excluded based on the second review.

Figure 1 follows the PRISMA template flow diagram detailing the identification of studies. The evidence identified and included in this report was limited to PubMed and may be considered too restrictive. While excluding non-PubMed studies is a limitation, an analysis showed that 90% (57/63) of the studies identified in the previous AAPP literature review⁴ are cataloged in PubMed, and 4 more were from the backfiles of journals that are now indexed. Additional studies may have been found through backward citation searching; however, this was not performed. Title, abstract, or full-text review were all used to exclude articles, but the proportion of articles excluded from each type of review was not quantified. An additional review of the excluded articles performed by a different reviewer on 7.5% of the articles resulted in the inclusion of 1.6% of those previously excluded articles. A total of 20 articles (0.5%) were excluded on the basis of inability to access the full text, which could be seen as a limitation. Reviewers made a reasonable attempt to obtain the full text of each article before marking it for exclusion.

Many of the studies (39, 19.3%) identified in this report were focused on tobacco cessation. This finding could pose a potential bias in the body of evidence as it may not be the most reflective of psychiatric pharmacy clinical practice. None of the tobacco cessation articles specified that a BCPP performed the intervention in the study design. A prior AAPP survey reviewing the current practice of psychiatric pharmacists in the United States¹⁷ found that the psychiatric conditions most commonly managed by BCPPs were depressive disorders, followed by anxiety disorders, bipolar disorders, and schizophrenia, which was not representative of the included articles. While some studies included details, such as pharmacist type, level of experience, or years of training, sufficient detail was not reported in 82.2% of the included studies, which may have offered more opportunities for critical appraisal. Because the body of evidence spanned 7 decades, the results in this report are limited by a lack of context, given how health systems and credentials for psychiatric pharmacists have evolved over time. Many excluded studies focused solely on adherence and economic outcomes, both of which are imperfect extrapolations of patient outcomes. Thus, focusing more on patient-level outcomes in such studies will be more compelling.

Despite these limitations, most outcomes in the articles included showed positive results. This may be a reflection of positive publication bias. Of the studies included, no trends were seen among those with negative outcomes. While the article selection process was not limited by year, the number of results since 1996 dramatically increased, potentially corresponding with the standardization of psychiatric pharmacy residencies with the goal of improving the quality of care provided by psychiatric pharmacists and the creation of the BCPP certification.⁵¹ As the number of BCPPs continues to grow, perhaps it would follow that the positive contributions toward patient care will expand as well. While the focus of the individual studies and the variety of outcomes found is problematic for aggregation, it nevertheless demonstrates the flexibility and wide scope of the BCPP role in patient care.

Only 36 (17.8%) articles reported sufficient detail related to study design, pharmacist training, and collaborators; only 20 of those articles had a duration of 1 year or longer. Also, the practice settings observed in the included articles do not reflect those observed by a prior AAPP survey.¹⁷ Almost half of the respondents in that study practiced in a hospital inpatient setting (47.6%), while some respondents worked in both hospital inpatient and outpatient settings (13.8%). In comparison, only 17.8% of the included articles in this review were based in inpatient settings. Most of the included articles involved a community setting, which was not specifically mentioned as a BCPP practice site in the prior AAPP survey.¹⁷ Ultimately, the benefit BCPPs bring to the healthcare team is useful knowledge. However, insufficient details about the pharmacists, such as residency or fellowship training and years of experience, were provided in the included articles. In some cases, the articles included were published before the establishment of BCPP.

Patient outcome data would be more impactful if derived from randomized controlled trials; however, with the majority of psychiatric pharmacists focusing on direct patient care, time and funding dedicated to randomized controlled trials may be limited. While potentially challenging with institutional review boards, more studies involving vulnerable populations (eg, children and adolescents) could further highlight the role of psychiatric pharmacists in medication management in these specific populations. Additionally, standardizing the outcomes, measures, and reported study characteristics is necessary to improve the ability to aggregate results and replicate studies. By reporting standardized data, areas of opportunity for BCPPs can be identified. Expansion in areas such as provider status and reimbursement could be better supported by data clearly outlining quadruple aims like improved care and reduced cost.

Future systematic literature reviews could re-evaluate or expand upon the search terms used. In the current review, articles were required to use the word “pharmacist” in the indexed content, which may have excluded articles that did not reference pharmacists in any indexed content (eg, title, abstract, keywords). Future reviews could consider additional secondary reviews of excluded articles. Finally, while the quadruple aims are a useful framework, articles studying patient experience, healthcare costs, and provider well-being would have been excluded if they did not also address clinical outcomes (ie, improved care). Future reviews could consider inclusion criteria for the other aims.

The existing data illustrate the varied and impactful roles that psychiatric pharmacists play to benefit patient care as part of the interdisciplinary team. The AAPP Systematic Literature Review Committee will continue to monitor new research as it is performed and published.